9ROXPH6XSSOHPHQW 1RYHPEHU ,661 European Journal of Cancer 26th EORTC – NCI – AACR Symposium on Molecular Targets and Cancer Therapeutics Barcelona, Spain, 18 – 21 November 2014 Proceedings Book Amsterdam • Boston • London • New York • Oxford • Paris • Philadelphia • San Diego • St Louis European Journal of Cancer Editor-in-Chief: Editors: Basic and Preclinical Research: Drug Development: Early Breast Cancer: Advanced Breast Cancer: Gastrointestinal Cancers: Genitourinary Cancers: Lung Cancer: Gynaecological Cancers: Head and Neck Cancer: Sarcomas: Melanoma: Neuro-oncology: Epidemiology and Prevention: Paediatric Oncology: Founding Editor: Past Editors: Editorial Office: Alexander M.M. Eggermont Institut Gustave Roussy Villejuif, France Richard Marais, Manchester, UK Ulrich Keilholz, Berlin, Germany Jordi Rodon, Barcelona, Spain Kathleen I. Pritchard, Toronto, Canada David Cameron, Edinburgh, UK Volker Heinemann, Munich, Germany Michel Ducreux, Villejuif, France Karim Fizazi, Villejuif, France Mary O’Brien, London, UK Ignace Vergote, Leuven, Belgium Kevin Harrington, London, UK Jean-Yves Blay, Lyon, France Dirk Schadendorf, Essen, Germany Roger Stupp, Zurich, Switzerland Jan Willem Coebergh, Rotterdam, The Netherlands Rob Pieters, Rotterdam, The Netherlands Henri Tagnon Michael Peckham, London, UK; Hans-Jörg Senn, St Gallen, Switzerland; John Smyth, Edinburgh, UK Elsevier, The Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, UK Tel: +44 (0) 1865 843590, Email: ejcancer@elsevier.com EDITORIAL BOARD CLINICAL ONCOLOGY J.-P. Armand (France) A. Ayhan (Japan) R. Blamey (UK) M. Bolla (France) J. Boyages (Australia) N. Brünner (Denmark) F. Cardoso (Portugal) J. Cassidy (UK) M. Castiglione (Switzerland) L. Cataliotti (Italy) L. Cheng (USA) H. Cody (USA) R. Coleman (UK) A. Costa (Italy) J. De Bono (UK) M.J.A. De Jong (The Netherlands) E. de Vries (The Netherlands) A. Dicker (USA) R. Dummer (Switzerland) F. Eisinger (France) S. Erridge (UK) G. Ferrandina (Italy) H. Gabra (UK) H. Gelderblom (The Netherlands) B. Hasan (Belgium) J.C. Horiot (Switzerland) C. Huber (Germany) R. Jakesz (Austria) J. Jassem (Poland) D. Jodrell (UK) V.C. Jordan (USA) A. Katz (Brazil) M. Kaufmann (Germany) I. Kunkler (UK) L. Lindner (Germany) P.E. Lønning (Norway) P. Lorigan (UK) K. McDonald (Australia) R. Mertelsmann (UK) F. Meunier (Belgium) T. Mok (Hong Kong) D. Nam (Korea) P. O’Dwyer (USA) J. Overgaard (Denmark) N. Pavlidis (Greece) J. Perry (Canada) P. Price (UK) D. Raghavan (USA) J. Ringash (Canada) J. Robert (France) A. Rody (Germany) D. Sargent (USA) M. Schmidinger (Austria) S. Sleijfer (The Netherlands) P. Sonneveld (The Netherlands) A. Sparreboom (USA) M. van den Bent (The Netherlands) M. Van Glabbeke (Belgium) G. Velikova (UK) U. Veronesi (Italy) A. Vincent-Salomon (France) A. Voogd (The Netherlands) E. Winquist (Canada) BASIC, PRECLINICAL AND TRANSLATIONAL RESEARCH A. Albini (Italy) P. Allavena (Italy) F. Balkwill (UK) M. Barbacid (Spain) M. Broggini (Italy) C. Catapano (Switzerland) J. Collard (The Netherlands) E. Garattini (Italy) A. Gescher (UK) R. Giavazzi (Italy) I. Hart (UK) W. Keith (UK) J. Lunec (UK) D.R. Newell (UK) G.J. Peters (The Netherlands) A. Puisieux (France) V. Rotter (Israel) M. Schmitt (Germany) C.G.J. Sweep (The Netherlands) G. Taraboletti (Italy) P. Vineis (UK) N. Zaffaroni (Italy) D. Forman (France) A. Green (Australia) K. Hemminki (Germany) C. Johansen (Denmark) L.A. Kiemeney (The Netherlands) E. Lynge (Denmark) M. Maynadié (France) H. Møller (UK) P. Peeters (The Netherlands) A.G. Renehan (UK) S. Sanjose (Spain) M.K. Schmidt (The Netherlands) I. Soerjomataram (France) H. Storm (Denmark) L.V. van de Poll-Franse (The Netherlands) H.M. Verkooijen (The Netherlands) E. de Vries (The Netherlands) R. Zanetti (Italy) G. Chantada (Argentina) F. Doz (France) A. Ferrari (Italy) M.A. Grootenhuis (The Netherlands) K. Pritchard-Jones (UK) L. Sung (Canada) M. van den Heuvel-Eibrink (The Netherlands) M. van Noesel (The Netherlands) EPIDEMIOLOGY AND PREVENTION B. Armstrong (Australia) P. Autier (France) J.M. Borras (Spain) C. Bosetti (Italy) H. Brenner (Germany) L.E.M. Duijm (The Netherlands) J. Faivre (France) S. Franceschi (France) PAEDIATRIC ONCOLOGY C. Bergeron (France) A. Biondi (Italy) E. Bouffet (Canada) M. Cairo (USA) H. Caron (The Netherlands) European Journal of Cancer Aims and Scope The European Journal of Cancer (EJC) is an international multidisciplinary oncology journal, which publishes original research, reviews, and editorial comments on basic and preclinical cancer research, translational oncology, clinical oncology – including medical oncology, paediatric oncology, radiation oncology, and surgical oncology, and cancer epidemiology and prevention. The EJC is the official journal of the European Organisation for Research and Treatment of Cancer (EORTC), the European CanCer Organisation (ECCO), European Association for Cancer Research (EACR) and the European Society of Breast Cancer Specialists (EUSOMA). For a full and complete Guide for Authors, please go to http://www.ejcancer.com Advertising information. Advertising orders and inquiries can be sent to: USA, Canada and South America: Pat Hampton Advertising Department, Elsevier Inc., 360 Park Avenue South, New York, NY 10010-1710, USA; phone: (+1) (212) 633 3181; fax: (+1) (212) 633 3820; e-mail: p.hampton@elsevier.com. Europe and ROW: Advertising Sales: Elsevier Pharma Solutions; 32 Jamestown Road, London NW1 7BY, UK; Tel.: +44 (0) 20 7424 4259; fax: +44 (0) 20 7424 4433; e-mail: elsevierpharma.uk@elsevier.com. Publication information: European Journal of Cancer (ISSN 0959-8049). For 2014, volume 50 (18 issues) is scheduled for publication. 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The paper used in this publication meets the requirements of ANSI/NISO Z39.48-1992 (Permanence of Paper). AACR-NCI-EORTC International Conference e on MOLECULAR TARGETS AND CANCER THERAPEUTICS The Premier International Meeting Featuring Novel Cancer Therapeutics +2!)!.ƫĆġĊČƫĂĀāĆƫđƫ5*!/ƫ+*2!*0%+*ƫ!*0!.ƫđƫ+/0+*Čƫ We look forward to seeing you in Boston! ORGANIZING COMMITTEE SCIENTIFIC COMMITTEE CO-CHAIRPERSONS Carlos L. Arteaga, MD Vanderbilt-Ingram Cancer Center, Nashville, TN (AACR) Levi A. Garraway, MD, PhD Dana-Farber Cancer Institute, Boston, MA, USA (AACR) James H. Doroshow, MD National Cancer Institute-DCTD, Bethesda, MD, USA (NCI) Lee J. Helman, MD National Cancer Institute, Bethesda, MD, USA (NCI) Roger Stupp, MD University Hospital Zurich (USZ), Zürich, Switzerland (EORTC) Jean-Charles Soria, MD, PhD Institut Gustave-Roussy, Villejuif, France (EORTC) ABOUT THIS CONFERENCE Join us for the premier international meeting featuring novel cancer therapeutics. This meeting brings together nearly 3,000 academics, scientists, and pharmaceutical industry representatives from across the globe to discuss innovations in drug development, target selection, and the impact of new discoveries in molecular biology. WHAT PAST ATTENDEES SAID... “Very exciting conference with excellent speakers. Great opportunity to broaden my knowledge of cancer biology and therapeutics.” “I felt stimulated to work in cancer and science again! Thank you!” For more information and to bookmark this important event, go to www.AACR.org/Targets15 v Table of Contents Letter of Welcome vii Societies’ Profiles Conference Committees ix xi Acknowledgement General Information xii xiii Travel Grants xvii CME Accreditation Scientific Programme Programme Overview xvii xviii Programme Details Abstracts Late Breaking Abstracts xx 1 193 Presenting Authors List Author Index 201 205 Subject Index 229 FUTURE MEETINGS AACR – NCI – EORTC International Conference on Molecular Targets and Cancer Therapeutics Boston, MA, USA, 5 – 11 November 2015 28th EORTC – NCI – AACR Symposium on Molecular Targets and Cancer Therapeutics Munich, Germany, 18 – 21 October 2016 As a significant number of cancers in Europe can be attributed to smoking a strict no-smoking policy will be enforced within all areas used by the conference. 28TH EORTC-NCI-AACR SYMPOSIUM EORTC NCI AACR 2016 ‘MOLECULAR TARGETS AND CANCER THERAPEUTICS’ 18 – 21 OCTOBER 2016 28TH EORTC-NCI-AACR SYMPOSIUM ON ‘MOLECULAR TARGETS AND CANCER THERAPEUTICS’ The 28th EORTC-NCI-AACR Symposium on ‘Molecular Targets and Cancer Therapeutics’ will bring together academics, scientists and representatives from the pharmaceutical industry to discuss innovations in drug development, target selection and the impact of new discoveries in molecular biology. During the last few years, numerous innovative agents have been discovered as a result of tremendous developments in the understanding of the molecular basis of cancer. Further clinical progress in cancer treatment will be accomplished mainly through the conduct of translational research projects, efficient new drug development and the execution of large, prospective, randomised, multicentre cancer clinical trials. This requires a joint and global approach and early and optimal exchange of information. Therefore, the Symposium will ensure the maximum amount of interaction and discussion through an exciting range of plenary sessions and lively workshops. MUNICH, GERMANY The future of cancer therapy For forthcoming announcements about the 28th EORTC-NCI-AACR Symposium on ‘Molecular Targets and Cancer Therapeutics’ please bookmark www.eortc.be, or contact the Secretariat directly: c/o ECCO – the European CanCer Organisation Avenue E. Mounier, 83 B-1200 Brussels Belgium Tel.: +32 (0) 2 775 02 01 Fax: + 32 (0) 2 775 02 00 E-mail: ena2016@ecco-org.eu www.ecco-org.eu/ENA SAVE THE DATE vii Letter of Welcome Dear Colleagues, It is our pleasure to invite you the 26th EORTC–NCI–AACR Symposium on Molecular Targets and Cancer Therapies. This annual meeting is taking place alternatingly in the USA and in Europe (since 1978) and is the premier international symposium on drug development, innovative approaches, targeted agents including biomarkers and translational research. Over 2000 delegates are exchanging ideas and results to foster drug and cancer therapeutic development, with a particular focus on early clinical application. For this edition, we have revamped the programme, by adding more slots for oral presentations populated by abstracts that contain brand new data that has never been presented before. We have particularly focused our efforts in bringing more clinical data by attracting additional original phase I/II trials. The latest in immunotherapy, oncolytic viruses, epigenetic targets as well as drug resistance will be discussed by eminent speakers in plenary and workshop sessions. This year, to compliment the poster presentations, we will have “posters in the spotlight” sessions, where selected poster presenters will be given a podium to present their posters and answer any questions from delegates. There will be ample opportunities to network during the welcome reception, evening poster viewing sessions and the DNA networking event which will be held in the Casa Llotja de Mar, located on the sea front in the historical centre of Barcelona. The 26th EORTC–NCI–AACR Symposium on Molecular Targets and Cancer Therapeutics is the place to meet new collaborators and old friends; gaining new insights that will aid the development of more effective treatments for the patients. We welcome you to the meeting! Jean-Charles Soria Scientific Chair Roger Stupp EORTC President ix Societies’ Profiles The European Organisation for Research and Treatment of Cancer (EORTC) The EORTC, based in Brussels, Belgium, unites European cancer clinical research experts from all disciplines for trans-national collaboration. It links a network of over 2,500 collaborators from all disciplines involved in cancer treatment and research in more than 300 hospitals in over 30 countries and offers an integrated approach to drug development, drug evaluation programmes and medical practices. EORTC Headquarters in Brussels handles some 30 protocols that are permanently open to patient entry, over 50,000 patients who are in follow-up, and a database of more than 180,000 patients. The ultimate goal of the EORTC is to improve the standard of cancer treatment by developing new agents and innovative approaches and to test more effective treatment strategies using commercially available drugs, or surgery and radiotherapy. EORTC studies have contributed to success stories in drugs development including the registration of several drugs by the United States Food and Drug Administration and the European Medicines Agency. The EORTC has a proven track record in establishing new standards, e.g. RECIST, QOL, etc., and in changing clinical practice. EORTC Headquarters staff provides full clinical, scientific, operational, quality assurance, and regulatory support for clinical and translational research projects, and augments this support with strong expertise in biostatistics, clinical study design and methodology, endpoint definition and analysis, etc. The EORTC fully supports the idea of Health Technology Assessment (HTA) becoming standard practice for the approval of new drugs or new indications and, moreover, has agreed that high quality clinical trials in the future should be HTA compliant. The role of pragmatic data and related methodology need to be developed within multi-stakeholder platforms, and with this goal in mind, the EORTC participates in projects such as those put forth by the Innovative Medicines Initiative. Such activities make the EORTC one of Europe’s leading players in transforming experimental discoveries into new treatments with a significant clinical impact. Alongside its own scientific and clinical programme, the EORTC collaborates with a number of research institutions including the US National Cancer Institute, the National Cancer Institute of Canada, and many other national and international research groups worldwide. Funders of the EORTC include the EORTC Charitable Trust (with the support of national cancer leagues), the “Fonds Cancer”, private donations and corporate sponsorship, annual grants allocated by BELSPO (the Belgian Federal Science Policy Office) and by the Belgian National Lottery, and, for specific research projects, the European Commission. Since the early 1970’s, EORTC headquarters has received continuous support from the US NCI. Support is also received from the pharmaceutical industry for specific studies. www.eortc.org x Societies’ profiles The National Cancer Institute (NCI) The National Cancer Institute (NCI) is part of the National Institutes of Health (NIH), which is one of 11 agencies that compose the United States (U.S.) Department of Health and Human Services (HHS). The NCI, established under the National Cancer Institute Act of 1937, is the Federal Government’s principal agency for cancer research and training. The National Cancer Act of 1971 broadened the scope and responsibilities of the NCI and created the National Cancer Program. Over the years, legislative amendments have maintained the NCI authorities and responsibilities and added new information dissemination mandates as well as a requirement to assess the incorporation of state-of-the-art cancer treatments into clinical practice. The National Cancer Institute coordinates the National Cancer Program, which conducts and supports research, training, health information dissemination, and other programs with respect to the cause, diagnosis, prevention, and treatment of cancer, rehabilitation from cancer, and the continuing care of cancer patients and the families of cancer patients. Specifically, the Institute: • Supports and coordinates research projects conducted by universities, hospitals, research foundations, and businesses throughout the U.S. and abroad through research grants and cooperative agreements. • Conducts research in its own laboratories and clinics. • Supports education and training in fundamental sciences and clinical disciplines for participation in basic and clinical research programs and treatment programs relating to cancer through career awards, training grants, and fellowships. • Supports research projects in cancer control. • Supports a national network of cancer centers. • Collaborates with voluntary organizations and other national and foreign institutions engaged in cancer research and training activities. • Encourages and coordinates cancer research by industrial concerns where such concerns evidence a particular capability for programmatic research. • Collects and disseminates information on cancer. • Supports construction of laboratories, clinics, and related facilities necessary for cancer research through the award of construction grants. The American Association for Cancer Research (AACR) Founded in 1907, the American Association for Cancer Research (AACR) is the world’s first and largest professional organization dedicated to advancing cancer research and its mission to prevent and cure cancer. AACR’s membership includes 34,000 laboratory, translational and clinical researchers; population scientists; other health care professionals; and cancer advocates residing in more than 90 countries. The AACR marshals the full spectrum of expertise of the cancer community to accelerate progress in the prevention, biology, diagnosis and treatment of cancer by annually convening more than 20 conferences and educational workshops, the largest of which is the AACR Annual Meeting with more than 17,000 attendees. In addition, the AACR publishes seven peer-reviewed scientific journals and a magazine for cancer survivors, patients and their caregivers. The AACR funds meritorious research directly as well as in cooperation with numerous cancer organizations. As the Scientific Partner of Stand Up To Cancer, the AACR provides expert peer review, grants administration and scientific oversight of individual and team science grants in cancer research that have the potential for near-term patient benefit. The AACR actively communicates with legislators and policymakers about the value of cancer research and related biomedical science in saving lives from cancer. For more information about the AACR, visit www.AACR.org xi Conference Committees Organising Committee EORTC NCI AACR Roger Stupp Jean-Charles Soria James Doroshow Lee Helman C.L. Arteaga Jeff Engelman EORTC President Scientific Chair NCI President Scientific Co-Chair AACR President Scientific Co-Chair Executive Scientific Committee Jean-Charles Soria (France), Scientific Chair Lee Helman (USA), Scientific Co-Chair Jeff Engelman (USA), Scientific Co-Chair Josep Tabernero (Spain) Anthony Tolcher (USA) Kapil Dhingra (USA) Roger Stupp (Switzerland) Scientific Committee Jeffrey Abrams Carlos L. Arteaga Udai Banerji Philippe Bedard Emiliano Calvo Lewis Cantley Anthony Chan Jerry M. Collins Barbara Conley Sara A. Courtneidge William Dahut Kapil Dhingra James Doroshow Susan Galbraith Levi A. Garraway James Gulley Toby Hecht Monika Hegi Lee J. Helman David Hong Axel Hoos Maria Koehler Scott Kopetz Shivaani Kumar Annette Larsen USA USA UK Canada Spain USA Hong Kong USA USA USA USA USA USA United Kingdom USA USA USA Switzerland USA USA USA USA USA USA France Emma M. Lees Elaine Mardis Paul Meltzer Gordon B. Mills Frits Peters Ruth Plummer Yves Pommier Victoria M. Richon Neal Rosen Jan Schellens Joel Schneider Jeffrey E. Settleman Alice T. Shaw Kevan Shokat David B. Solit Patricia S. Steeg Charles Swanton Josep Tabernero Beverly A. Teicher Anthony Tolcher Joseph E. Tomaszewski Matthew G. Vander Heiden Yi Long Wu James Zwiebel USA USA USA USA Netherlands United Kingdom USA USA USA Netherlands USA USA USA USA USA USA United Kingdom Spain USA USA USA USA China USA xii Acknowledgement EORTC, NCI and AACR would like to gratefully acknowledge the following companies for supporting the 26th EORTC–NCI–AACR Symposium on Molecular Targets and Cancer Therapeutics: Major Sponsor: Silver Partners: Grant Support: EORTC, NCI and AACR would like to thank the following sponsors and exhibitors for their support to this meeting. This list reflects the companies/organisations confirmed at the time of going to print. Company/Organisation Booth Company/Organisation Booth Advance Cell Diagnostics D1 Horizon Discovery A10 Affymetrix C9 Indivumed B2 Almac C6 Medical Prognosis Institute C1 Biocrates Life Sciences C4 Novella Clinical A4 Cancer Research Technology C2 Oncodesign SA A5 Cellecta, Inc. A15 Oncotest GmbH B1 Champions Oncology B9 OracleBio Limited B3 Charles River C10 PerkinElmer Inc. C5 Crown BioScience A2 Proqinase GmbH B4 Cureline, Inc. A6 Silicon Biosystems A9 Dove Medical Press A11 Studylog Systems A1 Epistem Ltd C3 Sysmex Inostics C8 European Association for Cancer Research (EACR) C11 vivoPharm B13 Xentech A3 GSK A13 xiii General Information Symposium Secretariat ECCO − the European CanCer Organisation Avenue E. Mounier, 83 B-1200 Brussels − Belgium E-mail: ena2014@ecco-org.eu During the Symposium, the Secretariat can be reached at +32 (0)2 880 15 21 Venue Centre de Convencions Internacional Barcelona (CCIB) Rambla Prim 1−17 ES-08019 Barcelona − Spain Tel.: +34 (0)93 230 10 00 App All attendees may download the free ECCO App on iPhone, iPad, or Android supported devices. Features include EORTC–NCI–AACR 2014 related information and news. The App contains the complete list of sessions, session types, speakers and exhibitors. Users can save their selected sessions, notes, favourites, as well as export sessions to their smartphone calendar. To download the App, search for ECCO cancer in iTunes or Google Play. Learn more at www.ecco-org.eu/app or use the QR code for direct download. Badges For security reasons, delegates are requested to wear their badge at all times during the Symposium. Delegates who have lost their badge can obtain a new one at the registration desk. A replacement fee of 75 EUR per participant will be charged. Catering Coffee breaks Coffee breaks courtesy of the organisers have been scheduled as follows: Tuesday 18 November: 14:45–15:15 Wednesday 19 November: 09:45–10:15 and 15:20–16:00 Thursday 20 November: 10:00–10:30 and 15.35–16:00 Friday 21 November: 10:30–11:00 Coffee breaks will take place in the catering areas of the exhibition except for Friday 21 November when the coffee break will take place in the poster area. Lunches Complimentary lunches will be served in the exhibition catering areas: Tuesday 18 November: 12:00–13:00 Wednesday 19 November: 12:00–13.15 Thursday 20 November: 12.30–13:30 During the poster viewing sessions, local tapas and drinks will be served. Delegates can also purchase food and beverages from the cash bar near the entrance of the Convention Centre. Free water fountains are located throughout the Convention Centre. xiv General information Certificate of Attendance To print your certificate of attendance after the Symposium, you will need your badge code number, so please keep your badge for this purpose. You can print your certificate of attendance via this link: http://www.ecco-org.eu/ENA1014 or in the Internet Zone located on the venue ground floor (as of Wednesday 19 November). Online certificates will be available until the end of December 2014. Please note that the Symposium Secretariat will not post certificates to participants after the event. City Information Barcelona Convention Bureau will operate a tourist and tour desk in the registration area as of Tuesday 18 November. Cloakroom A cloakroom is situated in the entrance hall near the registration area. Cloakroom Opening Hours Tuesday 18 November: 10:00–20:00 Wednesday 19 November: 07:30–19:30 Thursday 20 November: 07:30–19:30 Friday 21 November: 08:30–13:30 The price for this service is 2 EUR per item. Exhibition The EORTC–NCI–AACR 2014 Exhibition is held on the ground floor of the Convention Centre. Entrance is free for registered delegates. Exhibition Opening Hours: Tuesday 18 November: Wednesday 19 November: Thursday 20 November: 12:00–18:30 09:45–16:00 09:45–16:00 First Aid A first aid room is located on level −1. In case of emergency, please inform the nurse on duty via +34 697 324 433 and/or dial internal the extension number 257 from any internal phone in the Convention Centre. Insurance The organisers of the EORTC–NCI–AACR 2014 Symposium do not accept liability for individual medical, travel or personal insurance. Participants are strongly advised to take out their own personal insurance policies. The organisers of the EORTC–NCI–AACR 2014 Symposium accept no responsibility for loss due to theft or negligence. Internet WIFI access General WIFI access is available throughout the Convention Centre. To access WIFI, activate the WIFI network on your laptop or device, select the network listed as ENA2014, and enter the password ENA2014. Internet Zone The official EORTC–NCI–AACR Internet Zone is available free of charge during the Symposium. The terminals provide you with the following services: Internet browsing, access to web-based mail, the Symposium searchable programme and exhibitor information. General information xv Language and translation The official language of the Conference is English. No simultaneous translation is provided. Lost and Found All enquiries should be directed to the registration helpdesk in the entrance hall. Participants are advised to mark their own Symposium bag and programme book with their name. The organisers accept no responsibility for loss due to theft or negligence. Media Press Office Opening Hours Tuesday 18 November: Wednesday 19 November: Thursday 20 November: Friday 21 November: 10:00–18:00 08:00–18:00 08:00–18:00 09:00–13:00 Entry to the Press Office is restricted to accredited media staff only. The Press Office is located in Room M221. Posters Posters will be displayed in the exhibition area on the ground floor. Poster presentations: Poster presentations are scheduled on: Wednesday 19 November: 18:00–19:30 Thursday 20 November: 18:00–19:30 Friday 21 November: 09:00–10:30 Poster Viewing Poster presenters will present their work and answer questions from delegates. During this session, local tapas and drinks will be served. Posters in the Spotlight Session The Scientific Committee will make a special selection of posters which will be highlighted through short oral presentations (5 min + 5 min discussion each). Take this opportunity to discuss some of the hottest news at the Symposium! These spotlight sessions will take place in the exhibition area on Wednesday 19 and Thursday 20 November during the lunch break. Registration EORTC–NCI–AACR 2014 is open to all registered participants. Your official delegate name badge is required for admission to the Convention Centre and all Symposium events. For security reasons, participants are requested to wear their badge at all times. Registration Opening Hours: Monday 17 November: Tuesday 18 November: Wednesday 19 November: Thursday 20 November: Friday 21 November: Registration Package 15:00–18:00 08:00–18:00 07:00–18:00 07:00–18:00 08:00–12:00 The full Symposium registration package includes: • Entry to all scientific sessions, and to the Welcome Reception on Tuesday 18 November; • Entry to the exhibition; • Proceedings book; • EORTC–NCI–AACR 2014 coffee breaks and complimentary lunches; • Internet access via the internet zone and WIFI access in the Convention Centre. xvi General information The day registration package includes: • Access to all scientific sessions on that day; • Entry to the exhibition; • Proceedings book (depending on availability); • EORTC–NCI–AACR 2014 coffee breaks and lunch on that day; • Internet access via the internet zone and WIFI access in the Convention Centre. Speaker Preview Room The Speaker Preview Room is located on the ground floor. Speakers are requested to bring their PowerPoint presentations to the speaker preview room at least 4 hours before their session starts or one day in advance if the session starts early in the morning. To avoid breaks between speakers, NO laptop presentations are foreseen in session rooms. Speaker preview room opening Tuesday 18 November: Wednesday 19 November: Thursday 20 November: Friday 21 November: Social Events hours: 11:00–18:30 07:00–18:30 07:00–18:30 08:00–12:00 Welcome Reception All registered participants are invited to the Welcome Reception, organised on Tuesday 18 November, in the exhibition hall. The Welcome Reception starts at 17:30. Networking Event “It’s all about DNA” Thursday 20 November from 20:00. Casa Llotja de Mar, Passeig d’Isabel II, 1 08003 Barcelona Casa Llotja de Mar, located on the sea front in the historical centre of Barcelona, is one of the most significant and splendid monuments representing the economy and culture of the city. It was built in the second half of the 14th century, the most brilliant period of Catalan Gothic. Price per person: 65 EUR How to get there: From the Convention Centre, walk to the El Maresme/Fòrum subway station and take the L4 towards Trinitat Nova. Get off at Barceloneta station. Head west on Pia del Palau toward Plarca de Pau Vila. Turn left onto Passeig d’Isabel II. The Casa Llotja de Mar will be on the right. Social media We recommend and support Twitter as the main social platform during the Symposium − tweet and follow the latest updates about the 26th EORTC– NCI–AACR Symposium on Twitter using #ENA2014 Find links, tutorials and tips: www.ecco-org.eu/social xvii Travel Grants Through the generosity of its sponsors, EORTC, NCI and AACR have awarded 15 travel grants to attend the 26th EORTC–NCI–AACR Symposium in Barcelona. Baxter, Merissa USA Mittal, Deepak Australia Bhattacharya, Bhaskar Singapore Pettitt, Stephen United Kingdom Campagne, Cécile USA Rose, April Canada Choi, Min-ah South Korea Sahay, Debashish France Eun, Young-Gyu South Korea Sos, Martin USA Goldstein, Rebecca USA Willetts, Lian Canada Kim, Jisun Korea Zoni, Eugenio Netherlands Mantaj, Julia United Kingdom CME Accreditation The 26th EORTC–NCI–AACR Symposium on ‘Molecular Targets and Cancer Therapeutics’ is accredited by the European Accreditation Council for Continuing Medical Education (EACCME) to provide the following CME activity for medical specialists. The EACCME is an institution of the European Union of Medical Specialists (UEMS), www.uems.net The 26th EORTC–NCI–AACR Symposium is designated for a maximum of 18 hours of European external CME credits. Each medical specialist should claim only those hours of credit that he/she actually spent in the educational activity. The EACCME credit system is based on 1 ECMEC per hour with a maximum of 3 ECMECs for half a day and 6 ECMECs for a full-day event. European Accreditation is granted by the EACCME in order to allow participants who attend the above-mentioned activity to validate their credits in their own country. Through an agreement between the European Union of Medical Specialists and the American Medical Association, physicians may convert EACCME credits to an equivalent number of AMA PRA Category 1 Credits™. Information on the process to convert EACCME credit to AMA credit can be found at www.ama-assn.org/go/internationalcme Live educational activities, occurring outside of Canada, recognised by the UEMS-EACCME for ECMEC credits are deemed to be Accredited Group Learning Activities (Section 1) as defined by the Maintenance of Certification Program of The Royal College of Physicians and Surgeons of Canada. xviii Scientific Programme – Overview Tuesday18November Wednesday19November Auditorium Auditorium Room117 :RUNVKRS :RUNVKRS 0DQDJHPHQWRI7R[LFLW\RI 0ROHFXODU7DUJHWHG$JHQWV &DQFHU0HWDEROLVP :RUNVKRS :RUNVKRS /LTXLG%LRSVLHVLQ6ROLG 7XPRXUV 7UDQVODWLRQDO5HVHDUFK ZLWK ,PPXQRVWLPXODWRU\ 0RQRFORQDO$QWLERGLHV /XQFK 5DWLRQDOFRPELQDWLRQ WKHUDSLHVIRUFDQFHU .H\QRWH/HFWXUH ,PPXQRFKHFNSRLQWV *DWHZD\WR,PPXQRWKHUDS\ &RIIHH%UHDN ([KLELWLRQ ,QFOXGLQJ 3RVWHUVLQWKH6SRWOLJKW6HVVLRQ /XQFK 2SHQLQJ5HPDUNV 0LFKHO&ODYHO/HFWXUH “Navigating Your Career with Confidence” A Professional Advancement Session Organized by the AACR-Women in Cancer Research (WICR) Council 3OHQDU\6HVVLRQ 3URIIHUHG3DSHU6HVVLRQ &RIIHH%UHDN 3OHQDU\6HVVLRQ 2QFRO\WLF9LUXVHV 3OHQDU\6HVVLRQ ,VWKH*HQRPLF/DQGVFDSH &KDQJLQJWKH2XWFRPHIRU &DQFHU3DWLHQWV" WelcomeReception ([KLELWLRQ+DOO PosterViewing 3RVWHU$UHD Posters AnimalModels Cytotoxics DrugResistanceandModifiers DrugScreening Immunotherapy(Immunecheckpoints,Vaccination, Oncolyticviruses,Cytokines) PreclinicalModels RadiationInteractiveAgents ([KLELWLRQ &RIIHH%UHDN Scientific programme – overview xix Thursday 20 November Friday 21 November Auditorium 09.00 08.00 Plenary Session 4 10.00 Antibody-Based Therapies (ADC and others) Poster Viewing (Poster Area) 10:30 Coffee Break Coffee Break 10.30 Auditorium Plenary session 5 12.30 Lunch 12.30-13.30 Including Posters in the Spotlight Session 13.30 Plenary Session 6 Proffered Paper Session 15.35 Coffee Break 16.00 Plenary Session 7 Novel Mechanisms for Drug Resistance 17.50 18.0019.30 Poster Viewing (Poster Area) Networking Event Posters Chemoprevention Clinical Methodology DNA Repair Modulation (including PARP, CHK, ATR, ATM) Drug Delivery Drug Design Molecular Targeted Agents I Paediatric Oncology Toxicology Exhibition 09:45 - 16:00 11.00 Epigenetic Targets Plenary session 8 Targeting RAS and Other Driver Oncogenes 13.00 Posters Drug Synthesis Molecular targeted agents II New Therapies with Pleiotropic Activity xx Scientific Programme – Details Tuesday 18 November 2014 Opening Ceremony 13:00–13:15 13:15–14:00 Opening 13:00 13:05 13:10 Auditorium Remarks J.C. Soria (France) L.J. Helman (USA) J.A. Engelman (USA) EORTC NCI AACR Michel Clavel Lecture Chair: J.C. Soria (France) Auditorium 13:15 Rational combination therapies for cancer R. Bernards (Netherlands) 14:00–14:45 Keynote Lecture Chair: A.M.M. Eggermont (France) Auditorium 14:00 Immunocheckpoints − Gateway to Immunotherapy D. Chen (USA) Objectives: 1. Understand how cancer immunotherapy works, the cancer-immunity cycle and what makes it different from other forms of cancer therapy. 2. Understand what rationale approaches can be taken to monotherapy and combination therapy involving cancer immunotherapy. 3. Understand the role for biomarkers in understanding emerging immune biology, interpreting clinical results and identifying optimal treatment decisions. Key Messages: 1. Our understanding of how the immune system interacts with cancer is rapidly evolving. 2. Cancer immunotherapy approaches may be able to generate durable responses in patients with metastatic cancer. 3. Emerging biomarkers may be able to help us understand biology, define combination approaches and choose between therapeutic options. Plenary Session 1 15:15–17:30 Is the Genomic Landscape Changing the Outcome for Cancer Patients? Chairs: R. Stupp (Switzerland) and J. Tabernero (Spain) 15:15 Overview of academic precision medicine trials P. Bedard (Canada) 15:35 Lessons from SAFIR01 trial F. Andre (France) Main objectives: 1. Understand the pillars of personalised medicine. 2. Understand the main reasons of failures to deliver personalised medicine. 3. Understand what are the possible solutions to address these limitations. Auditorium Abstract number Scientific programme – details xxi Key messages: 1. There is a need for randomised trials before implementing multigene tools for personalised medicine. 2. Drug availability and rules to interpret genome data are mandatory. 3. Genome analysis will not provide all the informations needed to deliver personalised medicine. 15:55 Translating gene expression signatures into clinical practice: prospects and challenges in the context of ‘next-generation medicine’ R. Dienstmann (USA) Key messages: 1. There are unique issues with high-dimensional data that represent obstacles to generating performant genomic signature classifiers and translating initial research findings into robust diagnostics. 2. Better understanding of the intrinsic gene expression-based subtypes of a histopathologically defined cancer, independent of their prognostic and predictive values, may also lead to new biological insights and eventually to development of novel therapies directed toward homogeneous molecular subsets. 3. A rational and focused approach to the evaluation of genomic markers is needed, whereby analytically validated assays are prospectively investigated in clinical trials with adaptive designs that take into consideration primary–metastatic site tumour heterogeneity and clonal evolution in the decisionmaking process. 16:15 Genomic characterisation of cancer: Case studies E.R. Mardis (USA) Key objectives: 1. Provide detailed description of the molecular assays being used to characterise the cancer mutations and their expression in RNA for individual patients. 2. Describe the analytical approaches that permit integrated analysis of mutations and RNA expression toward two therapeutic ends: (1) identification of small molecule therapies that may provide relief of tumour burden, (2) identification of immunoepitopes that may contribute toward a personalised vaccine strategy for individual patients. 3. Illustrate the two aforementioned objectives by detailed descriptions of specific case studies from our work in this area of applied cancer genomics. 16:35 Screening Patients for Efficient Clinical Trial Access (SPECTA) D. Lacombe (Belgium) Key messages: 1. Cancer drug development is undergoing profound changes and the path to registration will be substantially altered due to challenges of big data (omics). 2. The forms and the methods of cancer clinical research are evolving with the need to integrate new technologies to understand biology early on in development. New efficient platforms for patient access (molecularly defined subgroups) are needed. 3. Clinical oncology will need to take into account new type of guidelines for treatment decision with an increased role played by molecular advisory boards. 16:55 ORAL PRESENTATION: Feasibility of large-scale genomic testing to facilitate enrollment on genomically-matched clinical trials F. Meric-Bernstam, L. Brusco, S. Kopetz, M. Davies, M.J. Routbort, S.A. Piha-Paul, R. Alvarez, S. Khose, J. DeGroot, V. Ravi, F. Janku, D. Hong, Y. Li, R. Luthra, K.P. Patel, R. Broaddus, K. Shaw, J. Mendelsohn, G.B. Mills 17:10 General discussion J. Tabernero (Spain) 17:15 Faster execution of clinical trials − has bioinformatics the solution? G. McVie (Italy) 1 xxii Scientific programme – details Wednesday 19 November 2014 Workshop 1 08:00–09:45 Auditorium Management of Toxicity of Molecular Targeted Agents Chairs: J.C. Soria (France) and P. Bedard (Canada) 08:00 Cardiac toxicities with MOA and TKI S. Ederhy (France) 08:20 Digestive and endocrine toxicities of checkpoint inhibitors N. Chaput (France) Main objectives: 1. To describe digestive toxicities (clinic/endoscopic/histological) in patients treated with anti-CTLA4 and/or anti-PD1. 2. To describe immune disorders in patients developing digestive toxicities (blood and colonic biopsies). Key messages: 1. Anti-CTLA-4 and/or anti-PD-1, monoclonal antibody treatment of cancer, are associated with several phenotypes of enterocolitis. 2. Intestinal inflammation observed in patients who were prescribed anti-CTLA-4, anti-PD1 or both, have distinct phenotypes: anti-CTLA-4 is associated with acute, often severe colitis, chronic duodenitis and less often with ileal and anal lesions. Anti-PD-1 seems to be associated with mild, chronic colitis. The combination of anti-CTLA-4 and anti-PD1 seems to lead to severe duodenal inflammation and severe colitis. 3. Anti-CTLA-4 colitis appears as a model of T-cell induced colitis in humans as suggested by the immune monitoring of patients. 08:40 Management of pulmonary toxicity due to targeted anticancer agents J. Porter (United Kingdom) 09:00 Ocular toxicity of MEK inhibitors and other targeted therapies J.P. Velazquez-Martin (Canada) Main objectives: 1. Identify the key agents associated with ocular toxicities. 2. Identify symptoms and clinical findings associated with ocular toxicity. 3. Learn the management, follow up and prognosis of these patients. Key messages: 1. Ocular toxicities from targeted therapies are frequent. 2. Symptoms range from none to moderate visual impairment. 3. Always consult with an ophthalmologist or retina specialist (preferable). 09:20 Discussion Workshop 2 08:00–09:45 Room 117 Cancer metabolism Chairs: C. Van Dang (USA) and G. Hardie (United Kingdom) 08:00 AMPK − opposing the metabolic changes in tumour cells G. Hardie (United Kingdom) Key messages: 1. The AMP-activated protein kinase (AMPK) is a highly conserved sensor of cellular energy status that is switched on by metabolic stresses causing depletion of cellular ATP, such as ischaemia (a frequent event within solid tumours). 2. Most tumour cells (and other rapidly proliferating cells) display elevated glucose uptake and glycolysis (the Warburg effect); this occurs in part because the TCA cycle is being used as an anabolic pathway providing precursors for biosynthesis, and can no longer satisfy the increased demand for ATP caused by activation of biosynthetic pathways. Scientific programme – details xxiii 3. By inactivating most biosynthetic pathways and promoting oxidative metabolism rather than glycolysis, AMPK opposes these metabolic changes; this explains why the pathway is often downregulated in tumour cells, but also why AMPK-activating drugs have potential in the treatment or prevention of cancer. 08:20 IDH1/IDH2 D.P. Schenkein (USA) Key messages: 1. Cancer metabolism, a newly validated area for oncology drug discovery. 2. Mutations in the metabolic enzyme IDH are present in a wide range of malignancies and increasingly recognised in pre-malignant conditions: the role of 2-HG as an oncometabolite. 3. Clinical trial results from the first IDH inhibitor, AG-221: significant single agent activity in AML, excellent safety profile, and a novel mechanism of action. 08:40 Targeting MYC-driven Glutaminolysis C. Van Dang (USA) 09:00 Identification of novel inhibitors of GLUT1 as potent cancer cell-killing agents A. Wise (United Kingdom) Key objectives: 1. Demonstrate chemical tractability of the glucose transporter GLUT1 as a drug target by identifying a lead series of potent and selective small molecule inhibitors. 2. Demonstrate in vitro validation of GLUT1 as a therapeutic target in cancer by utilising our novel GLUT1 inhibitors as tool compounds. 3. Demonstrate in vivo validation of GLUT1 as a therapeutic target in cancer by utilising our novel GLUT1 inhibitors as tool compounds. 09:20 Discussion Workshop 3 10:15–12:00 Auditorium “Liquid Biopsies” in Solid Tumours Chairs: K. Dhingra (USA) and A. Bardelli (Italy) 10:15 Application of CTC detection technologies in oncology clinical trials J.S. De Bono (United Kingdom) Key objectives: Showing that circulating blood biomarkers can have clinical utility as multi-purpose biomarkers as 1. Prognostic biomarkers. 2. Predictive biomarkers 3. Response and surrogate biomarkers. 10:35 Cancer mutation and transcriptome analysis in exosomes J. Skog (USA) Key objectives: 1. What is an exosome and what do they contain? 2. What is the benefit of analyzing exosome nucleic acids? 3. What do you need for successful analysis of exosomal RNA, and what types of analysis are possible? 10:55 cfDNA for detection of actionable cancer mutations C. Caldas (United Kingdom) 11:15 Precision medicine for colorectal cancers: liquid biopsies and preclinical models A. Bardelli (Italy) Key objectives: 1. Understanding the molecular bases of secondary resistance to EGFR blockade in CRC is necessary to design additional therapeutic options. 2. Molecular alterations in KRAS, NRAS, and MET are causally associated with the onset of acquired resistance to anti-EGFR antibodies in colorectal cancers. xxiv Scientific programme – details 3. Development of a diagnostic platform to detect ‘molecular resistance’ in the blood (liquid biopsy) months before clinical or radiographic evidences of disease progression. 11:35 Discussion Workshop 4 10:15–12:00 Room 117 Translational Research with Immunostimulatory Monoclonal Antibodies Chairs: J. Tabernero (Spain) and I. Melero (Spain) 10:15 The making of new immunotherapy agents A. Korman (USA) 10:35 Translational research of combined immunotherapies I. Melero (Spain) 11:05 Biomarkers for new immunotherapies M. Calahan (USA) 11:25 The interface of immunomodulation and vaccines A. Van Elsas (NL) Key messages: 1. Cancer vaccines enhance anti-tumour immune responses when used prophylactically, but lack robust efficacy in therapeutic setting. 2. Several immunomodulatory receptor-ligand pathways regulate T cell responses to cancer and vaccines. 3. Experimental combinations of cancer vaccines and immunomodulatory antibodies display efficacy in preclinical models of established cancer. 11:45 Discussion 12:15–12:45 Posters in the Spotlight Session Moderator: R. Plummer (United Kingdom) Exhibition Hall The following abstracts will be discussed: 364 (poster board P144), 161 (P155), 422 (P155). Professional Advancement Session 12:15–13:15 “Navigating Your Career with Confidence” − A Professional Advancement Session Organized by the AACR-Women in Cancer Research (WICR) Council Chair: P. LoRusso (USA) Room 117 Feel and project more confidence when seeking new career opportunities. This session will include an inspirational Keynote Lecture from Susan M. Galbraith, MBBCh, PhD, Vice President of Oncology, AstraZeneca, as well as a panel of professionals discussing the ways that women scientists in particular can bolster their confidence and overcome insecurities in order to embrace new opportunities. The panel will address topics such as assessing which career opportunities are a good fit, improving a resume or portfolio in order to secure an interview, blending personal and career life once on the job, and more. Although all conference attendees are invited to attend this session, it is geared toward early-career female investigators. Welcome P. LoRusso (USA) Keynote S.M. Galbraith (United Kingdom) Panel Discussion Susan M. Galbraith (United Kingdom), M. Foti (USA), F. Meunier (Belgium) Audience Engagement (Q&A) Closing Remarks and Evaluation P. LoRusso (USA) Scientific programme – details Plenary Session 2 13:15–15:20 Proffered Paper Session Chairs: C. Arteaga (USA) and R. Plummer (United Kingdom) xxv Auditorium Abstract number 13:15 Target validation as a crucial bottleneck in cancer drug discovery P. Workman (United Kingdom) Key objectives: 1. To illustrate the challenges of identifying and prioritising new cancer targets in the multiomics era and to show how target validation is a critical bottleneck in cancer drug discovery. 2. To exemplify the above with case histories from our recent research discoveries concerning potential molecular targets in the areas of oncogenic kinases and the HSP90 molecular chaperone pathway. 3. To set out criteria for robust target validation, including the use of genetic techniques and chemical probes, so as to give the best chance of clinical impact. 13:35 ORAL PRESENTATION: Safety and early evidence of activity of a first-in-human phase I study of the novel cancer stem cell (CSC) targeting antibody OMP-52M51 (anti-Notch1) administered intravenously to patients with certain advanced solid tumors A. Patnaik, P. LoRusso, P. Munster, A.W. Tolcher, S.L. Davis, J. Heymach, R. Ferraroto, L. Xu, A.M. Kapoun, L. Faoro, J.A. Lewicki, J. Dupont, S.G. Eckhardt 2 13:50 ORAL PRESENTATION: Afuresertib (GSK2110183), an oral AKT kinase inhibitor, in combination with carboplatin and paclitaxel in recurrent ovarian cancer S. Blagden, A. Hamilton, L. Mileshkin, M. Hall, T. Meniawy, S. Wong, S. Anandra, M. Buck, D. McAleer, B.A. Reedy, R.B. Noble, D.A. Smith, S.R. Morris, H. Gabra 3 14:05 ORAL PRESENTATION: Activity of galeterone in castrate-resistant prostate cancer (CRPC) with C-terminal AR loss: Results from ARMOR2 M.E. Taplin, K.N. Chi, F. Chu, J. Cochran, W.J. Edenfield, E.S. Antonarakis, U. Emmenegger, E.I. Heath, A. Hussain, V.C. Njar, A. Koletsky, D. Lipsitz, L. Nordquist, R. Pili, M. Rettig, O. Sartor, N.D. Shore, D. Marrinucci, K. Mamlouk, B. Montgomery 4 14:20 ORAL PRESENTATION: Mechanism based targeted therapy for hereditary leiomyomatosis and renal cell cancer (HLRCC) and sporadic papillary renal cell carcinoma: interim results from a phase 2 study of bevacizumab and erlotinib R. Srinivasan, D. Su, L. Stamatakis, M.M. Siddiqui, E. Singer, B. Shuch, J. Nix, J. Friend, G. Hawks, J. Shih, P. Choyke, W.M. Linehan 5 14:35 ORAL PRESENTATION: Imaging in cancer immunology: Phenotyping of multiple immune cell subsets in-situ in FFPE tissue sections J.R. Mansfield, C. Slater, C. Wang, K. Roman, C.C. Hoyt, R.J. Byers 6 14:50 LATE BREAKING ABSTRACT: Clinical safety and activity in a phase I trial of AG-120, a first in class, selective, potent inhibitor of the IDH1-mutant protein, in patients with IDH1 mutant positive advanced hematologic malignancies D.A. Pollyea, S. de Botton, A.T. Fathi, E.M. Stein, M.S. Tallman, S. Agresta, C. Bowden, B. Fan, M. Prah, H. Yang, K. Yen, R.M. Stone 1LBA 15:00 LATE BREAKING ABSTRACT: The identification of potent and selective inhibitors of oncogenes in 2LBA medullary thyroid carcinoma and lung adenocarcinoma disease models S. Fritzl, H. Small, B. Acton, S. Holt, G. Hopkins, S. Jones, A. Jordan, N. March, R. Newton, I. Waddell, B. Waszkowycz, M. Watson, D. Ogilvie 15:10 Discussion Late Breaking Abstracts C.L. Arteaga (USA) Plenary Session 3 16:00–17:50 Oncolytic Viruses Chairs: K. Harrington (United Kingdom) and L.J. Helman (USA) 16:00 T-VEC for the treatment of melanoma: Are we ready for prime time? H. Kaufman (USA) Auditorium Abstract number xxvi Scientific programme – details 16:20 Poliovirus oncolytic immunotherapy of glioblastoma M. Gromeier (USA) Key objectives: 1. Discuss the role of mechanisms of viral tumour cell killing in oncolytic immunotherapy. 2. Define principles of efficacious oncolytic immunotherapy: explain the role of the innate antiviral response to oncolytic poliovirus. 3. Communicate the major clinical/radiographic findings from oncolytic immunotherapy of recurrent glioblastoma with recombinant poliovirus. 16:40 Measles and vesicular stomatitis virus strains as novel oncolytic platforms E. Galanis (USA) 17:00 Challenges in clinical development of oncolytic viruses K. Harrington (United Kingdom) 17:20 LATE BREAKING ABSTRACT: Initial report of a first-in-human study of the first-in-class fatty acid 3LBA synthase (FASN) inhibitor, TVB-2640 J. Infante, M. Patel, D. Von Hoff, A. Brenner, C. Rubino, W. McCulloch, V. Zhukova-Harrill, M. Parsey 17:30 LATE BREAKING ABSTRACT: A phase 1 study of first-in-class microRNA-34 mimic, MRX34, in 4LBA patients with hepatocellular carcinoma or advanced cancer with liver metastasis M. Beg, A. Brenner, J. Sachdev, M. Borad, J. Cortes, R. Tibes, Y. Kang, A. Bader, J. Stoudemire, S. Smith, S. Kim, D. Hong 17:40 Discussion Late Breaking Abstracts L.J. Helman (USA) 18:00–19:30 Animal Models Poster board Poster Viewing Poster area Abstract number P001 Mouse clinical trial − A new preclinical study concept using patient-derived xenografts V. Vuaroqueaux, C. Gredy, S. Gorynia, S. Baltes, H.H. Fiebig, T. Metz P002 Imaging growth and anti-cancer activity in orthotopic patient derived tumors M. Baugher, C. Bull, A. Cohen-Barnhouse, A. Flecha, M. Franklin, K. Guley, P. McConville, W.R. Leopold P003 Antineoplastic effects of auranofin in canine lymphoma D. Thamm, B.J. Rose, J.K. Shoeneman P004 mTOR inhibition with everolimus − a novel treatment option for head and neck cancer identified in a translational research study using patient-derived xenografts K. Klinghammer, J.D. Raguse, T. Plath, A.E. Albers, B. Brzezicha, A. Wulf-Goldenberg, U. Keilholz, J. Hoffmann, I. Fichtner P005 A panel of patient derived xenograft models of different haematological malignancies suitable for preclinical drug screening campaigns E. Oswald, C. Tschuch, K. Klingner, B. Hammerich, D. Lehnhard, C. Rentsch, M. Lübbert, H.H. Fiebig, J. Schüler P006 Next generation sequencing (NGS) guided therapy prediction for the treatment of glioblastoma multiforme (GBM) J. Sarkaria, D.M. Ma, S.P. Peng, S.B. Byron, D.C. Craig, J.C. Carpten, M.B. Berens, B.O. O’Neill, N.T. Tran P007 Whole exome sequence analysis of canine transitional cell carcinoma of the bladder D.L. Duval, B. Hernandez, J. Brown, S.E. Lana, R. Page, K.L. Jones P008 Mixeno mouse models for in vivo evaluation of anti-human cancer immunotherapeutics J. Zhang, J. Qiu, M. Qiao, Q. Shi P009 Genetic and molecular validation of uterine sarcoma patient-derived xenograft models T. Cuppens, E. Hermans, J. Depreeuw, M. Moisse, T. Van Brussel, L. Coenegrachts, D. Lambrechts, F. Amant 7 8 9 10 11 12 13 14 15 Scientific programme – details Poster board xxvii Abstract number P010 Allografting improves the feasibility of genetically engineered mouse models (GEMM) for anti-cancer drug development K. Kukuk, K. Klingner, A.L. Peille, P. Müller, A. Zipelius, J. Schüler 16 P011 Studies on glycoprotein expression differences between MCF-7 and MCF-7-Z J. Ner-Kluza, A. Drabik, M. Kubbutat, A. Lingnau, J. Silberring 17 P012 Establishment and characterization of a Merkel Cell carcinoma PDX panel: Screening for potentially useful therapies M.J. Wick, J. Meade, M. Nehls, T. Vaught, J. Carlile, A.W. Tolcher, D.W. Rasco, A. Patnaik, K.P. Papadopoulos 18 P013 Syngeneic models for developing cancer therapeutics targeting immune system L. Zhang, J. Zhang, Q. Shi 19 P014 miR-25 is a key regulator of prostate cancer invasiveness by modulation of the cross-talk between Notch and TGF-b signaling E. Zoni, A.F. van de Merbel, G. van der Horst, J. Rane, T. Visakorpi, E.B. Snaar, N. Maitland, G. van der Pluijm 20 Cytotoxics Poster board Abstract number P015 Pharmacogenomics of mithramycin in thoracic malignancies W. Figg, T.M. Sissung, C.J. Peer, D. Schrump 21 P016 Novel combination therapy, TAS-102 combined with the anti-EGFR antibody or the anti-VEGF antibody showed therapeutic benefit toward colorectal cancer xenografts K. Ishida, K. Sakamoto, N. Tanaka, K. Oguchi, K. Yamamura, A. Fujioka, F. Nakagawa, K. Matsuo, T. Utsugi 22 P017 Phase I study of lurbinectedin (PM01183) administered on days (D) 1 & 8 every 3 weeks (q3wk) in patients (pts) with solid tumors M.J. Ratain, L. Gore, S. Szyldergemajn, J. Diamond, D. Geary, C. Fernandez-Teruel, A. Soto-Matos, M. Sharma, A. Jimeno 23 P018 Androgen receptor (AR) expression in triple negative breast cancer (TNBC): results from a phase II neoadjuvant trial with carboplatin and eribulin mesylate in TNBC patients K. Siziopikou, V. Parini, V. Kaklamani 24 P019 An ING1b-derived peptide that inhibits cancer cell viability and promotes apoptosis A. Boyko, K. Riabowol 25 P020 NPD926, a small molecule inducer of reactive oxygen species, kills cancer cells via glutathione depletion T. Kawamura, Y. Kondoh, M. Muroi, M. Kawatani, H. Osada 26 P021 TAS-102 treatment results in high trifluridine incorporation into DNA with pyrimidine metabolic pathway markedly up-regulated in cancer K. Oguchi, K. Sakamoto, H. Kazuno, H. Ueno, K. Ishida, T. Yokogawa, K. Yamamura, R. Kitamura, K. Matsuo, T. Utsugi 27 P022 Characterization of the type of cell death induced by novel tambjamine analogs in lung cancer A. Rodilla Martı́n, V. Soto-Cerrato, P. Manuel-Manresa, L. Korrodi-Gregório, R. Quesada, R. PérezTomàs 28 P023 TAS-114 is a novel dUTPase/DPD inhibitor, its DPD inhibition reduces capecitabine dosage but does not diminish therapeutic window in human tumor xenografts W. Yano, H. Kazuno, T. Yokogawa, K. Sakamoto, K. Yoshisue, T. Wakasa, M. Fukuoka, K. Matsuo, K. Noguchi, T. Utsugi 29 xxviii Poster board Scientific programme – details Abstract number P024 The fungal-derived cyclohexadepsipeptide Destruxin E exerts multifaceted anticancer and antiangiogenic activities R. Dornetshuber-Fleiss, P. Heffeter, T. Mohr, P. Hazemi, K. Kryeziu, C. Seger, W. Berger, R. Lemmens-Gruber P025 N-Myc amplification sensitizes tumor cells to inhibition by Danusertib, an Aurora kinase inhibitor P. Carpinelli, R. Ceruti, R. Alzani, C. Re, D. Ballinari, S. Cribioli, M. Russo, A. Degrassi, G. Texido, M. Ciomei, E. Pesenti, A. Montagnoli, A. Galvani P026 Replication stress is a determinant of synergy between gemcitabine and Chk1 inhibition S.B. Koh, A. Courtin, R. Boyce, B. Boyle, F.M. Richards, D.I. Jodrell P027 Combining the long-acting topoisomerase 1-inhibitor etirinotecan pegol with the PARP inhibitor rucaparib to provide anti-tumor synergy without increased toxicity U. Hoch, D. Charych P028 Phase I, dose-escalation study of the investigational drug D07001-F4, an oral formulation of gemcitabine HCl, in patients (pts) with advanced solid tumors or lymphoma C. Lin, W. Su, J. Lee, C. Hsu, A. Cheng, C. Lin, H. Ho, C. Huang, S. Hsueh, J. Yang P029 BRCA1 expression exploratory analysis in patients of the phase III trial of trabectedin vs. doxorubicin-based chemotherapy as first-line therapy in translocation-related sarcomas M. Aracil, P. Lardelli, A. Nieto, C.M. Galmarini P030 Suppression of metastasis and improvement of drug distribution by eribulin mesylate Y. Ozawa, K. Okamoto, Y. Adachi, M. Asano, K. Tabata, Y. Funahashi, J. Matsui P031 Effect of a microtubule-targeting drug on cell–cell contacts in bladder epithelial tumour cells L.M. Antón-Aparicio, R. Castosa, M. Haz, M. Blanco, M. Rodriguez, M. Valladares, A. Figueroa P032 The indolyl-chalcone CDD-026 induces cancer cell death through targeting of STMN1 and mitotic catastrophe B. Wegiel, Y. Wang, F. Jernigan, L. Sun P033 Phytochemical indole-3-carbinol synergizes strongly with fludarabine and induces p53-dependent and -independent cell death in chronic lymphocytic leukemia cells irrespective of their IGHV mutation state and treatment resistances G. Perez-Chacon, C. Martinez-Laperche, N. Rebolleda, B. Somovilla-Crespo, C. Muñoz-Calleja, I. Buño, J.M. Zapata P034 Selectivity and mechanism of action studies for Polo Box-targeted, non-ATP based inhibitors of PLK1 M. Baxter, S. Craig, C. McInnes, M.D. Wyatt P035 Clinical activity of BIND-014 (docetaxel nanoparticles for injectable suspension) as second-line therapy in patients (pts) with Stage III/IV non-small cell lung cancer R. Natale, M. Socinski, L. Hart, O. Lipatov, D. Spigel, B. Gershenhorn, G. Weiss, S. Kazmi, N. Karaseva, O. Gladkov, V. Moiseyenko, J. Summa, G. Otterson P036 Interaction of SJG-136 with cognate sequences of oncogenic transcription factors J. Mantaj, P.J. Jackson, D.E. Thurston, K.M. Rahman P037 CDKN1A-mediated responsiveness of MLL-AF4-positive acute lymphoblastic leukemia to Aurora kinase-A inhibitors L. Hung, Y. Chen, H. Lin, M. Tsai, H. Hsieh, J. Chang, N. Chen, S. Yang, T. Chen P038 Metformin and its impact on gastric cancer patients survival after gastrectomy C.K. Lee, M.K. Jung, I.K. Jung, S.J. Heo, J.Y. An, H.I. Kim, J.H. Chung, W.J. Hyung, S.H. Noh, H.S. Kim, S.Y. Rha, H.C. Chung P039 Early preclinical study of BO-2094 for treatment of human colon cancer, in combination with 5-fluorouracil T.L. Su, T.H. Ou, M.H. Wu, Y.W. Lin, T.C. Lee P040 Broad-spectrum preclinical combination activity of eribulin combined with various anticancer agents in human breast cancer, lung cancer, ovarian cancer, and melanoma xenograft models M. Asano, J. Matsui, M.J. Towle, J. Wu, S. McGonigle, T. Uenaka, K. Nomoto, B.A. Littlefield 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 Scientific programme – details Poster board xxix Abstract number P041 Lurbinectedin (PM01183) specifically targets RNA Pol II for degradation via the proteasome pathway in a transcription and TC-NER dependent fashion G. Santamaria, J.F. Martı́nez-Leal, C. Cuevas, L.F. Garcia-Fernandez, C.M. Galmarini P042 Trabectedin and lurbinectedin are effective against leukemic cells derived from patients affected by chronic and juvenile myelomonocytic leukemia M. Romano, A. Gallı̀, N. Panini, L. Paracchini, L. Beltrame, E. Bello, S.A. Licandro, C. Cattrini, R. Tancredi, S. Marchini, V. Rosti, M. Zecca, M. Della Porta, A. Zambelli, C.M. Galmarini, E. Erba, M. D’Incalci P043 siRNA targeting of mitochondrial thymidine kinase 2 (TK2) sensitizes cancer cells to gemcitabine and increases mitochondrial toxicity C. Di Cresce, P. Ferguson, R. Figueredo, M. Rytelewski, S. Maleki Vareki, M.D. Vincent, J. Koropatnick P044 The effect of esomeprazole, a proton pump inhibitor, on the pharmacokinetics of the investigational Aurora A kinase inhibitor alisertib (MLN8237) in patients with advanced solid tumors or lymphomas X. Zhou, J. Nemunaitis, S. Pant, T. Bauer, A. Lockhart, M. Patel, B. Zhang, V. Kelly, C.D. Ullmann, M. Bargfrede, K. Venkatakrishnan P045 Development of rational combination therapy strategies to optimize treatment for GPNMB expressing Her2+ and triple negative breast cancer A. Rose, G. Maric, M.G. Annis, H. Smith, W.J. Muller, P.M. Siegel P046 Platinum(IV) derivatives of oxaliplatin: Cellular effects and in vivo potency S. Göschl, V. Pichler, E. Brynzak, P. Heffeter, U. Jungwirth, M.A. Jakupec, W. Berger, M. Galanski, B.K. Keppler P047 Adeno-associated virus (AAV) carrying diphtheria toxin a gene for pancreatic cancer therapy M. Chen, C.Y. Ho, M. Teng, H. Chen P048 MGMT methylation assessed by methyl-BEAMing technique is a prognostic and predictive biomarker in glioblastoma and metastatic colorectal cancer patients L. Barault, A. Amatu, F.E. Bleeker, C. Moutinho, A. Cassingena, F. Tosi, T. Venesio, M. Esteller, A. Bardelli, S. Siena, A. Sartore-Bianchi, F. Di Nicolantonio P049 Low, frequent doses of PM060184 induce remarkable in vivo antitumor activity P. Aviles, M.J. Guillen, P.P. Lopez-Casas, F. Sarno, O. Cataluña, P. Nuñez, C. Cuevas, M. Hidalgo P050 Radiosensitizing effect of sodium metaarsenite in a metastatic brain tumor model W.Y. Kang, Y.M. Park, S.J. Kim P051 Differential antitumor activity of trabectedin, lurbinectedin, Zalypsis and PM00128 against a panel of human cells deficient in transcription and NER factors V. Moneo, S. Avila, P. Martı́nez, B. de Castro, S. Cascajares, C. Cuevas, L.F. Garcia-Fernandez, C.M. Galmarini P052 Pipecolidepsin A, Stellatolide A and Irvalec: New cyclodepsipeptides of marine origin with antitumor activity J.M. Molina-Guijarro, V. Moneo, J.F. Martinez-Leal, C. Cuevas, L.F. Garcia-Fernandez, C.M. Galmarini P053 Discovery of novel inhibitor of FOXO nuclear–cytoplasmic shuttling from natural products of marine origin F.J. Castillo Correa, N. De Pedro, L. Rodriguez Quesada, D. Oves Costales, J.R. Tormo, J. Martin, F. Reyes, O. Genilloud, F. Vicente, W. Link, B. Cautain P054 Sodium metaarsenite cytotoxic activity is associated with telomere length and many types of arsenic transporters in non-small cell lung cancer Y.M. Park, S.J. Kim P055 A panel of pediatric liver cancer patient-derived xenografts to improve stratification of children with hepatoblastoma M. Fabre, D. Nicolle, A. Gorse, O. Déas, C. Mussini, L. Brugières, M.R. Ghigna, E. Fadel, L. Galmiche-Rolland, C. Chardot, C. Armengol, J.G. Judde, S. Branchereau, S. Cairo 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 xxx Scientific programme – details Poster board Abstract number P056 Antitumor and temozolomide-sensitizing effects of sodium metaarsenite in an orthotopic glioblastoma xenograft model W.Y. Kang, Y.M. Park, S.J. Kim 62 P057 Radium-223 dichloride − Efficacy and mode-of-action in a mouse model of prostate cancer bone metastasis M.I. Suominen, K.M. Fagerlund, J.P. Rissanen, Y. Konkol, E. Alhoniemi, D. Mumberg, K. Ziegelbauer, S.M. Käkönen, J.M. Halleen, R.L. Vessella, A. Scholz 63 P058 Nifuroxazide halogenic derivatives induce ROS-mediated apoptosis and display antitumor activity against metastatic melanoma C. Fernandez de Farias, M.H. Massaoka, N. Girola, C.R. Figueiredo, R.A. Azevedo, L.C. Tavares, L.R. Travassos 64 P059 Phase II drug metabolism UGT1A enzyme affects cellular response of colon cancer cells to antitumor triazoloacridinone C-1305 treatment E. Augustin, E. Bartusik, A. Theus, B. Borowa-Mazgaj, Z. Mazerska 65 P060 Clinical validity of new genetic biomarkers of irinotecan neutropenia: An independent replication study F. Innocenti, J. Ramirez, W. Qiao, A.J. de Graan, M.J. Ratain, R.H.N. van Schaik, R.H.J. Mathijssen, G.L. Rosner, D.J. Crona 66 P061 Cytotoxic response as a result of the cross-talk between UGT mediated metabolism and modulation of UGT activity by C-1311 and C-1305 acridinone antitumor agents in selected solid tumor cell lines Z. Mazerska, M. Pawlowska, A. Bejrowska, M. Szydlowska, B. Fedejko, E. Augustin 67 P062 Can the P53 status predict the outcome of Polo-like kinase 1 inhibition in non-small cell lung cancer cell lines? J. Van den Bossche, A. Wouters, C. Deben, V. Deschoolmeester, P. Specenier, P. Pauwels, M. Peeters, F. Lardon 68 Drug Resistance and Modifiers Poster board Abstract number P063 AKT3 activation mediates resistance to HER2-targeted therapies in HER2-amplified breast cancer F. Carmona Sanz, F. Montemurro, V. Rossi, C. Verma, M. Berger, J. Baselga, M. Scaltriti 69 P064 Antitumor activity of S116836, a novel tyrosine kinase inhibitor, against imatinib-resistant FIP1L1PDGFRa-expressing cells J. Pan, Y. Shen, K. Ding 70 P065 Novel regulation of estrogen receptor transcription by the PI3K pathway E. Toska, M. Elkabets, A. Bosch, O. Litvin, M. Scaltriti, J. Baselga 71 P066 Nrf2 as a molecular target in overwhelming chemoresistance in breast cancer therapy N. Samadi, F. Ramezani, M. Sabzichi 72 P067 Differential pathway resiliency in response to MAPK inhibition in BRAF-mutant cancer M. Sos, R.S. Levin, J.D. Gordan, J.A. Oses-Prieto, J.T. Webber, M. Salt, B. Hann, A.L. Burlingame, F. McCormick, S. Bandyopadhyay, K.M. Shokat 73 P068 Increased EDN1 expression mediates acquired resistance to the combination therapy of PI3K and MEK inhibitors for colorectal cancer B. Bhattacharya, S.H.H. Low, T. Benoukraf, M.L. Chong, K.X. Koh, R. Soong 74 P069 Loss of PTEN leads to acquired resistance to the PI3Ka inhibitor BYL719: a case of convergent evolution under selective therapeutic pressure P. Castel, D. Juric, M. Griffith, O.L. Griffith, H.H. Won, B. Ainscough, H. Ellis, S. Ebbesen, I. Gopakumar, C. Quadt, M. Peters, D. Solit, S.W. Lowe, E.R. Mardis, M.F. Berger, M. Scaltriti, J. Baselga 75 Scientific programme – details Poster board xxxi Abstract number P070 Mixed lineage kinases activate MEK independently of RAF to mediate resistance to RAF inhibitors A.A. Marusiak, Z.C. Edwards, W. Hugo, E.W. Trotter, M.R. Girotti, N.L. Stephenson, X. Kong, M.G. Gartside, S. Fawdar, A. Hudson, W. Breitwieser, N.K. Hayward, R. Marais, R.S. Lo, J. Brognard P071 Tumor suppressive roles of miR-221 and miR-222 in lung cancer M. Sato, R. Yamashita, T. Kakumu, T. Hase, E. Maruyama, Y. Sekido, M. Kondo, Y. Hasegawa P072 A comprehensive in vitro screen to identify therapeutic candidates for inclusion with etoposide/platin combinations to improve treatment of SCLC D. Evans, R. Delosh, J. Laudeman, C. Ogle, R. Reinhart, M. Selby, T. Silvers, A. Monks, E. Polley, G. Kaur, J. Morris, B.A. Teicher P073 Quantitative proteomics as a tool to identify resistance mechanisms in erlotinib-resistant subclones of the non-small cell lung cancer cell line HCC827 K. Jacobsen, R.R. Lund, H.C. Beck, H.J. Ditzel P074 Determination of an oxidative stress gene signature in inflammatory breast cancer patient tumors and development of a novel redox modulatory strategy in overcoming chemotherapy resistance and mediating anti-tumor efficacy G.R. Devi, J.L. Allensworth, M. Evans, N. Ueno, D. McDonnell, F. Bertucci, S. Van Laere P075 Sensitization of triple-negative breast cancer to PI3K inhibition by cotargeting IGF1R K. de Lint, J.B. Poell, J. Vidal Rodriguez, H. Soueidan, W. Nijkamp, L.F. Wessels, R.L. Beijersbergen P076 Regorafenib resistance in colorectal carcinoma is associated with enhanced expression of type II interleukin 1 receptor and reversed by MEK/ERK inhibitor A.C. Mar, C.H. Chu, C.W. Shiau, T.C. Lee P077 Acquired resistance to BET bromodomain inhibitors is associated with modulation of the apoptotic signaling network P. Sandy, S. Nerle, A. Conery, C. Hatton, B. Bryant, R. Sims, E. Normant P078 Src family kinase activation is a compensatory survival mechanism for acquired resistance to EGFRTKIs in lung cancer cells M. Ono, K. Sonoda, K. Azuma, K. Watari, M. Molina, R. Rosell, M. Kuwano P079 Wnt secretion is required to maintain Wnt activity in colon cancer O. Voloshanenko, G. Erdmann, T.D. Dubash, I. Augustin, M. Metzig, C.R. Ball, H. Glimm, R. Spang, M. Boutros P080 Influence of EGFR exon 19 mutation subtypes on survival outcomes in advanced stage Asian nonsmall cell lung cancer patients receiving TKI therapy B. Chowbay, O. Singh, N. Sutiman, D.S.W. Tan, W.T. Lim, E.H. Tan P081 Critical difference in development of acquired resistance to MDM2 inhibitor SAR405838 in vitro and in vivo G. Hoffman-Luca, C.Y. Yang, J. Lu, D. Ziazadeh, D. McEachern, L. Debussche, S. Wang P082 Genome-wide drug sensitivity screens in haploid mouse embryonic stem cells S.J. Pettitt, D. Krastev, H. Pemberton, Y. Fontebasso, I. Bajrami, I. Kozarewa, J. Frankum, R. Rafiq, J. Campbell, R. Brough, A. Ashworth, C.J. Lord P083 Tie-2 regulates the stemness of prostate cancer cells K. Tang, M. Ling P084 Tumor infiltrating leukocyte subpopulations as a biomarker of response and resistance to targeted therapy in patients with BRAF mutation-positive metastatic melanoma M.C. Kelley, D.B. Doxie, A.R. Greenplate, H. Crandall, J.A. Sosman, J.M. Irish P085 4E-BP1 expression levels determine sensitivity of triple negative breast cancer cells to mTOR inhibitors K. Jastrzebski, B. Thijssen, J. Vidal Rodriguez, K. de Lint, C. Lieftink, L.F. Wessels, R.L. Beijersbergen P086 Role of ERK nuclear translocation in cisplatin-sensitive and -resistant ovarian cancer cells S. Dilruba, G.V. Kalayda, U. Jaehde 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 xxxii Scientific programme – details Poster board Abstract number P087 A stress induced early innate response causes multi-drug tolerance in melanoma D.R. Menon, S. Das, C. Krepler, A. Vultur, B. Rinner, S. Schauer, K. Kashofer, K. Wagner, G. Zhang, E. Bonyadi Rad, H.P. Soyer, B. Gabrielli, R. Somasundaram, G. Hoefler, M. Herlyn, H. Schaider 93 P088 Elucidating mechanisms of resistance to FGFR inhibitors in endometrial cancer L. Packer, S. Byron, C. Mahon, D. Loch, A. Wortmann, K. Nones, S. Grimmond, J. Pearson, N. Waddell, P. Pollock 94 Drug Screening Poster board Abstract number P089 Identification of synthetic lethality compounds from natural products for cancers K.W. Ng, K.S. Lee, V. Patel, E. Sundaramoorthy, N. Ayoub, X. Su, A. Venkitaraman, S.H. Teo 95 P090 Evaluation of hormone therapies in a panel of breast PDX models: Relevance of ER status on sensitivity to letrozole and tamoxifen M.J. Wick, T. Vaught, L. Gamez, J. Meade, A. Diaz, K.P. Papadopoulos, D.W. Rasco, A. Patnaik, M. Beeram, A. Lang, A.W. Tolcher 96 P091 Utilization of low passage adenoid cystic carcinoma PDX models to identify novel combination therapies M.J. Wick, J. Meade, T. Vaught, M. Nehls, J. Flores, J. Kaufman, A.W. Tolcher, D.W. Rasco, A. Patnaik, C.A. Moskaluk, K.P. Papadopoulos 97 P092 Synergistic inhibition of HER2 positive breast cancer by triptolide and lapatinib P. Chalugun, J.S. Shim, P. Korangath, S. Sukumar, J.O. Liu 98 P093 Combination screening of investigational oncology agents S. Holbeck, J.M. Collins, J.D. Doroshow 99 P094 Small molecules selectively targeting breast cancer cells J. Sakoff, J. Gilbert, A. McCluskey 100 P095 PIK3CA mutation-targeting compounds analyses using NCI60 cell line panel H. Bando, J. Lih, E.C. Polley, S.L. Holbeck, B. Das, D. Sims, T. Doi, A. Ohtsu, M. Williams, N. Takebe 101 P096 Comparison of platinum/taxane and anthracycline-based therapies in ovarian PDX models: Correlating stage of biopsy collection and engrafting with in vivo drug sensitivity J. Meade, M.J. Wick, T. Vaught, L. Gamez, M. Farley, A. Moriarty, A.W. Tolcher, A. Patnaik, D.W. Rasco, A.J. White, K.P. Papadopoulos 102 P097 The use of next generation sequencing (NGS) in the management of metastatic breast cancer (MBC): Defining a model for genomic-driven therapies L. Austin, M. Gooptu, T. Avery, R. Jaslow, J. Palazzo, M. Cristofanilli 103 P098 Identification of inhibitors of tryptophan metabolizing enzymes for cancer immunotherapy by highthroughput screening G. Zaman, J.C.M. Uitdehaag, S. van Gerwen, N. Seegers, A.M. van Doornmalen, J. de Man, R.C. Buijsman 104 P099 A platform to test multiple therapy options simultaneously in a patient’s own tumor N. Caffo, R. Klinghoffer 105 Immunotherapy (Immunecheckpoints, Vaccination, Oncolytic viruses, Cytokines) Poster board Abstract number P100 Beta-3 integrin inhibition reduces inflammatory cytokine release but not anti-cancer activity of oncolytic adenovirus in ovarian cancer A.K. Browne, L.A. Tookman, C.K. Ingemarsdotter, R. Bouwman, K. Pirlo, Y. Wang, K.M. HodivalaDilke, I.A. McNeish, M. Lockley 106 Scientific programme – details Poster board xxxiii Abstract number P101 CIGB-247: Anti-VEGF therapeutic vaccine in patients with advanced solid tumors F. Hernández-Bernal, J.V. Gavilondo, M. Ayala Ávila, A.V. de la Torre, J. de la Torre, K.H. SelmanHousein, Y. Morera, M. Bequet-Romero, C.M. Valenzuela, Y. Martin P102 CD70 (TNFSF7), a receptor involved in acute immune modulation of viral infection, is frequently overexpressed in solid and hematological malignancies J. Jacobs, K. Zwaenepoel, P. Aftimos, C. Rolfo, S. Rottey, L. Ysebrant de Lendonck, K. Silence, A. Awada, A. Thibault, P. Pauwels P103 Functional activity, but not PD-1 expression level, differentiates primary CLL from healthy PD1+ T cells using SCNP S. Liang, L. Leung, S. Putta, D. Hotson, D. Rosen, R.E. Hawtin P104 IL-6/STAT3/Fra-1 signaling axis promotes colorectal cancer aggressiveness through epithelial– mesenchymal transition J. Shao, H. Liu P105 Identification of peptides which could block PD-1 checkpoint for NSCLC immunotherapy Y. Zhu, C. Li P106 A novel primary human tumor explant platform provides a preclinical translational link from tissue culture to the clinic G. Juan, K. Paweletz, E. Trueblood, J. Rossi, M. Damore, A. Anderson, R. Loberg P107 Preclinical activity and pharmacodynamic biomarkers of W014A, a PD-1 decoy peptide blocking both PD-1 immune checkpoint ligands, PD-L1 and PD-L2 C. Bailly, M. Broussas, M. Ramachandra, P.G. Sasikumar, K. Shrimali, S. Adurthi, M. Ramachandra, L.K. Satyam, A.A. Dhudashia, S. Dhodheri, K.B. Sunilkumar, N. Corvaı̈a, P. Ferre P108 Toll-like receptor 5 agonist entolimod as a potential anticancer immunotherapeutic agent L. Burdelya, C. Brackett, B. Kojouharov, J. Veith, A. Gudkov P109 Anti-metastatic activity via co-blockade of PD-1 and adenosine A2A receptor D. Mittal, A. Young, K. Stannard, M.W. Teng, B. Allard, J. Stagg, M.J. Smyth P110 Novel targets for antibody–drug conjugate therapy A.G. Grandi, S.C. Campagnoli, M.P. Parri, E.D.C. De Camilli, B.J. Jin, P.S. Sarmientos, G.G. Grandi, L.T. Terracciano, P.P. Pileri, G.V. Viale, R. Grifantini P111 “Arming” the chimeric oncolytic adenovirus enadenotucirev to deliver checkpoint inhibitors and other therapeutics directly to tumours B. Champion, P. Kodialbail, S. Illingworth, N. Rasiah, D. Cochrane, J. Beadle, K. Fisher, A.C.N. Brown P112 Major synergy between Coxsackievirus A21 (CAVATAK™) and radiotherapy or chemotherapy in bladder cancer G.R. Simpson, N. Annels, M. Ajaz, F. Launchbury, G. Bolton, A.A. Melcher, K.J. Harrington, G. Au, D. Shafren, H. Pandha P113 3-Bromopyruvate as an inducer of immunogenic cell death in colon cancer cells K.H. Jung, J.H. Lee, J.W. Park, C. Quach, K.H. Lee P114 Density of CD 8 +ve T cells & CD 56 +ve NK cells in follicular adenoma & papillary carcinoma of thyroid in Pakistani population J. Varda, N. Naseem, A.H. Nagi P115 A modified double-deleted vaccinia virus combining viral oncolysis and potential gene therapy as a novel therapeutic for atypical teratoid/rhabdoid tumors Y. Ruan, A. Narendran P116 Analysis of immune-response markers in resectable NSCLC M. Usó, E. Jantus-Lewintre, R. Sirera, S. Calabuig-Fariñas, S. Gallach, E. Escorihuela, A. Blasco, R. Guijarro, C. Camps P117 Targeting tryptophan metabolism in human lung cancer J. Deshane, C. Schafer, Y. Wang, A. Sawant, T.H. Jin, D. Zhi, S. Ponnazhagan, S. Grant 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 xxxiv Scientific programme – details Poster board Abstract number P118 A WT1-derived peptide protects against metastatic melanoma in a syngeneic model by in vivo immunomodulatory effects on dendritic cells M.H. Massaoka, C.R. Figueiredo, N. Girola, R.A. Azevedo, L.R. Travassos 124 P119 Critical issues in the clinical development of oncolytic viruses − A regulatory perspective M. Schuessler-Lenz 125 P120 IMCgp100: A novel bi-specific biologic for the treatment of malignant melanoma W. Shingler, J. Harper, G. Bossi, D. Barker, J. Dukes, N. Liddy, S. Paston, T. Mahon, P. Molloy, M. Sami, E. Baston, B. Cameron, A. Johnson, A. Vuidepot, N. Hassan, Y. McGrath, B. Jakobsen 126 P121 Correlation of clinical activity of pembrolizumab (MK-3475) with immunohistochemical staining for programmed death-1 ligand (PD-L1) in 50% of tumor cells in a prospective non-small cell lung cancer (NSCLC) validation population E.G. Garon, N.A. Rizvi, N.B. Leighl, R. Hui, J.P. Eder, A. Patnaik, C. Aggarwal, L. Horn, A.S. Balmanoukian, M.A. Gubens, E. Felip-Font, E. Carceny Costa, J.C. Soria, M.J. Ahn, H.T. Arkenau, J.S. Lee, G. Robinet, G.M. Lubiniecki, J. Zhang, K. Emancipator, R. Rutledge, M. Dolled-Filhart, L. Gandhi 127 P122 T cell-mediated cancer immunotherapy through OX40 agonism M. Huseni, C. Du, J. Zhu, P. Pacheco-Sanchez, M. Moskalenko, H. Chiu, K. Dalpozzo, K. Totpal, L. Damico-Beyer, J. Kim 128 P123 Characterization of PD-L1 expression in circulating tumor cells (CTCs) of non-small cell lung cancer (NSCLC) patients R. Krupa, D. Lu, M. Harvey, J. Louw, A. Jendrisak, D. Marrinucci, R. Dittamore 129 P124 Preclinical results of ProCervix, a first in class, first in indication therapeutic vaccine targeting HPV16/18 infected women M. Esquerre, M. Bouillette-Marussig, A. Goubier, M. Momot, H. Keller, M. Bissery 130 P125 Zfra activates novel Hyal2+ CD3− CD19− memory spleen cells to block cancer growth, stemness, and metastasis in vivo N. Chang 131 P126 A novel anti-PDL1 antibody-based bifunctional protein with enhanced immunological activity Y. Wu, S. Martomo, Z. Zhong, D. Lu, Z. Polonskaya, X. Luna, Z. Zhang, H. Zhang, L. Witte, S. Waksal, Z. Zhu 132 P127 Analysis of immune microenvironment in resectable NSCLC: Prognostic value of regulatory and conventional T cell markers proportion M. Usó, R. Sirera, S. Calabuig-Fariñas, A. Blasco, E. Pastor, R. Guijarro, E. Jantus-Lewintre, J. Forteza, C. Camps 133 P128 Epigenetic immunomodulation by SGI-110 combined with immune checkpoint blockade for new therapeutic strategies A. Covre, C. Fazio, H.J.M.G. Nicolay, P.G. Natali, P. Taverna, M. Azab, S. Coral, M. Maio 134 P129 AD-O64.3: IFN-g–TRAIL fusion protein. Use of two independent signaling pathways for a strong synergistic antitumor effect B. Zerek, J.S. Pieczykolan, S.D. Pawlak, P.K. Rozga, A. Pieczykolan, M. Szymanik, A. Jaworski, M. Galazka, K. Bukato, K. Poleszak, M. Teska-Kaminska, W. Strozek 135 P130 Tumor-infiltrating lymphocytes (TILs) following intratumoral administration of ONCOS-102 are associated with prolonged overall survival in last line solid tumor patients S. Pesonen, T. Joensuu, E. Jager, J. Karbach, C. Wahle, K. Kairemo, K. Partanen, R. Turkki, A. Hemminki, C. Backman, M. von Euler, T. Hakonen, T. Ranki, L. Vassilev, A. Vuolanto, M. Jaderberg 136 P131 Immune checkpoint blockade enhances measles virotherapy C.E. Engeland, R. Veinalde, C. Grossardt, S. Bossow, I. Shevchenko, V. Umansky, D.M. Nettelbeck, D. Jäger, C. von Kalle, G. Ungerechts 137 Scientific programme – details Poster board xxxv Abstract number P132 Preclinical activity and safety of MGD006, a CD123xCD3 Bispecific DART® molecule for the treatment of hematological malignancies P. Moore, G.R. Chichili, L. Huang, H. Li, S. Burke, F. Chen, L. He, Q. Tang, L. Jin, S. Gorlatov, V. Ciccarone, S. Koenig, M. Shannon, R. Alderson, S. Johnson, E. Bonvini 138 P133 GBR1302: a BEAT® bispecific antibody for the treatment of HER2 positive cancers A. Croset, J. Macoin, R. Ollier, M. Pluess, C. Delon, D. Skegro, S. Blein, S. Hou, J. Back P134 Relationship between programmed death ligand 1 (PD-L1) expression and clinical outcome in patients (pts) with melanoma (MEL) treated with pembrolizumab (pembro; MK-3475) A. Daud, O. Hamid, C. Robert, F.S. Hodi, J.D. Wolchok, W.J. Hwu, J.S. Weber, R. Kefford, P. Hersey, A.M. Joshua, R. Joseph, T.C. Gangadhar, R. Dronca, A. Patnaik, H. Zarour, K. Gerigich, J. Lunceford, K. Emancipator, M. Dolled-Filhart, X. Li, P. Kang, S. Ebbinghaus, A. Ribas P135 Phase I study of ipilimumab with stereotactic radiosurgery for melanoma patients with brain metastases W. Shi, E. Wuthrick, K. Feeney, M. Werner-Wasik, D.W. Andrews, J.J. Evans, K. Judy, C. Farrell, A.P. Dicker P136 IL-17 as a novel molecular target for prostate cancer prevention A. De Angulo, R. Faris, C. Jolly, L. deGraffenried 139 Preclinical Models Poster board 140 141 142 Abstract number P137 Regional bias of intratumoral genetic heterogeneity of nucleotide repeats in colon cancers with microsatellite instability C. An, Y. Choi, M. Kim, J. Lee, N. Yoo, S. Lee P138 Association between interleukin 17/interleukin 17 receptor gene polymorphism and papillary thyroid cancer Y. Eun, H. Chung, Y.C. Lee P139 ARQ 087, a novel pan FGFR-inhibitor crosses the BBB (blood–brain barrier) and distributes to the brain of rats R. Savage, T. Hall, B. Schwartz P140 Establishment of patient-derived xenografts (PDX) models for triple negative breast cancer (TNBC) as a pre-clinical platform for drug development J. Thatte, M. Meza, J. Ricono, T. Broudy, C. Mirsaidi, P. Nair P141 An integrated approach for identifying E-cadherin synthetic lethality networks I. Bajrami, S.J. Pettitt, R. Brough, H. Pemberton, D. Kastrev, Y. Fontebasso, J. Frankum, J. Campbell, A. Ashworth, C.J. Lord P142 RAS synthetic lethal interactions from yeast to human cells S. van Wageningen, A. Prahallad, G. Heynen, R. Rothstein, R. Bernards P143 Quantitative mutational assessment of circulating tumor DNA using massively parallel deep sequencing in plasma and urine from advanced colorectal cancer patients J.C. Poole, C.R.T. Vibat, L. Benesova, B. Belsanova, S. Hancock, T.L. Lu, M.G. Erlander, M. Minarik P144 Pirin downregulates E-cadherin gene expression and contributes to EMT K. Komai, Y. Niwa, Y. Sasazawa, S. Simizu P145 Impact of EGFR amplification pattern on the expression of miRNA-200c in primary glioblastoma multiforme L. Muñoz Hidalgo, C. López Gines, E. Serna, D. Monleon, R. Callaghan, R. Gil Benso, H. Martinetto, A. Gregori Romero, J. Gonzalez Darder, M. Cerda Nicolas P146 Preclinical characterization of MM-151, an oligoclonal antibody therapeutic that targets EGFR by three distinct mechanisms of action A. King, M. Sevecka, N. Gerami-Moayed, O. Burenkova, J. Kearns, G. Tan, C. Sloss, R. Bukhalid, U. Nielsen, B. Wolf 143 144 145 146 147 148 149 150 151 152 xxxvi Scientific programme – details Poster board Abstract number P147 Moving beyond in vitro models and addressing the challenges of pooled RNAi screens in mouse xenografts D. Tedesco, K. Bonneau, M. Makhanov, D. Deng, P. Sun, A. Chenchik 153 P148 Drug response database with PDX tumor models in biomarker-driven multi-drug multi-arm clinical trial settings J. Jiang, T.F. Yu, Y. Yan, W. Du, T.T. Tan, L. Hua, J.L. Gu, X.Q. Yang, Z.H. Liu, X.K. Ye, Z. Gu 154 P149 SNIPER(TACC3) degrades TACC3 protein via the ubiquitin–proteasome pathway and induces apoptosis in cancer cells expressing a large amount of TACC3 N. Ohoka, K. Nagai, K. Okuhira, N. Shibata, T. Hattori, N. Cho, M. Naito 155 P150 Behaviour of platinum(IV) complexes with prodrug function in different models of hypoxia E. Brynzak, P. Heffeter, V. Pichler, M.A. Jakupec, B.K. Keppler 156 P151 Sensitive and specific detection of 1p/19q codeletion in gliomas by next generation sequencing E. Dubbink, P.N. Atmodimedjo, R.M. van Marion, J.M. Kros, M.J. van den Bent, W.N.M. Dinjens 157 P152 The development of a series of orthotopic solid tumour models of prostate, lung and ovarian cancer using optical and X ray imaging M. Batey, M. Brown, E. Bowden 158 P153 Neoadjuvant chemotherapy in breast cancer patients induces expression of miR-34a and miR-122 P. Freres, C. Josse, N. Bovy, M. Boukerroucha, I. Struman, V. Bours, G. Jerusalem 159 P154 Identification of fusion genes through kinome-centered RNA sequencing in different types of solid tumors L. Mittempergher, C. Sun, F.H. Groenendijk, A.J. Bosma, S.M. Willems, T. Sustic, I.J. Majewski, W. Grernrum, N.M. Davidson, I. de Rink, H.M. Horlings, W. Theelen-Engelsman, S.F. Chin, A. Oshlack, B.W. van Rhijn, M. van den Heuvel, M.S. van der Heijden, C. Caldas, R. Bernards 160 P155 Leveraging a novel DNA barcoding platform for integrated profiling and pharmacodynamic readouts C. Castro, V. Peterson, A. Ullal, S. Agasti, S. Tuang, N. Miller, M. Birrer, R. Weissleder 161 P156 Drug–drug interaction predictions for MLN2480, an investigational pan-RAF inhibitor, based on nonclinical data S.K. Balani, A. Bulychev, L. Cohen, M. Liao, C.Q. Xia, F. Wang, P. Li, B. LeClair, T. Bohnert, L. Gan, X. Zhou, V. Bozon, S. Prakash 162 P157 Interrogation of pharmacogenes in cancer patients using targeted DNA sequencing F. Innocenti, N. Gillis, J. Parker, N. Hayes, D. Eberhard, K. Richards, J.T. Auman, E. Seiser 163 P158 Augmentation of NAD+ by NQO1 activation attenuates cisplatin-mediated hearing impairment S. Yang, G.S. Oh, K.B. Kwon, R.K. Park, S.Y. Lee, S.R. Moon, H.S. So 164 P159 Effect of zoledronic acid on the post-translational modification of activated leukocyte cell adhesion molecule (ALCAM) in cancer cells R. Toth, G. Trombino, V. Castronovo, A. Bellahcene 165 P160 Pre-clinical and clinical activity of Anti-DLL4 (demcizumab) in combination with gemcitabine plus nab-paclitaxel in pancreatic cancer M. Hidalgo, A. Cubillo, R. Stagg, J. Dupont, Y. Wan-Ching, T. Hoey 166 P161 Genomic characterisation of 1003 cancer cell-lines G. Bignall, F. Iorio, P.A. Futreal, M.R. Stratton, P. Campbell, U. McDermott 167 P162 CDCP1 as a new marker of aggressiveness in triple-negative breast cancers M. Campiglio, F. Turdo, F. Bianchi, M. Sasso, L. De Cecco, P. Casalini, P. Gasparini, L. Forte, R. Agresti, I. Maugeri, G. Sozzi, E. Tagliabue 168 P163 BRAF mutation testing in cell-free DNA from plasma of patients with advanced cancers using a novel, rapid, automated molecular diagnostics prototype platform (Idylla™) F. Janku, H.J. Huang, B. Claes, G.S. Falchook, A. Naing, S. Piha-Paul, A.M. Tsimberidou, R.G. Zinner, D.D. Karp, S. Fu, V. Subbiah, D.S. Hong, J.J. Wheler, R.G. Luthra, S.P. Patel, E.S. Kopetz, E. Sablon, G. Maertens, R. Kurzrock, F. Meric-Bernstam 169 Scientific programme – details Poster board xxxvii Abstract number P164 Novel, ultra-deep next-generation sequencing for BRAF mutation testing using small amount of cellfree DNA from plasma of patients with advanced cancers F. Janku, H.J. Huang, N.M. Ramzanali, X. Cai, R. Klausner, F. Meric-Bernstam, J.B. Fan 170 P165 Antagonistic interaction between gemcitabine and erlotinib is influenced by EGR1 (early growth response 1) transcription factor expression C.D. Hose, Y. Zhao, E.C. Polley, J. Fang, N.D. Fer, A. Rapisarda, B.A. Teicher, R.M. Simon, J.D. Doroshow, A. Monks 171 P166 Modulation of estrogen-dependent transcription by cohesin in MCF7 human breast adenocarcinoma cells T. Dasgupta, J. Antony, J. Rhodes, M. McEwan, M. Eccles, J. Horsfield 172 P167 Ras-mediated activation of mitogen-activated protein kinase pathway unleashes basement membrane damaging activity of serine protease hepsin T. Tervonen, S. Pant, D. Belitskin, J. Englund, K. Närhi, E. Verschuren, P. Kovanen, J. Klefström 173 P168 Combination of molecular and drug response data in patient-derived xenografts to assist patient stratification S. Cairo, O. Déas, A. Beurdeley, V. Yvonnet, M.F. Poupon, J.G. Judde 174 P169 Functional analysis of [methyl-3 H]choline uptake in glioblastoma cells: Influence of anti-cancer and central nervous system drugs M. Inazu, C. Taguchi, T. Yamanaka, H. Uchino 175 P170 Resolvin D2 has mitogenic activity in estrogen receptor positive breast cancer cell lines via activation of estrogen receptor N. Al-Zaubai, C. Johnstone, M. Rizzacasa, A. Stewart 176 P171 Validation of 3D primary organoid cultures of colorectal carcinoma as discovery and validation platform for personalized cancer therapy P. Halonen, A. Kuijpers, B. Morris, B. Diosdado, S. Mainardi, R. Bernards, V. Verwaal, R. Beijersbergen 177 P172 Establishment of patient-derived xenografts (PDX) models for small cell lung (SCL) as a pre-clinical platform for drug development T. Broudy, J. Ricono, C. Mullins, C. Mirsaidi, P. Nair 178 P173 Effects of human breast cancer cells secreted factors on macrophage differentiation S. Coimbra de Sousa, R. Brion, J. Mönkkönen, H. Joensuu, D. Heymann, J. Määttä 179 P174 Identifying and monitoring somatic mutations in cell free DNA of patients with metastatic melanoma J. Wisell, C.M. Amato, W.A. Robinson 180 P175 Aberrant Wnt signaling activation in human cancers: In vitro and in vivo models to facilitate Wnt targeted drug development G. Liu, C. Dong, R. Zhang, L. Zhang, S. Qian, J. Cai, J. Zhang, J. Ning 181 P176 TRAP1 represents a key mediator of stemness and glycolytic metabolism in colorectal cancer cells G. Lettini, F. Maddalena, L. Sisinni, V. Condelli, L. Del Vecchio, M. Gemei, T. Notarangelo, M. Landriscina 182 P177 Spatio-temporal characterization of tumor growth and invasion A.M. Jimenez, O. Yogurtcu, M. Horn-Lee, P. Rao, S.X. Sun, D. Wirtz 183 P178 Molecular profiling of heterogeneous tumor cells A. Chenchik, D. Deng, K. Bonneau, M. Makhanov, M. Coram, G. Dolganov, S.S. Jeffrey 184 P179 Treatment of patient-derived NSCLC xenograft preclinical models using image-guided small animal irradiation N. Papadopoulou, A. McKenzie, J. King, M. Page, R. Kumari 185 P180 The use of Quantitative Textural Analysis imaging biomarkers to predict response to temsirolimus treatment in advanced HCC subjects R. Korn, R. Osarogiagbon, R. Newbold, D. Burkett, J. Sachdev 186 xxxviii Poster board Scientific programme – details Abstract number P181 Targeted genomic profiling of penile squamous cell carcinoma using the Oncomine cancer research panel A.S. McDaniel, D. Hovelson, A. Cani, C.J. Liu, Y. Zhang, S. Sadis, S. Bandla, P. Williams, D. Rhodes, S.A. Tomlins 187 P182 RANBP2 knock-down is synthetic lethal with BRAF V600E in colon cancer L. Vecchione, V. Gambino, G. d’Ario, S. Tian, A. Schlicker, S. Mainardi, B. Diosdado, I. Simon, M. Delorenzi, C. Lieftink, R. Beijersbergen, S. Tejpar, R. Bernards 188 P183 Molecular and pharmacological characterization of primary mesothelioma tumor cell lines orthotopically xenografted in nude mice C. Pisano, A. Cole, A. Barbarino, E. Bianchino, M. Guglielmi, C. Melito, G. Mercadante, A. Porciello, A. Riccio, I. La Porta, S. Orecchia, R. Libener, L. Mazzucco, S. Licandro, M. Ceccarelli, F. D’Angelo, P. De Luca 189 P184 Differential chemosensitivity between CETCs and tumour spheroids in cancer patients with solid tumors D. Zimon, M. Pizon, E.L. Stein, U. Pachmann, K. Pachmann 190 P185 Homotypic and heterotypic cell signaling transduction using a dielectrophoresis microfluidic device M. Tellez Gabriel, D. Heymann 191 P186 Extensive characterization of patient derived colon cancer xenografts for preclinical biomarker identification V. Vuaroqueaux, F. Kiefer, P. Bronsert, A.L. Peille, B. Zeitouni, F. Foucault, T. Kees, J. Guo, J. Schüler, H.H. Fiebig 192 P187 The identification of new therapies for ependymoma subgroups N. Boulos, J.D. Dapper, Y.T. Patel, M. DeCuypere, B. Bianski, K.M. Mohankumar, M.O. Jacus, B. Freeman III, K.D. Wright, A. Gajjar, A.A. Shelat, C.F. Stewart, R.K. Guy, R.J. Gilbertson 193 P188 Pancreatic ductal organoids as a new platform for drug discovery M. Ponz-Sarvise, V. Corbo, D. Öhlund, T. Oni, A. Handly-Santana, D. Engle, H. Tiriac, C. Chio, M. Feigin, L. Baker, C. Ardito-Abraham, Y. Park, C. Hwang, E. Elyada, K. Yu, H. Clevers, D.A. Tuveson 194 P189 A humanized mouse model for preclinical testing of molecules targeting immune checkpoints G. Baia, D. Vasquez, D. Ciznadija, D. Sidransky, A. Katz, K. Paz 195 P190 Neuropilin 2 (NRP2) modifies CXCL12/CXCR4 signaling and promotes lymph node metastases in colon cancer H. Schneider, P. Hönscheid, S. Schölch, C. Jakob, M. Muders 196 P191 Statistical aspects of kinetic analysis of gliomas with FDG-PET D. Hawe, F.R. Hernandez, S. Murphy, E. Wolsztynski, J. Huang, J. O’Sullivan, M. Muzi, J. Eary, K. Krohn, F. O’Sullivan 197 P192 Genetic and pharmacological inhibition of PIM-1 reduces tumor development in a K-Ras-driven mouse model of non-small cell lung cancer E. Aguirre, O. Renner, M.C. Rodriguez de Miguel, M.I. Albarran, A. Cebria, D. Cebrian, F. RamosLima, J. Pastor, C. Blanco-Aparicio 198 P193 Inhibitor of differentiation 1 (Id1) expression in lung cancer cells and liver microenvironment is required for liver metastasis (LM) development from non-small cell lung cancer (NSCLC) by regulating EMT-related and proliferation-related proteins E. Castanon, A. Soltermann, I. López, M. Ecay, M. Collantes, J.M. Lopez Picazo, M. Ponz, C. Rolfo, A. Calvo, I. Gil-Bazo 199 P194 The influence of different cMET and EGFR backgrounds on the cytotoxicity of cMET and EGFR small molecule inhibitors in vitro N. Van Der Steen, K. Zwaenepoel, C. Rolfo, E. Giovannetti, M. Castiglia, V. Deschoolmeester, A.P. Carreca, P. Germonpre, P. Pauwels 200 Scientific programme – details Poster board xxxix Abstract number P195 Transcriptome analysis of CD133-positive stem cells and prognostic value of survivin in colorectal cancer S. Kim, S.H. Park, J. Lee, Y.S. Park, H.C. Kim Radiation Interactive Agents Poster board 201 Abstract number P196 The novel microtubule-destabilizing drug BAL101553 (prodrug of BAL27862) sensitizes a treatment refractory tumor model to ionizing radiation A. Broggini-Tenzer, F. Bachmann, V. Vuong, A. Messikommer, K. Nytko-Karouzakis, T. O’Reilly, H.A. Lane, M.N. Pruschy 202 P197 Ionizing radiation induced phosphatidylserine externalization on endothelial cell surface − a potential target for vascular targeting Z. Zhao, M. Johnson, B. Chen, M. Grace, J. Ukath, V. Lee, M. Stoodley 203 P198 High-throughput functional screening identifies the flavoreductase POR as a principal determinant of sensitivity to the hypoxia-targeting prodrug SN30000 F.W. Hunter, Z. Shalev, J. Wang, J. Moffat, T. Katella, M. Koritzinsky, W.R. Wilson, B.G. Wouters 204 P199 Metformin to modulate AMP-kinase and enhance chemotherapy and radiotherapy in non-small cell lung cancer M.J. Troncone, S.M. Cargnelli, G. Pond, E. Tsiani, J. Wright, G. Steinberg, H. Skinner, L. Bo, J. Bradley 205 P200 Identification of novel targets for radiosensitisation of non-small cell lung cancer by secretome analysis A. Sharma, S. Bender, O. Riesterer, A. Broggini-Tenzer, M. Pruschy 206 P201 The enhancement of radiotherapy efficacy with docetaxel-titanate nanotubes as a new nanohybrid for localized high risk prostate cancer C. Mirjolet, J. Boudon, A. Loiseau, S. Chevrier, T. Gautier, R. Boidot, J. Paris, N. Millot, G. Crehange 207 P202 Combined treatment of a DNA-PKcs inhibitor (NU7441) and ionizing radiation causes a differential mode of cell death in a panel of NSCLC cell lines and exhibits robust radiosensitisation D. Saha, Y. Lan, F. Hsu, V. Tumati, Z. Zhang, Y. Lin, B. Chen 208 xl Scientific programme – details Thursday 20 November 2014 Plenary Session 4 08:00–10:00 Antibody-Based Therapies (ADC and others) Chairs: A. Tolcher (USA) and N. Gökbuget (Germany) Auditorium Abstract number 08:00 Antibody mediated payload delivery: Cautionary lessons from 20 years of clinical trials A. Tolcher (USA) Key objectives: 1. Understand the disconnect between activity with antibody drug conjugates (ADC) in preclinical models versus clinical results. 2. Understand the multiple challenges associated with ADCs as a drug from the 3 components: antibody, linker and payload. 3. Understand patient selection based on target and potential mitigation strategies when the target is also expressed on normal tissues. 08:20 Challenging the dogmas: Clinical efficacy of SN38 conjugated antibodies in solid tumours D.A. Goldenberg (USA) Key objectives: 1. Discuss current status and challenges of antibody-drug conjugates (ADC) in solid cancer therapy. 2. Supertoxic drugs used in ADC may compromise therapeutic index. 3. A moderate cytotoxic drug in an ADC may allow higher doses and a higher therapeutic index. 08:40 Targeted alpha particle therapy for haematologic malignancies J. Jurcic (USA) Key objectives: 1. List the advantages and disadvantages of targeted alpha-particle therapy. 2. Summarise the results of recent clinical trials using targeted alpha-particle therapy for the treatment for haematologic malignancies. 3. Describe the results of recent preclinical studies using alternative radioisotopes and pre-targeting strategies. 09:00 Bispecific T-cell engaging antibodies in acute leukaemia − Recent advances and future challenges Speaker: N. Gökbuget (Germany) Key messages: 1. Relapsed and refractory ALL has a very poor outcome and there is an urgent medical need for new, alternative treatment options. 2. Blinatumomab is a bispecific antibody which represents a new treatment principle based redirected cell kill of CD19 positive target cells by T-cells. 3. Reponse rates are promising and the compound is currently studied in a randomised trial. 09:20 ORAL PRESENTATION: Pre-clinical and translational pharmacology, pharmacokinetics and pharmacodynamics for a humanized anti-OX40 antibody MOXR0916, a T-cell agonist in the treatment of solid tumors S. Sukumaran, J.M. Kim, M. Huseni, J. Ruppel, H. Taylor, K. Totpal, J. Zhu, C. Zhang, H. Chiu, E.G. Stefanich 209 09:35 ORAL PRESENTATION: A phase 1 study of KTN3379, a human anti-ErbB3 monoclonal antibody in patients with advanced cancers P. LoRusso, T. LaVallee, L. Kimmel, C. Lubeski, R. Gedrich, C. Sidor 210 09:50 General discussion A. Tolcher (USA) Scientific programme – details Plenary Session 5 10:30–12:30 Epigenetic Targets Chairs: K. Helin (Denmark) and T. Helleday (Sweden) xli Auditorium Abstract number 10:30 Histone demethylases and methyltransferases as novel targets for cancer therapeutics K. Helin (Denmark) 10:50 DOT1 and EZH2 targeted therapies R. Copeland (USA) Key messages: 1. EZH2 plays a critical role in normal B-cell maturation and is frequently dysregulated in germinal center-derived lymphomas. 2. EPZ-6438 is a potent and selective inhibitor of EZH2 that demonstrates robust and durable antilymphoma activity in preclinical animal models both as a single agent and in combination with standards of care. 3. EPZ-6438 is the first EZH2 inhibitor to enter human clinical studies and early observations from this clinical trial will be discussed. 11:10 Targeting non-oncogene addiction with MTH1 inhibitors T. Helleday (Sweden) 11:30 ORAL PRESENTATION: A novel synthetic lethal interaction between the histone mark H3K36me3 and checkpoint kinases S.X. Pfister, E. Markkanen, Y. Jiang, S. Sarkar, V. D’Angiolella, G. Dianov, A.J. Ryan, T.C. Humphrey 211 11:45 ORAL PRESENTATION: Novel anti-tumor activity of targeted LSD1 inhibition by GSK2879552 H. Mohammad, K. Smitheman, G. Van Aller, M. Cusan, S. Kamat, Y. Liu, N. Johnson, C. Hann, S. Armstrong, R. Kruger 212 12:00 LATE BREAKING ABSTRACT: Results of a first-in-man phase I trial assessing OTX015, an orally available BET-bromodomain (BRD) inhibitor, in advanced hematologic malignancies A. Stathis, B. Quesnel, S. Amorim, C. Thieblemont, E. Zucca, E. Raffoux, H. Dombret, Y. Peng, A. Palumbo, N. Vey, X. Thomas, M. Michallet, C. Gomez-Roca, C. Recher, L. Karlin, K. Yee, K. Rezai, C. Preudhomme, T. Facon, P. Herait 5LBA 12:10 LATE BREAKING ABSTRACT: Phase 1 first-in-human study of the enhancer of zeste-homolog 2 (EZH2) histone methyl transferase inhibitor E7438 as a single agent in patients with advanced solid tumors or B cell lymphoma V. Ribrag, J.C. Soria, L. Reyderman, R. Chen, P. Salazar, N. Kumar, G. Kuznetsov, H. Keilhack, L.H. Ottesen, A. Italiano 6LBA 12:20 Discussion Late Breaking Abstracts T. Helleday (Sweden) 12:45–13:15 Posters in the Spotlight Session Moderator: E. Calvo (Spain) Exhibition Hall The following abstracts will be discussed: 41 (poster board P035), 195 (P189) and one to be announced. Plenary Session 6 13:30–15:35 Proffered Paper Session Chairs: E. Calvo (Spain) and J. Doroshow (USA) Auditorium Abstract number 13:30 ORAL PRESENTATION: A phase I dose-finding study of BI 853520, a potent and selective inhibitor of focal adhesion kinase (FAK), in Japanese and Taiwanese patients with advanced or metastatic solid tumors T. Doi, C.C. Lin, A. Ohtsu, J.C.H. Yang, K. Shitara, L.C. Pronk, A. Sarashina, A.L. Cheng 213 xlii Scientific programme – details 13:45 ORAL PRESENTATION: Homologous recombination deficiency (HRD) score and niraparib efficacy in high grade ovarian cancer P. Haluska, K.M. Timms, M. AlHilli, Y. Wang, A.M. Hartman, J. Jones, A. Gutin, Z. Sangale, C. Neff, J. Lynchbury, L. Rudolph-Owen, M.A. Becker, S. Agarwal, K.M. Wilcoxen 214 14:00 ORAL PRESENTATION: Updated clinical and preliminary correlative results of ARIEL2, a Phase 2 study to identify ovarian cancer patients likely to respond to rucaparib E. Swisher, J. Brenton, S. Kaufmann, A. Oza, R.L. Coleman, D. O’Malley, G. Konecny, L. Ma, M. Harrell, D. Visscher, A.W. Hendrickson, K. Lin, M. Raponi, E. Mann, H. Giordano, L. Maloney, L. Rolfe, I. McNeish 215 14:15 ORAL PRESENTATION: Phase I study of panobinostat and fractionated stereotactic re-irradiation therapy (FSRT) for recurrent high grade gliomas W. Shi, Y.R. Lawrence, M. Werner-Wasik, D.W. Andrews, J.J. Evans, J. Glass, L. Kim, V. Bar Ad, Y. Moshel, K. Judy, C. Farrell, N.L. Simon, A.P. Dicker 216 14:30 ORAL PRESENTATION: Results of a phase I, open-label, multicentre study to assess the safety, tolerability, pharmacokinetics and preliminary anti-tumour activity of AZD9150 in patients with advanced/metastatic hepatocellular carcinoma Y.K. Kang, B.Y. Ryoo, T.Y. Kim, K.H. Lee, H.Y. Lim, S.J. Lee, M. Ikeda, T. Okusaka, S. Nadano, C.C. Lin, T.P. Poon, C.J. Yen, P. McCoon, F. Neumann, K. Vishwantahan, R. DuPont, P. Lyne 217 14:45 ORAL PRESENTATION: Genomic analysis identifies novel drivers and targetable pathways in inflammatory breast cancer patient samples D.M. Moran, K. Rao, P. Bacon-Trusk, K. Pry, V. Weigman, V. Velculescu, M. Cristofanilli, S. Bacus 218 15:00 ORAL PRESENTATION: Phase I trial evaluating the antiviral agent Cidofovir in combination with chemoradiation in cervical cancer patients: A novel approach to treat HPV related malignancies? E. Deutsch, A. Levy, R. Mazeron, A. Gazzah, E.A. Angevin, V. Ribrag, R. Balheda, A. Varga, C. Lhomme, C. Haie-Meder, J.C. Soria 219 15:15 LATE BREAKING ABSTRACT: Phase 1 dose-expansion study of AMG 900, a pan-Aurora kinase inhibitor, in adult patients with advanced taxane-resistant solid tumors B. Markman, D. Mahadevan, S. Hurvitz, D. Kotasek, M. Shaheen, M. Carducci, O. Goodman, X. Jiang, V. Chow, G. Juan, G. Friberg, E. Gamelin, J. Desai 7LBA 15:25 Discussion Late Breaking Abstract J. Doroshow (USA) Plenary Session 7 16:00–17:50 Novel Mechanisms for Drug Resistance Chairs: U. Banerji (United Kingdom) and S.A. Courtneidge (USA) Auditorium Abstract number 16:00 Genomic instability, diversity and resistance during cancer evolution N. McGranahan (United Kingdom) Key messages: 1. Driver mutations are often subclonal in non-small cell lung cancer (NSCLC), potentially comprising the efficacy of targeted therapy approaches. 2. A single NSCLC tumour may follow multiple distinct evolutionary trajectories simultaneously, with mutational processes varying over space and time. 3. NSCLCs have a long period of tumour latency prior to clinical detection. 16:20 Immune-scape to PD1/PDL1 blockade D. Chen (USA) Key objectives: 1. Understand what responses and durability of responses looks like for cancer immunotherapy and PD-L1/PD-1 inhibitors to date. 2. Understand potential reasons for primary resistance. 3. Understand potential reasons for secondary resistance. Scientific programme – details xliii Messages: 1. Responses to PD-L1/PD-1 inhibitors appear highly durable, but not every patient responds and not every responding patient is “cured”. 2. Primary resistance may be driven by lack of adequate active anti-cancer T cell immune responses in tumours. 3. It is too early to tell what might account for secondary resistance, but it could involve factors that lead to fluctuations in immunity and a break in the cancer-immunity cycle. 16:40 EMT as mechanism of resistance to TKI J.P. Thiery (Singapore) Key objectives: 1. Malignant cells harbor numerous genetic alterations at the time of clinical detection. The mutational landscape is extraordinarily complex, exhibiting considerable heterogeneity within the primary tumour, in circulating tumour cells and in metastases. 2. These findings are in support of the original hypothesis of clonal evolution, and suggest that the current therapeutics strategies must be revisited to delay the onset of tumour refractoriness. 3. It is imperative to develop treatment strategies that do not strictly rely on specific activating mutations. In particular, one can leverage on the Epithelial–Mesenchymal Transition (EMT) status of a tumour, as it has an impact on the tumour’s potential to progress and resist treatment. This can be achieved by establishing an EMT score for each tumour along the EMT spectrum. Targeted therapeutics can then be used to move the tumour along the EMT spectrum rather than inhibiting its growth in order to improve its response to conventional therapeutics and to restore the body’s immune response. 17:00 The landscape of kinase fusions in cancer C. Lengauer (USA) Key messages: 1. We have performed a pan-cancer analysis of kinase fusions across all TCGA RNA-seq data (>7,000 samples). 2. Our analysis unveiled several new and recurrent kinase fusions. Overall, kinase fusions are a driver event in at least 3% of solid tumours. 3. These discoveries have profound and immediate implications for the diagnosis and treatment of cancer patients, as well as potential avenues for new drug discovery programmes. 17:20 ORAL PRESENTATION: Overcoming drug-resistance in multiple myeloma by XPO1 inhibitor combination therapy J. Turner, J. Dawson, S. Grant, K. Shain, C. Cubitt, Y. Dai, L. Zhoui, M. Kauffman, S. Shacham, D. Sullivan 220 17:35 LATE BREAKING ABSTRACT: Activity of the PARP inhibitor olaparib in ATM-deficient gastric 8LBA cancer: from preclinical models to the clinic D. Hodgson, H. Mason, L. Oplustilova, C. Harbron, X. Yin, S.A. Im, H. Jones, L. Zhongwu, B. Dougherty, M. McLoughlin, A. Dickinson, A. Fielding, J. Robertson, W.H. Kim, C. Womack, Y. Gu, Y.J. Bang, A. Lau, J.C. Barrett, M.J. O’Connor 17:45 Discussion Late Breaking Abstract U. Banerji (United Kingdom) 18:00–19:30 Poster Viewing Chemoprevention Poster board Poster area Abstract number P001 Docosahexaenoic acid along with modulation of actin binding proteins reduces cancer cell migration M. Ali, L.K. Rogers 221 P002 Estimating predictive values of short-term morphologic assays of cancer chemoprevention for efficacy in animal tumor assays B. Dunn, V.E. Steele, R.M. Fagerstrom, C.F. Topp, D. Ransohoff, C. Cunningham, R. Lubet, L.G. Ford, B.S. Kramer 222 xliv Poster board Scientific programme – details Abstract number P003 Preclinical assessment of nintedanib for chemoprevention in hepatocellular carcinoma V. Tovar, A. Moeini, S. Torrecilla, M. Higuera, J. Peix, I.M. Quetglas, L. Rodriguez-Carunchio, H. Cornella, M. Sole, J.M. Llovet 223 P004 Synergic tumor growth suppression with carbohydrate-restriction diet and natural AMP-dependent protein kinase activators M. Choi, J. Lee 224 P005 Molecular targets of interest to the NCI PREVENT cancer preclinical drug development program R.H. Shoemaker, B.K. Dunn, C. Suen, R.A. Lubet, D.L. Boring, B.D. Klein, M.S. Miller, V.E. Steele 225 P006 Efficacy of cancer preventing drugs administered by intermittent dosing regimens V.E. Steele, C. Grubbs, C.V. Rao, R.A. Lubet 226 Clinical Methodology Poster board Abstract number P007 Multiplexed ICE COLD-PCR: A mutation detection methodology for achieving sensitivities of <0.01% using either Sanger or NGS G. Wu, B. Legendre, S. Cherubin, C. Cubrich, A. Dowers, S. Jensen, J. Gniffke, A. Kruempel, P. Krzycki, E. McCutchen, E. Montagne, S. Peterson, J. Pope, K. Scott, K. Richardson 227 P008 Her2−3 heterodimer is a new and better than HER2 IHC score for clinical outcome prognosis G. Weitsman, P.R. Barber, K. Lawler, C. Gillett, N. Woodman, B. Kholodenko, L.K. Nguyen, T. Santra, B. Vojnovic, T. Ng 228 P009 DNA methyltransferase 1 expression in human solid tumors and lymphomas by immunohistochemistry S.X. Yang, D. Nguyen, L. Rubinstein, S. Kummar, J.E. Tomaszewski, J.H. Doroshow 229 P010 High correlation between clinical responses to first line AML patients treated with cytarabine and idarubicin and their pharmacological profiles in patient samples measured by ExviTech J. Ballesteros, P. Hernandez, D. Primo, A. Robles, A.B. Espinosa, E. Arroyo, V. Garcia-Navas, J. Sanchez-Fenoy, M. Jimenez, M. Gaspar, J.L. Rojas, J. Martinez-Lopez, J. Gorrochategui 230 P011 Clinical pharmacodynamic assay development for the first in class investigational ubiquitin activating enzyme (UAE) inhibitor MLN7243 B. Bahamón, F. Gao, B. Stringer, Y. Yang, J. Shi, K. Burke, J. Huck, T. Traore, D. Bowman, H. Danaee, M. Millhollen, M. Hyer, N. Bence, Y. Ishii 231 P012 Development of a targeted NGS assay system for patient enrollment to the NCI-MATCH study M. Williams, D. Sims, J. Lih, A. Datta, S. Hamilton, A.J. Iafrate, J. Sklar, S. Sadis, N. Takabe, J. Tricoli, J. Doroshow, B. Conley 232 P013 Analytical validation and application of the MPACT assay, a next generation sequencing based targeted mutation detection assay for treatment selection C. Lih, D.J. Sims, R.D. Harrington, E.C. Polley, Y. Zhao, R.M. Simon, M.G. Mehaffey, T.D. Forbes, W.D. Walsh, V. Datta, B.A. Conley, A.P. Chen, S. Kummar, J.H. Doroshow, P.M. Williams 233 P014 Kinetic analysis of dynamic 11 C-verapamil PET study: Compartmental v adaptive mixture models comparison F. Hernandez, D. Hawe, S. Murphy, J. O’Sullivan, E. Wolsztynski, J. Huang, M. Muzi, J. Eary, K. Krohn, F. O’Sullivan 234 P015 Kinetic analysis of dynamic 11 C thymidine PET imaging studies: Compartmental and nonparametric approaches S. Murphy, D. Hawe, F. Hernandez, E. Wolsztynski, J. Huang, J. O’Sullivan, M. Muzi, J. Eary, K. Krohn, F. O’Sullivan 235 P016 Whole genomic assay on endoscopic ultrasound-guided fine needle aspiration samples of unresectable pancreatic cancer J.M. Ha, K.H. Lee, J.K. Lee, K.T. Lee, W.Y. Park, J.S. Bae, J.K. Jung, D.H. Park, Y.K. Seong, E. Kim 236 Scientific programme – details Poster board xlv Abstract number P017 Impact of phase 1 expansion cohorts on probability of success in phase 2 and time-to-drug-approval: analysis of 385 new drugs in oncology D. Bugano, K. Hess, L.L. Siu, F. Meric-Bernstam, A.R.A. Razak, D.S. Hong DNA Repair Modulation (including PARP, CHK, ATR, ATM) Poster board 237 Abstract number P018 Reversal of primary and acquired PARP-inhibitor resistance in BRCA-mutated triple-negative breast cancers by inhibition of transcriptional cyclin-dependent kinases (CDKs) S. Johnson, N. Johnson, D. Chi, B. Primack, C. Cruz, D. Stover, A.K. Greifenberg, S. Cao, K. O’Connor, J. Baselga, J. Balmaña, V. Serra, M. Geyer, A. D’Andrea, E. Lim, G.I. Shapiro 238 P019 Niraparib, a selective PARP 1/2 inhibitor, is efficacious in pre-clinical models of small-cell lung cancer Y. Wang, J. Ricono, K. Admunson, S. Agarwal, R.J. Fram, T. Broudy, K.M. Wilcoxen 239 P020 The combination of Chk-1 and ATR inhibitor synergistically kills cancer cells K. Sanjiv, A. Hagenkort, P.M. Reaper, T. Koolmeister, O. Mortusewicz, N. Schultz, M. Scobie, U.W. Berglund, P.A. Charlton, J.R. Pollard, T. Helleday 240 P021 Epigenetic loss-of-function BRCA1 mediates tumor cure by single dose radiotherapy C. Campagne, T.H. Thin, J.D. Fuller, K. Manova-Todorova, A. Haimovitz-Friedman, S.N. Powell, R.N. Kolesnick, Z. Fuks 241 P022 BMN 673 as single agent and in combination with temozolomide or PI3K pathway inhibitors in small cell lung cancer and gastric cancer models Y. Feng, L.E. Post, R. Cardnell, L.A. Byers, B. Wang, Y. Shen 242 P023 Modulation of PI3K/mTOR pathway following PARP inhibition in small cell lung cancer R.J. Cardnell, Y. Feng, L. Diao, Y. Fan, F. Masrorpour, S. Mukherjee, J. Shen, J. Wang, L.A. Byers 243 P024 Development of xenoimplants from germline BRCA1/2 mutant breast cancer (BC) for the identification of predictive biomarkers, mechanisms of resistance against poly(ADP-ribose) polymerase (PARP) inhibitors and evaluation of novel therapies C. Cruz, Y. Ibrahim, B. Morancho, P. Anton, J. Grueso, P. Cozar, M. GuzmÁn, P.M. Avilés, M.J. Guillén, C. Galmarini, J. Arribas, J. Baselga, J. Balmaña, V. Serra 244 P025 Chk1 is a potential novel therapeutic target that regulates cell survival and potentiates chemotherapy in osteosarcoma (OS) models S.J. Strauss, P. Mistry, A. Mendoza, M. Robson, H. Holme, P. Nandabhiwat, B. Kwok, M. Qadir, R.B. Pedley, J.S. Whelan, P.H.B. Sorensen 245 P026 PARP inhibitors trap PARP1 onto damaged DNA via catalytic inhibition and not by an allosteric mechanism T. Hopkins, L. Solomon, Y. Shi, L. Rodriguez, C. Donawho, E. DiGiammarino, S. Panchal, A. Olson, D. Stolarik, D. Osterling, W. Gao, E. Johnson, D. Maag 246 P027 Selective inhibitors of nuclear export (SINE) block the expression of DNA damage repair proteins and sensitize cancer cells to DNA damage therapeutic agents T. Kashyap, M. Crochiere, S. Friedlander, B. Klebanov, W. Senapedis, E. Baloglu, D. del Alamo, S. Tamir, T. Rashal, D. McCauley, R. Carlson, M. Kauffman, S. Shacham, Y. Landesman 247 P028 Use of ATR inhibitor in combination with topoisomerase I inhibitor kills cancer cells by disabling DNA replication initiation and fork elongation R. Jossé, S.E. Martin, R. Guha, P. Ormanoglu, T. Pfister, J. Morris, J. Doroshow, Y. Pommier 248 P029 Preclinical efficacy of the PARP inhibitor rucaparib (CO-338/AG014699/PF-01367338) in pancreatic cancer models with homologous recombination deficiencies (HRD) L. Robillard, K. Lin, P.P. Lopez-Casas, M. Hidalgo, T.C. Harding 249 xlvi Scientific programme – details Poster board Abstract number P030 Comprehensive genomic profiling of pancreatic acinar cell carcinomas identifies recurrent RAF fusions and frequent inactivation of DNA repair genes J. Chmielecki, K.E. Hutchinson, G.M. Frampton, Z.R. Chalmers, A. Johnson, C. Shi, J. Elvin, S.M. Ali, J.S. Ross, O. Basturk, S. Balsubramanian, D. Lipson, R. Yelensky, W. Pao, V.A. Miller, D.S. Klimstra, P.J. Stephens 250 P031 A combined in vitro and mathematical modelling approach for understanding the impact of an inhibitor of ATR on DNA damage and repair after ionising radiation J. Yates, S. Checkley, L. MacCallum, R. Odedra, J. Barnes, A. Lau 251 P032 The DNA damage response gene Schlafen 11 (SLFN11) is a transcriptional target of ETS transcription factors in Ewing’s sarcoma and other cancers Y. Pommier, S.W. Bilke, F. Sousa, M. Yamade, J. Murai, V. Rajapakse, L. Helman, P. Meltzer 252 P033 Phase 1 correlative study of ARQ761, a b-lapachone analogue that promotes NQ01-mediated programmed cancer cell necrosis D. Gerber, Y. Arriaga, M.S. Beg, J.E. Dowell, J.H. Schiller, A.E. Frankel, R. Leff, C. Meek, J. Bolluyt, O. Fatunde, R.T. Martinez, P. Vo, F. Fattah, V. Sarode, Y. Zhou, Y. Xie, M. McLeod, B. Schwartz, D.A. Boothman 253 P034 Molecular analysis in breast cancer: correlation with immunohistochemical classification and pathologic complete response (pCR) to neoadjuvant chemotherapy (NAC) S. Baulies, M. Gonzalez-Cao, N. Karachaliou, A. Rodriguez Capitan, M.A. Molina-Vila, M.T. Cusido, C. Teixido, S. Viteri, R. Fabregas, X. Gonzalez, R. Rosell 254 Drug Delivery Poster board Abstract number P035 Pre-clinical in vivo characterization of MLN7243, an investigational ubiquitin activating enzyme inhibitor, in solid tumor models T. Traore, J.H. Huck, J.S. Shi, D.S. Sappal, J.D. Duffey, Y.Y. Yang, E.K. Kadakia, A.C. Chakravarty, B.S. Stringer, Y.I. Ishii, R.G. Griffin, C.X. Xia, M.M. Milhollen, J.C. Ciavarri, P.F. Fleming, N.B. Bence, M.H. Hyer 255 P036 Minicell packaged targeted delivery of shRNA to cancer cells M. Jivrajani, N. Shrivastava, M. Nivsarkar 256 P037 Development of peptide-mediated drug delivery systems for colon cancer targeted imaging and therapy H.C. Wu, C.H. Wu, Y.H. Kuo 257 P038 Pancreatic cancer cells expressing the OATP1B3 transporter show promising sensitivity to the highly cytotoxic microcystin-LR molecule V. Kounnis, G. Chondrogiannis, M.D. Mantzaris, D. Fokas, N.A. Papanikolaou, I. Sainis, E. Briasoulis 258 P039 Factors that limit delivery of Cdk4/6 inhibitor palbociclib to GBM K. Parrish, J. Pokorny, R. Mittapalli, K. Bakken, J. Sarkaria, W. Elmquist 259 P040 Hsp90 Inhibitor Drug Conjugates (HDC): Payloads and possibilities D. Chimmanamada, W. Ying, J. Zhang, D. Proia, T. Przewloka, J. Jiang, D. Vutukuri, G. Lu, S. Osman, S. Chen, J. Chu, P. Rao, D. Zhou, T. Inoue, L. Shin Ogawa, R. Singh, N. Tatsuta, A. Sonderfan, C. Cortis 260 P041 Lesion characterization with ferumoxytol MRI in patients with advanced solid tumors and correlation with treatment response to MM-398, nanoliposomal irinotecan (nal-IRI) R.K. Ramanathan, R.L. Korn, J.C. Sachdev, G.J. Fetterly, G. Jameson, K. Marceau, V. Marsh, N. Raghunand, J. Prey, S.G. Klinz, J. Kim, E. Bayever, J.B. Fitzgerald 261 P042 Improved cytotoxic activity of Nor-b-lapachone-loaded PLGA microcapsules in PC3M prostate cancer cell line C. Pessoa, A.C.S. Feitosa, M.P. Costa, F.C. Evangelista, F.A.M. Sales, I.S. Bomfim, E.N. Silva Júnior, G.G. Dias, V.N. Freire, W.S. Caetano 262 Scientific programme – details Poster board xlvii Abstract number P043 Controlled release of cisplatin using hyaluronic oligosaccharides-coated gold nanoparticles as an efficient delivery system applied to the treatment of pancreatic tumors H. Parkkola, L. Sobrevals Amieva, L. Vivero, R. Miñana, J. Sendra P044 Vasculogenic mimicry in small cell lung cancer F. Trapani, R.L. Metcalf, R. Polanski, A. Fusi, C. Hodgkinson, D. Nonaka, M.J. Hendrix, C. Morrrow, F. Blackhall, K.L. Simpson, C. Dive P045 Pretargeted nanoparticles to deliver both chemotherapeutics and radiation for the treatment of lymphoma C. Fang, J.C. Jones, S.M. Frayo, M.H. Hylarides, M. Zhang, O.W. Press P046 Auxiliar treatment by targeting the extracellular matrix to improve drug delivery and therapeutic response E. Henke, F. Roehrig, H. Hoffmann, F. Escorcia, M. Wartenberg, S. Volova, S. Gaetzner, A. Rosenwald, S. Erguen, D.A. Scheinberg, Z.V.I. Granot P047 Novel adjuvant therapy with leptin peptide receptor antagonist-2 conjugated to nanoparticles (IONPLPrA2) to minimize chemoresistance in triple negative breast cancer T. Harmon, A. Harbuzariu, L. Yang, R.R. Gonzalez-Perez Drug Design Poster board 263 264 265 266 267 Abstract number P048 A potent and highly efficacious bivalent Smac Mimetic APG-1387 in Phase I clinical development J. Lu, S. Rong, H. Sun, L. Liu, D. McEachern, G. Wang, J. Wen, Y. Zhai, M. Guo, D. Yang, S. Wang P049 The NCI-60 as an effective tool for scaffold hopping: A phenotypic systems-based approach to the design of novel chemotherapeutics D.G. Wishka, V. Kumar, B. Teicher, G. Kaur, B. Fang, P. Risbood, M. Hollingshead, J. Zais, J. Morris P050 Discovery, development and optimization of low molecular weight EPH−ephrin protein–protein inhibitors M. Tognolini, C. Giorgio, I. Hassan-Mohamed, E. Barocelli, M. Mor, D. Pala, S. Russo, M. Incerti, A. Lodola P051 Data integration and graph analysis for cancer genomics and drug discovery B. Bernard, M. Miller, H. Rovira, I. Shmulevich P052 8-(1-Anilino)ethyl)-2-morpholino-4-oxo-4H-chromene-6-carboxamides as PI3Kbeta/delta inhibitors: structure–activity relationships and identification of AZD8186, a clinical candidate for the treatment of PTEN deficient tumours B. Barlaam, S. Cosulich, S. Degorce, M. Fitzek, S. Green, U. Hancox, C. Lambert-van der Brempt, J.J. Lohmann, M. Maudet, R. Morgentin, M.J. Pasquest, A. Peru, P. Ple, T. Saleh, M. Vautier, M. Walker, L. Ward, N. Warin P053 Significance of serine-167 and cysteine-129 residues in the active site of the immune-suppressive enzyme indoleamine 2,3-dioxygenase 1 (IDO1) for the binding of novel inhibitors P. Tomek, B.D. Palmer, J.U. Flanagan, L. Ching P054 Novel cysteine derivatives for the next generation anticancer agents acting on KSP N. Ogo, J. Sawada, Y. Ishikawa, K. Matsuno, A. Hashimoto, A. Asai P055 Modulation of PIP2 levels through small molecule inhibition of PIP5K D. Andrews, S. Cosulich, N. Divecha, D. Fitzgerald, V. Flemington, C. Jones, D. Jones, O. Kern, E. MacDonald, S. Maman, J. McKelvie, K. Pike, M. Riddick, G. Robb, K. Roberts, J. Smith, M. Swarbrick, I. Treinies, M. Waring, R. Wood P056 An X-ray crystal structure-based understanding of the inhibition of the MDM2−p53 protein–protein interaction by isoindolinones B. Anil, E. Blackburn, T. Blackburn, S. Cully, J. Liu, C.J. Drummond, J.A. Endicott, B.T. Golding, R.J. Griffin, K. Haggerty, J. Lunec, D.R. Newell, C.H. Revill, C. Riedinger, A.F. Watson, Q. Xu, Y. Zhao, I.R. Hardcastle, M.E.M. Noble 268 269 270 271 272 273 274 275 276 xlviii Poster board Scientific programme – details Abstract number P057 The discovery and pre-clinical development of the first clinical stage EZH2-inhibitor, EPZ-6438 (E7438) K. Kuntz, H. Keilhack, R. Pollock, S. Knutson, N. Warholic, V. Richon, R. Chesworth, R. Copeland, M. Porter-Scott, C. Sneeringer, T. Wigle P058 Sentinel lymph nodes mapping of macrophage targeted mannosyl human serum albumin-indocyanine detected by combined color and near infrared fluorescence imaging system in esophagus Y. Quan, Y. Oh, J.I.H.O. Park, J. Park, J. Jeong, B. Kim, H. Kim P059 Discovery of multiple kinases inhibitors, DBPR114, as the novel anti-cancer agent H.P. Hsieh, C.C. Kuo, J.J. Chiu, T.A. Hsu, T.K. Yeh, C.T. Chen P060 A hybrid drug design approach to overcome imatinib resistance for treating leukemia Y.M. Wei, K.K.W. To, S.C.F. Au-Yeung P061 Novel hybrid drug design strategy to circumvent erlotinib resistance and to optimize its pharmacokinetic properties for treating lung cancer D.C.S. Poon, S.C.F. Au-Yeung, K.K.W. To P062 Membrane anchorage of Stat3 via artificial protein lipidation M. Avadisian, S. Fletcher, B. Liu, W. Zhao, J. Turkson, C. Gradinaru, P. Gunning P063 The development of the first selective inhibitors of the UBA5 enzyme to probe for E1 activity in diseased cells S.R. da Silva, S.L. Paiva, M. Bancerz, M. Geletu, A.M. Lewis, J. Chen, Y. Cai, H. Li, P.T. Gunning P064 Poly(ADP-ribose) glycohydrolase (PARG) inhibitors increase nuclear poly(ADP-ribose) after methylating DNA damage A. Jordan, B. Acton, E. Fairweather, N. Hamilton, S. Holt, J. Hitchin, C. Hutton, D. James, S. Jones, A. McGonagle, H. Small, K. Smith, A. Stowell, I. Waddell, B. Waszkowycz, D. Ogilvie P065 A nanomolar-potency small molecule inhibitor of the STAT5 protein A.A. Cumaraswamy, A. Lewis, M. Geletu, A. Todic, D.B. Diaz, X.R. Cheng, C.E. Brown, R. Laister, D. Muench, K. Kerman, H.L. Grimes, M.D. Minden, P.T. Gunning P066 Potent and selective non-sulfamate-containing small molecule inhibitors of the ubiquitin activating enzyme S. Paiva, S.R. da Silva, M. Bancerz, H. Quereshi, G.W. Xu, A.D. Schimmer, P.T. Gunning P067 The discovery and optimization of small molecule antagonists of the WDR5−MLL interaction R. Al-Awar, R.S. Al-Awar, M. Getlik, D. Smil, Y. Bolshan, G. Poda, G. Senisterra, H. Wu, A. AllaliHassani, G.A. Wasney, D. Barsyte-Lovejoy, L. Dombrovski, A. Dong, H. He, A. Seitova, I. Chau, F. Li, J.F. Couture, E. Kuznetsova, R. Marcellus P068 Synthetic isomalyngamide A analogs that inhibit breast cancer migration W. Li, T. Chang, C. Hung, C. Chen, S. Jao P069 Progress in drugging CYP1A1, 1B1 and CYP2W1 overexpressed in cancer K. Pors, V. Le Morvan, S. Travica, S.D. Shnyder, M. Sutherland, H.M. Sheldrake, M. Searcey, I. Johansson, S. Mkrtchian, P.M. Loadman, J. Robert, M. Ingelman-Sundberg, L.H. Patterson P070 Exosome analysis in cancer patients: From the preclinical towards the clinical application: Trial design I. Mertens, M. Castiglia, A.P. Carreca, G. Baggertman, M. Peeters, P. Pauwels, C. Rolfo Molecular Targeted Agents I Poster board 277 278 279 280 281 282 283 284 285 286 287 288 289 290 Abstract number P071 Aflibercept has anti-tumor activity in bevacizumab-escaping tumors of colorectal cancer: Molecular profiles and mechanisms C. Dib, R.G. Bagley, P. Mankoo, J. Pollard, J. Watters, M. Chiron P072 Salmonella typhimurium A1-R decoys quiescent cancer cells to cycle rendering them chemosensitive S. Yano, Y. Zhang, M. Zhao, Y. Hiroshima, S. Miwa, F. Uehara, H. Kishimoto, H. Tazawa, T. Fujiwara, R.M. Hoffman 291 292 Scientific programme – details Poster board xlix Abstract number P073 Inhibition of the cell cycle regulated Cdc7 kinase pathway is an efficacious therapeutic approach for hematologic malignancies and solid tumors R. Santos, D. Shum, D. Carrillo, R. Zhang, M. Churchill, S. Mukherjee, R. Brentjens, C. Radu, T.J. Kelly, H. Djaballah, M.G. Frattini P074 Synthetic lethal screen identifies Aurora A as a selective target in HPV driven cervical cancer B. Gabrielli, F. Bokhari, M. Ranall, A. Stevenson, M. Murell, M. Kelly, S. McKee, G. Leggatt, T. Gonda, N. McMillan P075 Combining forces: Study of the cytotoxic effect of the MDM2 inhibitor Nutlin-3 in combination with CDDP in non-small cell lung cancer cell lines C. Deben, C. Rolfo, V. Deschoolmeester, A. Wouters, M. Peeters, I. Gil-Bazo, F. Lardon, P. Pauwels P076 A first-in-Asian phase I dose escalation study to evaluate the safety and pharmacokinetics of VS-6063 (defactinib), a focal adhesion kinase inhibitor in subjects with non-hematologic malignancies T. Shimizu, H. Aida, J. Horobin, M. Keegan, M. Padval, A. Poli, C. Hashii, K. Nakagawa P077 Genetic and pharmacologic inhibition of EPHA2 promotes apoptosis in NSCLC J. Chen, K. Amato, S. Wang, V. Youngblood, D. Brantley-Sieders, R. Cook, L. Tan, N. Gray P078 Met degradation by SAIT301, a Met monoclonal antibody, reduces the invasion and migration of nasopharyngeal cancer cells via inhibition of EGR-1 expression C. Kim, B.S. Lee, K.A. Kim, Y.J. Song, K.H. Cheong P079 Tyk2-src dependence of kidney cancer B. Krishnan, S.C. Hanna, H.L. Wilson, S.T. Bailey, J.S. Damrauer, T. Simamura, R.L. Levine, K.K. Wong, G.L. Johnson, W.Y. Kim 293 294 295 296 297 298 299 P080 Preclinical pharmacologic characterization of GSK2849330, a monoclonal AccretaMab® antibody with optimized ADCC and CDC activity directed against HER3 N. Clarke, C. Hopson, A. Hahn, K. Sully, F. Germaschewski, J. Yates, C. Akinseye, B. Mangatt, Z. Jonak, C. Matheny P081 Using PK/PD/efficacy modeling to predict potential of AZD9291 to target brain metastases from advanced NSCLC with EGFR sensitizing mutations (EGFRm+) J. Yates, P. Ballard, S. Ashton, D. Cross, R. Dattani, M. Mellor, J. Wilson, P. Yang, L. Xie P082 FAK inhibitor VS-6063 (defactinib) targets mesothelioma cancer stem cells which are enriched by standard of care chemotherapy J. Pachter, V.N. Kolev, P. Baas, D.T. Weaver, Q. Xu P083 Genomic and epigenomic analysis identify potential therapeutic targets in luminal B breast cancer molecular subtype L. Addou Klouche, A. Belhadj, A. Bendaoud, M. Benyelles, I. Ziane, M. Chaffanet, D. Birnbaum 300 P084 PI3 -Kinase inhibition forestalls the development of drug resistance in BRAFV600E/PTENNull melanoma M. Deuker, V. Marsh Durban, W. Phillips, M. McMahon P085 Selinexor, a novel selective inhibitor of nuclear export, potentiates the antitumor activity of gemcitabine against pancreatic cancer by nuclear retention of p27 M. Amit, S. Kazim, H. Kazim, S. Shacham, M. Kauffman, M.P. Malafa P086 CC-115 inhibits DNA damage and repair pathways in vitro T. Tsuji, L. Sapinoso, S. Sankar, D.S. Mortensen, S. Xu P087 Stromal delivery of long Pentraxin-3 impairs FGF/FGFR-dependent tumor growth and metastasis A. Giacomini, E. Di Salle, D. Coltrini, S. Rezzola, M. Belleri, M. Presta, R. Ronca P088 Androgen deprivation therapy sensitizes prostate cancer cells to T-cell killing through androgen receptor dependent modulation of the apoptotic pathway S. Gameiro, A. Ardiani, A.R. Kwilas, R.N. Donahue, J.W. Hodge P089 RNA sequencing and in silico analysis identifies an unannotated antisense long non-coding RNA involved in cancer progression S. Inoue, K. Horie-Inoue, K. Ikeda 304 301 302 303 305 306 307 308 309 l Scientific programme – details Poster board Abstract number P090 Inhibition of Trk-driven tumors by the pan-Trk inhibitor RXDX-101 D. Anderson, M. Ciomei, P. Banfi, S. Cribioli, E. Ardini, A. Galvani, G. Li 310 P091 IGF-1R inhibition induced activation of Yes/SFK acts as a by-pass resistance pathway in rhabdomyosarcoma X. Wan, C. Yeung, C. Heske, A. Mendoza, L.J. Hlman 311 P092 The prognostic role of mesothelin expression and its association with KRAS mutation in advanced lung adenocarcinoma A. Thomas, Y. Chen, S. Steinberg, J. Luo, G. Giaccone, I. Pastan, M. Miettinen, R. Hassan 312 P093 Development of a one-step isolation platform for exosomal RNA and circulating cell-free DNA from cancer plasma samples D. Enderle, K. Brinkmann, T. Koestler, S. Bentink, C. Berking, J. Skog, M. Noerholm 313 P094 Optimal sequencing schedules for combining BRAF inhibition with BCL-2 inhibition A. Schalck, D.T. Frederick, M.R. Hammond, I. Ferreiro-Neira, Z.A. Cooper, J.C. Cusack, D.P. Lawrence, K.T. Flaherty, J.A. Wargo, R.J. Sullivan 314 P095 Biological characterization of TAS3681, a new type of androgen receptor antagonist with androgen receptor downregulating activity K. Minamiguchi, M. Seki, H. Aoyagi, T. Mori, D. Kajiwara, N. Masuko, R. Fujita, S. Okajima, Y. Hayashi, E. Sasaki, T. Utsugi 315 P096 Potent, partial agonists at ERalpha as selective estrogen mimics for treatment of tamoxifen-resistant breast cancer G. Thatcher, R. Xiong, H.K. Patel, J. Zhao, X. Liang, Y. Wang, M.E. Molloy, D. Tonetti 316 P097 IKKb inhibition suppresses sphere formation and self-renewal of lung cancer initiating cells T. Carneiro-Lobo, A.C.P. Salviatto, A.S. Baldwin, D.S. Basseres 317 P098 Novel therapeutic targets for ARID1A mutant ovarian clear cell carcinoma (OCCC) R.E. Miller, I. Bajrami, R. Brough, A. Konde, J. Campbell, R. Rafiq, A. Ashworth, C.J. Lord 318 P099 Genomic profiling of uterine leiomyosarcomas reveal frequent alterations in Akt/mammalian target of rapamycin (mTOR) pathway genes and other actionable genomic abnormalities linked to targeted therapies J.A. Elvin, Z.R. Chalmers, J. Chiemlicki, K.A.I. Wang, N. Palma, S.M. Ali, A. Huho, C.E. Sheehan, V.A. Miller, P.J. Stephens, J.S. Ross 319 P100 First-in-human study with ARQ 092, a novel pan AKT-inhibitor, in subjects with advanced solid tumors or recurrent malignant lymphoma M. Saleh, K. Papadpoulos, A. Arabnia, A. Patnaik, R.M. Stein, F. Chai, M. Lamar, R. Savage, G. Abbadessa, A. Tolcher 320 P101 Potent and selective inhibition of EZH2 by AU-2121 leads to significant tumor growth inhibition in mutant EZH2 dependent non-Hodgkin lymphoma S. Ahmed, K. Narayanan, A. Gadakh, S. Dodheri, S. Surendranath, S. Nathan, S. Mukherjee, S. Marappan, R. Sushmita, S. Dhadunia, K.M. Obilisetti, J. Anil, J. Reddy, K. Reddy, A. Basavaraju, C. Naik, C. Pandit, M. Ramachandra 321 P102 Novel alternative splice variants as potential biomarkers and therapeutic targets in aggressive prostate cancer in men of African descent S. Patierno, J. Freedman, B. Wang, N. Lee, D. George 322 P103 The development of short form of mimic microRNA for lung cancer therapy S. Ohno, K. Sudo, M. Kuroda 323 P104 Clinical pharmacokinetics (PK), translational PK/pharmacodynamics (PD), and exposure– adverse events (AEs) relationship of MLN2480, an oral investigational pan-RAF kinase inhibitor X. Zhou, A.J. Olszanski, M. Middleton, R. Gonzalez, M.J. Bargfrede, M. Kneissl, V. Bozón, E. Gangolli, K. Venkatakrishnan, M. Patel, C. Zopf, D.W. Rasco 324 Scientific programme – details Poster board li Abstract number P105 Identification and characterization of an irreversible inhibitor of CDK2 M. Martin, E. Anscombe, E. Meschini, D. Staunton, M. Geitmann, U.H. Danielson, L.Z. Wang, R. Mora Vidal, T. Reuillon, B.T. Golding, D.R. Newell, S. Wedge, M.E.M. Noble, J.A. Endicott, R.J. Griffin 325 P106 A novel non-ligand competing anti-EGFR antibody for cancer treatment X. Wang, S. Rust, F. Comer, V. Muniz-Medina, Q. Du, A. Yuan, K. Senthil, R. Fleming, R. Minter, S. Coats 326 P107 Combination of MDM2 antagonists with RAS pathway inhibitors in colorectal cancer B. Higgins, C. Tovar, K. Kolinsky, Y. Zhang, S.A. Middleton, G. Nichols, K. Packman, F. Su, L. Vassilev 327 P108 Jagged1 expression and its relevance in metastatic progression of breast cancers N. Bednarz-Knoll, A. Efstathiou, F. Gotzhein, H. Wilkman, V. Mueller, Y. Kang, K. Pantel 328 P109 A first-in-human study evaluating the safety and pharmacology of MM-151, a novel oligoclonal antiEGFR antibody combination in patients with refractory solid tumors M. Beeram, C. Lieu, W. Harb, L. Power, J. Kearns, R. Nering, V. Moyo, B. Wolf, A. Adjei 329 P110 Preclinical development of BIS-1602, first in class growth hormone releasing hormone antagonist Y.Y. Maxuitenko, N.L. Block, A.V. Schally, S.J. Reich, P. Goldstein 330 P111 Biomarker discovery and validation for assessing the response to cMet inhibition and functional inactivation S. Jung, S. Selzer, C. Lößner, K. Kuhn, U. Fiedler, A. Klotzbücher, H.D. Zucht, S. Koncarevic, T. Prinz, D. Hertfelder, K.A. Boehme, H. Volkmer, M.H.G. Kubbutat, P. Budde, I. Pike 331 P112 Dual PI3K delta/gamma inhibition by RP6530 accentuates bortezomib activity in multiple myeloma cell lines S. Viswanadha, G. Babu, S. Veeraraghavan, S. Vakkalanka 332 P113 Short antisense oligonucleotides antagonize Lin28 and enable pre-let-7 processing and suppression of cell growth in human hepatocarcinoma cells M. Roos, G. Civenni, M. Lucic, D. Pavlicek, U. Pradere, H. Towbin, C.V. Catapano, J. Hall 333 P114 Aplidin: first in class compound targeting EEF1A in tumor cells A. Losada, J.F. Martinez, P. Moral, L. Carrasco, F. Gago, C. Cuevas, L.F. Garcı́a-Fernández, C.M. Galmarini 334 P115 RICTOR amplification as a novel molecular target for the treatment of lung cancer H. Cheng, B. Piperdi, Y. Zou, A. Verma, X. Liu, E. Schwartz, C. Zhu, C. Montagna, B. Halmos, A. Chachoua, R. Perez-Soler 335 P116 The effect of food on the pharmacokinetics of the investigational Aurora A kinase (AAK) inhibitor, alisertib (MLN8237), in patients (pts) with advanced solid tumors or lymphomas X. Zhou, T.M. Bauer, S. Goel, J. Sarantopoulos, B. Zhang, V. Kelly, J. Mertz, K. Venkatakrishnan 336 P117 Sensitisation of HPV+ HNSCC to cytotoxic treatments by targeting the G2/M checkpoint with AZ1775 to improve survival A. Osman, N. Tanaka, A. Patel, J. Wang, A. Fitzgerald, T. Xie, M. Zhao, S. Jasser, M. Gadhikar, H. Skinner, M. Frederick, F. Johnson, J.N. Myers 337 P118 BM-1252 (APG-1252): a potent dual specific Bcl-2/Bcl-xL inhibitor that achieves complete tumor regression with minimal platelet toxicity L. Bai, J. Chen, L. Liu, D. McEachern, A. Aguilar, H. Zhou, C.Y. Yang, H. Wang, J. Wen, G. Wang, Y. Zhai, M. Guo, D. Yang, S. Wang 338 P119 NAMPT inhibition as strategy to impair tumor growth A. Cerezo, S. Jiménez, E. Lospitao, N. Bravo, R. Campos-Olivas, C. Aguilera, M. Cañamero, R. Gilmour, S. Geeganage, G. Zhao, S. Velasco-Miguel 339 lii Scientific programme – details Poster board Abstract number P120 Preclinical activity of the VEGFR, FGFR and PDGFR inhibitor lucitanib in FGFR2 aberrant endometrial and gastric cancer models F. Guffanti, R. Chilà, E. Bello, L. Ceriani, M. Zangarini, M. Zucchetti, C. Saba, A. Jacquet-Bescond, M. Pierrat, G. Damia 340 P121 Dinaciclib alters cell cycle dynamics and induces cell death in Soft Tissue Sarcomas N. Mulet Margalef, S. Rello-Varona, S. Garcia-Monclús, M. Fuentes-Guirado, O.M. Tirado, X. Garcia del Muro 341 P122 A phase 1/2 study evaluating the safety, pharmacokinetics and efficacy of ABT-414 in subjects with advanced solid tumors likely to over-express the epidermal growth factor receptor (EGFR) A. Tolcher, G. Goss, M. Gordon, L. Gandhi, K.P. Papadopoulos, D. Rasco, M. Pedersen, J. Fischer, W. Ames, H. Xiong, M. Dudley, W. Munasinghe, P. Ansell, K. Holen, E. Vokes 342 P123 Salmonella typhimurium A1-R effectively targets experimental breast cancer brain metastasis Y. Zhang, S. Miwa, N. Zhang, R.M. Hoffman, M. Zhao 343 P124 Search for new blood biomarkers for response to antiangiogenic therapy in non-small cell lung cancer patients A. Rodrı́guez-Garzotto, M.T. Agulló-Ortuño, S. Ponce, C.V. Dı́az-Garcı́a, A. Agudo-López, C. Pérez, E. Prieto-Garcı́a, H. Cortés-Funes, L. Iglesias 344 P125 Interaction of plitidepsin with eEF1A in living tumor cells C. Garcı́a, A. Losada, J.M. Molina-Guijarro, M.A. Sacristán, J. Martinez, C.M. Galmarini, M.P. Lillo 345 P126 Inhibition of Wnt pathway by novel thiazole-based Traf2- and Nck-interacting kinase (TNIK) inhibitor Y. Uno, H. Moriyama, S. Kashimoto, M. Masuda, M. Sawa, T. Yamada 346 P127 Can a link between the EGFR and cMET pathway in non-small cell lung cancer explain resistance against targeted therapies and open new therapeutic opportunities? N. Van Der Steen, K. Van Der Steen, K. Zwaenepoel, E. Giovannetti, M. Castiglia, A.P. Carreca, P. Pauwels, C. Rolfo 347 P128 Two NSCLC-PDXs with different EGFR exon 20-insertions respond differently to different TKIs H. Li, M. Yang, J. Cai 348 P129 Synergistic drug combinations that target beta-catenin-driven and MYC-driven cancers J.C.M. Uitdehaag, J.A.P. Spijkers-Hagelstein, J.A.D.M. de Roos, A.M. van Doornmalen, M.B.W. Prinsen, J. de Man, R.C. Buijsman, G.J.R. Zaman 349 P130 Oncogenic Ras mutants differentially utilize PLC-dependent calcium flux and PKC activation for MAPK signaling C. Pitt, F. McCormick 350 P131 hz515H7, a humanized antibody exerts its antitumor activity via antagonism of the CXCR4/SDF-1 axis, and through effector functions C. Klinguer-Hamour, M. Broussas, B. Akla, S. Berger, N. Boute, C. Beau-Larvor, A. Robert, J.F. Haeuw, L. Goetsch, C. Bailly, N. Corvaia 351 P132 UNC2025, a novel small molecule MerTK and Flt3 tyrosine kinase inhibitor, has therapeutic activity and promotes sensitivity to chemotherapy in animal models of acute leukemia D. Graham, D. DeRyckere, X. Wang, A.A. Hill, W. Zhang, S.V. Frye, H.S. Earp 352 P133 Protein expression for receptor activator of NFkB (RANK) and its ligand (RANKL) in non-small cell lung cancer (NSCLC) M. D’Arcangelo, S. Ekman, W. Dougall, D. Branstetter, M. Bergqvist, P. Liv, D. Chan, J. Botling, F. Hirsch 353 P134 PCR-based assay for BRAFV600 mutation analysis in ctDNA: clinical results from plasma and serum samples M. Gonzalez-Cao, C. Mayo de las Casas, M.A. Molina-Vila, L. De Mattos-Arruda, J.L. Manzano, E. Muñoz, J. Cortes, J.P. Berros, M. Sanmamed, A. Gonzalez, C. Alvarez, N. Karachaliou, N. JordanaAriza, S. Martin Algarra, R. Rosell 354 Scientific programme – details Poster board liii Abstract number P135 Altiratinib (DCC-2701): a balanced inhibitor of MET, TIE2, and VEGFR2 kinases that exhibits broad anti-tumor and anti-angiogenic activities D. Flynn, B.D. Smith, C.B. Leary, M.D. Kaufman, B.A. Turner, M.M. Hood, W.P. Lu, T.J. Rutkoski, T. Samarakoon, S. Vogeti, S.C. Wise, O. Rosen 355 P136 Discovery of novel pyrido[2,3-b]pyrazine as fibroblast growth factor receptor (FGFR-1, 2, 3 & 4) kinase inhibitors with nanomolar affinity P. Angibaud, O. Querolle, V. Berdini, G. Saxty, A. Cleasby, H. Colombel, I. Csoka, R. Gilissen, P. King, L. Meerpoel, C. Paulussen, I. Pilatte, V. Poncelet, D.C. Rees, B. Roux, V. Tronel, T. Verhulst, B. Wroblowski, C.W. Murray, J. Vialard 356 P137 Multi-color flow cytometry immunophenotyping for detection of CSC in NSCLC A. Martinez-Romero, J.M. Pardo, S. Tejedor, S. Calabuig Fariñas, R. Lucas, S. Figueroa, E. JantusLewintre, C. Camps, R. Farras 357 P138 Knockdown of beta-catenin with dicer-substrate siRNAs down-regulates Wnt/beta-catenin pathway signaling N. Pursell, W. Zhou, R. Diwanji, B. Holmes, N. Avitahl-Curtis, C. Dutta, H. Dudek, S. Ganesh, M. Abrams, W. Wang, B. Ying, D. Chen, S. Shui, U. Saxena, H. Yang, A. Shah, R. Arvan, M. Koser, C. Lai, B.D. Brown 358 P139 Correlation of tumour-associated macrophage, but not tumour-infiltrating lymphocyte, levels with progression-free survival in patients with metastatic renal cell carcinoma treated with axitinib J.A. Williams, J.F. Martini, B. Escudier, B.I. Rini, R.J. Motzer, J. Tarazi, S. Li, P.A. English 359 P140 Tumor suppressive microRNA-192 as a prognostic factor for recurrence of surgically resected nonsmall cell lung cancer J.H. Hong, K.S. Roh, E.K. Jeon, J.H. Kang, S.S. Suh, S.C. Lee 360 P141 Nanoformulations of the PARP inhibitors olaparib and BMN 673 for cancer nanotherapy S. Sridhar, S. Tangutoori, P. Baldwin 361 P142 Phenotypic plasticity in epithelial progenitors and mesenchymal carcinoma is regulated by Axl signaling A. Engelsen, K. Wnup-Lipinska, C. Tiron, F. Pelissier, T. Jokela, G. Haaland, G. Gausdal, T. Sandal, R. Frink, X. Liang, S. Hinz, L. Ahmed, M. Hellesøy, D. Mickelm, J. Minna, M. LaBarge, R. Brekken, J. Lorens 362 P143 Cytosolic p21 is a pharmacodynamic marker of CHEK1 and IKKe inhibition in ovarian cancer cells M. Kim, D.J. Min, G. Wright, C. Annunziata 363 P144 First-in-human phase 1 study of MLN2480, an investigational oral pan-RAF kinase inhibitor, in patients (pts) with relapsed or refractory solid tumors, including BRAF/NRAS-mutant melanoma M. Middleton, D.W. Rasco, A.J. Olszanski, P. Corrie, P. Lorigan, R. Plummer, J. Larkin, A. Pavlick, X. Zhou, Z. Yuan, E. Gangolli, M. Kneissl, V. Bozón, R. Gonzalez 364 P145 Pim-1 kinase: Validated as a therapeutic cancer target for MYC-driven tumours O. Renner, Y. Cecilia, M.C. Rodriguez de Miguel, S. Peregrina, B. Garcia-Serelde, M.I. Albarran, A. Cebria, D. Cebrian, F. Ramos-Lima, A. Carnero, J. Pastor, C. Blanco-Aparicio 365 P146 Targeting colorectal and pancreatic cancer stem cells with the LGR5 monoclonal antibody BNC101 P. Chu, F. Shojaei, K. Smith, J. Norton, C. Walsh, J. Iglesias, C. Reyes 366 P147 Induction of apoptosis and inhibition of angiogenesis by novel fusion protein − AD-O54.9 as a new preclinical strategy in cancer treatment P. Rozga, B. Zerek, A. Pieczykolan, M. Galazka, K. Bukato, S. Pawlak, M. Szymanik, A. Jaworski, M. Teska-Kaminska, K. Poleszak, A. Grochot-Przeczek, W. Strozek, J. Pieczykolan 367 P148 NP137, the first humanized monoclonal antibody directed against netrin-1, exhibits antitumor activity by inducing dependence receptors-mediated cell death J.G. Delcros, B. Ducarouge, R. Abes, D. Goldschneider, B. Gibert, J.G. Blachier, D. Neves, P. Mehlen, A. Bernet, S. Depil 368 liv Scientific programme – details Poster board Abstract number P149 Diagnosis and molecular targeting for individualized treatment of patients with pre-neoplastic lesions and locally advanced cervical cancer P.M.A. Moreno-Acosta, A.R.R. Alfredo Romero-Rojas, A.H.S. Antonio Huertas Salgado, D.M. Diana Mayorga, N.M. Nicolas Morales, J.A. Jinneth Acosta, O.G. Oscar Gamboa, N.M. Nicolas Magne, M.M. Monica Molano 369 P150 Discovery of the genes that underpin the transition to malignant phenotype of breast tissues in a highly consanguineous region I. Gupta, S. Shanmuganathan, A. Ouhtit 370 P151 Selective targeting of head and neck cancer cells by perturbing reactive oxygen species homeostasis M. Kwon, J.W. Kim, E.H. Kim, J.Y. Park, S.Y. Kim, J.L. Roh 371 P152 Specific inhibition of hTERT expression by targeting common promoter mutations which cause quadruplex DNA instability D. Miller, A. Sokolova, S. Thomas, F. Rezzoug, J. Chaires, W. Dean, R. Buscaglia, J. Trent 372 P153 AKT2 gene amplification is a marker for sensitivity to allosteric but not ATP-competitive AKT inhibitors T. Abe, K. Ichikawa, R. Fujita, M. Okada, K. Tanaka, M. Ohkubo, K. Yonekura, T. Shimomura, T. Utsugi 373 P154 Neuregulin 1 (NRG1) expression is a predictive biomarker for response to AV-203, an ERBB3 inhibitory antibody, in human tumor models K. Meetze, S. Vincent, S. Tyler, E. Mazsa, A. Delpero, S. Bottega, D. McIntosh, J. Gyuris, Z. Weng 374 P155 MER as a novel therapeutic target in colorectal cancer K. Wong, A.C. Tan, T. Pitts, P. Klauck, S. Earp, S. Frye, X. Wang, D.K. Graham, S.G. Eckhardt 375 P156 Tumor-targeting Salmonella typhimurium A1-R enhances gemcitabine–bevacizumab efficacy on a patient-derived orthotopic xenograft (PDOX) pancreatic cancer nude mouse model Y. Hiroshima, M. Zhao, M.H.G. Katz, J.B. Fleming, S. Sato, T. Murakami, M. Yamamoto, F. Uehara, S. Miwa, S. Yano, M. Momiyama, Y. Zhang, A. Maawy, T. Chishima, K. Tanaka, M. Bouvet, I. Endo, R.M. Hoffman 376 P157 Plucked hair as a platform for monitoring pharmacodynamic and mechanistic consequences of clinical exposure to the Wnt/beta-catenin inhibitor PRI-724 G. Miele, B. Reed, E. Harrison, T. Mefo, J. Read, T. Senba, T. Odagami 377 P158 A first-in-human (FIH) safety and pharmacological study of SAR405838, a novel HDM2 antagonist, in patients with solid malignancies V. de Weger, M.P. Lolkema, M. Dickson, A. Le Cesne, A. Wagner, M. Merqui-Roelvink, A. Varga, W. Tap, G. Schwartz, G. Demetri, W. Zheng, G. Tuffal, S. Macé, H. Miao, J.H.M. Schellens, M. de Jonge 378 P159 Identification and rational in silico-based targeting of a novel mediator of metastatic breast cancer R. Clarkson, J. Soukupova, A. Wakefield, D. Turnham, W. Yang, C. Bordoni, A. Westwell, A. Brancale 379 P160 Induction of apoptosis with a novel dual cIAP1/XIAP antagonist in models of melanoma G. Ward, G. Chessari, C.N. Johnson, J. Lewis, S. Rich, N. Thompson 380 P161 Efficacy of specific FGFR inhibitors against gatekeeper resistance mutations and shared mechanism of cell death in FGFR2-dependent endometrial cancer cell lines L. Packer, S. Byron, S. Stehbens, D. Loch, F. Dehkhoda, S. Stephenson, P. Pollock 381 P162 Phase Ib study of oral dual-PI3K/mTOR inhibitor GDC-0980 in combination with capecitabine and mFOLFOX6 + bevacizumab in patients with advanced solid tumors and colorectal cancer L. Rosen, J. Goldman, J.M. Hubbard, M. Roos, J. Capdevila, J. Maynes, W. Lin, B. O’Keeffe, M. Lackner, J. Spoerke, J. Ware, B. Arnieri, E. Freas, S. Leong 382 P163 Identification of potent and selective tankyrase 1/2 inhibitors with activity in a subset of APC mutant colorectal cancer S.M. Guichard, Y. Zhang, D. Ferguson, A. Mazzola, H. Wang, L. Bao, S. Grosskurth, J. Johannes, M. Wagoner, M. Zinda, S. Fawell, E.J.E. Pease, A. Schuller 383 Scientific programme – details Poster board lv Abstract number P164 REDX04988, a novel dual B-RAF/C-RAF inhibitor and a potential therapeutic for BRAF-mutant colorectal cancer J. Rainard, R. Testar, R. Poonawala, H. Mason, P. Smith, H. Brooke, V. Huart, S. Frith, J. Ahmet, J. Hall, A. Morrison, M.A. Campbell, M. Bingham, R. Armer 384 P165 Noninvasive monitoring of acquired EGFR-T790M mutation and discovery of its heterogeneity in patients with advanced NSCLC treated with EGFR-TKI X. Ye, D. Zheng, M.Z. Zhang, Y. Sun, J.Y. Wang, J. Ni, H.P. Zhang, L. Zhang, J. Luo, J. Zhang, L. Tang, B. Su, G. Chen, G.S. Zhu, J.F. Xu, Y. Gu 385 P166 PI3K and MEK inhibitor combination toxicities and relative dose intensity: Vall d’Hebron experience A. Azaro, D. Marino, A. Garrido-Castro, C. Cruz, M. Alsina, J. Perez, R. Dienstmann, G. Argiles, C. Hierro, M. Berzosa, B. Adamo, J. Tabernero, J. Rodon 386 P167 Combination of the ERK inhibitor GDC-0994 with the MEK inhibitor cobimetinib significantly enhances anti-tumor activity in KRAS and BRAF mutant tumor models M. Merchant, J. Chan, C. Orr, J. Cheng, X. Wang, T. Hunsaker, M.C. Wagle, S.A. Huang, J. Tremayne, H. Ngu, M. Solon, J. Eastham-Anderson, H. Koeppen, L. Friedman, M. Belvin, J. Moffat, M. Junttila 387 P168 An integrated molecular analysis of lung adenocarcinomas identifies potential therapeutic targets among TTF1-negative tumors R.J. Cardnell, C. Behrens, L. Diao, Y. Fan, X. Tang, J.D. Minna, G.B. Mills, J.V. Heymach, I.I. Wistuba, J. Wang, L.A. Byers 388 P169 A phase 1, dose-escalation, first-in-human study of ARQ 087, an oral pan-FGFR inhibitor, in adult subjects with advanced solid tumors K. Papadopoulos, A. Tolcher, M. Kittaneh, A. Patniak, D. Rasco, G. Chambers, G. Newth, R. Savage, T. Hall, B. Schwartz, J. Kazakin, P. LoRusso 389 P170 Inhibitors of EZH2 act synergistically with type 1 interferon to induce a potent interferon-stimulated gene response, triggering apoptosis in diffuse large B-cell lymphoma B. Bradley, F. Zhao, C.C. Yuan, S. Balasubramanian, P. Iyer, C. Hatton, B. Bryant, E. Normant, P. Trojer 390 P171 LOXO-101, a pan TRK inhibitor, for the treatment of TRK-driven cancers S. Winski, B. Baer, D. Hartley, S. Rhodes, R. Wallace, S. Smith, N. Nanda, L. Kunkle, P. Lee, K. Bouhana 391 P172 Using modelling & simulation to integrate mouse PK−PD-efficacy with preliminary human PK data to inform the Phase II doses and schedule for the experimental c-Met inhibitor AZD6094 (Volitinib) R. Jones, A. Cheung, T. Coleman, P. Ballard, C. D’Cruz, A. Schuller, M. Frigault, Y. Gu, Y. Sai, S. Weiguo, Y. Ren, W. Qing, L. Lindbom, K. Petersson 392 P173 Small modification of ceritinib enhances the activity against ALK C.H. Park, C.H. Kang, H.J. Jung, H.R. Kim, C.O. Lee, H.K. Lee, S.U. Choi 393 P174 Sensitivity of acute myeloid leukemia cells to a urokinase-activated anthrax lethal toxin (PrAgU2/lf) is dependent on uPAR expression and phospho-MEK1/2 levels A. Bekdash, S.H. Liu, S.H. Leppla, A.E. Frankel, R. Abi-Habib 394 P175 cMet: Proof-of-concept clinical trial with volitinib in patients with advanced papillary renal cell cancer (PRCC) T.K. Choueiri, B. Escudier, S. Kumar Pal, E. Jonasch, D. Heng, T. Powles, H.T. Arkenau, E. Clark, C. D’Cruz, M. Frigault, A.F. Nash, S.R. Morgan 395 P176 Gastrointestinal stromal tumor associated with neurofibromatosis type I T. Takahashi, T. Nishida, R. Nakatsuka, M. Kaneda, S. Hirota, Y. Miyazaki, Y. Kurokawa, M. Yamasaki, H. Miyata, K. Nakajima, S. Takiguchi, M. Mori, Y. Doki, S. Serada, T. Naka 396 lvi Poster board Scientific programme – details Abstract number P177 Characterization of molecular targets of therapy in Non-Small Cell Lung Cancer (NSCLC) utilizing a liquid biopsy S. Greene, D. Lu, R. Krupa, M. Harvey, J. Louw, A. Jendrisak, N. Bales, D. Marrinucci, J. Gray, R. Dittamore P178 TAS-119 a selective inhibitor of Aurora A kinase, potentiates taxane therapy in breast and lung cancer models Y. Nakatsuru, A. Hashimoto, H. Sootome, K. Ito, M. Sakuragi, A. Miura, N. Oda, H. Hirai, T. Utsugi P179 Rho-GTPase, RAC1 and Cdc42 mediates Wnt−beta-catenin signals for metastasis associated phenotypes in TNBC: A proof of concept study N. Dey, P. De, B. Leyland-Jones P180 Optimization of novel pyrido[2,3-b]pyrazine based small molecule fibroblast growth factor receptor 1, 2, 3 & 4 (FGFR) inhibitors into a potential clinical candidate P. Angibaud, O. Querolle, V. Berdini, G. Saxty, A. Cleasby, H. Colombel, I. Csoka, N. Esser, R. Gilissen, L. Meerpoel, C. Paulussen, I. Pilatte, V. Poncelet, D.C. Rees, B. Roux, T. Verhulst, V. Tronel, B. Wroblowski, C.W. Murray, J. Vialard P181 TAS-121, a highly potent and mutant-specific EGFR inhibitor, overcomes T790M-acquired resistance with promising antitumor activity through specific inhibition of mutant EGFR signaling M. Kato, K. Miyadera, K. Ito, Y. Aoyagi, A. Hashimoto, K. Yonekura, Y. Iwasawa, T. Utsugi P182 Characterization of the oncogenic properties of mutant isocitrate dehydrogenase 1 (IDH1R132H) in human primary cells M. Barradas, L. Diezma, C.M. Pérez-Ferreiro, A. Cerezo, E. Lospitao, S. Peregrina, S. Jiménez, N.A. Brooks, R. Torres, S. Geeganage, R. Gilmour, S. Velasco-Miguel P183 A novel dielectrophoretic microwell array system for detection and single cell analysis of circulating tumor cells from breast cancer patients T. Sawada, A. Morimoto, T. Mogami, K. Iijima, Y. Akiyama, K. Katayama, T. Futami, M. Yunokawa, K. Tamura, M. Watanabe, Y. Koh, F. Koizumi P184 Targeting PI3K somatic mutations reduces invasion and EMT in squamous cell carcinoma of the lung A. Cavazzoni, M. Bonelli, F. Saccani, S. La Monica, M. Galetti, C. Caffarra, D. Cretella, C. Fumarola, R. Alfieri, P.G. Petronini P185 Aurora kinases A and B are required for KRAS-induced lung cell oncogenicity E.O. Ozorio dos Santos, M.N. Aoki, E. Levantini, D.S. Bassères P186 Aflibercept (Zaltrap) directly attenuates the migration and invasion of colorectal cancer cells A. Bouygues, P. Mésange, M. Ayadi, V. Poindessous, M. Chiron, E. Dochy, T. André, A. de Gramont, A.K. Larsen P187 Structural basis for inhibition of ligand-dependent and -independent ErbB3 activation by KTN3379 D. Alvarado, S. Lee, E. Greenlee, G.F. Ligon, J.S. Lillquist, E.J. Natoli, J. Amick, Y. Hadari, J. Schlessinger P188 A potent and selective small molecule inhibitor of MCL-1 sensitizes DLBCL cell lines to the BCL-2 selective inhibitor ABT-199 D.C. Phillips, Y. Xiao, L. Lam, E. Litinovic, L. Roberts-Rapp, A.J. Souers, J.D. Leverson Paediatric Oncology Poster board 397 398 399 400 401 402 403 404 405 406 407 408 Abstract number P189 Transcription factor activating protein 2 beta (TFAP2B) mediates neuronal differentiation in neuroblastoma F. Ikram, S. Ackermann, F. Roels, R. Volland, B. Hero, F. Hertwig, H. Kocak, D. Dreidax, K.O. Henrich, F. Berthold, P. Nürnberg, F. Westermann, M. Fischer P190 Pediatric Preclinical Testing Program (PPTP) Evaluation of the p53−MDM2 Antagonist MK-8242 M. Smith, M. Kang, P. Reynolds, R. Lock, H. Carol, R. Gorlick, A. Kolb, J. Maris, S. Keir, J. Wu, R. Kurmasheva, P. Houghton 409 410 Scientific programme – details Poster board lvii Abstract number P191 Druggability of p16 deleted pediatric leukemia: The novel cell line POETIC3 identifies potential agents and drug combinations for mechanism based targeted therapeutics J. Reimer, A. Kovulchuk, Y. Ruan, R. Shah, A. Jayanthan, M. Perinpanayagam, T. Truong, I. AuerGrzesiak, J. Luider, O. Kovulchuk, T. Trippett, A. Narendran 411 P192 The Pediatric Preclinical Testing Program (PPTP): Analysis of the first 10 years in vivo testing P. Houghton, R. Lock, H. Carol, R. Gorlick, A. Kolb, J. Maris, S. Keir, J. Wu, M. Kang, P. Reynolds, R. Kurmasheva, M. Smith 412 P193 Next-generation sequencing identifies the mechanism of tumourigenesis caused by loss of SMARCB1 in malignant rhabdoid tumours M.A. Finetti, M. Selby, A. del Carpio Pons, J. Wood, B. Skalkoyannis, A. Smith, S. Crosier, S. Bailey, S. Clifford, D. Williamson 413 P194 Genomic profiling using a clinical next generation sequencing (NGS) assay reveals genomic alterations to guide targeted therapy in advanced neuroblastoma patients S. Ali, E.M. Sanford, M.J. Hawryluk, J. Chmielecki, K. Wang, G.A. Palmer, N.A. Palma, D. Morosini, R. Erlich, R. Yelensky, D. Lipson, J.S. Ross, Y. Mosse, P.J. Stephens, J.M. Maris, V.A. Miller 414 P195 Comprehensive next generation sequencing of solid tumors from 669 adolescents and young adults reveals a distinct spectrum of targetable genomic alterations D. Morosini, K. Wang, K. Wagner, B. Gershenhorn, R. Yelensky, D. Lipson, J. Chmielecki, S.M. Ali, J.S. Ross, P.J. Stephens, V.A. Miller 415 P196 Results of phase I study of bolus 5-fluorouracil in children and young adults with recurrent ependymoma K.D. Wright, D.C. Turner, K.M. Haddock, M.O. Jacus, K.E. Harstead, S.L. Throm, V.M. Daryani, G.W. Robinson, G.T. Armstrong, A. Onar-Thomas, C.F. Stewart, A. Gajjar 416 P197 Evaluating the activity of the p53−MDM2 inhibitor NDD0005 in Ewing sarcoma J. Pecqueur, B. Vormoor, Y. Zhao, H. Newell 417 P198 Population pharmacokinetics of intravenous bolus 5-fluorouracil in a phase I trial for children and young adults with recurrent ependymoma D.C. Turner, K.M. Haddock, M.O. Jacus, K.E. Harstead, S.L. Throm, V.M. Daryani, C.F. Stewart, K.D. Wright 418 P199 Targeted inhibition of casein kinase II (CK2) produces a strong therapeutic effect in pediatric leukemia S. Dovat, C. Song, C. Gowda, K.J. Payne 419 P200 Analysis of genomic alterations in Ewing sarcoma (German cohort) reveals cooperating mutations and novel therapy targets G.H.S. Richter, K. Agelopoulos, E. Schmidt, K. von Heyking, B. Moser, H.U. Klein, U. Kontny, M. Dugas, K. Poos, E. Korsching, T. Buch, G. Köhler, C. Rössig, D. Baumhoer, H. Jürgens, S. Burdach, W.E. Berdel, C. Müller-Tidow, U. Dirksen 420 P201 Molecular profiling for factors predicting sensitivity or resistance to therapy in relapsed child cancer F. Saletta, C. Wadham, J. Byrne, D. Ziegler, G. McCowage, M. Haber, G. Marshall, M. Norris 421 P202 CBL0137, a novel NFkB suppressor and p53 activator, is highly effective in pre-clinical models of neuroblastoma M. Haber, J. Murray, L. Gamble, A. Carnegie-Clark, H. Webber, M. Ruhle, D. Carter, A. Oberthur, M. Fischer, D. Ziegler, G.M. Marshall, K. Gurova, C. Burkhart, A. Purmal, A.V. Gudkov, M.D. Norris 422 P203 RNA helicase A is essential for 1p36 gene KIF1Bb tumor suppression in neuroblastomas Z.X. Chen, K. Wallis, S.M. Fell, V.R. Sobrado, M.C. Hemmer, D. Ramsköld, Z. Choo, U. Hellman, R. Sandberg, R.S. Kenchappa, T. Martinsson, J.I. Johnsen, P. Kogner, S. Schlisio 423 lviii Scientific programme – details Poster board Abstract number Toxicology Poster board Abstract number P204 Nonclinical safety assessment of a humanized anti-OX40 agonist antibody, MOXR0916 R. Prell, W. Halpern, J. Beyer, J. Tarrant, S. Sukumaran, M. Huseni, R. Kaiser, D. Wilkins, S. Karanth, H. Chiu, J. Ruppel, C. Zhang, K. Lin, L. Damico-Beyer, J. Kim, H. Taylor 424 P205 Evaluation of drug reactions to anti-neoplastic agents in Phase I clinical trials M. Bupathi, J. Hajjar, K. Hess, S. Bean, D. Karp, F. Meric-Bernstam, A. Naing 425 P206 Serum levels of CCL22 and CCL25 might predict skin rash induction the commonest adverse event by bendamustine in the treatment of malignant lymphoma Y. Terui, R. Kuniyoshi, Y. Mishima, K. Hatake 426 P207 Hematotoxicity potential of new drug candidates measured in hematopoietic progenitors in bone marrow samples J. Ballesteros, D. Primo, P. Hernandez, A. Robles, A.B. Espinosa, E. Arroyo, V. Garcia-Navas, J. Sanchez-Fenoy, M. Jimenez, M. Gaspar, J.L. Rojas, J. Martinez-Lopez, J. Gorrochategui 427 Scientific programme – details lix Friday 21 November 2014 09:00–10:30 Poster Viewing Plenary Session 8 11:00–13:00 Targeting RAS and Other Driver Oncogenes Chairs: J.A. Engelman (USA) and M. Barbacid (Spain) Poster area Auditorium Abstract number 11:00 Targeting KRAS driven lung and pancreatic adenocarcinoma M. Barbacid (Spain) 11:20 Systematic interrogation of vulnerabilities in KRAS driven cancers W. Hahn (USA) Key objectives: 1. Understand the concept of synthetic lethality. 2. Understand systematic genetic screens to identify targets. 3. Understand the role of innate immune regulators in KRAS induced tumorigenesis. 11:40 Targeting synthetic lethal partners of KRAS J. Luo (USA) Main objectives: 1. To inform the participants about therapeutic strategies in targeting KRAS mutant cancer. 2. To inform the participants about the concept of synthetic lethality and its therapeutic utilities. 3. To provide the participants examples of synthetic lethal interactions with the KRAS oncogene. Take home messages: 1. Current difficulties in treating KRAS mutant tumours warrant exploration of new therapeutic strategies. 2. Synthetic lethality is a powerful approach for identifying functional vulnerabilities in cancer cells. 3. Synthetic lethal partners of the KRAS oncogene could be potential targets for drug discovery. 12:00 ORAL PRESENTATION: Clinical acquired resistance to combined RAF/EGFR or RAF/MEK inhibition in BRAF mutant colorectal cancer (CRC) patients through MAPK pathway alterations R. Corcoran, E.M. Coffee, E. Van Allen, L.G. Ahronian, N. Wagle, E.L. Kwak, J.E. Faris, A.J. Iafrate, L.A. Garraway, J.A. Engelman 12:15 LATE BREAKING ABSTRACT: Antitumor activity of ASP8273, an irreversible mutant selective EGFR-TKI, in NSCLC patients with tumors harboring EGFR activating mutations and T790M resistance mutation H. Murakami, H. Nokihara, T. Shimizu, T. Seto, A. Keating, A. Krivoshik, K. Uegaki, S. Morita, K. Nakagawa, M. Fukuoka 428 9LBA 12:25 LATE BREAKING ABSTRACT: Interim phase 2 results of study CO-1686-008: A phase 1/2 study 10LBA of the irreversible, mutant selective, EGFR inhibitor rociletinib (CO-1686) in patients with advanced non small cell lung cancer J. Soria, L.V. Sequist, J.W. Goldman, H.A. Wakelee, S.M. Gadgeel, A. Varga, H.A. Yu, B.J. Solomon, S.H. Ou, V. Papadimitrakopoulou, G.R. Oxnard, L. Horn, R. Dziadziuszko, B. Chao, A.I. Spira, S. Liu, T. Mekhail, S. Matheny, J. Litten, R.D. Camidge 12:35 LATE BREAKING ABSTRACT: Phase I study of the selective BRAFV600 inhibitor 11LBA encorafenib (LGX818) combined with cetuximab and with or without the a-specific PI3K inhibitor alpelisib (BYL719) in patients with advanced BRAF mutant colorectal cancer J. Tabernero, R. van Geel, J.C. Bendell, A. Spreafico, M. Schuler, T. Yoshino, J.P. Delord, Y. Yamada, M.P. Lolkema, J.E. Faris, F.A.L.M. Eskens, S. Sharma, R. Yaeger, H.J. Lenz, Z. Wainberg, E. Avsar, A. Chatterjee, S. Jaeger, T. Demuth, J.H.M. Schellens 12:45 Discussion Late Breaking Abstracts J.A. Engelman (USA) lx Scientific programme – details Poster Sessions Poster area Drug Synthesis Poster board Abstract number P001 Development of extracellular signal-regulated kinase 5 (ERK5) inhibitors for anti-cancer therapy S. Myers, N. Martin, R. Bawn, T. Blackburn, L. Barrett, T. Reuillon, B. Golding, R. Griffin, T. Hammonds, I. Hardcastle, H. Leung, D. Newell, L. Rigoreau, A. Wong, C. Cano 429 P002 Design and structure–activity relationships of highly potent and bioavailable imidazolinone FASN KR domain inhibitors G. Bignan, R. Alexander, J. Bischoff, P. Connolly, M. Cummings, S. De Breucker, N. Esser, E. Fraiponts, R. Gilissen, B. Grasberger, B. Janssens, T. Lu, D. Ludovici, L. Meerpoel, C. Meyer, M. Parker, D. Peeters, C. Rocaboy, C. Schubert, K. Smans 430 Molecular Targeted Agents II Poster board Abstract number P003 Real-time pharmacokinetic (PK) results from an ongoing randomized, parallel-dose phase 1 study of onapristone in patients (pts) with progesterone receptor (PR)-expressing cancers F. Lokiec, J. Bonneterre, A. Italiano, A. Varga, M. Campone, T. LeSimple, A. Leary, V. Dieras, K. Rezai, S. Giacchetti, S. Proniuk, A. Bexon, E. Gilles, J. Bisaha, A. Zukiwski, P. Cottu 431 P004 ODM-203, a novel, selective and balanced FGFR and VEGFR inhibitor with strong anti-tumor activity in FGFR- and VEGFR-dependent cancer models T. Holmström, A. Moilanen, T. Linnanen, G. Wohlfahrt, S. Karlsson, R. Oksala, T. Korjamo, M. Björkman, S. Samajadar, S. Rajagopalan, S. Chelur, K. Narayan, R. Ramachandra, T. Anthony, S. Ds, M. Ramachandra, P. Kallio 432 P005 Genomic predictors of therapeutic sensitivity to TAS-119, a selective inhibitor of Aurora-A kinase H. Sootome, N. Fujita, A. Miura, T. Suzuki, H. Fukushima, S. Mizuarai, H. Hirai, T. Utsugi 433 P006 Bipolar androgen therapy for men with castration sensitive and castration resistant prostate cancer: Reversing resistance and maintaining sensitivity to androgen ablative therapies S.R. Denmeade, E.S. Antonarakis, M.A. Eisenberger, M.A. Carducci, H. Wang, C.J. Paller, J.T. Isaacs, M.T. Schweizer 434 P007 A pan-cancer tumor-derived epithelial-to–mesenchymal transition (EMT) signature determines patterns of drug sensitivity and enrichment in immune target expression following EMT M.P. Mak, P. Tong, L. Diao, P.K.S. Ng, Y. Fan, R.J. Cardnell, D.L. Gibbons, W.N. William, J.V. Heymach, K.R. Coombes, L.A. Byers, J. Wang 435 P008 Monitoring activity of RXDX-101 in Phase 1/2 patients using a pharmacodynamic assay for TrkA activation D. Murphy, H. Ely, R. Patel, G. Wei, A. Diliberto, R. Shoemaker, J. Christiansen 436 P009 PIM kinase inhibitor AZD1208 sensitises SCLC to BH3 mimetic AZD4320 R. Sloane, B. Bola, M. Lancashire, C. Hodgkinson, C. Morrow, K. Simpson, C. Dive 437 P010 MM-131: A bispecific antibody that inhibits c-Met signaling through avid binding to the EpCAM tumor antigen B.D. Harms, A. Lugovskoy, A. Abu-Yousif, A. Fulgham, M. Geddie, S.V. Su, N. Kohli, B. Johnson, K. Masson, U.B. Nielsen, B. Schoeberl, G. MacBeath 438 P011 PI3K/mTOR inhibitor VS-5584 targets cancer stem cells and prevents tumor regrowth after chemotherapy in preclinical models of small cell lung cancer V. Kolev, M. Padval, Q. Wright, J. Ricono, D. Weaver, J. Pachter, Q. Xu 439 P012 Phenotypic alteration in a highly metastatic variant of the MDA-MB-231 cell line: role of Annexin A1 Y. Tu, E. Fietz, J. Cameron, A. Stewart 440 Scientific programme – details Poster board lxi Abstract number P013 The role of methylation in metastasis of oral squamous cell carcinoma: understanding the OSCC methylome M. Clausen, L.J. Melchers, T. De Meyer, S. Denil, W. Criekinge, G.B. Wisman, J.L.N. Roodenburg, E. Schuuring P014 Targeting urokinase plasminogen activator for radioimmunotherapy using an antagonistic internalizing human antibody A. LeBeau, H.F. VanBrocklin P015 Notch3-targeted antibody drug conjugates have superior preclinical efficacy to Notch signaling inhibitors K.G. Geles, Y. Gao, L. Sridharan, A. Giannakou, T.T. Yamin, J. Golas, M. Charati, J. Lucas, K. Wang, S. Pirie-Shepherd, M. Roy, M. Follettie, A. Maderna, X. Li, L. Tchistiakova, H.P. Gerber, P. Sapra P016 Debio 1143 in combination with carboplatin and paclitaxel in patients with non-small cell lung cancer (NSCLC), triple-negative breast cancer (TNBC) and platinum-refractory epithelial ovarian cancer (EOC). Preliminary results of a Phase I dose-escalation study C. Le Tourneau, I. Ray-Coquard, N. Isambert, C.A. Gomez-Roca, P. Cassier, M.P. Sablin, E. Ruits, B. Gavillet, C. Zanna, P. Fumuleau, J.P. Delord P017 MEK inhibition enhances gemcitabine efficacy by increasing MDM2-mediated ubiquitination and degradation of RRM1 F. Vena, E. Li Causi, T. Hagemann, J.A. Hartley, S. Goodstal, D. Hochhauser P018 The cancer stem cell inhibitors VS-6063 (defactinib) and VS-5584 exhibit synergistic anticancer activity in preclinical models of mesothelioma Q. Xu, W.F. Tam, C.M. Vidal, V.N. Kolev, Y. Kadariya, C.W. Menges, J.R. Testa, J.A. Pachter P019 Novel, quantitative in vivo shRNA screening approach identifies new molecular targets to block cancer metastasis L. Willetts, R. Paproski P020 Exposure to EGFR inhibitors influences release of extracellular vesicles by tumor cells R. van der Meel, S.M. van Dommelen, P. de Corte, M. Coimbra, W.W. van Solinge, P. Vader, R.M. Schiffelers P021 Cytokine induces MIR-424 expression and modulates SOCS2/STAT5 signaling pathway in oral cancer S.G. Shiah, H.Y. Peng, S.L.C. Jin, J.Y. Chang, C.C. Kuo P022 Precise gene editing of mutant NRAS using CRISPR to determine sensitivity to trametinib C. Hose, N.D. Fer, M. Burkett, J. Connelly, E. Harris, J. Lih, M. Williams, D. Evans, T. Silvers, A. Monks, R. Parchment, B.A. Teicher, J.H. Doroshow, A. Rapisarda P023 Correlative and updated clinical endpoint analysis of a multicenter phase II trial of selumetinib (AZD6244) plus erlotinib in chemotherapy-refractory advanced pancreatic adenocarcinoma (PDAC) A.H. Ko, A.H. Tempero, T.B. Bekaii-Saab, P. Kuhn, R. Courtin, S. Ziyeh, S. Tahiri, R.K. Kelley, E. Dito, A. Ong, R. Linetskaya, A. Talasaz, A.P. Venook, W. Korn P024 eIF2alpha phosphorylation determines the adaptation of tuberous sclerosis complex mutant cells to stress and their response to anti-tumor therapies A. Koromilas, C. Tenkerian, J. Krishnamoorthy, R. Kamindla, U. Kazimierczak, S. Wang P025 Plasma metabolomic signature of novel signal transduction inhibitors from preclinical identification to clinical validation J.E. Ang, R. Pandher, Y. Asad, D.J. Skene, P. Workman, S. Eccles, J. De Bono, S. Kaye, U. Banerji, S. Davies, F.I. Raynaud P026 Monitoring therapy response and resistance mutations in circulating RNA and DNA of plasma from patients with malignant melanoma D. Enderle, K. Brinkmann, T. Koestler, S. Bentink, K.T. Flaherty, J. Skog, M. Noerholm P027 Role of MDM2 as therapeutic target in gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) F. Briest, I. Grass, F. Christen, F. Lewens, H. Freitag, D. Kaemmerer, J. Saenger, M. Hummel, B. Siegmund, P. Grabowski 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 lxii Poster board Scientific programme – details Abstract number P028 SF3B1 mutations induce disease relevant aberrant mRNA splicing in cancer and confer sensitivity to spliceosome inhibition S. Buonamici, K. Lim, J. Feala, R. Darman, K. Myint, E. Park, D. Aird, B. Chan, P. Fekkes, R. Furman, G. Keaney, P. Kumar, K. Kunii, X. Puyang, M. Thomas, Y. Mizui, M. Warmuth, P. Zhu, L. Yu, P. Smith P029 Preclinical pharmacology of AZD5312, a generation 2.5 antisense oligonucletotide targeting the androgen receptor with differentiated activity from enzalutamide B.R. Davies, A. Thomason, R. Ellston, H. Campbell, C. D’Cruz, A.M. Mazzola, T. Zhou, J. Schmidt, M. Jo, Y. Kim, A.R. McLeod, D. Blakey, N. Brooks P030 Combinational genome and proteome survey of therapeutic targets of hepatocellular carcinoma T. Yamada P031 Preclinical characterization of CC-115, a novel inhibitor of DNA-PK and mTOR kinase currently under clinical investigation D.S. Mortensen, K.E. Fultz, W. Xu, T. Tsuji, M. Hickman, M. Abbasian, G. Khambatta, B. Cathers, P. Worland, M.F. Moghaddam, J. Apuy, S. Richardson, J. Elsner, G. Shevlin, S. Perrin-Ninkovic, S. Canan, H.K. Raymon, R.K. Narla, S. Peng, S. Sankar P032 Molecular biomarkers of inflammatory signature in melanoma S. Ekmekcioglu, M. Shin-Sim, K. Tanese, V.G. Prieto, D.S. Hoon, E.A. Grimm P033 A phase I trial of dabrafenib (BRAF inhibitor) and pazopanib in BRAF mutated advanced malignancies S. Haraldsdottir, F. Janku, C. Timmers, S. Geyer, L.J. Schaaf, J. Sexton, J. Thurmond, V. VelezBravo, V.M. Stepanek, E. Bertino, K. Kendra, A. Mortazavi, V. Subbiah, M. Villalona-Calero, M. Poi, M. Phelps, M.H. Shah P034 Clinical sequencing of cancer in real-time by digital sequencing of cell-free DNA for tailoring targeted therapy in refractory cancer patients A. Talasaz, S. Mortimer, B.J. Schiller, G. Mei, S. Huang, D.S.B. Hoon, H. Eltoukhy P035 PTPN11 is a central node in intrinsic and acquired resistance to targeted cancer drugs A. Prahallad P036 Influence of warm and cold ischemia on molecular patterns in clinical biospecimen F.T. Unger, N. Lange, P.C. Uhlig, H. Juhl, K.A. David P037 Biomarker analysis in Phase 1b study of anti-cancer stem cell antibody Tarextumab (TAR) in combination with nab-paclitaxel and gemcitabine (Nab-P+Gem) demonstrates pharmacodynamic (PD) modulation of the Notch pathway in patients (pts) with untreated metastatic pancreatic cancer (mPC) A. Kapoun, E. O’Reilly, A. Cohn, J.C. Bendell, L. Smith, J.H. Strickler, W. Gluck, Y.W. Liu, B. Wallace, R. Tam, B. Cancilla, A. Brunner, D. Hill, L. Zhou, J. Dupont, C. Zhang, M. Wang P038 IGF2 drives IGF oncogenic signaling in HCC and emerges as a potential target for therapies I.M. Quetglas, R. Pinyol, D. Dauch, A. Portela, A. Villanueva, J. Peix, M. Higuera, A. Moeini, J. Zucman-Rossi, M. Esteller, V. Mazzaferro, L. Zender, J.M. Llovet P039 Two in one − Delivery of apoptotic signal into cancer cells by new class of TRAIL derived, fusion protein S.D. Pawlak, B.M. Zerek, P.K. Rozga, K. Bukato, M. Szymanik, M. Teska-Kaminska, A. Pieczykolan, A. Jaworski, M. Galazka, K. Poleszak, W. Strozek, J.S. Pieczykolan P040 Clinicopathologic implication of c-MYC gene copy number gain and overexpression in colorectal cancer K. Lee, Y. Kwak, G. Choe, W. Kim, D. Kim, S. Kang, H. Lee P041 OTX015, a novel BET-bromodomain (BET-BRD) inhibitor, is a promising anticancer agent for human glioblastoma L. Ouafik, C. Berenguer, M. Cayol, L. Astorgues-Xerri, M. Bekradda, E. Odore, K. Rezai, M.E. Riveiro, E. Cvitkovic P042 Transcriptional regulation of cancer stem cells marker CD133 by p53 E.K. Park, S.Y. Bang, S.A. Yi, J.W. Han 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 Scientific programme – details Poster board lxiii Abstract number P043 Screening of Champions predictive TumorGraft platform guides the clinical development of the selective dual BRAF-EGFR inhibitor CEP-32496 B. Ruggeri, M. Wabler, E. Bruckheimer, B. Wilkinson, B. Dorsey, S. Trusko, J. Friedman 471 P044 Do we hit the target? Phospho-reactome measurements determine efficacy of targeted therapies L. van ’t Veer, M. Moro, Z. Chen, P.R.E. Lee, B. Pan, D. Brunen, A. Prahalled, R. Bernards, J.P. Coppe 472 P045 FDG PET/CT as imaging biomarker in the era of molecular targeting therapies: sequential FDG PET/CT demonstrated biological response and acquisition of resistance to tyrosine kinase inhibitor therapy for renal cell carcinoma N. Nakaigawa, K. Namura, D. Ueno, U. Tateishi, T. Inoue, M. Yao 473 P046 Potentiation of oxaliplatin in colon cancer by JNK inhibition I. Vasilevskaya, M. Selvakumaran, L. Cabal-Hierro, P. O’Dwyer 474 P047 The synergistic anti-proliferative effect of combining the FGFR inhibitor, ARQ 087 with the AKT inhibitor, ARQ 092 in human cancer cell lines and PDX models E. Marchlik, Y. Yu, E. Chiesa, D. Dransfield 475 P048 FGFR2 targeting with allosteric inhibitor RPT835 I. Tsimafeyeu, F. Daeyaert, W. Yin, J. Ludes-Meyers, M. Byakhov, S. Tjulandin 476 P049 Jab1/Csn5: a new player driving the resistance to HER2-targeted therapies for breast cancer F. Claret, T. Vu, T.J. Shackleford, J.L. Allensworth, Q. Zhang, F.J. Esteva, E. Drakos, R. Zhang, L. Tian, G.Z. Rassidakis 477 P050 Pharmacological disruption of the Astrocytic Elevated Gene-1 (AEG1) in anticancer intervention: PB0412_3 (PB03) as a first-in-class AEG1 interacting agent J. Jimeno, G. Acosta, C. Teixido, C. Olbiol, N. Karachaliou, M.A. Molina, O. Villacañas, M. SanchezRonco, J. Bertran, A. Gimenez-Capitan, J.C. Monasterio, M. Taron, R. Rosell, F. Albericio 478 P051 The discovery and development of potent and specific anti-SialylTn antibodies for the treatment of solid tumors K. Meetze, D. Ghaderi, M. Zhang, I. Purnajo, J. Hermann, J. Fett, J. Behrens, A. Paula Galvao da Silva 479 P052 Identification of novel small molecules as selective PAK4 allosteric modulators (PAMs) by stable isotope labeling of amino acids in cells (SILAC) W. Senapedis, Y. Landesman, M. Schenone, B. Karger, S. Wu, S. Shacham, E. Baloglu 480 P053 In vitro and vivo evaluation of the pan FGFR inhibitor ARQ 087 and selective pan AKT inhibitor ARQ 092 in endometrial cancer: potential for combination therapy J. Meade, M.J. Wick, T. Vaught, R. Chavez, M. Rundle, K. Stanfield, B. Quattrochi, K.P. Papadopoulos, D.T. Dransfield, Y. Yu, E. Marchlik, E. Chiesa, A.W. Tolcher 481 P054 Repurposing the antihelminthic mebendazole as a hedgehog inhibitor A.R. Larsen, R.Y. Bai, J.H. Chung, A. Borodovsky, G.J. Riggins, F. Bunz 482 P055 Irreversible covalent pan-FGFR inhibitors are highly efficacious against FGFR-dependent cancers V.T. Phan, E. Verner, M. Gerritsen, J.M. Bradshaw, D.M. Goldstein, R.J. Hill, D. Karr, J. LaStant, P. Nunn, D. Tam, J. Shu, J.O. Funk, K. Brameld 483 P056 Treatment of advanced solid tumors with golvatinib (E7050) in combination with lenvatinib (E7080) E.L. Kwak, D. Juric, J.M. Cleary, G. Cote, J.F. Hilton, K.T. Flaherty, K. Wood, C. Rance, S. Barrett, G.I. Shapiro 484 P057 Glutathione S-transferases M1−5 reduce the aggressive behaviour in breast cancer by modulating the PI3K/AKT pathway A. Bergamaschi, S. Levy, A. Scott, J. Jeong, M. Kiefer, E. Beasley, J. Baker 485 P058 Development of small molecule activators of protein phosphatase 2A for the treatment of lung cancer J. Sangodkar, S. Mazhar, D. Kastrinsky, M. Ohlmeyer, G. Narla 486 lxiv Poster board Scientific programme – details Abstract number P059 EC-70124, a multi-kinase inhibitor, blocks NF-kB and STAT3 dependent signaling in prostate cancer stem cells G. Civenni, P. Costales, C. Garcı́a-Inclán, D. Albino, N. Longoni, L.E. Nuñez, F. Moris, G.M. Carbone, C.V. Catapano 487 P060 Development of a publicly accessible knowledgebase to facilitate decision support for clinical cancer genomics reporting K. Shaw, J. Zeng, A.M. Bailey, A. Johnson, V. Holla, E.V. Bernstam, J. Butts, J. Mendelsohn, G.B. Mills, F. Meric-Bernstam 488 P061 Development and clinical validation of a quantitative mass spectrometric assay for PD-L1 protein in FFPE NSCLC samples E. An, W. Liao, S. Thyparambil, J. Rodriguez, R. Salgia, I. Wistuba, J. Burrows, T. Hembrough 489 P062 Potent and selective inhibitors of the KRAS-signaling nanocluster protein, CNKSR1, block oncogenic KRAS signaling and mut-KRAS cell growth L. Kirkpatrick, G. Triana-Baltzer, M. Indarte, M. Scott, R. Lemos, G. Powis 490 P063 Development and characteristics of resistance to the HER family tyrosine kinase inhibitor AZD8931 V.G. Brunton, H. Creedon, M. Muir, T. Klinowska, K. McLeod, A. Byron 491 P064 Quantification of exportin-1 (XPO1) occupancy by selective inhibitors of nuclear export (SINE) M. Crochiere, B. Klebanov, E. Baloglu, O. Kalid, T. Kashyap, W. Senapedis, D. del Alamo, S. Tamir, D. McCauley, R. Carlson, M. Kauffman, S. Shacham, Y. Landesman 492 P065 Preclinical pharmacokinetic (PK)/pharmacodynamic (PD)/Efficacy modeling for MLN2480, an investigational pan-RAF kinase inhibitor, in A375 and SKMEL-2 human melanoma xenografts M. Patel, J. Chouitar, J. Mettetal, E. Gangolli, S. Balani, P. Shimoga, K. Galvin, W.C. Shyu, A. Chakravarty, C.J. Zopf 493 P066 LPA6 promotes growth and tumorigenicity of hepatocellular carcinoma via activation of PIM-3 protooncogene kinase C. Lopane, V. Goffredo, F. Dituri, F. De Santis, A. Filannino, R.C. Betz, Y.Y. Li, N. Mukaida, P. Winter, C. Tortorella, G. Giannelli, C. Sabbà, A. Mazzocca 494 P067 Divergent androgen regulation of UPR pathways drives prostate cancer Y.J. Arnoldussen, M. Storm, X. Sheng, M. Tesikova, Y. Jin, H.Z. Nenseth, S. Zhao, I.G. Mills, L. Fazli, P. Rennie, B. Risberg, H. Wæhre, H.E. Danielsen, G.S. Hotamisligil, F. Saatcioglu 495 P068 Prevalence of MET amplification, MET expression, and MET-related genomic alterations in nonsmall cell lung cancer (NSCLC) A.L. Ang, H. Yang, A.A. Anderson, R. Tang, M.A. Damore, R.D. Loberg 496 P069 Preclinical evaluation of dimeric IAP proteins inhibitor APG-1387, in triple negative breast cancer both in vitro and in vivo G. Wang, P. Min, H. Wang, Z. Du, M. Wu, H. Dong, D. McEachern, L. Liu, Y. Lin, X. Lin, J. Wen, Y. Zhang, L. Gu, M. Guo, Y. Zhai, S. Wang, D. Yang 497 P070 CDK4/6 inhibitor (LY2835219) exhibits potent anti-tumor activity in human lung cancer cell lines with intact retinoblastoma J.W. Goldman, E.B. Garon, D. Conklin, D.J.L. Wong, B. Wolf, D.D. Silveira, N. Kamranpour, S. Pitts, R.S. Finn, D.J. Slamon 498 P071 Phase 2a study of copanlisib, a novel phosphatidylinositol-3-kinase (PI3K) inhibitor, in patients with relapsed/refractory, indolent or aggressive lymphoma M. Dreyling, P.L. Zinzani, K. Bouabdallah, D. Bron, D. Cunningham, K. Linton, C. Thieblemont, E. Van den Neste, U. Vitolo, J. Grunert, M. Giurescu, S. Mappa, B.H. Childs, F. Morschhauser 499 P072 Triple blockade with LEE011, everolimus, and exemestane in women with ER+/HER2− advanced/metastatic breast cancer: results from a Phase Ib clinical trial A. Bardia, C. Chavez-MacGregor, S. Modi, M. Campone, B. Ma, M. Kittaneh, L. Dirix, M. Motta, V. Zhang, S. Bhansali, M.L. Fjaellskog, M. Oliveira 500 Scientific programme – details Poster board lxv Abstract number P073 Immunological STAT3 knockdown associated with anti-tumor activity in pre-clinical models translates to clinical samples, suggesting immune modulation contributes to the clinical activity of AZD9150, a therapeutic STAT3 ASO P. McCoon, R. Woessner, R. DuPont, K. Bell, M. Collins, L. Pablo, D. Lawson, P. Nadella, V. Jacobs, C. Womack, C. Reimer, D. Hong, J. Nemunaitis, Y.K. Kang, T.Y. Kim, H.Y. Lim, T. Okusaka, S. Nadano, C.C. Lin, P. Lyne P074 MI130004, an antibody–drug conjugate including a novel payload of marine origin: Evidences of in vivo activity P.M. Aviles, M.J. Guillen, J.M. Dominguez, M.J. Muñoz-Alonso, L.F. Garcia-Fernandez, M. Garranzo, V. Martinez, A. Francesch, S. Munt, C.M. Galmarini, C. Cuevas P075 UNC2025: A small molecule inhibitor of merTK with efficacy in mouse melanoma models S. Earp, D. Darr, A. Holtzhausen, A. Zimmermann, K. Clark, L. Hunter, N. Sharpless, X. Wang, S. Frye, D. Graham P076 Frequent loss-of-function mutations in MLK4 suppresses signaling in the JNK-cJUN-p21/p15 pathway to promote growth of colon cancer cells A. Marusiak, N. Stephenson, H. Baik, E. Trotter, Y. Li, E. Testoni, K. Blyth, S. Mason, L. Puto, C. Miller, T. Hunter, O. Sansom, J. Brognard P077 The anti-ErbB3 antibody, EV20, counteracts vemurafenib resistance in BRAF-mutated colorectal cancer stem cells G. Sala, P.R. Prasetyanti, D. Barcaroli, S. Volpe, E. Capone, C. Rossi, R. Carollo, M. Todaro, G. Stassi, J.P. Medema, S. Iacobelli, V. De Laurenzi P078 Phase (Ph) 1/2a study of TSR-011, a potent inhibitor of ALK and TRK, in advanced solid tumors including crizotinib-resistant ALK positive non-small cell lung cancer J. Sachdev, H.T. Arkenau, J.R. Infante, M.M. Mita, S.P. Anthony, R.B. Natale, S. Ejadi, K. Wilcoxen, V. Kansra, H. Laken, L. Hughes, R. Martell, G.J. Weiss P079 Amplification of D-type cyclin genes CCND2 and CCND3 confers an oncogene addiction phenotype in tumor cells and hypersensitivity to the CDK4/6 inhibitor LY2835219 S. Buchanan, X. Gong, M. Lallena, L. Chio, F. Merzoug, J. Dempsey, R. Beckman, C. Reinhard P080 A phase Ib trial of AMG386 and temsirolimus in patients with advanced sold tumors (PJC-008/NCI#9041) J.W. Chiu, S.J. Hotte, C.K. Kollmannsberger, D.J. Renouf, D.W. Cescon, D. Hedley, S. Chow, J. Moscow, M. Perry, I. Diaz-Padilla, D. Tan, H. Hirte, E. McWhirter, H. Chen, L.L. Siu, P.L. Bedard P081 Detecting gene amplification in circulating tumor cells of patients with gastric cancer for clinical trial Y. Mishima, S. Matsusaka, Y. Terui, M. Mikuniya, T. Takayama, N. Mizunuma, K. Hatake P082 Inhibition of STAT3 enhances the radiosensitising effect of temozolomide in malignant glioma cells in vitro and in vivo I. Kim, E. Choi, B. Cho, T. Han, S. Song, J. Kim, S. Paek 501 P083 ComboPredictor: identification of synergy biomarkers and enrichment within tumor sample populations M. Tomilo, A. Bankhead III, M.E. Urick, S. Eddy, R. Rickles, J. Ledell, E.T. Bowden 511 P084 Somatically mutated ABL1 represents an actionable and essential lung cancer survival gene E. Testoni, N.L. Stephenson, A.A. Marusiak, E.W. Trotter, A. Hudson, J. Brognard P085 Synergistic inhibition of ovarian and endometrial cancer cell lines using combined treatment of ARQ 092 and ARQ 087 in vitro and in vivo Y. Yu, E. Nakuci, E. Chiesa, C.R. Chen, E. Marchlik, D.T. Dransfield P086 Hypoxia inducible factor (HIF)-1a expression levels and p53 mutations are prognostic factors for survival in breast cancer patients treated with neoadjuvant chemotherapy M. Molina-Vila, S. Baulies, M. Gonzalez-Cao, N. Karachaliou, A. Rodriguez Capitan, S. Viteri, M. Cusido, R. Fabregas, C. Teixido, R. Rosell 512 502 503 504 505 506 507 508 509 510 513 514 lxvi Scientific programme – details Poster board Abstract number P087 TAS-115, a potent MET/VEGFR-targeted kinase inhibitor, is a new therapeutic approach for the treatment of bone metastasis of lung cancer A. Gomori, M. Sakuragi, A. Hashimoto, K. Ito, T. Haruma, T. Suzuki, H. Fujita, Y. Fujioka, K. Yonekura, T. Utsugi 515 P088 Different genetic profiles of resistant and sensitive patients with EGFR wild type NSCLC undergoing tyrosine kinase inhibitor (TKI) treatment P.U. Ulivi, E.C. Chiadini, A.D. Dubini, D.C. Calistri, M.P. Puccetti, M.A.B. Burgio, A.D. Delmonte, A.V. Verlicchi, A.G. Gamboni, M.P. Papi, W.Z. Zoli, L.C. Crinò, C.D. Dazzi 516 P089 Identification and characterization of selective MELK kinase inhibitors P. Carpinelli, N. Amboldi, D. Ballinari, S. Re Depaolini, U. Cucchi, G. Canevari, M. Caruso, R. Galli, D. Donati, A. Isacchi, E.R. Felder, A. Montagnoli, A. Galvani 517 P090 The HSP90 inhibitor, AT13387, overcomes resistance to crizotinib and second generation ALK inhibitors A. Courtin, A. Smyth, K. Hearn, V. Martins, J. Lewis, N. Thompson, J. Lyons, N. Wallis 518 P091 AD-O53.2 − novel biological anticancer therapeutic agent with a dual mechanism of action K. Poleszak, J. Pieczykolan, S. Pawlak, B. Zerek, P. Rozga, M. Teska-Kaminska, M. Galazka, M. Szymanik, A. Jaworski, A. Pieczykolan, K. Bukato, W. Strozek 519 P092 Validation of Nanostring for FGFR1 gene expression analysis in squamous non-small cell lung cancer (sqNSCLC) tissue C. Rooney, C. Geh, V. Williams, C. Cresswell, K. Al-Kadhimi, M. Dymond, T. French, P.D. Smith, C. Barrett, E.A. Harrington, E. Kilgour 520 P093 Tisular expression of the EGFR and N-Glycolyl GM3 Ganglioside as recognized by ior egf/r3 and 14F7 Mabs in triple negative breast cancer A. Calvo Pérez, R.I. Alvarez Goyanes, E. Rengifo Calzado, S. Franco Odio, R. Camacho Rodrı́guez 521 P094 Evaluation of the efficacy of melatonin in breast cancer metastasis mediated by ROCK-1 T. Borin, A.S. Arbab, L.C. Ferreira, G.B. Botaro, L.B. Maschio, G.M. Moschetta, N.N. Gonçalves, G.R. Martins, D.A.P.C. Zuccari 522 P095 Antitumor activity of mTOR kinase and DNA-PK inhibitor CC-115 in a mouse model of glioblastoma H. Raymon, S. Peng, J. Katz, C. Zhao, C. Phan, M.F. Moghaddam, K.E. Fultz, S. Sankar, D.S. Mortensen, R.K. Narla 523 P096 Targeting MET for a differentiation therapy of rhabdomyosarcoma K. Skrzypek, A. Jagiello, B. Szewczyk, T. Adamus, K. Miekus, M. Majka 524 P097 Analysing Src and phosphoinositide 3-kinase pathway inhibition in a radiotherapy context − pathway interplay and therapeutic response E. Rowling, N. Burrows, P. Elvin, K. Williams 525 P098 A Phase I study of the dual, intravenous (IV) phosphatidylinositol 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) inhibitor PF-05212384 in combination with irinotecan in patients (pts) with colorectal cancer (CRC) and other advanced solid tumors Z. Wainberg, J. Tabernero, M.A. Maqueda, S. Leong, G. Del Conte, C. Britten, N. Brega, C. Davis, B. Houk, K. Pierce, J. Vermette, L. Siu, I. Brana 526 P099 Is CRAF required for the maintenance of KRAS mutant non-small cell lung cancer? P. Russell, J. Wickenden, K. Cadwallader, S. Maguire, J. Joel, M. Stockdale, A. Chicas, D. Banka, R. Darman, S. Perino, P. Fekkes, P. Smith, P. Zhu, S. Buonamici, J. Moore 527 P100 A procaspase activator shows preclinical promise for glioblastoma therapy G. Riggins, A. Joshi, P.J. Hergenrother 528 P101 The Cancer Research UK Stratified Medicine Programme: From national screening to national trial I. Mirabile, E. Shaw, C. Lindsay, I. Walker, P.W.M. Johnson 529 Scientific programme – details Poster board lxvii Abstract number P102 Anti-angiogenic therapy induces T-lymphocyte infiltration associated with poor survival in metastatic renal cell carcinoma patients X.D. Liu, A. Hoang, L. Zhou, S. Kalra, A. Yetil, M. Sun, Z. Ding, S. Bai, P. German, X. Zhang, P. Tamboli, P. Rao, J. Karam, C. Wood, S. Matin, A. Zurita, N. Tannir, K. Sircar, E. Jonasch P103 In vitro and in vivo anti-tumor activity of ARQ 092, a potent and selective pan-AKT inhibitor Y. Yu, S. Cornell-Kennon, C.R. Chen, E. Marchlik, T. Isoyama, K. Tazaki, K. Fujiwara, D.T. Dransfield P104 Evaluation of a BRCAness signature as a predictive biomarker of response to veliparib/carboplatin plus standard neoadjuvant therapy in high-risk breast cancer: results from the I-SPY 2 trial A. Glas, J. Peeters, C. Yau, D.M. Wolf, A. Sanil, Y. Li, T. Severson, S. Linn, I-SPY 2 TRIAL Investigators, M. Buxton, A. DeMichele, N. Hylton, F. Symmans, D. Yee, M. Paoloni, L. Esserman, D. Berry, H. Rugo, O. Olopade, L.J. van ’t Veer P105 Detection of recurrent novel fusion transcripts from whole transcriptome sequencing of 120 primary breast cancer J. Kim, S.Y. Go, S.W. Kim, S. Lee, H.S. Lee, J. Park, M.J. Lee, H.G. Moon, D.Y. Noh, S. Kim, S. Kim, W. Han P106 Expression of c-MET in invasive meningioma S. Yun, J. Koh, K. Lee, A. Seo, K. Nam, G. Choe 530 531 532 533 534 P107 Tumor targeting and tissue distribution of solitomab (AMG 110; anti-EpCAM BiTE® ) in human EpCAM-positive tumor bearing mice F.J. Warnders, S. Waaijer, M.N. Lub-de Hooge, M. Friedrich, A.G.T. Terwisscha van Scheltinga, P. Deegen, S.K. Stienen, P.C. Pieslor, H.K. Cheung, J.G.W. Kosterink, E.G.E. de Vries P108 Shifts in microRNA expression pattern can facilitate the cancer cell stemness V. Halytskiy P109 Absolute quantitation of MET using mass spectrometry for clinical application: assay precision, stability, and correlation with MET gene amplification in FFPE tumor tissue F. Cecchi, W.L. Liao, S. Thyparambil, K. Bengali, J. Uzzell, M. Darflar, D. Krizman, J. Burrows, T. Hembrough, T. Veenstra, D.P. Bottaro, T. Karrison, L. Henderson, P. Xu, B. Rambo, S.Y. Xiao, L. Zhao, J. Hart, D. Catenacci P110 Development of a novel anti-tumor antibody targeting CXADR M. Kawada, H. Inoue, M. Kajikawa, M. Sugiura, S. Sakamoto, S. Urano, T. Masuda, A. Nomoto P111 Reversing the epithelial to mesenchymal transition with N-myc downstream regulated gene-1 and novel iron chelators in pancreatic cancer L. Fouani, Z. Kovacevic, D. Richardson 535 P112 Vemurafenib alters glucose utilization in BRAF-driven human melanoma cells M. Falck Miniotis, T. Delgado-Goni, S. Wantuch, P. Workman, R. Marais, M.O. Leach, M. Beloueche-Babari 540 P113 The abnormal bone remodeling associated with prostate cancer bone metastasis is attenuated by TAS115, the dual inhibitor for HGF/VEGF signaling H. Fujita, C. Matsumoto, K. Yonekura, K. Watanabe, M. Hirata, C. Miyaura, T. Utsugi, M. Inada P114 Tivantinib in combination with gemcitabine shows strong antitumor activity on mesothelioma cell lines and cytoskeletal effects via inhibition of actin M. Simonelli, P. Zucali, M. Suter, L. Rubino, A. Santoro, C. Carlo-Stella P115 MEK1/2 specific inhibitor, SMK-17 selectively induces apoptosis in b-catenin mutated tumors M. Kiga, A. Nakayama, Y. Sasazawa, Y. Shikata, H. Ikeda, E. Tashiro, M. Imoto P116 Preclinical studies of a dual Bcl-2/Bcl-xL inhibitor APG-1252 with strong anti-tumor efficacy and significantly reduced platelet toxicity H. Wang, G. Wang, Z. Du, M. Wu, D. McEachern, A. Aguilar, Y. Lin, X. Lin, J. Wen, L. Gu, M.I.N.G. Guo, Y. Zhai, S. Wang, D. Yang 541 536 537 538 539 542 543 544 lxviii Scientific programme – details Poster board Abstract number P117 MiRNAs related to KRAS mutational status in resectable non-small cell lung cancer S. Gallach, S. Calabuig-Fariñas, E. Jantus-Lewintre, D. Montaner, E. Escorihuela, J. Castellano, S. Figueroa, A. Blasco, C. Hernando, R. Guijarro, C. Camps 545 P118 The PI3Kbeta/delta inhibitor AZD8186 combines with the dual mTORC1/2 inhibitor AZD2014 to give comprehensive PI3K pathway inhibition and drive tumour regression in vivo B. Simon, U. Hancox, U. Polanska, L. Hanson, P. Dudley, R. Ellston, J. Maynard, M. Kraus, J. Curwen, T. Klinowska, L. Ward, F. Cruzalegui, S. Symeonides, K. Cronin 546 P119 Preclinical activity of Debio 1347, an oral selective FGFR1, 2, 3 inhibitor, in models harboring FGFR alterations A. Vaslin Chessex, C. Moulon, V. Nicolas-Métral, A. Ménétrey, H. Maby-El Hajjami, S. Rigotti, C. Zanna, G. Vuagniaux 547 P120 Development of a small molecule activator of protein phosphatase 2A for the treatment of prostate cancer K. McClinch, D. Callejas, M. Cooper, A. Stachnik, D. Kastrinsky, M. Ohlmeyer, M. Galsky, G. Narla 548 P121 A novel cancer marker and potential therapeutic target M.P. Parri, S.C. Campagnoli, A.G. Grandi, A.S. Santi, E.D.C. De Camilli, G.V. Viale, P.C. Chiarugi, L.T. Terracciano, P.P. Pileri, R. Grifantini 549 New Therapies with Pleiotropic Activity Poster board Abstract number P122 Nupharidine inhibits NF-kB activity, induces apoptosis and has synergistic cytotoxic activity with cisplatin and etoposide J. Gopas, J. Ozer, N. Eisner, D. Benharroch, A. Golan-Goldhirsh 550 P123 Phase 1B study of CC-486 (oral azacitidine) in tumors associated with a viral etiology D.D. Von Hoff, N. Isambert, J. Lopez-Martin, P.N. Munster, D.W. Rasco, J.C. Bendell, J.H.M. Schellens, J. Tomaro, R. Sarmiento, K. Liu, A. Nguyen, G.L. Bray, S.R. Hatty, J.F. DiMartino, C. Le Tourneau 551 P124 Discovery of an unexpected vulnerability of cancer stem-like cells via a functional dissection of EMT biology Y. Feng, E.S. Sokol, C.A. Del Vecchio, S. Sanduja, J.H. Claessen, T.A. Proia, D.X. Jin, F. Reinhardt, H.L. Ploegh, Q. Wang, P.B. Gupta 552 P125 PRPF6, a tri-snRNP spliceosome protein, regulates the alternative splicing of a distinct oncogenic ZAK variant and promotes colon tumor growth R. Firestein, A. Adler, M. McCleland, M. Yaylaoglu, Z. Zhang, J. Liu, Z. Jiang 553 P126 Dual EZH2 and EHMT2 histone methyltransferase inhibition increases biological efficacy in breast cancer cells R. Brown, M. Fuchter, E. Curry, I. Green, S. Kandil, F. Cherblanc, L. Payne, N. Chapman-Rothe, E. Shamsaei, N. Srimongkolpithak, J. Snyder, M. Vedadi 554 P127 CB-5083, a first in class inhibitor of the AAA-ATPase p97/VCP, induces irresolvable ER stress that results in antitumor activity in solid and hematological tumor models F. Yakes, R. Le Moigne, S. Wong, D.J. Anderson, S. Djakovic, E. Valle, M.K. Menon, J. Rice, B. Yao, F. Soriano, J. Wang, S. Kiss von Soly, M. Chesi, P.L. Bergsagel, H.J. Zhou, M. Rolfe, D. Wustrow 555 P128 Antagonizing microRNA mediated epigenetic reprogramming as therapeutic strategy for aggressive prostate cancer C. Dallavalle, D. Albino, G. Civenni, P. Ostano, M. Mello-Grand, R. Garcia-Escudero, G. Chiorino, C.V. Catapano, G.M. Carbone 556 P129 A rational approach for discovery of inhibitors of YAP−TEAD interaction L. Chene, A. Soude, C. Valaire, S. Delaporte, S. Jacquet, Y. Cambet, I. Braccini, M. Barth, C. Montalbetti, P. Broqua, C. Fromond 557 Scientific programme – details Poster board lxix Abstract number P130 RNA G-quadruplexes cause eIF4A-dependent oncogene translation in cancer H. Wendel, K. Singh, A. Wolfe, Y. Zhong, P. Drewe, J. Porco, J. Pelletier, G. Rätsch P131 Development of a unique biologic for treating cysteine-dependent malignancies E. Stone, S. Cramer, A. Saha, S. Tiziani, J. Digiovanni, G. Georgiou P132 ZEN3365 is a novel BET bromodomain inhibitor for the treatment of hematologic malignancies and solid tumors K.G. McLure, R. Jahagirdar, O.A. Kharenko, E.M. Gesner, E. Campeau, D. Gilham, J. Wu, L. Tsujikawa, S. Attwell, C. Calosing, N. Sharma, J. Tobin, H.C. Hansen P133 Nonclinical characterization of the first in class investigational ubiquitin activating enzyme inhibitor MLN7243 in cellular and in vivo models of cancer in support of a phase I study M. Milhollen, M. Hyer, J. Ciavarri, T. Traore, D. Sappal, J. Huck, J. Shi, J. Duffy, J. Gavin, J. Brownell, Y. Yang, B. Stringer, Y. Ishii, E. Koenig, A. Lublinsky, R. Griffin, C. Xia, J. Powe, P. Fleming, N. Bence P134 Lysophosphatidic acid-induced breast cancer metastasis depends on LPA1/ZEB1/miR-21-activation pathway D. Sahay, R. Leblanc, J. Ribeiro, P. Clezardin, O. Peyruchaud P135 Hsp90 pharmacoproteomics: Harnessing pleiotropy for therapeutic synergy R. Goldstein, G. Chiosis, L.C. Cerchietti, A.M. Melnick P136 OTX015, a novel BET-BRD inhibitor is active in non-small-cell lung cancer cell (NSCLC) lines harboring different oncogenic mutations M. Riveiro, L. Astorgues-Xerri, N. Ijaz, M. Bekradda, R. Vazquez, R. Frapolli, A. Rinaldi, I. Kwee, E. Cvitkovic, E. Raymond P137 Preclinical evaluation of OTX015, a novel BET-BRD inhibitor, on small cell lung cancer (SCLC) cell lines N. Ijaz, L. Astorgues-Xerri, E. Odore, M. Bekradda, E. Cvitkovic, K. Noel, E. Raymond, M. Riveiro P138 GNS396 and analogues are potent new small molecules to target and kill chemotherapy-resistant subpopulation cells in acute myeloid leukemia F. Bassissi, R. Castellano, E. Josselin, C. Motersino, L. Pouyet, A. Goubard, A. Rostouin, G. Nicolas, S. Brun, J. Courcambeck, C. Dubray, T. Prébet, N. Vey, A. Béret, P. Halfon, Y. Collette P139 OTX015, a BET-bromodomain (BET-BRD) inhibitor, potentiates the in vitro effects of chemotherapy drugs and targeted agents in human leukemic cell lines L. Astorgues-Xerri, C. Canet-Jourdan, M. Bekradda, E. Cvitkovic, P. Herait, E. Raymond, M. Riveiro P140 The BET bromodomain inhibitor OTX015 shows synergy with several anticancer agents in preclinical models of mantle cell lymphoma (MCL) and multiple myeloma (MM) E. Bernasconi, C. Tarantelli, E. Gaudio, I. Kwee, A. Stathis, E. Riveiro, P. Herait, E. Cvitkovic, E. Zucca, F. Bertoni P141 Biological consequences of selective inhibition of the first BET bromodomain J.G. Seitzberg, M.H. Hansen, T.T.A. Kronborg, C.R. Underwood, V. Polyak, G. Friberg, B. Tonnesen, M. Nørregaard-Madsen, L. Teuber, T. Franch, S. Nielsen P142 Modulation of chromatin-related processes in DNA damage response as a potential strategy to treat acute myeloid leukemia K. Chomej, M. Lagergren Lindberg, D. Zong, T. Juntti, L. Kanter, L. Stenke, R. Lewensohn, K. Viktorsson, P. Hååg P143 Novel potent inhibitors of the Histone Demethylase KDM1A: Synthesis, pharmacological evaluation and in vivo activity M. Varasi, O. Botrugno, A. Cappa, R. Dal Zuffo, P. Dessanti, A. Mai, A. Mattevi, C. Mercurio, G. Meroni, S. Minucci, F. Thaler, P. Trifiro’, S. Valente, P. Vianello, M. Villa P144 Oral panobinostat in patients with advanced tumors and impaired renal function: Relationship between pharmacokinetics and key safety parameters M. Porro, S. Sharma, P.O. Witteveen, M.P. Lolkema, D. Hess, H. Gelderblom, S.A. Hussain, E. Waldron, S. Valera, S. Mu 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 lxx Poster board Scientific programme – details Abstract number P145 Suppression of c-Myc oncogene and hematological tumor growth by a novel benzazepine BET inhibitor K.A. Gelato, P. Lejeune, A.E. Fernández-Montalván, R. Neuhaus, N. Schmees, S. Siegel, H. Weinmann, V. Gekeler, B. Haendler P146 M-COPA, a Golgi disruptor, inhibits cell surface expression of MET protein and exhibits antitumor activity against MET-addicted cancers Y. Ohashi, M. Okamura, A. Hirosawa, A. Akatsuka, I. Shiina, K. Yoshimatsu, T. Yamori, S. Dan P147 SF3B1 mutations are associated with alternative splicing in ER-positive breast cancer S. Maguire, A. Leonidou, P. Wai, C. Marchio, C.K.Y. Ng, B. Weigelt, A. Sapino, A. Vincent-Salomon, J.S. Reis-Filho, R. Natrajan P148 Novel inhibitors of peritoneal seeding Y. Shen, X.L. Li, X. Lu, S. Kuwada P149 Characterization of the cellular mechanism of action of the first in class investigational inhibitor of the Ubiquitin Activating Enzyme, MLN7243 M. Milhollen, D. Sappal, J. Duffy, K. Hoar, J. Huck, P. Sha, E. Koenig, M. Hyer, J. Ciavarri, N. Bence P150 Invadopodia are required for cancer cell extravasation and are a therapeutic target for metastasis H.S. Leong, A.E. Robertson, K. Stoletov, S.J. Leith, C.A. Chin, A.E. Chien, M.N. Hague, A.L. Ablack, K. Carmine Simmen, V.A. McPherson, C.O. Postenka, E.A. Turley, S.A. Courtneidge, A.F. Chambers, J.D. Lewis P151 Eph/ephrin-B interactions modulate a BAFF-R/TACI dependent survival of chronic lymphocytic leukemia (CLL) cells mediated in vitro by bone marrow stromal cells L.M. Alonso-Colmenar, A.G. Zapata, P. Fortea, M.A. Flores, F. Ortuño, G. Soler, M.D. Garcı́a, J. Garcı́a-Cantalejo P152 Evaluation of the pan-BET-bromodomain inhibitor OTX015 as a single agent and in combination with everolimus (RAD001) in triple-negative breast cancer models R. Vázquez, L. Astorgues-Xerri, M.E. Riveiro, M. Di Marino, L. Beltrame, M. Bekradda, E. Cvitkovic, E. Erba, R. Frapolli, M. D’Incalci P153 Identification of genomic and chromatin features that predict transcriptional response to BET bromodomain inhibition J. Mertz, H.R. Huang, N. Follmer, A. Reddy, R. Centore, B. Bryant, C. Hatton, H. Franco, W.L. Krause, R. Sims III P154 Rational for targeting chromatin-modifying genes in clear-cell renal cell carcinomas G. Malouf, J. Zhang, D. Khayat, X. Su, J.P. Spano P155 The 8p11 amplicon in luminal breast cancers harbors multiple interacting epigenome modifying oncogenes: implications for epigenome-targeted therapy S. Ethier, J. Irish, R. Wilson, B. Turner P156 The correlation between EMT and cancer stemness in lung adenocarcinoma affects on its prognosis T. Sowa, T. Menju, T. Nakanishi, K. Shikuma, N. Imamura, T. Yamada, A. Aoyama, M. Sato, T. Sato, F. Chen, M. Sonobe, M. Omasa, H. Date, T. Sozu P157 The investigational HSP90 inhibitor ganetespib displays robust single agent activity in gastric cancer models both as monotherapy and in combination with standard of care therapeutics S. He, C. Zhang, J.P. Jimenez, J. Sang, M. Sequeira, D. Smith, J. Acquaviva, M. Nagai, R. Bates, D.A. Proia P158 Phase I study of pan-histone deacetylase inhibitor abexinostat in combination with cisplatin in patients with advanced solid tumors M. Campone, N. Isambert, R. Sabatier, H. Castanie, S. Zanetta, I. Sudey, F. Cantero, J. Pauly, E. Leroux, S. Malasse, A. Goncalves P159 Cellular pharmacokinetics and molecular pharmacodynamics studies of the BRD-BET inhibitor OTX015 in sensitive and resistant leukemic cell lines E. Odore, L. Astorgues-Xerri, M. Bekradda, E. Cvitkovic, P. Herait, F. Lokiec, K. Rezai, M. Riveiro 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 Scientific programme – details Poster board lxxi Abstract number P160 Neddylation as a therapeutic target in refractory pediatric malignancies: Evaluation of the activating enzyme inhibitor MLN4924 Y. Ruan, A. Jayanthan, T. Cooper, A. Narendran 588 P161 N-myc downstream regulated gene 1 (NDRG1) as a novel anti-angiogenic and therapeutic target for VEGF/VEGF receptor signaling by vascular endothelial cells K. Watari, A. Shinoda, T. Shibata, A. Kawahara, T. Nakama, S. Yoshida, M. Kage, M. Kuwano, M. Ono 589 P162 A dose dense schedule improves antitumor activity of trabectedin in myxoid liposarcoma with type III FUS-CHOP chimera S. Uboldi, R. Frapolli, E. Bello, S. Brich, F. Bozzi, R. Sanfilippo, P.G. Casali, A. Gronchi, C.M. Galmarini, J.M. Fernandez Sousa-Faro, S. Pilotti, M. D’Incalci 590 P163 Mechanistic analysis of reversible FASN inhibition in preclinical tumor models identifies highly susceptible tumor types and enriches biomarker discovery for clinical applications T.S. Heuer, R. Ventura, J. Waszczuk, K. Mordec, J. Lai, M. Fridlib, R. Johnson, L. Hu, H. Cai, A. Wagman, M. O’Farrell, D. Buckley, G. Kemble 591 P164 TAS-116, a highly selective inhibitor of heat shock protein 90a/b, inhibits tumor growth in biliary tract cancer mouse models S. Ohkubo, H. Muraoka, Y. Kodama, K. Ito, S. Ito, A. Hashimoto, C. Yoshimura, T. Utsugi 592 P165 Strategies to overcome resistance to BET bromodomain inhibitor in KRAS/LKB1 mutant NSCLC M. Soucheray, E. Kikuchi, I. Pulido, E. Akbay, J.H. Becker, C.L. Christensen, N. Johnson, T.B. Patel, J. Carretero, K.K. Wong, T. Shimamura 593 P166 Identification of novel EZH2 inhibitor scaffolds X. Espanel, L. Chene, A. Soude, S. Estevez, V. Adarbes, B. Loillier, B. Boubia, P. Masson, C. Montalbetti, P. Broqua, C. Fromond 594 P167 Improving specificity of epigenetic therapy through combined targeting of DNA and histone methylation T. Sato, M. Cesaroni, J. Jelinek, J.P. Issa 595 th 26 EORTC–NCI–AACR Symposium on Molecular Targets and Cancer Therapeutics Tuesday 18 November 2014 Plenary Session 1 Tuesday 18 November 2014 Tuesday 18 November 2014 15:15–17:30 PLENARY SESSION 1 Is the Genomic Landscape Changing the Outcome for Cancer Patients? 1 ORAL PRESENTATION Feasibility of large-scale genomic testing to facilitate enrollment on genomically-matched clinical trials F. Meric-Bernstam1 , L. Brusco2 , S. Kopetz3 , M. Davies4 , M.J. Routbort5 , S.A. Piha-Paul2 , R. Alvarez6 , S. Khose2 , J. DeGroot7 , V. Ravi8 , F. Janku2 , D. Hong2 , Y. Li9 , R. Luthra5 , K.P. Patel5 , R. Broaddus10 , K. Shaw11 , J. Mendelsohn11 , G.B. Mills12 . 1 The University of Texas MD Anderson Cancer Center, Investigational Cancer Therapeutics, Houston Texas, USA; 2 The University of Texas MD Anderson Cancer Center, Investigational Cancer Therapeutics, Houston Texas, USA; 3 The University of Texas MD Anderson Cancer Center, GI Medical Oncology, Houston Texas, USA; 4 The University of Texas MD Anderson Cancer Center, Melanoma Medical Oncology, Houston Texas, USA; 5 The University of Texas MD Anderson Cancer Center, Hematopathology, Houston Texas, USA; 6 The University of Texas MD Anderson Cancer Center, Breast Medical Oncology, Houston Texas, USA; 7 The University of Texas MD Anderson Cancer Center, Neuro-Oncology, Houston Texas, USA; 8 The University of Texas MD Anderson Cancer Center, Sarcoma Medical Oncology, Houston Texas, USA; 9 The University of Texas MD Anderson Cancer Center, Biostatistics, Houston Texas, USA; 10 The University of Texas MD Anderson Cancer Center, Pathology, Houston Texas, USA; 11 The University of Texas MD Anderson Cancer Center, Institute for Personalized Cancer Therapy, Houston Texas, USA; 12 The University of Texas MD Anderson Cancer Center, Systems Biology, Houston Texas, USA Background: We sought to determine the feasibility of performing standardized somatic mutation analysis for patients with a variety of advanced cancer types at a major cancer center. We report the experience with the first 2000 patients who underwent testing on a genomic testing protocol, including the frequency of actionable alterations across tumor types, subsequent enrollment on clinical trials, and the challenges for trial enrollment. Materials and Methods: From February 2012 to July 2013, after informed consent, 2000 patients underwent genomic testing using a ‘hot-spot’ platform, an 11-gene Sequenom assay (251 patients) or 46gene Ion Torrent (Ampliseq) assay (1749 patients). Of the 46 genes tested, 35 were considered ‘potentially actionable’, as these genes might be directly or indirectly targeted by approved or investigational agents. TP53 was not considered actionable. Trials that require a genomic alteration for enrollment were considered ‘genotype-selected’, and biomarker-unselected trials using agents relevant to a genomic alteration were designated ‘genotype-relevant’; either type of trial was considered ‘genomically-matched’. Results: Of the 2000 patients, 38.4% had at least one potentially actionable alteration. The most commonly mutated potentially actionable genes were PIK3CA (12.8%), KRAS (11.3%), BRAF (7%), NRAS (4.2%), EGFR (1.8%), AKT1 (1.4%) and PTEN (hot-spot mutations, 1.2%). Patients with mutations in potentially actionable genes were more likely to be treated on clinical trials than those without mutations (30% vs 25%, p = 0.0046). Of the patients with mutations in potentially actionable genes, 7% were treated on genotype-selected trials, 5% were treated on genotype-relevant trials and 20% were treated on other therapeutic trials. Of 97 patients treated on genotype-matched trials, 67% had PIK3CA/AKT1/PTEN or BRAF mutations. Eighty-five patients with PI3K/AKT1/PTEN/BRAF mutations had a discussion about genotype-matched trials documented but were not enrolled; most common reasons were election of treatment closer-to-home (22%), non-investigational therapy (20%), poor performance status (13%), ineligibility for trials for other reasons (17%), stable disease (9%), lack of relevant trials (8%) or enrollment in other trials (6%). Discussion: Broad implementation of multiplex hot-spot testing is feasible and identifies potentially actionable alterations. Patients with actionable alterations are more likely to be enrolled on clinical trials; however, only a small portion of patients with actionable alterations were enrolled on genotype-matched trials. Novel solutions to increase awareness of test results and therapeutic implications, increased awareness of existing trials such as clinical trial alert systems, and increased access to targeted drugs through basket trials and novel just-in-time clinical trial systems are needed. 3 th 26 EORTC–NCI–AACR Symposium on Molecular Targets and Cancer Therapeutics Wednesday 19 November 2014 Plenary Session 2 Wednesday 19 November 2014 Wednesday 19 November 2014 13:15–15:20 PLENARY SESSION 2 Proffered Paper Session 2 ORAL PRESENTATION Safety and early evidence of activity of a first-in-human phase I study of the novel cancer stem cell (CSC) targeting antibody OMP-52M51 (anti-Notch1) administered intravenously to patients with certain advanced solid tumors A. Patnaik1 , P. LoRusso2 , P. Munster3 , A.W. Tolcher1 , S.L. Davis4 , J. Heymach5 , R. Ferraroto5 , L. Xu6 , A.M. Kapoun6 , L. Faoro6 , J.A. Lewicki6 , J. Dupont6 , S.G. Eckhardt4 . 1 South Texas Accelerated Research Therapeutics (START), San Antonio TX, USA; 2 Wayne State University Karmanos Cancer Institute Detroit MI, Center for Translational Therapeutics, Detroit MI, USA; 3 University of California San Francisco, Department of Medicine, San Francisco CA, USA; 4 University of Colorado-Denver, University of Colorado Cancer Center, Aurora CO, USA; 5 MD Anderson Cancer Center, Houston TX, USA; 5 Oncomed Pharmaceuticals Inc., Redwood City CA, USA Background: The Notch pathway plays a key role in embryonic development, the regulation of stem and progenitor cells, and is implicated in human cancer. Notch1 (N1) signaling is activated by various mechanisms including N1 activating mutations in certain solid tumors. OMP-52M51 is a humanized IgG2 antibody that inhibits the signaling function of N1. As such, OMP-52M51 is a novel anti-cancer agent that inhibits tumor growth through direct actions on tumor cells, including CSCs, and effects on tumor angiogenesis. Materials and Methods: A phase I dose escalation and expansion study was initiated in patients (pts) with certain advanced solid tumors (cholangiocarcinoma, breast (BC), colorectal (CRC), esophageal, gastric, pancreatic, and small cell lung cancers) that have rates of N1 activation between 12−29%. OMP-52M51 was administered intravenously to study safety, pharmacokinetics (PK), pharmacodynamics, preliminary efficacy, and to determine the maximum tolerated dose. The trial has a N1 IHC biomarker selected expansion cohort. Results: 20 pts have been enrolled in 5 cohorts at doses of 0.25, 0.5, 1, and 2.5 mg/kg every 4 weeks (Q4W) and 2.5 mg/kg every 3 weeks (Q3W). The most frequent adverse events (AE) were: mild to moderate diarrhea (75%), fatigue (65%), and nausea (40%). Grade 3 or higher AEs included diarrhea (20%), increased alkaline phosphatase (15%), and pain (15%). Diarrhea was manageable. Two pts experienced dose-limiting toxicity (DLTs) AEs with gr 3 fatigue (2.5 mg/kg Q4W) and gr 3 diarrhea (2.5 mg/kg Q3W). PK exhibited dose-dependent clearance with a T 12 of 4 days at 2.5 mg/kg. One pt with an N1 activating mutation in adenoid cystic carcinoma (ACC) had partial response (38% decrease in lesions) after 2 doses. 1 BC and 1 CRC pt had stable disease (110 days and 280 days, respectively). Sequencing the cell-free DNA from the CRC pt found a loss-of-function mutation in FBXW7, a negative regulator of N1. A prototype immunohistochemistry (IHC) test showed high levels of activated N1 in the ACC and CRC pts. Biomarker analyses revealed reductions in circulating tumor cells with OMP-52M51 treatment. The MTD has not been established. Conclusions: OMP-52M51 is generally well tolerated. Diarrhea is the primary toxicity of this antibody. Potential early efficacy consistent with the predictive biomarker hypothesis is noted. Enrollment continues. Updated efficacy, safety, and PK results will be presented. Clinical trial information: NCT01778439. 7 3 ORAL PRESENTATION Afuresertib (GSK2110183), an oral AKT kinase inhibitor, in combination with carboplatin and paclitaxel in recurrent ovarian cancer S. Blagden1 , A. Hamilton2 , L. Mileshkin3 , M. Hall4 , T. Meniawy5 , S. Wong6 , S. Anandra2 , M. Buck5 , D. McAleer7 , B.A. Reedy7 , R.B. Noble7 , D.A. Smith8 , S.R. Morris9 , H. Gabra1 . 1 Imperial College Hammersmith Hospital Campus, Department of Medical Oncology, London, United Kingdom; 2 Royal Women’s Hospital, Department of Medical Oncology, Parkville, Australia; 3 Peter MacCallum Cancer Centre, Department of Cancer Medicine, East Melbourne, Australia; 4 Mount Vernon Cancer Centre, Department of Medical Oncology, Middlesex, United Kingdom; 5 Sir Charles Gairdner Hospital, Department of Medical Oncology, Perth, Australia; 6 Western Hospital, Department of Oncology, Footscray, Australia; 7 GlaxoSmithKline, GSK Alternative Discovery & Development, Upper Merion, USA; 8 GlaxoSmithKline, GSK Clinical Pharmacology, Modelling and Simulations; 9 GlaxoSmithKline, GSK Alternative Discovery & Development, Research Triangle Park, USA Background: Afuresertib is a highly selective oral pan-AKT kinase inhibitor in development for patients with hematologic and solid malignancies. Preclinically, AKT inhibition by afuresertib can reverse platinum resistance in ovarian cancer cell lines isolated from patients with platinum-resistant ovarian cancer. Materials and Methods: Study objectives were to evaluate the maximum tolerated dose (MTD), pharmacokinetics (PK), and clinical activity of afuresertib in combination with carboplatin & paclitaxel in patients (pts) with recurrent, platinum sensitive, resistant or refractory epithelial ovarian cancer (EOC). This two part study included a dose escalation (part1) and expansion phase (part2). Part 1 evaluated the PK and toxicity profile of increasing doses [50 mg-150 mg daily] of afuresertib with IV carboplatin (AUC 5) & paclitaxel (175 mg/m2 ) q3 weekly for up to 6 cycles followed by afuresertib monotherapy until progression. Efficacy was evaluated using GCIG CA125 and RECIST 1.1 criteria. Results: Part 1 has completed enrolment (n = 29; mean age 59), 23 of the 29 pts had platinum-resistant or refractory EOC with a median platinum-free interval of 4 months. Pts had a median of 3 prior therapies; 17% had 6 prior therapies. Dose-limiting-toxicities were grade 3 rash (n = 3, at 125 mg (1) and 150 mg (2)) and grade 3 syncope (1) at 125 mg afuresertib. MTD of afuresertib with carboplatin & paclitaxel was defined as 125 mg daily. The most frequent adverse events (AEs) regardless of relatedness were diarrhea (72%), nausea (72%) and fatigue (69%); all Grade 2. The most common AEs grade 3 were neutropenia (40%), hyperglycemia (10%), thrombocytopenia (7%), and ascites (7%). There was no clinically relevant PK interaction between afuresertib and paclitaxel. The ORR (overall response rate) regardless of dose was 60% (CA125) and 29% (RECIST). For those patients who received afuresertib at the MTD dose of 125 mg, the ORR was 50% by both GCIG CA125 and RECIST 1.1 criteria; the clinical benefit rate (RECIST partial responses plus stable disease of 6 months) was 63%. Conclusions: Afuresertib can be safely combined with carboplatin and paclitaxel at a MTD of 125 mg once daily. This triplet shows promising clinical activity in a heavily pretreated patient population. Part 2 is now open to pts with resistant or refractory EOC (in two separate cohorts) to further evaluate the safety and clinical efficacy of afuresertib within this treatment combination. 8 Wednesday 19 November 2014 4 ORAL PRESENTATION Activity of galeterone in castrate-resistant prostate cancer (CRPC) with C-terminal AR loss: Results from ARMOR2 M.E. Taplin1 , K.N. Chi2 , F. Chu3 , J. Cochran4 , W.J. Edenfield5 , E.S. Antonarakis6 , U. Emmenegger7 , E.I. Heath8 , A. Hussain9 , V.C. Njar9 , A. Koletsky10 , D. Lipsitz11 , L. Nordquist12 , R. Pili13 , M. Rettig14 , O. Sartor15 , N.D. Shore16 , D. Marrinucci17 , K. Mamlouk18 , B. Montgomery19 . 1 Dana Farber Cancer Institute, Department of Medicine Harvard Medical School, Boston MA, USA; 2 BC Cancer Agency, Genitourinary Oncology, Vancouver BC, Canada; 3 San Bernadino Urological Associates, Urology, San Bernadino Ca, USA; 4 Urology Clinics of North Texas, Urology, Dallas Tx, USA; 5 Cancer Centers of the Carolinas, Oncology, Greenville SC, USA; 6 The Sidney Kimmel Comprehensive Cancer Center at John Hopkins, Genitourinary Oncology, Baltimore MD, USA; 7 Sunnybrook Health Sciences Centre, Oncology, Toronto ON, Canada; 8 Karmanos Cancer Institute Wayne State University, Genitourinary Oncology, Detroit MI, USA; 9 Univ of Maryland, Genitourinary Oncology, Baltimore MD, USA; 10 Center for Hematology-Oncology, Oncology, Boca Raton FL, USA; 11 Carolina Urology, Urology, Concord NC, USA; 12 Urology Cancer Center and GU Research Network LLC, Oncology, Omaha NE, USA; 13 Roswell Park Center Institute, Genitourinary Oncology, Buffalo NY, USA; 14 Institute of Urologic Oncology, Genitourinary Oncology, Los Angeles CA, USA; 15 Tulane University, Genitourinary Oncology, New Orleans LA, USA; 16 Carolina Urologic Research Center Atlantic Urology Clinics, Urology, Myrtle Beach SC, USA; 17 EPIC Sciences, Sciences, San Diego CA, USA; 18 Tokai Pharma, Medical Affairs, Cambridge MA, USA; 19 University of Washington, Genitourinary Oncology, Seattle WA, USA Plenary Session 2 5 ORAL PRESENTATION Mechanism based targeted therapy for hereditary leiomyomatosis and renal cell cancer (HLRCC) and sporadic papillary renal cell carcinoma: interim results from a phase 2 study of bevacizumab and erlotinib R. Srinivasan1 , D. Su1 , L. Stamatakis1 , M.M. Siddiqui1 , E. Singer1 , B. Shuch1 , J. Nix1 , J. Friend1 , G. Hawks1 , J. Shih1 , P. Choyke1 , W.M. Linehan1 . 1 National Cancer Institute, Urologic Oncology Branch, Bethesda Maryland, USA This abstract is part of the media programme and is embargoed until the day of presentation, when it will be published online at 08:00. This abstract is part of the media programme and is embargoed until the day of presentation, when it will be published online at 08:00. 6 ORAL PRESENTATION Imaging in cancer immunology: Phenotyping of multiple immune cell subsets in-situ in FFPE tissue sections J.R. Mansfield1 , C. Slater2 , C. Wang1 , K. Roman1 , C.C. Hoyt1 , R.J. Byers2 . 1 PerkinElmer, LST, Hopkinton, USA; 2 University of Manchester, Pathology, Manchester, United Kingdom Background: There has been a rapid grown in the field of tumor immunobiology in recent years as a result of recent successes in cancer immunotherapies, and it is becoming clear that immune cells play many sometimes conflicting roles in the tumor microenvironment. However, obtaining phenotypic information about the various immune cells Poster Session – Animal Models that play these roles in and around the tumor has been a challenge. Existing methods can either deliver phenotypic information on homogenous samples (e.g., flow cytometry or PCR) or morphologic information on single immunomarkers (standard IHC). We present here a methodology for delivering quantitative per-cell marker expression and phenotyping, analogous to that obtained from flow cytometry, but from cells imaged in situ in FFPE tissue sections. Materials: This methodology combines the sequential multi-marker labeling of up to 8 antigens using antibodies all of the same species in a single section; automated multispectral imaging (MSI) to remove problematic FFPE tissue autofluorescence and correct cross-talk between markers; and an automated analysis that can quantitate the per-cell marker expression, determine the cellular phenotype, count these cells separately in the tumor compartment and stroma, and provide high-resolution images of their distributions. A tissue microarray comprising 35 post-transplant lymphoproliferative disorder (PTLD) samples was immunostained for CD3, CD8 and FOXP3. Single FFPE slides from 9 HER2+ breast cancer patients receiving neoadjuvant chemotherapy were stained with fluorophores targeting cytokeratin, CD8, CD4, FoxP3, CD20 and PD-L1. MSI and analysis was used to enumerate specific phenotypes of cells, as well as to map their spatial locations. Results: MSI successfully captured and quantified multiple immune cell types in all tissues. Validation of singly stained versus multiply stained samples for PTLD showed excellent correlation (R > 0.9). Breast cancer patients not achieving a pathologic complete response (pCR), the density of both the CD8 (p = 0.03) and CD4 (p = 0.05) infiltrates in the stroma were significantly greater than in the tumor. For patients achieving a pCR, there was no significant difference in the densities of stromal and intratumoral CD8 (p = 0.11) or CD4 (p = 0.75) infiltrates suggesting that T cell infiltration into the tumor from the stroma is critical. Conclusions: Multispectral imaging allows different immune cell phenotypes to be visualized and quantified simultaneously in the same tissue section enabling further study of the relationships and distribution of these cells within the tumor and tumor microenvironment, and their spatial distribution and proximity to the tumor cells. This technology will enable improved understanding of the immune infiltrate in solid tumors thereby facilitating the rational design and use of immunotherapeutic agents in combination with standard systemic therapies. Wednesday 19 November 2014 Poster Sessions Animal Models 7 POSTER (Board P001) Mouse clinical trial − A new preclinical study concept using patient-derived xenografts V. Vuaroqueaux1 , C. Gredy1 , S. Gorynia1 , S. Baltes1 , H.H. Fiebig1 , T. Metz1 . 1 Oncotest GmbH, Freiburg, Germany Patient tumor explants passaged in immunocompromised mice (patientderived xenografts, PDXs) represent the most commonly used system for preclinical efficacy testing of anti-cancer agents. The standard format for efficacy tests typically uses preselected PDXs and group sizes of 8 to 12 PDX-bearing mice to test the efficacy of a treatment relative to a vehicle control group. The strength of this approach is the high reliability of the efficacy data obtained. However, in the face of limitations of available resources this test format restricts the number of PDX models that can be tested. In many studies less than 10 PDX models are used which, in view of the genetic diversity of cancer, is often not satisfactory. The need for in vivo efficacy tests in broader PDX panels is addressed by the emerging mouse clinical trial (MCT) format. Ideally, this format relies on only one mouse per PDX model and treatment arm (referred to as xenopatient), thus enabling the investigation of efficacy in substantially larger panels of PDX models (typically 40 or 50 models which are not preselected) which collectively better mirror the inter-patient response heterogeneity observed in the clinic. However, given that all PDX models display some growth heterogeneity, results obtained for individual models are less reliable. To compare results obtained for individual PDXs in the standard and in the MCT format, in the present work five SoC drugs were tested in colorectal (cetuximab, oxaliplatin, irinotecan, 5-FU) and non-small-cell lung cancer (cetuximab, paclitaxel) PDXs. Dosing and schedules were adapted to clinical standards. Preliminary data for 17 PDX models suggest that Wednesday 19 November 2014 9 in approximately 80% of cases the results obtained in the MCT format (single mouse trial) are in line with the results of the standard efficacy tests. Furthermore, in about 10% of cases the results obtained with both formats were similar by trend. The proportion of false positive or false negative results obtained with tests in the MCT format was below 5%. Our findings indicate that for the drugs tested here the risk of misjudging the sensitivity of a given PDX model based on MCT efficacy data is relatively low. This risk could probably be further lowered by increasing group sizes to three mice. For the identification of biomarkers which profits from accurate efficacy data such an intermediate format between the MCT and the standard format may be advantageous. 8 POSTER (Board P002) Imaging growth and anti-cancer activity in orthotopic patient derived tumors M. Baugher1 , C. Bull2 , A. Cohen-Barnhouse1 , A. Flecha2 , M. Franklin3 , K. Guley2 , P. McConville2 , W.R. Leopold4 . 1 Molecular Imaging Inc, Pharmacology, Ann Arbor MI, USA; 2 Molecular Imaging Inc, Imaging, Ann Arbor MI, USA; 3 Molecular Imaging Inc, Pharmaco-Imaging, Ann Arbor MI, USA; 4 Molecular Imaging Inc, Oncology, Ann Arbor MI, USA Background: Preclinical models that more closely mimic the clinical setting are being sought using patient-derived tumors (PDX). Utilization of PDX material in an orthotopic (OT) setting provides a preclinical model in a disease-relevant location. Here we describe the growth and treatment response data of OT pancreas, lung and breast PDX material with conventional and non-invasive imaging techniques. Materials and Methods: All patient-derived tumor material was obtained in collaboration with Oncotest GmbH. SCID beige mice were used with the appropriate material surgically implanted into the pancreas, directly injected into the left lung or directly injected into the mammary fat pad. All dosing is as shown. Results: OT implantation of pancreatic PDX material resulted in robust disease establishment with a near 100% take rate. We utilized MRI and Fluorescence Molecular Tomography (FMT) imaging to non-invasively track tumor progression. We found that different FMT probes had different capabilities for detecting tumor burden. Both MRI and FMT showed that this model was highly sensitive to treatment with docetaxel, where a significant number of mice had complete response and increased overall survival when compared to control mice. The NSCLC PDX material showed near 100% take rates as determined by CT evaluation. By CT we found a minor bevacizumab response, as is consistent with this drug not being an optimal VEGFR inhibitor in the mouse. PET imaging was performed and demonstrated FDG avidity. However, no drug response was observed. In the breast model, treatment with cyclophosphamide resulted in a robust response with approximately 34 of mice having no measurable tumors on day 77. In this setting, FDG PET and FMT imaging were utilized to determine metabolic activity and avidity. FMT reflected the decrease in tumor burden with treatment. At the time of imaging, no difference in FDG SUV values was observed with treatment. In all models, disease latency and tumor volume doubling times were consistent with expectations based on known subcutaneous data. Conclusions: We have shown the establishment of OT PDX pancreas, lung and breast models. The use of multi-modality imaging non-invasively tracked tumor burden over time and provided useful readouts of disease progression and drug treatment response in these more disease-relevant models. Future work continues to investigate the metastatic potential of OT PDX material and non-invasive imaging to track this. 9 POSTER (Board P003) Antineoplastic effects of auranofin in canine lymphoma D. Thamm1 , B.J. Rose1 , J.K. Shoeneman1 . 1 Colorado State University, Dept. of Clinical Sciences, Fort Collins, USA Background: Lymphoma (LSA) is a serious condition for which there remain unmet medical needs in humans and dogs. The gold complex auranofin has been utilized as a human therapeutic, primarily as an antirheumatic agent. Antiproliferative and pro-apoptotic activity has been observed in a variety of human tumor-derived cell lines, including carcinomas of the breast, head and neck, ovary, lung, and a variety of hematopoietic tumors, including LSA. Putative antitumor mechanisms include inhibition of NF-kB and STAT3 signaling, and induction of reactive oxygen species via thioredoxin reductase (TrxR1) inhibition. The dog is a well-established model for spontaneous LSA in humans, owing to striking similarity in biology and gene expression. Dogs with spontaneous tumors naturally develop therapy resistance and metastasis. In addition, tumor burdens in spontaneous canine tumors are more similar to humans than those in murine models, which may be important with regard to biologic factors such as hypoxia and clonal variation. The size of canine tumors 10 Wednesday 19 November 2014 also allows for serial imaging and tissue collection over time. The goal of the current study was to investigate the antineoplastic effects of auranofin in a panel of canine lymphoma-derived cell lines, and to identify potential biomarkers of drug activity for future translational studies in spontaneous canine LSA. Materials and Methods: 4 canine LSA-derived cell lines were incubated in varying concentrations of auranofin +/− bortezomib, elesclomol, or the conventional antineoplastic agents doxorubicin (DOX), CCNU and vincristine (VCR) for 24−72 hours. Relative viable cell number was assessed using MTS. Cell cycle distribution and apoptosis induction were evaluated cytometrically with propidium iodide staining and Annexin V/PI staining respectively. Induction of ROS was assessed using the redoxsensitive fluorescent dye CM-H2 DCFDA. Results: Auranofin induced dose-dependent antiproliferative effects in all canine LSA cell lines, with 50% inhibitory concentrations between 0.1 and 1 uM. These are similar to those observed in human hematopoietic tumor cells, and well within clinically achievable serum concentrations. Dose- and time-dependent apoptosis induction was observed, and additive to synergistic antiproliferative/propaptotic activity was observed with bortezomib and elesclomol, but not DOX, CCNU or VCR. Dose- and timedependent induction of ROS was observed following auranofin treatment. Conclusions: Auranofin-associated antitumor activity is observed in vitro in canine LSA cells, at pharmacologically achievable concentrations. This is similar to activity observed in human LSA and leukemia. Cooperative activity was observed with the targeted agents bortezomib and elesclomol. These data support translational evaluation of auranofin in canine LSA as a model for the human disease. 10 POSTER (Board P004) mTOR inhibition with everolimus − a novel treatment option for head and neck cancer identified in a translational research study using patient-derived xenografts K. Klinghammer1 , J.D. Raguse2 , T. Plath2 , A.E. Albers3 , B. Brzezicha4 , A. Wulf-Goldenberg4 , U. Keilholz5 , J. Hoffmann4 , I. Fichtner4 . 1 Charité University Medicine, Department of Hematology & Oncology, Berlin, Germany; 2 Charité University Medicine, Department of Maxillio-Facial Surgery, Berlin, Germany; 3 Charité University Medicine, Department of ENT, Berlin, Germany; 4 Experimental Pharmacology & Oncology GmbH, Berlin, Germany; 5 Charité University Medicine, Cancer Comprehensive Center, Berlin, Germany Background-Aims: We recently established a large panel of head and neck squamous cell carcinoma (HNSCC) patient-derived xenografts for exploration of novel treatment approaches and biomarker evaluation. Next to activation of the EGFR-RAS-RAF-ERK pathway the PI3K-AKT-mTOR axis is often amplified and activated in HNSCC. We evaluated the mTOR inhibitor everolimus in a panel of HNSCC PDX derived from 29 different patients. Treatment response of everolimus was compared to treatment response of cetuximab and further correlated to gene expression of mTOR pathway members such as mTOR, RPS6KB1, Akt1, FKBP1B and TSC1. Since PI3K mutation has been associated with pathway activation, we aimed to define the predictive role of PI3K mutations for everolimus response. Methods: Specimens from head and neck tumor surgery were transplanted subcutaneously to immunodeficient mice. Groups of 6 mice were treated with cetuximab or everolimus as single agent. A T/C (mean tumor volume of treatment versus control) of less than 50% was defined as biological meaningful activity of the treatment. Transcription of mTOR pathway members were analyzed in detail using RT-PCR. Sequencing analysis was accomplished on Illumina TruSeq Amplicon − Cancer Panel. Results: Response to treatment was very individual. Response rate of everolimus was 20/29 (68%) and for cetuximab 23/29 (79%). RPS6KB1 gene expression showed a trend to positive correlation with treatment response to everolimus (p = 0.0784). PI3K mutations were identified in 7 models at different gene regions. All but one model harbouring mutations within the PI3K gene showed a significant growth inhibition (6/7, 85%), when treated with everolimus. Activity is slightly lower in the cohort with PI3K wildtype (14/22, 63%). Conclusion: The study demonstrated a significant therapeutic activity of everolimus in the majority of our HNSCC models. Although not significant, analysis of mutations in PI3K and the expression of RPS6KB1 mRNA provide some first mechanistic evidence, that an activated PI3K/mTOR pathway may predict sensitivity. Analysis needs to be extended to a larger study group. In conclusion, we demonstrate a comprehensively characterized panel of head and neck cancer PDX models, which represent a valuable and renewable tissue resource for evaluation of novel compounds and associated biomarkers. Poster Session – Animal Models 11 POSTER (Board P005) A panel of patient derived xenograft models of different haematological malignancies suitable for preclinical drug screening campaigns E. Oswald1 , C. Tschuch1 , K. Klingner1 , B. Hammerich1 , D. Lehnhard1 , C. Rentsch2 , M. Lübbert3 , H.H. Fiebig4 , J. Schüler4 . 1 Oncotest GmbH, In Vivo Tumorbiology, Freiburg, Germany; 2 University Hospital Basel, Division of Urology, Basel, Switzerland; 3 University Hospital Freiburg, Hematology and Oncology, Freiburg, Germany; 4 Oncotest GmbH, Freiburg, Germany In order to obtain a better understanding of hematological malignancies and to develop improved therapeutic strategies, the generation of functional and reproducible in vivo models is widely pursued. Here, we report the establishment of transplantable PDX models of acute myeloid and acute lymphoid leukemia (AML, ALL) and Non-Hodgkin Lymphoma (NHL) growing subcutaneously as well as in a disseminated fashion in immunocompromised mice. Bone marrow and peripheral blood cells from 18 AML/ALL patients were injected intratibially into NSG or NOG mice (n = 4−8/patient). Separately, tumor tissue from 27 prostate cancer patients and one lung cancer patient was transplanted either under the subrenal capsule or subcutaneously into NSG or NOG mice (n = 4−10/patient), leading to the outgrowth of nine NHLxenografts (eight from transplanted prostate cancer and one from transplanted lung cancer tissue). Tumor growth was monitored via determination of overall survival, flow cytometry analyses, caliper measurement where applicable and Immunohistochemistry (IHC). Transplantable models as well as primary in vivo cultures were further characterized by treatment with respective standard of care drugs (SoC). Six out of 18 AML/ALL patient-derived specimens engrafted in immunocompromised mice, following transplantation into murine bone marrow. Human leukemic cells were detected in murine peripheral blood, bone marrow and spleen by flow cytometry as well as by IHC. One T-ALL and one AML could also be propagated when injected subcutaneously. Two transplantable AMLs and one transplantable ALL were treated with SoC drugs decitabine, cytarabine and dexamethasone. Efficacy tests using primary AML cells were feasible although availability of tumor material limited experiment size to maximally 25−30 mice. The eight NHL xenografts derived from prostate cancer tissue were all Epstein-Barr-Virus-positive. Seven were diagnosed as diffuse large B-cell lymphomas (DLBCL), one is T-cell-derived. The NHL excised from the lung was diagnosed as a MALT lymphoma. All lymphomas were transplantable and showed stable growth when propagated subcutaneously. Subtyping of the DLBCL lymphomas by IHC revealed that four of them were of the ABC-subtype. Our results confirm that PDX models of haematological malignancies replicate the heterogeneity and other important clinical characteristics of the respective disease, and are valuable tools for preclinical drug testing and investigation of tumour biology. 12 POSTER (Board P006) Next generation sequencing (NGS) guided therapy prediction for the treatment of glioblastoma multiforme (GBM) J. Sarkaria1 , D.M. Ma1 , S.P. Peng2 , S.B. Byron2 , D.C. Craig3 , J.C. Carpten4 , M.B. Berens2 , B.O. O’Neill5 , N.T. Tran6 . 1 Mayo Clinic Cancer Center, Radiation Oncology, Rochester Minnesota, USA; 2 Translational Genomics Research Institute (TGen), Cancer and Cell Biology Division, Phoenix Arizona, USA; 3 Translational Genomics Research Institute (TGen), Neurogenomics Division, Phoenix Arizona, USA; 4 Translational Genomics Research Institute (TGen), Genomics Division, Phoenix Arizona, USA; 5 Mayo Clinic, Neuro-oncology, Rochester Minnesota, USA; 6 Translational Genomics Research Institute (TGen), Cancer and Cell Biology Division, Rochester Minnesota, USA Background: The genomic heterogeneity of glioblastoma likely underlies the low response rates (8−24%) for targeted agents among unselected populations. We tested whether NGS would be useful in identifying therapeutically-actionable genetic alterations; we sought to test if this translated into improved tumor control in a patient-derived GBM model. Methods: Tumor specimens from each patient (n = 11) that were used for analyte extraction contained between 70−80% viable tumor cellularity. Genome sequence coverage was more than 30× for both tumor and germline genomes; tumor RNA sequencing included over 100 million reads. NGS of paired tumor and germline DNA enabled detection of single nucleotide variations (SNVs), indels, translocations, intra-chromosomal rearrangements, and copy number alterations. A custom drug-matching workflow utilizing publically available databases and curated literature on reported drug effects, pharmacokinetics, and blood–brain barrier penetration was used to map individual gene alterations in tumors with Poster Session – Animal Models associated drug-response relationships. One specimen was tested in vitro and in vivo using a matched, patient-derived xenograft model. Results: NGS for the 11 tumor panel found ~30% of cases with EGFR amplification, p16, and/or PTEN deletion. Novel potentially actionable targets included a TRIM54-FGFR3 fusion, STAG2 mutation, MDM2 amplification, KIF11 and KIF15 mutation, and BRAF amplification. GBM150 is derived from a recurrent tumor and harbors the TRIM54-FGFR3 fusion, and this line is the first to be analyzed for chemovulnerability. In a Cyquant proliferation assay, GBM150 were relatively resistant to TMZ (IC50 300 uM) but significantly more sensitive to pan-FGFR1−3 inhibitors as compared to GBM108: ponatinib IC50 0.3 uM vs. 1.2 uM; AZD4547 IC50 3 uM vs. >10 uM. Similarly, in a flank tumor regrowth study, established GBM150 tumors were randomized to therapy with placebo, temozolomide, ponatinib or AZD4547. While TMZ-treated tumors were marginally smaller than placebo treated tumors (mean tumor volume 1312±208 vs. 992±183 mm3 , 97 days after therapy initiation), both ponatinib or AZD4547 resulted in sustained tumor stasis with a mean tumor volume of 240±35 and 199±40 mm3 , respectively, at the same time-point. Conclusions: These results support the concept that NGS can be used to individualize treatment of GBM and highlight how corresponding patient derived xenograft models can be used to validate the accuracy of potential therapeutic predictions. 13 POSTER (Board P007) Whole exome sequence analysis of canine transitional cell carcinoma of the bladder D.L. Duval1 , B. Hernandez1 , J. Brown2 , S.E. Lana1 , R. Page1 , K.L. Jones2 . 1 Colorado State University, Clinical Sciences, Fort Collins, USA; 2 University of Colorado Cancer Center, Biochemistry and Molecular Genetics, Aurora, USA Transitional cell carcinoma (TCC) is the most common bladder cancer in both humans and their canine companions, accounting for approximately 2% of all diagnosed malignancies in both populations. Clinical presentation of human TCC is broken into 2 groups: superficial non-muscle-invasive TCC (~70% of cases) and muscle invasive TCC (~30% of cases) which is associated with a high risk of death from distant metastasis. The majority of canine TCCs are papillary infiltrative TCCs of intermediate to high grade at diagnosis. Similarities in risk factors, histopathology, sites of metastasis, and other common features indicate that canine TCC may serve as an excellent model for invasive human TCC. Previous studies of human TCCs have identified genetic defects that may aid in the diagnosis and therapy of human bladder cancer. To further assess the value of spontaneous canine TCCs as a model for human TCC, we have utilized whole exome sequencing to screen a panel of canine TCCs for cancer gene mutations that contribute to the pathogenesis and progression of canine bladder cancer. Genomic DNA was isolated from 11 archived canine TCCs, 3 matched normal tissue samples, and 2 canine TCC cell lines. Whole exome capture was conducted using the Agilent Sure-select insolution capture system designed for the canine genome, and the captured fragments were sequenced using an Illumina HiSeq2000 next generation sequencing platform. The sequences were mapped to the CanFam3.1 canine reference genome and single-nucleotide polymorphisms, insertions and deletions were identified using Freebayes. Somatic mutations were characterized and compared to the Cancer Gene Census (COSMIC). Similar to a variety of human cancers including bladder cancers, the mutation spectrum in these genes is dominated by C:G>T:A transitions. Nonsense, missense, and insertion/deletion mutations were identified in 75 genes shown to be drivers or repressors in human cancer. Pathway analysis (Pathway Studio) identified DNA damage, genomic instability, and chromatin remodeling as the top 3 cellular pathways affected. The 10 genes most frequently exhibiting potentially deleterious mutations were: MITF, KDM6A, MLLT6, AKAP9, C2orf44, ROS1, NSD1, BRAF, FANCD2, and PCM1. This mutation spectrum, including members of the RTK/Ras/Raf pathway, histone modifying and chromatin remodeling enzymes, indicates that similar activating pathways drive both human and canine transitional cell carcinoma of the bladder. 14 POSTER (Board P008) Mixeno mouse models for in vivo evaluation of anti-human cancer immunotherapeutics J. Zhang1 , J. Qiu2 , M. Qiao2 , Q. Shi1 . 1 Crown Biosciences, Cancer Pharmacolgy, Santa Clara CA, USA; 2 Crown Biosciences, Cancer Signaling, Santa Clara CA, USA The past few years have witnessed a renaissance in the field of cancer immunotherapy, relating largely to the clinical advances associated with the development of immunomodulatory agents, e.g. monoclonal antibodies targeting the immune inhibitory pathways (CTLA-4 and PD-1/PD-L1). Wednesday 19 November 2014 11 Often, the preclinical efficacy assessments are based on the evaluation of surrogate anti-mouse target antibodies using mouse syngenic tumor models. However, this strategy is limited due to the fact it can only be used to test surrogate molecules, rather than directly evaluate the therapeutic molecules that target human targets. Here we set out to validate mouse models that harbor human immune cells by engrafting the immuno-deficient mice with human PBMC (the MixenoTM model), and use them for efficacy evaluation of the humanized anti-PD-1 antibody. PD-L1 high-expression human tumor cell lines are selected using Xenobase® and FACS analysis to develop the in vivo models. BMS-936558, a fully humanized anti-PD-1 IgG4 produced promising anti-tumor activity in the HCC827 lung cancer MixenoTM model. Based on the preliminary result, the MixenoTM models may be a useful tools in immunotherapeutic antibody development, and may greatly increase the clinical translatability of animal studies. 15 POSTER (Board P009) Genetic and molecular validation of uterine sarcoma patient-derived xenograft models T. Cuppens1 , E. Hermans1 , J. Depreeuw2 , M. Moisse2 , T. Van Brussel2 , L. Coenegrachts1 , D. Lambrechts2 , F. Amant1 . 1 Catholic University of Leuven, Gynaecologic Oncology, Leuven, Belgium; 2 Catholic University of Leuven-Vesalius Research Center VIB, Oncology Translational Genetics, Leuven, Belgium Background: Genetic and molecular heterogeneity within tumor types directly affects a patient’s response to a given compound, warranting more personalized therapeutic strategies based on predictive markers. However, for rare malignant tumors in particular, randomized trials are scarce, emphasizing the need for reliable pre-clinical tumor models. Traditional approaches for pre-clinical evaluation of cancer therapies rely on the use of xenograft models of commercially available cell lines. Whereas these models are human in origin, they are unlikely to fully recapitulate human cancers. In contrast, patient-derived tumor xenografts (PDTXs), established directly from patient’s tumors, may better preserve the initial tumor characteristics as they represent the heterogeneity and retain the most important genetic features of the original tumor. Here, we aim to establish and validate PDTX models for uterine leiomyosarcoma, a highly aggressive tumor arising from the myometrium. We explore the genetic and molecular stability of xenografted tumors, which will ultimately serve as pre-clinical models for individualized treatment. Materials and Methods: In collaboration with the PDTX platform, 8 uterine leiomyosarcomas (obtained from surgery after patient’s informed consent) were subcutaneously implanted into immune-deficient mice. Engrafted tumors were re-implanted for several generations (F1, F2, F3, etc.) and then compared to their original tumors by means of copy number analysis (SNP arrays-Illumina), tissue-specific marker expression (immunohistochemistry) and histology (H&E). Results: We have established 5 uterine leiomyosarcoma models (take rate >60%), of which one diploid and one tetraploid model have been analyzed at present. Both tumors retained their histologic features, as well as their expression of mesenchyme-specific (vimentin) and muscle-specific (desmin/caldesmon) markers. Further, copy numbers of the F4 xenograft derived from the diploid tumor were >99% identical to the original tumor. However, the F3 xenograft of the same model showed tetraploidy and some additional copy number changes. In the tetraploid PDTX model, 37% of all genes in F2 and F3 tumors had changed in copy number when compared to the original tumor. Comparing the F2 and F3 tumor revealed a copy number stability of only 56%. Hence, in both models, the later xenograft generation shows greater resemblance to the original tumor than to the prior xenograft from which it was derived. This finding strongly suggests the presence of subclones. Conclusions: We successfully established patient-derived tumor xenograft models for pre-clinical individualized therapy testing. Of note, the genetic stability and in particular the presence of subclones should be taken into account when selecting therapies based on genetic features. 16 POSTER (Board P010) Allografting improves the feasibility of genetically engineered mouse models (GEMM) for anti-cancer drug development K. Kukuk1 , K. Klingner1 , A.L. Peille2 , P. Müller3 , A. Zipelius3 , J. Schüler2 . Oncotest GmbH, In Vivo Tumorbiology, Freiburg, Germany; 2 Oncotest GmbH, Freiburg, Germany; 3 University Hospital Basel, Basel, Switzerland 1 Genetically engineered mouse models (GEMMs) represent an attractive system for preclinical research since GEMM tumors develop in the presence of a competent immune system. Unlike classical syngeneic mouse tumor models, in GEMMs the identity of some of the oncogenic 12 Wednesday 19 November 2014 alterations is known. Typical drawbacks of GEMM tumors include slow and heterogeneous tumor development, making the use of these models challenging for routine in vivo efficacy studies. These disadvantages can be avoided by grafting autochthonous GEMM tumors on mice of the parental strain. Here, we describe the establishment and characterization of such allografts from a non-small cell lung cancer (NSCLC) and two breast cancer models, among them an invasive lobular carcinoma (ILC) and a model carrying a Brca-1 alteration. Tumors were excised from their organ of origin and tumor pieces were implanted subcutaneously (s.c.) and orthotopically (o.t.) into C57BL/6N (NSCLC model) and FVB/N mice (breast cancer models). Arising tumors were passaged and compared to the original in-situ tumors molecularly, histologically, and immunohistochemically (e.g. Ki67 proliferation marker). In parallel, cell lines were established from the in-situ tumors. Subcutaneous allografts were passaged at least 8 times with stable and consistent tumor growth as documented by tumor-growth-kinetics and H&E staining of tumor sections. The allografts of the ILC model metastasized to multiple organs when transplanted o.t. For all three models, patho-histology of in-situ tumors and allografts was congruent and no signs of an immunological reaction against allografts were detected. IHC analysis revealed differences between Ki-67 and CD31 expression among different allografts representing the same GEMM. Efficacy tests with standard of care (SoC) drugs performed on allografted NSCLC tumors revealed significant anti-tumor activity of the dual PI3K and mTOR inhibitor. BEZ235 displayed good antitumoral activity both in monotherapy and in combination with the dual EGFR and HER2 inhibitor afatinib. The selective EGFR inhibitor erlotinib had no significant effect, which is in line with the low mEGFR expression detected. In conclusion, s.c. and o.t. transplantable allografts, which replicate key aspects of the human disease, were obtained from the investigated GEMMs and enable efficacy tests in immunocompetent mice in a suitable time frame. Further studies will elucidate the feasibility of these models for preclinical testing of immunomodulatory drugs. 17 POSTER (Board P011) Studies on glycoprotein expression differences between MCF-7 and MCF-7-Z J. Ner-Kluza1 , A. Drabik2 , M. Kubbutat3 , A. Lingnau3 , J. Silberring2 . 1 Uniwersity of Science and Technology, Department of Biochemistry and Neurobiology, Krakow, Poland; 2 AGH Uniwersity of Science and Technology, Department of Biochemistry and Neurobiology, Krakow, Poland; 3 ProQinase GmbH, Freiburg, Germany According to the American Cancer Society, in 2014, more than 230,000 women will be positively diagnosed for breast cancer in the US, demonstrating the urgent need for more promising anti-tumor drugs worldwide. The human breast cancer cell line MCF-7 has been commonly used in subcutaneous xenograft tumor models in order to screen for novel cancer drugs. By comparing two different variants of MCF-7 (MCF-7 and MCF7-Z), both authentic when analysed by STR profiling, we found completely different tumor growth characteristics in mice. We excluded the possibility that a loss in estradiol dependency was responsible for these differences, and started analysing the proteome of the MCF-7 tumors by an approach to discriminate between the glycosylation pattern. Among post-translational modifications glycosylation is one of the most important involved in tumor progression. The presented project is based on monitoring changes in glycoprotein profiles of two cell lines MCF-7 and MCF-7-Z. For the isolation of glycoproteins lectin affinity chromatography (LAC) was applied, followed by one-dimensional SDSPAGE electrophoresis. After digestion, peptides extracted from the gel were analyzed by nanoLC-MS/MS system. The identified glycoproteins were identified by bioinformatics tools, such as Osprey and Panther databases. Final part of the research is based on quantitative analysis using labelfree approach of the identified proteins using Bruker software called Profile Analysis. The research was supported by the The Polish National Science Center 2012/07/B/NZ4/01468, and EuroNanoMed ‘META’ 05/EuroNanoMed/2012. 18 POSTER (Board P012) Establishment and characterization of a Merkel Cell carcinoma PDX panel: Screening for potentially useful therapies M.J. Wick1 , J. Meade1 , M. Nehls1 , T. Vaught1 , J. Carlile1 , A.W. Tolcher1 , D.W. Rasco1 , A. Patnaik1 , K.P. Papadopoulos1 . 1 South Texas Accelerated Research Therapeutics, (START), San Antonio TX, USA Background: Merkel cell carcinoma (MCC) is an uncommon, aggressive neuroendocrine skincancer with a poor prognosis and few effective treatment options for advanced disease. Recent studies have identified Poster Session – Animal Models a strong association between infection with the Merkel cell polyomavirus (MCPyV) and MCC transformation. MCPyV antigens have been shown to affect cell growth and proliferation through apoptosis and cell cycle pathways. Targeted therapies have shown promise in vitro and in vivo; however, their utility in the clinical setting is anecdotal. To better understand which targeted therapies are effective in MCC, we established and screened a panel of MCC patient-derived xenograft (PDX) models evaluating approved and investigational therapies. Methods: Methods: Merkel cell carcinoma START-PDX models were established in immune-deficient mice from primary or metastatic patient tissue and once established were confirmed by histologic comparative analysis and linked with patient treatment and outcome data. Drug sensitivity studies were performed evaluating each model to available targeted therapies including pazopanib, everolimus and sunitinib and investigational Akt, IAP and CDK 4/6 inhibitors. Study endpoints included tumor volume and time from treatment initiation with tumor growth inhibition, delay and regression reported at study completion. Results: Five MCC models evaluated in this project demonstrated differential responses to test agents; statistically significant (p < 0.05) tumor growth inhibition was reported with pazopanib. Drugs targeting the PI3K/mTOR pathway, including an Akt inhibitor and everolimus as single agents, were not effective in these studies. Conclusion: We have established a panel of MCC PDX models and evaluated a panel of approved and investigational therapies. We found differential responses to these therapies, with pazopanib the most active as a single agent. These models may be of utility in identifying effective single and combination regimens for MCC. 19 POSTER (Board P013) Syngeneic models for developing cancer therapeutics targeting immune system L. Zhang1 , J. Zhang1 , Q. Shi1 . 1 Crown Biosciences, Cancer Pharmacolgy, Santa Clara CA, USA Syngeneic tumor models have long been used in cancer research, from mechanistic study to developing cancer therapeutics, especially those that require intact immune system, such as antibody therapeutics that have ADCC effect. Recently, cancer immunotherapy reignited to become one of the most promising therapies, largely because of the success of the clinical studies of CTLA-4, PD-1/PD-L1 antibodies. Researchers are now believe there are many novel therapeutics, both small and large molecules, and many novel targets, to be discovered and developed in this field. To meet this demand, Crown has established a large collection of syngeneic models that covers most of the tumor types and mutational profiles. In addition, we’ve also profiled the models using anti-mouse PD1/PD-L1 antibodies. The syngeneic models display very different responses towards the immunotherapeutics, ranging from shrinking the tumor to stimulating the tumor growth. These results emphasize the need to carefully select models based on the development goals. A single agent development approach would require selecting the models with the best response, while a combination study design would require a model with suboptimal response. Our comprehensive list of syngeneic models and profiling data are essential in developing cancer immunotherapies that may one day benefit the patients. 20 POSTER (Board P014) miR-25 is a key regulator of prostate cancer invasiveness by modulation of the cross-talk between Notch and TGF-b signaling E. Zoni1 , A.F. van de Merbel1 , G. van der Horst1 , J. Rane2 , T. Visakorpi3 , E.B. Snaar4 , N. Maitland2 , G. van der Pluijm1 . 1 Leiden University Medical Center, Department of Urology, Leiden, Netherlands; 2 YCR Cancer research Unit, Department of Biology, York, United Kingdom; 3 Institute of Medical Technology, University of Tampere, Tampere, Finland; 4 University of Leiden, Department of Biology, Leiden, Netherlands Background: Prostate cancer is the most commonly diagnosed cancer in males and the second leading cause of death from cancer in men. Prostate cancer stem/progenitor cells (CSCs) have been shown to play a crucial role in carcinogenesis, metastasis and therapy resistance. Previously, we have shown that the ALDHhigh subpopulation of human prostate cancer cells is enriched for CSCs. ALDHhigh cells display strong clonogenicity and migration when compared to the more differentiated ALDHlow . Material and Methods: We performed microRNA (miR) expression profiling of ALDHhigh vs ALDHlow subpopulation of prostate cancer cells. We studied the functional effects of miR-25 on Notch signaling on mRNA and proteins and used Luciferase reporters to monitor the effect of miR-25 on TGF-b signaling and to validate the interaction between miR-25 and Notch1. Finally we used zebrafish model to demonstrate that Poster Session – Cytotoxics miR-25 reduces dissemination of human prostate cancer cells in the intact organism. Results: In this study we have identified miRs that are differentially expressed between the metastatic subpopulation of PC-3M-Pro4 cells (ALDHhigh /a2high /CD44+ ) vs non-tumorigenic/non-metastatic ALDHlow . miR-25 was strongly downregulated in the ‘driver’ ALDHhigh CSC subpopulation. In both clinical prostate cancer specimens and prostate cancer cell lines we found that miR-25 is low/absent in CSC compartment and steadily increases during differentiation into luminal epithelial cells. We used Targetscan to discover novel miR-25 predicted targets and identified Notch1 as putative target of miR-25. Previously published studies have highlighted the role of Notch and Jag1 (Notch ligand) in skeletal metastasis. Interestingly, overexpression of miR-25 strongly decreases the expression of Notch1 and Jag1 together with other Notch downstream targets in two prostate cancer cell lines. Moreover, we found that miR-25 is able to decrease TGF-b signaling in prostate cancer cells and can block the induction of Jag1 driven by TGF-b. In line with these observations, we further demonstrate that miR-25 reduced metastasis by blocking the extravasation of human prostate cancer cells in vivo. Conclusion: Previously we have shown that miR-25 directly target av- and a6-integrins and strongly reduces migration of human prostate cancer cells. Here we show that miR-25 affects Notch pathway and can interfere with the TGF-b signaling, reducing the TGF-b induced expression of Jag1. Our data are supported by previous studies on the critical role of av-integrin in activation of TGF-b signaling and its role in skeletal metastasis. In conclusion, we suggest that miR-25 seems to be a master regulator of invasiveness in human prostate cancer through its interaction with Notch and TGF-b signaling pathways. The identification of miRs and functional validation of their target genes, is crucial for the elucidation of the mechanisms involved in tumor progression and bone metastasis formation in human prostate cancer. Cytotoxics 21 POSTER (Board P015) Pharmacogenomics of mithramycin in thoracic malignancies W. Figg1 , T.M. Sissung1 , C.J. Peer1 , D. Schrump2 . 1 National Cancer Institute, Clinical Pharmacology Program, Bethesda, USA; 2 National Cancer Institute, Thoracic Oncology Section, Bethesda, USA Background: Mithramycin inhibits expression of the fusion oncogene EWS-FLI1, and is therefore under investigation for use in thoracic malignancies. One of the major obstacles to mithramycin therapy is significant liver toxicity and unknown plasma concentrations. Materials and Methods: To discover genetic variants that are associated with these obstacles, we used the Drug Metabolizing Enzymes and Transporters (DMET) genotyping array on germline DNA from 12 patients with various thoracic malignancies receiving mithramycin. We also developed a novel assay to detect mithramycin plasma concentrations in these patients. Results: Grade 3−4 ALT and AST rises were observed in 8 of 12 patients that typically occurred after three daily administrations. Mithramycin plasma concentrations remained at sub-therapeutic levels, and pharmacokinetic parameters were not related to the LFT rises (P > 0.061). DMET analysis revealed two polymorphisms that are related to LFT rises in genes responsible for hepatocellular bile transport, ABCB4 (encoding PC-flopase) and ABCB11 (encoding BSEP). Patients without LFT rises carried wild-type alleles at both of these sites, whereas those with LFT rises carried at least one variant allele [OR (95% CI) = 153.0 (2.6–9100); P = 0.0020]. When DMET results were applied to pharmacokinetic data, an increasing trend was observed in which patients carrying (TA)6 /(TA)6 at UGT1A1*2 had low AUC that became progressively higher in those carrying (TA)6 /(TA)7 and (TA)7 /(TA)7 respectively. Conclusions: Taken together, the data indicate that mithramycin likely causes liver toxicity by inhibiting bile acid flow. Mithramycin is known to inhibit hepatic transporter expression that we suspect causes progressive bile acid accumulation in hepatocytes and subsequent cellular damage. Mithramycin is also most-likely glucuronidated by the liver; thus, extensive UGT1A1 metabolizers are likely to have sub-therapeutic plasma concentrations. Wednesday 19 November 2014 13 22 POSTER (Board P016) Novel combination therapy, TAS-102 combined with the anti-EGFR antibody or the anti-VEGF antibody showed therapeutic benefit toward colorectal cancer xenografts K. Ishida1 , K. Sakamoto1 , N. Tanaka1 , K. Oguchi1 , K. Yamamura1 , A. Fujioka1 , F. Nakagawa2 , K. Matsuo1 , T. Utsugi1 . 1 Taiho Pharmaceutical Co. Ltd, Tsukuba Research Center, Tsukuba, Japan; 2 Taiho Pharmaceutical Co. Ltd, Tokushima Research Center, Tokushima, Japan Background: TAS-102 (Lonsurf® ) consists of trifluridine (FTD) and tipiracil hydrochloride, thymidine phosphorylase inhibitor (TPI), at a molar ratio of 1:0.5. FTD is a thymidine analog and the antitumor component of TAS-102 and exerts its antitumor activity via FTD incorporation into DNA. FTD is activated to F3 dTMP by thymidine kinase and further phosphorylated to triphosphate form, F3 dTTP which is incorporated into DNA. TPI prevents degradation of FTD by thymidine phosphorylase in liver. TAS-102 was found to significantly improve overall survival of patients with metastatic colorectal cancer that is refractory/intolerable to the standard chemotherapies in a global Phase III study. We investigated TAS-102 based combination therapy with cetuximab (Cmab), panitumumab (Pmab), or bevacizumab (Bmab) that are key drugs for the treatment of metastatic colorectal cancer. Material and Method: Antitumor effects of TAS-102 combined with Cmab, Pmab or Bmab were evaluated in human colorectal cancer xenograft implanted SW48, HCT116 and HT-29. TAS-102 was administered orally twice daily for 14 days, and Cmab, Pmab or Bmab were administered twice a week intravenously or intraperitoneally. Tumor growth inhibition on day 15 and tumor growth delay was calculated from the tumor volume. Moreover, we measured accumulation of FTD and its phosphorylated forms in tumor with LC-MS/MS in the study of the combination with Bmab. Results: The antitumor effects of TAS-102 were enhanced by the combination with Cmab or Pmab toward KRAS wt tumor SW48, compared with monotherapy with TAS-102 or anti-EGFR antibodies as measured by both tumor growth inhibition and tumor growth delay. Similarly, tumor growth inhibition by Bmab plus TAS-102 was stronger than monotherapy toward both KRAS wt and mut tumors, SW48 and HCT-116 as well as in a BRAF mut tumor, HT-29. The tumor growth delays were also extended by Bmab combined administration in comparison with monotherapy. Interestingly, it was observed that the level of FTD and its phosphorylated forms in the tumor treated with TAS-102 plus Bmab were increased compared with TAS102 monotherapy. Conclusions: TAS-102 plus anti-EGFR therapy for KRAS wt tumors and TAS-102 plus Bmab therapy for tumors with KRAS and BRAF mutations could be effective combinations for colorectal cancer. TAS-102 based therapy may prove to be an effective alternative to standard 5-FU based chemotherapy in combination with antibody treatment for advanced colorectal cancer. 23 POSTER (Board P017) Phase I study of lurbinectedin (PM01183) administered on days (D) 1 & 8 every 3 weeks (q3wk) in patients (pts) with solid tumors M.J. Ratain1 , L. Gore2 , S. Szyldergemajn3 , J. Diamond2 , D. Geary1 , C. Fernandez-Teruel3 , A. Soto-Matos3 , M. Sharma1 , A. Jimeno2 . 1 The University of Chicago, Chicago, USA; 2 The University of Colorado, Denver CO, USA; 3 PharmaMar, Colmenar Viejo Madrid, Spain Background: PM01183 is a new anticancer agent with broad clinical activity against several solid tumors. The recommended dose (RD) when administered on D1 every three weeks (q3wk) is 4.0 mg/m2 or 7.0 mg as flat dose (FD). Reversible myelosuppression is its dose-limiting toxicity (DLT). Here we explored a D1&8 q3wk schedule. Material and Methods: Pts with solid tumors (other than colorectal cancer), adequate organ function and PS 0−1 were treated at 3 dose levels (DLs) using a 3+3 design, from 3.0 mg to 5.0 mg FD on D1&8 q3wk. Results: 21 pts were treated and 20 were evaluable: (M/F: 5/15); median age 63 years (39−75); BSA 1.8 m2 (1.6−2.5); albumin 3.8 g/dL (2.8−4.3); prior lines 5 (2−13). Most pts had ovarian (8, 38%), soft tissue sarcoma (STS) (5, 24%) or pancreatic/biliary tract (5, 24%) cancer. DL3 (5.0 mg FD/D1&8) was defined as the RD whereas 3 of 13 (23%) evaluable pts had DLT in Cycle 1: G4 neutropenia lasting >7 days (n = 2) and D8 omission and C2 delay due to toxicity (n = 1). Six pts (46%) received the full RD without delay, omissions or dose reductions; 5 (36%) pts required either a dose reduction or G-CSF prophylaxis from Cycle 2. No dose reductions or delays were needed in pts treated below the RD (n = 7). G4 neutropenia occurred in 43% of pts and one pt had G4 thrombocytopenia, at the RD. Other G3 events included nausea/vomiting and hyponatremia (1 each). Nonhematological G1/2 toxicity in 15% of pts: fatigue (64%), nausea (57%), anorexia (36%), vomiting (28%), pyrexia (21%) and ALT/AST increase (64% and 50%). At the RD, 8/13 pts had stable disease (4 months in 5 pts). Two previously progressing pts with STS and ovarian cancer were on study 14 Wednesday 19 November 2014 for 57+ weeks. At the RD (n = 14): mean (SD) clearance (CL) 18.1 (7.2) L/h; AUC 318 (123) h·mg/L; Cmax 90.5 (30.7) mg/L; t1/2 30.5 (13.6) h. No apparent association between CL and DLT or magnitude of neutropenia was found. Conclusions: The RD of PM01183 is 5 mg FD on D1&8 q3wk. At this RD, myelosuppression led to frequent dosing delays or omissions, but G-CSF support enabled the targeted dose intensity in some individuals. Two patients had prolonged disease stabilization lasting over a year. No signs of cumulative toxicity were observed. Interindividual variability in CL was high, but did not appear to be associated with toxicity. 24 POSTER (Board P018) Androgen receptor (AR) expression in triple negative breast cancer (TNBC): results from a phase II neoadjuvant trial with carboplatin and eribulin mesylate in TNBC patients K. Siziopikou1 , V. Parini2 , V. Kaklamani3 . 1 Northwestern University Feinberg School of Medicine, Pathology, Chicago IL, USA; 2 Robert H. Lurie Comprehensive Cancer Center, Pathology Core Facility, Chicago IL, USA; 3 Northwestern University Feinberg School of Medicine, Oncology, Chicago IL, USA Background: Triple negative (ER-negative/PR-negative/HER2-negative) breast cancer remains a therapeutic challenge for the oncologist since these carcinomas do not qualify for endocrine manipulation or HER2targeted therapy. Platinum agents were lately used in TNBC resulting in a 16−32% pathologic complete response (pCR) in neoadjuvant trials. Eribulin mesylate, a nontaxane microtubule dynamics inhibitor with a novel mechanism of action also showed clinical activity in breast cancer. In addition, different subgroups of TNBC were identified, with an AR expressing subgroup reported to be associated with a better prognosis. Our group recently reported that, in a phase II neoadjuvant trial, the combination of carboplatin and eribulin mesylate in patients with TNBC was well tolerated and showed significant efficacy. Our current study aimed to investigate the role of AR in this patient population of TNBC cases uniquely treated with a combination of carboplatin and eribulin mesylate. Materials and Methods: 30 patients with stage I-III TNBC were treated in a neoadjuvant setting with eribulin 1.4 mg/m2 over 2−5 min IV on days 1 and 8 plus carboplatin AUC6 over 30 min IV in Day 1 for four cycles. The expression of AR (Dako, AR 441) was assessed immunohistochemically in breast cancer specimens prior to treatment and at the time of definitive surgery. Staining was considered negative if <1%, low positive if 1−9% and positive if 10%. Results: 30 patients were diagnosed with TNBC. 26 (86.7%) had a grade III tumor and 4 (13.3%) a grade II tumor. No grade I cases were seen in this group. All patients underwent definite surgery and were evaluated for pathologic response. pCR was observed in 13 (43.3%); of the remaining patients 15 (51.7%) showed a residual cancer burden (RCB) II and 1 (3.5%) patient a RCBIII as per Symmans criteria. Of the 21 patients for whom pretreatment material was available 3 (14.2%) were positive for AR expression. Of the 17 patients without a complete response post-treatment, 2 were positive for AR expression. Of the 3 cases that were AR-positive pre-treatment, 2 remained positive post-treatment and 1 had a pCR. Conclusions: 1. Combination of carboplatin and eribulin mesylate resulted in a pCR in almost half (43.3%) of the TNBC patients. 2. Expression of AR does not appear to play a role in the promising response rate seen with this novel neoadjuvant combination. Additional studies are underway to further characterize the molecular mechanisms that drive response in this challenging subtype of breast cancer. 25 POSTER (Board P019) An ING1b-derived peptide that inhibits cancer cell viability and promotes apoptosis A. Boyko1 , K. Riabowol1 . 1 University of Calgary, Department of Biochemistry & Molecular Biology, Calgary, Canada The ING1b protein is a type II tumor suppressor and stoichiometric member of HDAC-containing protein complexes. ING1b contributes to regulation of gene expression, senescence and apoptosis. Mislocalization and decreased levels of ING1b are commonly observed in human tumors and cancer cell lines. Multiple independent studies show that ING1b overexpression promotes apoptosis in targeted cells. Since the inactivation of apoptosis pathways is frequent in cancer cells, modulating ING1b expression may serve as a viable approach for cancer therapy. We are defining ING1b regions necessary for apoptotic function in order to design minimal recombinant peptides with potent apoptosis-inducing properties. Based on the predicted protein structure and published data, we produced a number of expression constructs that encompass various portions of the Poster Session – Cytotoxics ING1b protein. Following the initial screening stage, pro-apoptotic effects of the most successful expression constructs were further confirmed and quantified by western blotting using the levels of PARP cleavage, and by FACS analysis using the Annexin V assay. We have established that ING1b-derived peptides containing its third alpha helix (A3H) and nuclear localization sequence (NLS)/nucleolar translocation signal (NTS) domains are able to induce apoptosis at levels comparable to those of the full length ING1b as determined using Annexin V assays. The A3H-NLS/NTS peptide exhibited strong nucleolar localization, characteristic of full length ING1b. Cells overexpressing the full length ING1b and A3H-NLS/NTS peptide showed similar changes in cell morphology characteristic of apoptosis and exhibited increased levels of PARP cleavage. While the A3H region was necessary but not sufficient, the NLS/NTS domain was required, and partially sufficient, for induction of apoptosis. Adenoviral delivery of A3H-NLS/NTS peptide led to a drastic increase in the number of cells undergoing apoptosis and resulted in a strong dose-dependent inhibition of cancer cells viability that was independent of p53 status. The strong anti-tumorigenic effects were observed in a broad range of tested cancer cell lines including those of osteosarcoma, glioblastoma and breast cancer origin. The evaluation of the synergy between the A3H-NLS/NTS peptide and common chemotherapeutic agents is currently ongoing. Our longterm goal is to develop ING1b-based therapeutics that can be used as an adjuvant therapy in combination with the existing cancer treatments. 26 POSTER (Board P020) NPD926, a small molecule inducer of reactive oxygen species, kills cancer cells via glutathione depletion T. Kawamura1 , Y. Kondoh1 , M. Muroi1 , M. Kawatani1 , H. Osada1 . 1 Riken, Antibiotics Laboratory, Wako Saitama, Japan Background: Elucidation of the mechanisms of action of bioactive compounds may render a therapeutic regimen to be more successful. However, this process is generally time-consuming. By a combination of proteomic profiling and affinity purification, we recently elucidated the mechanism of action of a newly identified cytotoxic compound, NPD926. Here we report the mechanism of action of NPD926 and its effects on cancer cells. Material and Methods: Prediction of the mechanism of action of NPD926 was performed by ChemProteoBase profiling, which is based on the proteomic perturbation in HeLa cells induced by treatment with bioactive compounds. NPD926-binding proteins were purified using affinity matrices, separated by SDS-PAGE, and identified by MALDI-TOF-MS. Results: NPD926 showed cytotoxicity against 19 types of human cancer cell lines. ChemProteoBase proteomic profiling showed that NPD926 shared similarity with 1-chloro-2,4-dinitrobenzene, a substrate for glutathione S-transferase (GST). By affinity purification, an isozyme of GSTs was identified as a specific NPD926-binding protein. Based on these findings and the subsequent biochemical assays, we elucidated the mechanism of action underlying NPD926-induced cell death: (i) conjugation with glutathione as a substrate for GSTs, (ii) depletion of cellular glutathione, and subsequent (iii) generation of reactive oxygen species (ROS). NPD926 preferentially induced cytotoxicity against KRAStransformed fibroblast NIH3T3 cells, compared with their untransformed counterparts. Furthermore, NPD926 sensitized cells to inhibitors of system xc− , a cystine-glutamate antiporter considered as a potential therapeutic target in cancers including cancer stem cells. Conclusions: By the chemical biological methods, we elucidated the mechanism of action of NPD926. Induction of excessive levels of ROS by compounds has been considered as a potentially effective therapeutic strategy against cancer cells. Our present study shows the effectiveness of a newly identified ROS inducer, which targets glutathione metabolism, in cancer cells including those harboring oncogenic KRAS. Poster Session – Cytotoxics 27 POSTER (Board P021) TAS-102 treatment results in high trifluridine incorporation into DNA with pyrimidine metabolic pathway markedly up-regulated in cancer K. Oguchi1 , K. Sakamoto1 , H. Kazuno1 , H. Ueno1 , K. Ishida1 , T. Yokogawa2 , K. Yamamura1 , R. Kitamura1 , K. Matsuo1 , T. Utsugi1 . 1 Taiho Pharmaceutical Co. Ltd., Tsukuba Research Center, Tsukuba, Japan; 2 Taiho Pharmaceutical Co. Ltd., Business Development Dept., Chiyoda-ku, Japan Background: TAS-102 (Lonsurf® ) consists of trifluridine (FTD) and tipiracil hydrochloride (TPI), at a molar ratio of 1:0.5. FTD is a thymidine analog and the antitumor component of TAS-102. TPI prevents degradation of FTD by thymidine phosphorylase in liver. TAS-102 was found to significantly improve overall survival of patients with metastatic colorectal cancer that is refractory/intolerable to the standard chemotherapies in a global Phase III study. The mechanism of FTD is considered to be based on its incorporation into DNA, however its intracellular metabolism is not completely defined. Here, we investigate the cellular uptake and phosphorylation of FTD, and substrate specificity of incorporation into DNA by DNA polymerase a. Material and Methods: Intra-cellular uptake of FTD was evaluated with nucleoside transporter specific inhibitors, NBMPR and dipyridamole. Substrate specificity for nucleoside kinase and nucleotide phosphorylase was evaluated with recombinant proteins. DNA elongation with FTD triphosphate (F3 dTTP) by DNA polymerase a was analyzed. The levels of FTD incorporated into DNA were analyzed with [3 H]FTD or LC-MS/MS. Results: FTD was transported via ENT1 and ENT2 into cytoplasm, and was phosphorylated by thymidine kinase 1 as effectively as dThd. F3 dTTP was not recognized by dUTPase, whereas FdUrd-triphosphate was degraded to monophosphate form. F3 dTTP was inserted at the opposite site of adenine by DNA polymerase a. DNA extension was effectively carried out at the site of inserted FTD, and was evident on the single strand DNA template inserted FTD.The level of FTD incorporated into DNA was much higher than that of FdUrd in vitro, and FTD remained in DNA after the FTD removal from culturing medium. In vivo study also showed high FTD accumulation in tumor implanted in nude mice. Nucleosomal abnormalities such as swollen nuclei and decreased hetero-chromatin were observed in the cells treated with FTD. Conclusions: These results indicate that FTD is recognized and activated through the thymidine salvage pathway highly up-regulated in tumor, and incorporated into DNA during DNA replicating phase like the natural substrate dThd. FTD might exert antitumor activity by nucleosomal abnormalities caused by high level FTD incorporation into DNA. These unique properties might underlie the clinical benefit of prolonged survival of colorectal cancer patients treated with TAS-102 after failure on prior 5-FU based chemotherapy. 28 POSTER (Board P022) Characterization of the type of cell death induced by novel tambjamine analogs in lung cancer A. Rodilla Martı́n1 , V. Soto-Cerrato1 , P. Manuel-Manresa1 , L. KorrodiGregório1 , R. Quesada2 , R. Pérez-Tomàs1 . 1 University of Barcelona, Department of Pathology and Experimental Therapeutics, Barcelona, Spain; 2 University of Burgos, Department of Chemistry, Barcelona, Spain Lung cancer is the leading cause of cancer death worldwide. Despite of new advances in diagnosis and clinical care, the success of standard treatments is still limited, especially in chemotherapy. Therefore, novel anticancer compounds with different mechanisms of action are eagerly needed. In this view, our research group proposes a new therapeutic strategy against cancer that involves modulating the intracellular pH (pHi). Cancer cells have a reversed pH gradient compared to normal cells, which allows cancer progression by promoting proliferation and evasion of apoptosis. Hence, anion transporter compounds, such as tambjamine analogs, have been selected in this study for their potential as anticancer agents through the modulation of the pHi. First, the effect of our compounds in cell viability was evaluated in several lung cancer cell lines by the MTT assay. A significant decrease was observed in most of them, and two compounds (3 and 9) were chosen for further studies. To test whether these compounds have a cytostatic effect, cytometry assays were performed and showed that tambjamines did not induce a significant cell cycle arrest. Then, to characterize the type of cell death, we analyzed different molecular markers related to apoptosis and autophagy by western blot and we observed some evidence of caspases activation and LC3II accumulation. Furthermore, it could be seen at the microscope, phase contrast as well as electron microscope, that the compounds also induced massive cytoplasmic vacuolization. We tested several markers to distinguish among different potential organelles, which could have undergone this phenomenon. We Wednesday 19 November 2014 15 used LAMP1 and LC3II by immunofluorescence and we could exclude lysosomes and autophagosomes, respectively. The origin of the vacuoles could also be from the incorporation of extracellular fluid by endocytosis or macropinocytosis, or by the swelling of organelles such as mitochondria or endoplasmic reticulum, which we are trying to identify. Altogether, these results show that these anion transporters have potent cytotoxic effects in lung cancer cell lines, inducing some kind of cell death in which traits of several cell death processes are involved. Acknowledgements: This work was supported by a grant from the Spanish government and the EU (FIS PI13/00089) and a grant from La Marató de TV3 Foundation (65/C/2013). LKG holds a postdoctoral fellowship through the Portuguese Foundation for Science and Technology-FCT (SFRH/BPD/91766/2012). 29 POSTER (Board P023) TAS-114 is a novel dUTPase/DPD inhibitor, its DPD inhibition reduces capecitabine dosage but does not diminish therapeutic window in human tumor xenografts W. Yano1 , H. Kazuno1 , T. Yokogawa2 , K. Sakamoto1 , K. Yoshisue1 , T. Wakasa1 , M. Fukuoka3 , K. Matsuo1 , K. Noguchi1 , T. Utsugi1 . 1 Taiho Pharmaceutical Co. Ltd., Tsukuba Research Center, Tsukuba, Japan; 2 Taiho Pharmaceutical Co. Ltd., Business Development Dept., Chiyoda-ku, Japan; 3 Taiho Pharmaceutical Co. Ltd., CMC Center, Tokushima, Japan Background: Deoxyuridine triphosphatase (dUTPase) is a gatekeeper enzyme for uracil misincorporation and is considered to be an important factor for resistance to 5-fluorouracil (5-FU). Dihydropyrimidine dehydrogenase (DPD) is a rate-limiting enzyme for 5-FU degradation. TAS-114 is a firstin class oral dUTPase/DPD inhibitor and is under clinical development in combination with 5-FU prodrugs. Previously, it was reported that the combination of capecitabine and a selective DPD inhibitor could reduce the maximum tolerated dose (MTD) of capecitabine. However, the therapeutic window of capecitabine/DPD inhibitor was no better than capecitabine alone. In contrast, we found that the combination of capecitabine with TAS-114, a dual inhibitor of dUTPase/DPD, significantly enhanced the antitumor efficacy and improved the therapeutic window. Here, we report the mode of DPD inhibition by TAS-114, and roles of dUTPase inhibition and DPD inhibition in capecitabine/TAS-114. Material and Methods: Mode of DPD inhibition was determined by measuring 5-FU degradation in human liver S9 fraction. Plasma levels of 5-FU were measured by LC/MS for pharmacokinetics. The antitumor activity of capecitabine/TAS-114 was evaluated in xenografts of MX-1 and MC-2 (human breast cancers), and KB/TP (cancer cell stably overexpressed thymidine phosphorylase (TP)). MX-1 is a dUTPase inhibition sensitive tumor, and MC-2 and KB/TP are sensitive to capecitabine due to high TP expression. Results: TAS-114 possessed moderate DPD inhibitory activity and its inhibition mode was reversible. In combination with capecitabine, TAS114 increased 5-FU concentration in plasma due to DPD inhibition. This increase in 5-FU exposure led to reduction of capecitabine MTD in all tumor models. In both MC-2 and KB/TP xenograft models, which were highly sensitive to capecitabine, TAS-114 did not reduce maximal antitumor activity and therapeutic window of capecitabine, despite a reduction in the dosage. In the MX-1 xenograft model, which is inherently less sensitive to capecitabine, TAS-114 significantly enhanced antitumor activity of capecitabine, demonstrating the importance of dUTPase inhibition. Conclusions: TAS-114 is a moderate and reversible inhibitor of DPD. Its favorable profile of DPD inhibition reduces the MTD of capecitabine but does not diminish therapeutic window. Phase 1 study of capecitabine/TAS114 is ongoing and therapeutic efficacy as a dUTPase/DPD dual inhibitor can hopefully be demonstrated. 16 Wednesday 19 November 2014 30 POSTER (Board P024) The fungal-derived cyclohexadepsipeptide Destruxin E exerts multifaceted anticancer and antiangiogenic activities R. Dornetshuber-Fleiss1 , P. Heffeter2 , T. Mohr2 , P. Hazemi3 , K. Kryeziu4 , C. Seger5 , W. Berger2 , R. Lemmens-Gruber3 . 1 University of Vienna and Medical University of Vienna, Institute of Pharmacology and Toxicology and the Institute of Cancer Research Department of Medicine I and Comprehensive Cancer Center of the Medical University, Vienna, Austria; 2 Medical University of Vienna, Institute of Cancer Research Department of Medicine I and Comprehensive Cancer Center of the Medical University, Vienna, Austria; 3 University of Vienna, Department of Pharmacology and Toxicology, Vienna, Austria; 4 Medical University of Vienna, Institute of Cancer Research Department of Medicine I and Comprehensive Cancer Center of the Medical University, Vienna, Austria; 5 Leopold-Franzens University Innsbruck, Institute of Pharmacy Department of Pharmacognosy, Vienna, Austria Background: Destruxins − a group of secondary metabolites of the entomopathogenic fungus Metarhizium anisopliae − recently came into focus of interest as anticancer therapeutics for colorectal cancer. However, the knowledge on their anticancer effects is fragmentary. Consequently, the present study aimed to investigate the impact of the representative derivative Destruxin E (Dtx E) on human colon cancer cell growth and survival. Materials and Methods: 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays and Western blot analyses were used to assess the cytostatic/cytotoxic activity of Dtx E on Caco-2 and HCT116 cells. Impact of cell cycle distribution was evaluated using PI-stainings and FACS analyses. Apoptotic effects were determined with DAPI stainings and Western blot analyses. Angiogenesis inhibition was evaluated using scratch and tube-formation assays. To investigate the impact on the intracellular redox potential flow cytometry with dihydroxyethidium (DHE) and combination studies with the radical scavenger N-acetyl cysteine (NAC) and the glutathione inhibitor BSO were performed. Results: The experimental data showed that Dtx E exerts potent antiproliferative activity in the nanomolar range in CaCo-2 and HCT116 cells. Moreover, Dtx E caused an imbalance of cell cycle distribution and the cytostatic/cytotoxic effects were shown to be widely p53-independent but reduced by p21- and bax-deletion, respectively. Cytotoxicity is based on intrinsic apoptosis induction and associated with phosphoinositide-3kinase (PI3K)/Akt pathway inhibition. Additionally, anticancer activity of Dtx E involves disturbance of the intracellular redox balance and finally, Dtx E inhibits the migration and tube formation of human endothelial cells indicating antiangiogenic potential. Conclusion: The data of the present study indicate that Dtx E represents a feasible, multifunctional anticancer drug candidate for preclinical development against colorectal cancer. 31 POSTER (Board P025) N-Myc amplification sensitizes tumor cells to inhibition by Danusertib, an Aurora kinase inhibitor P. Carpinelli1 , R. Ceruti2 , R. Alzani2 , C. Re1 , D. Ballinari1 , S. Cribioli2 , M. Russo2 , A. Degrassi2 , G. Texido2 , M. Ciomei2 , E. Pesenti2 , A. Montagnoli1 , A. Galvani1 . 1 Nerviano Medical Sciences Srl, Cell Biology, Nerviano (Milano), Italy; 2 Nerviano Medical Sciences Srl, Pharmacology, Nerviano (Milano), Italy Amplification of N-Myc is a driving mutational event in a subset of tumor types, particularly those of neural origin and neuroendocrine tumors such as neuroblastoma (NB), neuroendocrine prostate cancer (NEPC), small cell lung cancer (SCLC) and others. Thus, inhibition/reduction of N-Myc protein levels may be of therapeutic benefit for such tumor types but to date small molecules that specifically target this oncogene are not clinically available. Aurora A kinase has been shown to interact directly with N-Myc in neuroblastoma and to induce its stabilization by preventing binding of the Fbxw7 ubiquitin ligase, which mediates its ubiquitination and subsequent proteasomal degradation. Moreover, there is clear evidence that pharmacological intervention with small molecule inhibitors which target Aurora A represents a promising therapeutic approach for this tumor subtype. Danusertib (PHA-739358) is a small molecule ATP competitor that inhibits Aurora A, B and C kinases. Aurora kinases inhibition by Danusertib results in cell cycle block with concomitant inhibition of cell proliferation. The compound is in clinical investigation in both solid tumor and hematological malignancy settings. Here we report the in vitro and in vivo activity of Danusertib in N-Myc amplified tumor models. We demonstrate that in vitro, NB cell lines bearing amplified N-Myc display greater sensitivity to Danusertib than Poster Session – Cytotoxics non-amplified cell lines. In such sensitive NB cell lines, inhibition of histone H3 phosphorylation, a marker of Aurora kinase inhibition, is associated with decreased levels of N-Myc and induction of apoptosis. In NB tumor xenograft models, Danusertib induced significant in vivo tumor growth inhibition, including tumor regression, accompanied by robust reductions of N-Myc protein levels, again concomitant with inhibition of phospho-histone H3 and induction of apoptosis. Additionally, Danusertib also displayed significant in vivo activity against the TRAMP, a transgenic mouse prostate carcinoma model, which displays several molecular and pathological features of NEPC. Here again, treatment with Danusertib induced decreased levels of N-Myc, associated with inhibition of histone H3 phosphorylation. Thus, Danusertib destabilizes N-Myc both in vitro and in vivo and therefore merits further investigation as a potential option for the therapy of N-Myc amplified neuroendocrine tumors, as well as other settings which are dependent on this oncogene. 32 POSTER (Board P026) Replication stress is a determinant of synergy between gemcitabine and Chk1 inhibition S.B. Koh1 , A. Courtin1 , R. Boyce2 , B. Boyle2 , F.M. Richards1 , D.I. Jodrell1 . 1 Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, United Kingdom; 2 Sentinel Oncology Limited, Cambridge, United Kingdom Background: Chk1 plays multiple regulatory roles within the cell cycle and this study interrogates the mechanism of synergy between Chk1 inhibition and gemcitabine in cancer cells. Methodology: We evaluated the cytotoxicity of FS105, a Chk1-specific inhibitor (IC50 2.8nM), with gemcitabine in human and murine cancer cells. We then employed established mathematical models to quantitatively identify drug concentrations that yielded synergistic growth inhibition. Subsequent mechanistic studies, achieved by quantitative high-content imaging, immunofluorescence microscopy, flow cytometry and immunoblotting, were performed at the identified synergistic drug concentrations. Results: Synergy with FS105 was found at sub-GI50 concentrations of gemcitabine in all tested cell lines, e.g. Emax 91±3% growth inhibition at 3uM FS105+30nM gemcitabine in Panc-1 cells compared to Bliss predicted 33±1% growth inhibition. At these concentrations, we did not observe substantial premature mitotic entry, contrary to the prevailing model that inhibiting Chk1 abrogates the G2/M checkpoint. Downstream checkpoint effector CDK1 Y15 was not inhibited by FS105 at synergistic concentrations with gemcitabine. In agreement with this, significant S phase arrest with hallmarks of elevated replication stress and DNA damage such as ùH2AX was observed. For example, 63±6% MIA PaCa-2 cells were in S phase 24 hours after the combination treatment, compared to control (33±2%), FS105 alone (35±4%) and gemcitabine alone (43±4%). The induction of S phase arrest and ùH2AX by the combination was inhibited when the activity of replication initiator CDC7 was suppressed by PHA-767491. This observation is consistent with Chk1 role in regulating origin firing and our hypothesis that Chk1 inhibition synergises with gemcitabine via destabilisation of the replication machinery. Conclusions: This study elucidates how Chk1 inhibition with gemcitabine at synergistic concentrations perturbs predominantly the S-phase homeostasis in cancer cells. It also provides a molecular rationale to reassess the current scheduling paradigm of Chk1 inhibitors with DNA-damaging agents. 33 POSTER (Board P027) Combining the long-acting topoisomerase 1-inhibitor etirinotecan pegol with the PARP inhibitor rucaparib to provide anti-tumor synergy without increased toxicity U. Hoch1 , D. Charych2 . 1 Nektar Therapeutics, Development, San Francisco CA, USA; 2 Nektar Therapeutics, Research, San Francisco CA, USA Background: PARP inhibition sensitizes cells to DNA-damaging agents, particularly topoisomerase 1-inhibitors, where the combination shows synergy in nonclinical studies. However, in the clinic, the combination of either topotecan or irinotecan with PARP inhibitors showed severe hematologic toxicities, requiring dose reductions beyond optimal therapeutic effects. Etirinotecan pegol (NKTR-102) is the first long-acting Topoisomerase 1-inhibitor providing continuous exposure to active metabolite throughout the entire chemotherapy cycle with reduced peak concentrations, resulting in better efficacy and safety, including a low rate of Grade 3 neutropenia (11%). Here we present in vivo combination data of etirinotecan pegol and rucaparib in the MX-1 breast cancer model. Methods: Mice bearing BRCA1-deficient MX-1 breast cancer tumors (~100 mm3 ) received either vehicle, PO rucaparib, IV etirinotecan pegol, or a combination of etirinotecan pegol and rucaparib as follows: 30 or Poster Session – Cytotoxics 150 mg/kg rucaparib qd×21; 10 or 50 mg/kg etirinotecan pegol q7d×4; or 30/10, 30/50, 150/10, or 150/50 mg/kg rucaparib/etirinotecan pegol (n = 10/group). Anti-tumor efficacy was evaluated by tumor growth delay (TGD) and regression responses. Results: Control tumors grew to the 2000 mm3 endpoint in a median of 25 days. Rucaparib at 30 and 150 mg/kg resulted in TGDs of 14 and 18 days, respectively. Tumor growth was slower following rucaparib but was continuous in all animals. Etirinotecan pegol at 10 mg/kg resulted in TGD of 32 days with one tumor-free animal. Any combination of etirinotecan pegol and rucaparib, and single-agent etirinotecan pegol at 50 mg/kg caused complete tumor regression in all animals that persisted for at least 10 weeks. All single-agent and combination doses were well tolerated without clinical signs or body weight loss, except rucaparib/etirinotecan pegol 150/50 where individual animals showed BW loss of 15% (group mean: 6%). Conclusions: Combined etirinotecan pegol and rucaparib showed clear synergy in the BRCA1-deficient MX-1 breast cancer model with 100% complete responses and no tumor regrowth, even 7 weeks after last dose. The combination was well tolerated. SN38 trough and rucaparib plasma exposure at the dose levels employed in mice are achieved clinically. Our results suggest that this combination may diminish previously observed toxicities of combined Topoisomerase 1- and PARP-inhibitors while improving efficacy and support pursuing further studies with etirinotecan pegol and PARP-inhibitors. 34 POSTER (Board P028) Phase I, dose-escalation study of the investigational drug D07001-F4, an oral formulation of gemcitabine HCl, in patients (pts) with advanced solid tumors or lymphoma C. Lin1 , W. Su2 , J. Lee1 , C. Hsu1 , A. Cheng1 , C. Lin3 , H. Ho3 , C. Huang3 , S. Hsueh3 , J. Yang1 . 1 National Taiwan University Hospital, Oncology, Taipei, Taiwan; 2 National Cheng Kung University Hospital, Oncology, Tainan, Taiwan; 3 InnoPharmax Inc., Taipei, Taiwan Background: This phase 1 dose-escalation trial, using a 3+3 design, was conducted to evaluate the safety, tolerability, pharmacokinetics (PK), and preliminary efficacy of D07001-F4, an oral formulation of gemcitabine HCl, in pts with advanced solid tumors or lymphoma. The primary objectives were to determine the MTD, characterize DLT(s) and define the recommended phase 2 dose of D07001-F4. Methods: Patients aged 20 yrs with PS 0−2 were eligible. Gemcitabine 5 mg IV in cycle 0 and D07001-F4 from 2 mg PO were given on days 1, 3, 5, 8, 10, and 12 of a 21-day cycle to determine the MTD based on DLTs in cycle 1. Plasma and peripheral blood samples were obtained for PK analysis in cycle 1. Results: As of May 2014, 15 pts (10 M, 5 F; median 59 years [range 42−67]) were enrolled into 5 dose escalation cohorts (2−30 mg). A median of 3 cycles were given (range 0−13+). So far, no DLTs occurred and the MTD has not yet been reached. Enrollment is ongoing. Two pts at cohort 4 (20 mg) experienced 3 drug-related G1 AEs (1 fever, 2 fatigue) and 2 pts at cohort 5 (30 mg) experienced 3 drug-related G1 AEs (1 vomiting, 2 nausea). PK results showed a dose proportional increase in exposure of dFdC after repeated dosing. Plasma dFdC was fast eliminated after dosing. The average Cmax 7474 pg/mL and AUC0−24 5603 hr·pg/ml at day 1 and Cmax 6588 pg/mL and AUC0−24 7926 hr·pg/ml at day 12 were observed at cohort 4 (20 mg). 10 pts had SD, 7 of whom were on study for 3 months. One ongoing pt (5 mg) with thyroid cancer had tumor shrinkage of 28%. Conclusions: From preliminary data, D07001-F4 appears to be well tolerated and has shown signs of anti-tumor activity in pts with advanced solid tumors. Accrual at the 30 mg dose level is ongoing and a recommended phase 2 dose is expected to be reached soon. Updated results will be presented. Clinical trial registration: NCT01800630 35 POSTER (Board P029) BRCA1 expression exploratory analysis in patients of the phase III trial of trabectedin vs. doxorubicin-based chemotherapy as first-line therapy in translocation-related sarcomas M. Aracil1 , P. Lardelli2 , A. Nieto2 , C.M. Galmarini1 . 1 PharmaMar S.A., R&D, Colmenar Viejo (Madrid), Spain; 2 PharmaMar S.A., Clinical Development, Colmenar Viejo (Madrid), Spain Background: BRCA1 mRNA and protein expression levels were analyzed in translocation-related soft tissue sarcoma (TRS) patients treated with trabectedin (arm A) or doxorubicin (arm B) as first-line therapy (phase III trial ET-C-002−07). Expression levels were analyzed in tumor tissue samples obtained at diagnosis with the aim to determine the potential role of BRCA1 as prognostic and/or predictive biomarker. Wednesday 19 November 2014 17 Materials and Methods: A total of 83 samples with clinical and molecular data were subjected to biostatistical analysis in order to correlate the expression values with the clinical outcome (ORR, PFS and OS). PFS and objective tumor response were evaluated by an Independent External Review Committee according to RECIST v.1.0. The IHC staining intensity was evaluated by a pathologist and reported following a 4-level scale from 0 (no staining) to +3 (strong staining). Expression levels were categorized using as cutoff the median value. Results: In the trabectedin arm, lower BRCA1 protein expression (<3) was associated with higher tumor control (PR+SD) (91.7% for low BRCA1 vs. 57.1% for high BRCA1, p = 0.0095) and longer median PFS (not reached for low BRCA1 vs. 2.4 m for high BRCA1; p = 0.0013). In the doxorubicin arm, lower BRCA1 protein expression was associated with longer median PFS (18.9 m for low BRCA1 vs. 5.5 m for high BRCA1; p = 0.0156). In a multivariate analysis including the most common clinical variables, where treatment is not selected, BRCA1 protein expression correlated with a worse PFS (HR = 4.539, 95% CI: 1.941–10.613; p = 0.0005). Conclusions: The results point out the potential importance of BRCA1 in the clinical outcome of patients with TRS treated with trabectedin or doxorubicin. In particular, high protein expression of BRCA1 seems to be associated with a worse clinical outcome. Its potential prognostic and/or predictive value in TRS patients needs to be further evaluated. 36 POSTER (Board P030) Suppression of metastasis and improvement of drug distribution by eribulin mesylate Y. Ozawa1 , K. Okamoto1 , Y. Adachi1 , M. Asano1 , K. Tabata1 , Y. Funahashi2 , J. Matsui1 . 1 Eisai Co. Ltd., Oncology PCU, Tsukuba Ibaraki, Japan; 2 Eisai Co. Ltd., BPM CFU, Andover, USA Background: Eribulin mesylate (eribulin) has shown trends toward greater overall survival compared to progression-free survival in late stage metastatic breast cancer patients in the clinic. This finding suggests that eribulin may have additional, previously unrecognized antitumor mechanisms. To investigate this possibility, eribulin’s effects on microenvironment including tumor vessels were investigated and we found that eribulin demonstrated improvement in tumor perfusion through vascular remodeling in human breast cancer models. Material and Methods: For in vitro study, cells were cultured under 1% O2 and 0.1 mg/ml glucose. EMT markers were analyzed by western blot analysis. For in vivo model, after 15 days post-4T1 cell inoculation into the 3rd mammary fad pad of Balb/c mice, drug treatment was started, and after 28 days lung metastases were counted. In MDA-MB-231 model, treatments with capecitabine or eribulin were started on day 1. On day 12, eribulin treated mice were divided into no-treatment and capecitabine treatment groups. Results: The remodeling of tumor vessels evoked 2 possibilities, antimetastatic effect and enhancement of antitumor activity thorough the improvement of drug influx into tumors. Our data showed that hypoxic conditions induced EMT phenotype in breast cancer cells in vitro, and eribulin treatment reduced hypoxic markers in xenorafts. Furthermore, eribulin significantly reduced the lung metastasis in 4T1 OT model in which eribulin did not have any antitumor effect against primary tumor because of MDR over expression. We next investigated the effect of eribulin on improvement of drug influx into tumors. We compared the antitumor effects of capecitabine with or without pre-treatment of eribulin in MDA-MB-231 xenograft model. In eribulin pre-treated group, eribulin treatment induced clear tumor regression, and then, capecitabine treatment was started when tumor volumes returned to baseline prior to eribulin treatment. Interestingly, antitumor effect of capecitabine was enhanced in eribulin-pretreated group, compared to non-treated group. We think this enhancement of antitumor effect is the result of improvement of capacitabine influx into tumors. Conclusion: We have found the new effects of eribulin, anti-metastatic effect and improvement of drug influx into tumors via the remodeling of tumor vessels, using human and mouse breast cancer models. These preclinical finding may provide new insights into the clinical observations. 37 POSTER (Board P031) Effect of a microtubule-targeting drug on cell–cell contacts in bladder epithelial tumour cells L.M. Antón-Aparicio1 , R. Castosa2 , M. Haz2 , M. Blanco2 , M. Rodriguez2 , M. Valladares1 , A. Figueroa2 . 1 Complejo Hospitalario Universitario A Coruña (INBIC-CHUAC), Medical Oncology Unit, Coruna, Spain; 2 Instituto Investigación Biomédica A Coruña-Complejo Hospitalario Universitario A Coruña (INBIC-CHUAC), Translational Cancer Research Group, Coruna, Spain Background: Bladder cancer is a common malignancy affecting the genitourinary system that represents the fifth most common cancer in 18 Wednesday 19 November 2014 the world. Transitional cell carcinoma (TCC) represents 95% of these tumours. Vinflunine (VFL) is a microtubule-targeting drug that suppresses microtubule dynamics, showing anti-metastatic properties both in vitro and in living cancer cells. An increasing body of evidence underlines the influence of the microtubules dynamics on the cadherin-dependent cell– cell adhesions. In this report, we investigate the role of VFL on cell–cell contacts in bladder epithelial tumour cells. Methods: Human bladder epithelial tumour cell lines HT1376, 5637 and UMUC3 were used to analyse cadherin-dependent cell–cell adhesions under VFL treatment. VFL effect on growth inhibition was measured by using a MTT colorimetric cell viability assay. Western blot, immunofluorescence and transmission electron microscopy analyses were performed to assess the roles of VFL effect on cell–cell adhesions, epithelial-to-mesenchymal markers and apoptosis. The role of the proteasome in controlling cell–cell adhesion was studied using the proteasome inhibitor MG132. Results: We show that VFL induces cell death in bladder cancer cells and activates epithelial differentiation of the remaining living cells, leading to an increase of E-cadherin-dependent cell–cell adhesion and a reduction of mesenchymal markers, such as N-cadherin or vimentin. Moreover, while E-cadherin is increased, the levels of Hakai, an E3 ubiquitin-ligase for E-cadherin, were significantly reduced in presence of VFL. In 5637, this reduction on Hakai expression was blocked by MG132 proteasome inhibitor, indicating that the proteasome pathway could be one of the molecular mechanisms involved in its degradation. Conclusions: Our findings underscore a critical function for VFL in cell–cell adhesions of epithelial bladder tumour cells, suggesting a novel molecular mechanism by which VFL may impact upon EMT and metastasis. 38 POSTER (Board P032) The indolyl-chalcone CDD-026 induces cancer cell death through targeting of STMN1 and mitotic catastrophe B. Wegiel1 , Y. Wang1 , F. Jernigan1 , L. Sun1 . 1 Beth Israel Deaconess Medical Center, Surgery, Boston MA, USA Background: Patients with metastatic prostate cancer are still in needs of more effective treatments. Mitotic catastrophe is a tumor suppressive process that is driven by aberrant mitosis and in many cases associated with changes in microtubules stability. The activation of mitotic catastrophe is a highly desirable therapeutic endpoint and the focus of this study. The aim of this study was to investigate the anticancer activities of a series of novel indolyl-chalcones and validate their targets in inducing mitotic catastrophe in prostate cancer cells lines. Materials and Methods: We have performed screen of synthetic indolyl-chalcones in induction of apoptosis and inhibition of proliferation of cancer cells. We have applied multiple cell biology assays to test apoptosis (AnnexinV/PI staining, crystal violet staining), proliferation (BrDU incorporation assay, PI cell cycle analysis), targets analysis (PCR Real time profiler) and targets validation (real time PCR). We conducted molecular modeling analyses to develop a QSAR model. Results: We have identified and improved the potency of a series of novel indoly-chalcones. Our results indicated that the lead molecule CDD026 (Formula: C20H16FNO) at 1−10 mM induced early apoptosis without affecting incorporation of BrdU in S-phase, suggesting its critical role in interrupting late phases of cell cycle. In contrast, the non-indolyl analog CDD-023 inhibited cell cycle progression through G1/S phase in a dose dependent manner (1, 10, 25 mM) but did not induce significant cell death. We then focused our analysis on CDD-026, which at as low dose as 0.1 mM induced apoptosis in PC3 cells. In addition, CDD-026 demonstrated potent inhibitory activity in lung and other cancer cells. To evaluate the potential target for this drug, we have employed Cancer Pathway Finder PCR array (Qiagen) and identified Stathmin 1 (STMN1) and adrenomedullin genes as the most highly upregulated in response to treatment with CDD026. We have validated these targets by real time PCR in PC3 cells treated with CDD-026. Further, we showed that in contrast to taxanes that stabilized microtubules, CDD-026 destabilized microtubules. This effect may be dependent on STMN1 upregulation leading to mitotic catastrophe, which is currently being addressed in our studies. Conclusions: CDD-026 induces mitotic catastrophe in PC3 cells via upregulation of STMN1, which destabilizes microtubules and disrupts cell cycle. Poster Session – Cytotoxics 39 POSTER (Board P033) Phytochemical indole-3-carbinol synergizes strongly with fludarabine and induces p53-dependent and -independent cell death in chronic lymphocytic leukemia cells irrespective of their IGHV mutation state and treatment resistances G. Perez-Chacon1 , C. Martinez-Laperche2 , N. Rebolleda1 , B. SomovillaCrespo3 , C. Muñoz-Calleja3 , I. Buño2 , J.M. Zapata1 . 1 Instituto de Investigaciones Biomedicas “Alberto Sols” CSIC/UAM, Madrid, Spain; 2 Hospital General Universitario and Instituto de Investigacion Sanitaria Gregorio Marañon, Servicio de Hematologia, Madrid, Spain; 3 Hospital Universitario de la Princesa, Servicio de Inmunologia, Madrid, Spain Background: Chronic lymphocytic leukemia (CLL) is the most common type of leukemia found in adults in Western countries, which still is lacking a cure. A variety of chemotherapy regimens are being used in CLL, but unfortunately patients will eventually become refractory to treatments and die. It is therefore a priority to develop new treatments and therapeutic approaches that improve patient prognosis and survival. Indole-3-carbinol (I3C) is a glucobrassicine derivative that is found in edible Cruciferae plants, such as the broccoli and the cabbage. Phase I and II clinical trials have demonstrated its antitumoral activity in precancerous cervix lesions and in vulvar epidermal neoplasia, while lacking significant toxicity. Materials and Methods: We have tested whether I3C was active against CLL cells. We used a cohort of CLL cells from 36 patients representing different Rai stages, IGHV mutation status, cytogenetic alterations, and responses to treatments. The effect of increasing concentrations of I3C, F-ara-A and combinations of both drugs (keeping a constant 50:1 ratio) on CLL cell survival was determined. CLL samples were grouped according to their characteristics. Results: Our results show that I3C potently reduced the viability of CLL cells with a LD50 of ~37 mM, while it was much less cytotoxic in PBMCs from normal donors (LD50 ~100 mM). Moreover, I3C showed strong synergy with F-ara-A in all cases studied (Table). Remarkably, I3C was able to synergize with F-ara-A even in p53-deficient CLL cells (70% TP53/ATMdeletions) and in CLL cells that showed in vitro resistance to F-ara-A. Indeed, the concentrations of F-ara-A required to kill 90% of CLL cells in the combined I3C/F-ara-A treatment resulted in an F-ara-A dose reduction index (DRI) of 31 for CLL cells harboring TP53/ATM deletions and of 82.5 for CLL cells showing in vitro resistance to F-ara-A. The combination of I3C + F-ara-A was equally active in CLL cells with mutated and unmutated IGHV and were also active in CLL cells from patients that have developed treatment resistances (patients that have received 2−4 treatments). Of note is that I3C could also synergize with vincristine and chlorambucil (Table). Conclusions: Our data indicate that I3C, alone or in combination with F-ara-A and other chemotherapeutic drugs, is a potent inductor of apoptosis in CLL in vitro. I3C strongly synergizes with F-ara-A in all types of CLL tested, including CLL from refractory patients and CLL cells with deficient p53 pathway. The striking DRI for F-ara-A in combination with I3C would likely reduce harmful secondary effects associated to fludarabine while having a similar or better effectiveness. Moreover, the low toxicity of I3C, already clinically tested, and its anti-CLL activity would also support its use as a novel neoadjuvant and adjuvant therapy in CLL, even in those patients with relapsed or refractory disease. 40 POSTER (Board P034) Selectivity and mechanism of action studies for Polo Box-targeted, non-ATP based inhibitors of PLK1 M. Baxter1 , S. Craig1 , C. McInnes1 , M.D. Wyatt1 . 1 University of South Carolina, Drug Discovery and Biomedical Sciences, Columbia, USA Polo-like Kinase 1 (PLK1) performs critical roles in the coordination of mitosis and is also an oncogene over-expressed in many cancer types. ATP-binding site inhibitors of PLK1 have progressed to clinical trials, and one was recently given FDA breakthrough status to treat acute myeloid leukemia. However, recent data suggests that there are major disadvantages to blocking the kinase activity of PLK1. First, PLK family specificity is an issue with ATP-competitive compounds because they commonly inhibit all PLK paralogs, including PLK3, a known tumor suppressor. Second, a single point mutant in the active site of PLK1 (Cys67Val) results in dramatic resistance to structurally distinct ATPcompetitive inhibitors (Burkard et al, ACS Chem. Biol. 2012, 7, 978– 981), suggesting that the emergence of resistance in the clinic against these agents is likely. We have validated the innovative REPLACE strategy by discovering non-ATP competitive and PLK1-selective inhibitors as an alternative therapeutic strategy for this important target. The Polobox domain (PBD) of each PLK is a phospho-peptide binding motif that determines substrate recognition and subcellular localization. Our approach targets the PBD of PLK1 to achieve desired selectivity and improve efficacy. Through modeling and design we produced series Poster Session – Cytotoxics of fragment-ligated inhibitory peptides (FLIPs). We report three FLIPs with an octyl-benzamide group, having the following different amino acid C-terminus sequences: −PNGL, −AI, and −PL. In vitro binding to the PBDs of PLK1 and PLK3 was measured by a fluorescence polarization assay. The IC50 values for PLK1 calculated from the competition assay are 0.36 mM, 0.41 mM, and 1.2 mM, respectively, and all three are at least >1800fold more selective for PLK1. Initial testing in two cancer lines revealed respectable anti-proliferative activity for two of the FLIPs. In addition, we report the investigation of our PBD-inhibitors in cells expressing the mutant C67V PLK1 that is resistant to ATP-based inhibitors. We find that our compounds are equally active in cells expressing wild-type or C67V PLK1, whereas cells expressing C67V PLK1 are dramatically resistant to the ATPbased inhibitor, BI 2536. Current work is characterizing the mechanism of action for these FLIPs in cancer cells, including their ability to induce a G2/M cell cycle arrest, and induce aberrant mitotic phenotypes associated with PBD-inhibition. These exciting developments demonstrate the validity of our approach to produce drug-like lead PBD-inhibitors that are PLK1 selective and are active against tumors resistant to ATP-inhibitors. PBDinhibitors could ultimately be used in combination therapy regimens with ATP-based inhibitors for a dual attack on this important, clinically validated oncology target. 41 POSTER (Board P035) Clinical activity of BIND-014 (docetaxel nanoparticles for injectable suspension) as second-line therapy in patients (pts) with Stage III/IV non-small cell lung cancer R. Natale1 , M. Socinski2 , L. Hart3 , O. Lipatov4 , D. Spigel5 , B. Gershenhorn6 , G. Weiss7 , S. Kazmi8 , N. Karaseva9 , O. Gladkov10 , V. Moiseyenko11 , J. Summa12 , G. Otterson13 . 1 Cedars-Sinai Medical Center Samuel Oschin Comprehensive Cancer Center, Clinical Lung Cancer Program, Los Angeles, USA; 2 University of Pittsburgh Cancer Pavilion, Lung and Thoracic Malignancies Program, Pittsburgh, USA; 3 Florida Cancer Specialists, Clinical Research Director Drug Development Program, Fort Meyers, USA; 4 Republic Clinical Oncology Dispensary, Department of Medical Oncology, Ufa, Russian Federation; 5 Sarah Cannon Research Institute, Lung Cancer Research Program, Nashville, USA; 6 Cancer Treatment Centers of America Midwestern Regional Medical Center, Department of Clinical Research and Clinical Trials, Zion, USA; 7 Cancer Treatment Centers of America Western Regional Medical Center, Department of Clinical Research and Clinical Trials, Goodyear, USA; 8 Cancer Treatment Centers of America Eastern Regional Medical Center, Department of Clinical Research and Clinical Trials, Philadelphia, USA; 9 City Clinical Oncology Dispensary, Department of Medical Oncology, Saint Petersburg, Russian Federation; 10 Chelyabinsk Regional Clinical Oncology Dispensary, Department of Medical Oncology, Chelyabinsk, Russian Federation; 11 N.N. Petrov Research Institute of Oncologists, Department of Medical Oncology, Saint-Petersburg, Russian Federation; 12 BIND Therapeutics, Department of Clinical Development, Cambridge, USA; 13 Ohio State University Comprehensive Cancer Center, Thoracic Oncology Program, Columbus, USA Background: BIND-014 is a novel, polymeric nanoparticle containing docetaxel (D) targeted to prostate-specific membrane antigen (PSMA), a protein expressed on prostate cancer cells and on the vasculature of many non-prostate solid tumors. BIND-014 is anticipated to improve the clinical benefit of D by increasing its concentration and duration of exposure in tumors. In a phase 1 study, BIND-014 was generally well-tolerated and displayed anti-tumor activity at low doses and in tumors where solventbased D (sbD; Taxotere® ) has minimal activity. Material and Methods: APhase 2 study was conducted of BIND-014 administered by a 60-minute intravenous infusion at 60 mg/m2 on Day 1 of a 21-day cycle as second-line therapy after a Pt-containing regimen in pts with Stage III/IV NSCLC with characterized genomic status (EGFR mutation, ALK rearrangement, KRAS mutation). A 2-stage design for futility was incorporated with a maximum of 40 pts anticipated. The primary endpoint was ORR. Results: Forty pts were enrolled and received a median of 3 doses (range 1−12); the study is closed to enrollment with several pts continuing on study. To date, 33 pts are evaluable for response, 5 (15%) had PR and 12 (36%) had stable disease lasting 12 weeks (SD 12 wks). Among 8 pts testing positive for a KRAS mutation, 2 (25%) had PR and 3 (38%) had SD 12 wks. Among the 40 treated pts, 4 experienced an SAE classified as related to study drug (Gr 2 neutropenic fever [1 pt], Gr 2 DVT [1 pt], Gr 3 dyspnea [1 pt], Gr 3 hypoxia [1 pt]). There were 174 drug-related AEs, 102 (59%) of which were Gr 1. Drug-related AEs Gr 2 occurring in at least 3 pts included anemia (3 pts), dehydration (4 pts) and fatigue (5 pts). Two pts experienced Gr 3 lymphocytopenia and 2 pts experienced Gr 2 neutropenia. There was no evidence of hepatotoxicity and only 1 incident of peripheral neuropathy (Gr 3). Wednesday 19 November 2014 19 Conclusions: BIND-014 administered at 60 mg/m2 on Day 1 of a 21-day cycle is clinically active and well-tolerated assecond-line therapy in Stage III/IV NSCLC pts with broad tumor mutation status. BIND-014 demonstrated a 63% disease control rate (25% PR + 38% SD 12 wks) in pts with KRAS mutations, a population generally unresponsive to sbD. Neutropenia, anemia and neuropathy, commonly observed with sbD, were significantly reduced with BIND-014. The potential safety and activity advantages of BIND-014 compared to historical sbD data warrant further evaluation in pts with NSCLC, including those with KRAS mutations. Final data will be presented. 42 POSTER (Board P036) Interaction of SJG-136 with cognate sequences of oncogenic transcription factors J. Mantaj1 , P.J. Jackson1 , D.E. Thurston1 , K.M. Rahman1 . 1 King’s College London, Institute of Pharmaceutical Sciences, London, United Kingdom The pyrrolo[2,1-c][1,4]benzodiazepines (PBDs) are sequence-selective DNA minor-groove binding agents. They possess a ‘soft’ electrophilic imine moiety at their N10-C11 position which can form an aminal linkage with the C2-NH2 group of a guanine base. The PBD dimer SJG-136 is presently in Phase II clinical trials in ovarian cancer and leukaemia. There is growing evidence that PBD monomers exert their pharmacological effects through transcription factor inhibition, for example GWL-78, a C8linked PBD-Py-Py conjugate, has been shown to block interaction of the transcription factor NF-Y and KMR-28−39, a GC sequence selective PBDMPB conjugate, inhibits the transcription factor NF-kB. The aim of this study is to investigate whether PBD dimers like SJG-136 also interact with transcription factor binding sequences and exert their antitumor activity through this mechanism in addition to previously reported DNA strand breakage, inhibition of endonucleases, RNA polymerases and arrest of replication fork. We have developed an ion pair reverse phase HPLC/MS analytical methodology and demonstrated for the first time the ability of the PBD dimer SJG-136 to bind to specific DNA consensus sequences of the transcription factors NF-kB, EGR-1, AP-1 and STAT3. As a dimer, SJG-136 can form intra-, inter-strand and mono-alkylated adducts with DNA. Interestingly, we have been able to observe that SJG-136 formed three distinct adducts with the STAT3 consensus sequence, while only single adducts were observed in the case of NF-kB-1, NF-kB-2, EGR-1 and AP-1. After completing the biophysical study, the effect of SJG-136 on the expression of STAT3 dependent genes was carried out by RTPCR, qPCR and Western Blot experiments using the STAT3 dependent breast cancer cell line MDA-MB-231. Our results demonstrate a significant dose dependent down regulation of STAT3 dependent genes cyclin D1, survivin, NNMT, Bcl-2, STAT3 and fascin. These findings have implications for understanding the mechanism of action of SJG-136 and can potentially explain the differences in activity of SJG-136 against various tumour cell lines. Future work will focus on establishing the correlation with transcription factors NF-kB, AP-1 and EGR-1 following a similar procedure. 43 POSTER (Board P037) CDKN1A-mediated responsiveness of MLL-AF4-positive acute lymphoblastic leukemia to Aurora kinase-A inhibitors L. Hung1 , Y. Chen2 , H. Lin3 , M. Tsai4 , H. Hsieh5 , J. Chang6 , N. Chen1 , S. Yang1 , T. Chen7 . 1 Institute of Bioinformatics and Biosignal Transduction, Department of Life Sciences National Cheng Kung University, Tainan, Taiwan; 2 Institute of Clinical Medicine and Division of Hematology/Oncology, Department of Internal Medicine National Cheng Kung University, Tainan, Taiwan; 3 Department of Pharmacology, National Cheng Kung University, Tainan, Taiwan; 4 Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha NE, USA; 5 Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhunan Miaoli County, Taiwan; 6 Institute of Clinical Medicine and National Institute of Cancer Research, National Cheng Kung University and National Health Research Institutes, Tainan, Taiwan; 7 Institute of Clinical Medicine and Division of Hematology/Oncology Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan Background: The prognosis of patients with relapsed or resistant acute lymphoblastic leukemia (ALL) is quite poor, and resistance to chemotherapy in ALL cells remains a challenge to successful treatment. Overexpression of Aurora kinases is largely observed in many cancers, including hematologic malignancies. Aurora kinases have become attractive therapeutic targets to help overcome chemotherapy resistance. Methods: The expression of Aurora kinases and their activators was analyzed by Western blot analysis. Drug susceptibility was determined by MTT assay. Expression of CDKN1A was detected by Western blot 20 Wednesday 19 November 2014 and Q-PCR. The status of TP53 in ALL cells was determined by Sanger sequencing. Results: Nine ALL cell lines exhibited different susceptibilities to Aurora kinase inhibitors (AKIs). Cells sensitive to AKIs underwent apoptosis at an IC50 of approximately 10 to 30 nM and displayed a phenotype of Aurora-A inhibition, whereas cells resistant to Aurora kinase inhibitors (with an IC50 more than 10 mM) accumulated polyploidy, which may have resulted from Aurora-B inhibition. Drug susceptibility was not correlated with the expression level or activation status of Aurora kinases. RS4;11 and MV4;11 cells, which contain the MLL-AF4 gene, were both sensitive to Aurora-A inhibitors. CDKN1A might govern the drug responsiveness of ALL cell lines in a TP53-independent manner. Primary ALL cells with MLL-AF4 and CDKN1A expression were sensitive to AKIs. Conclusions: Our study suggests that Aurora-A kinase inhibitors may have clinical utility in MLL-AF4-positive ALL. CDKN1A can be used as a biomarker to determine drug responsiveness in MLL-AF4-positive ALL. 44 POSTER (Board P038) Metformin and its impact on gastric cancer patients survival after gastrectomy C.K. Lee1 , M.K. Jung1 , I.K. Jung2 , S.J. Heo1 , J.Y. An3 , H.I. Kim3 , J.H. Chung3 , W.J. Hyung3 , S.H. Noh3 , H.S. Kim1 , S.Y. Rha1 , H.C. Chung1 . 1 Yonsei Cancer Center, Division of Medical Oncology, Seoul, Korea; 2 Yonsei University College of Medicine, Department of Biostatistics, Seoul, Korea; 3 Yonsei Cancer Center, Department of Surgery, Seoul, Korea Background: One of the most widely used oral anti-diabetes agent, metformin has recently received attention as anti-cancer treatment with accumulating evidences. But study showing survival benefit of metformin for gastric cancer patients has never been reported. Patients and Methods: We conducted a retrospective study of gastric cancer patients who have undergone gastrectomy as curative aim from May 2003 to December 2010 at a single institution (Yonsei Cancer Center, Severance Hospital, Korea) based on electronic medical records. Survival analysis was done using Kaplan–Meier plot and Cox proportional hazards regression model. Results: Among 1974 gastric cancer patients who underwent gastrectomy as curative aim, 326 patients were diagnosed as diabetes and 132 patients were treated with metformin. During a median follow up duration of 5.5 years (IQR, 3.8−7.4 years), 381 (19.3%) patients died, and 302 (15.3%) patients died as a result of gastric cancer. Gastric cancer patients diagnosed with diabetes who were treated with metformin showed significant survival benefit compared to diabetic gastric cancer patients who were not treated with metformin (Overall survival: P = 0.021, HR = 0.584, 95% CI = 0.369–0.926; cancer-specific survival: P = 0.038, HR = 0.57, 95% CI = 0.334–0.975). Non-diabetes group (n = 1648) showed significant better recur-free survival, overall survival and cancer-specific survival compared to diabetes group (n = 326), and metformin usage prolonged diabetes patients’ survival comparable to that of non-diabetes patients. In multivariable analysis using Cox proportional hazard model with timedependent covariate, each cumulative 6 months of metformin use was significantly associated to decreased risk of recur, cancer-specific mortality and all-cause mortality (HR = 0.847, 95% CI = 0.769–0.934; HR = 0.850, 95% CI = 0.770–0.939; HR = 0.861, 95% CI = 0.794–0.933). Conclusions: Our results show that increased cumulative duration of metformin use decrease recur rate, all-cause and cancer-specific mortality among gastric cancer patients with diabetes who had undergone gastrectomy. Further prospective study of evaluating metformin for adjuvant therapy in gastric cancer will be needed. 45 POSTER (Board P039) Early preclinical study of BO-2094 for treatment of human colon cancer, in combination with 5-fluorouracil T.L. Su1 , T.H. Ou1 , M.H. Wu1 , Y.W. Lin1 , T.C. Lee1 . 1 Institute of Biomedical Sciences, Academia Sinica, Taipei City, Taiwan Among cancers, colon cancer is the second leading cause of cancer deaths in the United States. Every year, about 140,000 Americans are diagnosed with colon. Surgery, radiotherapy, and chemotherapy are the main strategies for treating CRC patients. However, the mortality risk associated with CRC is metastasis leading to the diminishing of systemic treatments. Therefore, there is an urgent need of finding a better agent to treat CRC. Recently, we have designed a series of novel water soluble and chemically stable phenyl N-mustard-benzenealkylamide conjugates. Of these derivatives, we found that compound BO-2094 exhibits a broad spectrum of antitumor activity against a panel of human leukemia and solid tumor cell lines in vitro and potent therapeutic efficacy in various tumor xenograft models. We found that BO-2094 exhibited potent antitumor Poster Session – Cytotoxics activity in xenograft models. It also demonstrated that that the combination of BO-2094 and 5-FU at ratios of 1:3 persuaded synergistic cytotoxicity to HCT-116 cells in vitro. Notable, more than 98% of tumor suppression was achieved in HCT-116-bearing nude mice when co-treated compound BO-2094 (30 mg/kg, QD×6, iv. inj.) with 5-FU [75 mg/kg, every 7 days for 2 doses (Q7D×2), intraperitoneal injection (ip. inj.)]; all mice (n = 5). The early preclinical studies showed that BO-2094 has LD50 value of 115.4 mg/kg 14-day acute toxicity of in mice via a single administration by iv injection. This agent is likely to have no cardiac arrhythmic side effect based on hERG assay. BO-2094 showed high degree protein binding in rat plasma, indicating that can be as drug reserve and allows drug to be slowly released. Additionally, BO-2094 has an acceptable PK profile in rats. The present studies indicate that the combination of compound BO-2094 + 5-FU has great potential benefit for the treatment of advanced colon cancer. 46 POSTER (Board P040) Broad-spectrum preclinical combination activity of eribulin combined with various anticancer agents in human breast cancer, lung cancer, ovarian cancer, and melanoma xenograft models M. Asano1 , J. Matsui1 , M.J. Towle2 , J. Wu2 , S. McGonigle2 , T. Uenaka3 , K. Nomoto2 , B.A. Littlefield2 . 1 Eisai Co. Ltd., Oncology PCU, Tsukuba, Japan; 2 Eisai Inc., Oncology PCU, Andover MA, USA; 3 Morphotek Inc., Oncology, Exton PA, USA Eribulin is a pharmaceutically optimized, fully synthetic analog of the marine sponge natural product halichondrin B. As its mesilate salt (E7389, Halaven® ), eribulin is approved in 54 countries worldwide for treatment of certain patients with advanced breast cancer. Eribulin is a microtubule dynamics inhibitor that binds to high affinity sites on microtubule plus ends, a distinct binding profile compared to most other tubulin-targeted agents. Previous preclinical studies have shown that under monotherapy conditions, eribulin has broad spectrum anticancer activity against a wide variety of human cancer cell types in vitro and human tumor xenograft types in vivo. The present preclinical studies were undertaken to evaluate eribulin’s in vivo antitumor activity when combined with a variety of cancer drugs in various human tumor xenograft types. In xenograft models of triple negative (MDA-MB-231, MDA-MB-436, MX-1) and HER2+ (UISO-BCA-1) breast cancer, eribulin variously showed combination activity (defined as greater activity than either agent alone with acceptable tolerability) with bevacizumab, capecitabine, everolimus, and the experimental PARP inhibitor E7449, although it failed to show combination activity with doxorubicin in the triple negative MDA-MB-435 model. In xenograft models of non-small cell lung cancer (NCI-H1993, NCI-H322M, NCI-H522, PC-9), eribulin variously showed combination activity with erlotinib, gemcitabine, and two experimental drugs, the PI3K inhibitor BKM-120 and the multi-targeted tyrosine kinase inhibitor lenvatinib. Eribulin also showed combination activity with bevacizumab in the SKOV-3 ovarian cancer model, and with lenvatinib in the A375 melanoma model. Taken together, these preclinical results suggest that eribulin can exert combination activity in a variety of tumor types with acceptable safety profiles when administered together with a wide range of combination agents having different mechanisms of action. 47 POSTER (Board P041) Lurbinectedin (PM01183) specifically targets RNA Pol II for degradation via the proteasome pathway in a transcription and TC-NER dependent fashion G. Santamaria1 , J.F. Martı́nez-Leal1 , C. Cuevas1 , L.F. Garcia-Fernandez1 , C.M. Galmarini1 . 1 PharmaMar S.A.U., Cell Biology Department, Colmenar Viejo (Madrid), Spain Lurbinectedin (PM01183) is a synthetic tetrahydroisoquinoline alkaloid currently evaluated as single agent and in combination in phase I and II clinical trials for solid tumors and hematological malignancies. In living cells, PM01183-DNA adducts stall replication and transcription giving rise to double strand breaks, inducing accumulation of cells in the S-phase of the cell cycle and triggering apoptosis. In this work, we examined the effects of PM01183 on the activity and stability of the RNA Pol II as well as on other factors of the transcriptional machinery, including TBP (TFIID), p62 (TFIIH) and XPD. Our results showed that PM01183 induced a rapid, time- and concentration-dependent degradation of RNA Pol II in a panel of different human tumor cell lines, including HCT-116 (colon), A549 (NSCLC), HeLa (cervix) and A763 (sarcoma). This degradative process was efficiently abrogated in the presence of transcriptional (DRB), ubiquitination (PYR41), and proteasome inhibitors (MG132), demonstrating that PM01183 specifically targets the transcriptionally active RNA Pol II for degradation via the proteasome pathway. In addition, it was also shown that the effect of PM01183 on the RNA Pol II was dependent on the presence of a functional TC NER repair machinery. PM01183 induced degradation of Poster Session – Cytotoxics RNA Pol II in global NER (XPC) deficient cells, but failed to do it in TC NER (CSB, XPD and XPG) deficient cells. Importantly, these effects were confirmed to be specific for the Rpb1 subunit of RNA Pol II, since other subunits were not affected (Rpb2 and Rpb4) as well as other factors of the transcriptional machinery, such as TBP (TFIID), p62 (TFIIH), XPD or the RPA194 subunit of the RNA Pol I. Finally, it was also demonstrated that, contrary to what occurs after DNA damage with UV light, the transcription of p53 target genes important for DNA repair, including p21 or mdm2, was irreversibly inhibited after PM01183 treatment. Together, these results show the mechanism by which PM01183 inhibits trans-activated transcription process on tumor cells. 48 POSTER (Board P042) Trabectedin and lurbinectedin are effective against leukemic cells derived from patients affected by chronic and juvenile myelomonocytic leukemia M. Romano1 , A. Gallı̀2 , N. Panini1 , L. Paracchini1 , L. Beltrame1 , E. Bello1 , S.A. Licandro1 , C. Cattrini3 , R. Tancredi3 , S. Marchini1 , V. Rosti4 , M. Zecca5 , M. Della Porta2 , A. Zambelli3 , C.M. Galmarini6 , E. Erba1 , M. D’Incalci1 . 1 IRCCS − Istituto di Ricerche Farmacologiche Mario Negri, Oncology, Milano, Italy; 2 Fondazione IRCCS Policlinico San Matteo, Onco-Hematology, Pavia, Italy; 3 IRCCS Fondazione Salvatore Maugeri, Oncology, Pavia, Italy; 4 Fondazione IRCCS Policlinico San Matteo, Center for the Study of Myelofibrosis Research Laboratory of Biotechnology, Pavia, Italy; 5 Fondazione IRCCS Policlinico San Matteo, Pediatric Onco-Hematology, Pavia, Italy; 6 PharmaMar S.A., Research and Development, Colmenar Viejo, Italy Background: Chronic (CMML) and juvenile myelomonocytic leukemia (JMML) are mixed myelodysplastic/myeloproliferative (MDS/MPN) haematological diseases of elderly and childhood patients, respectively. Any kind of chemotherapy is unable to improve the outcome of these patients, so allogeneic stem cell transplantation remains the only curative option for MDS/MPN neoplasms. Trabectedin and its analogue lurbinectedin are DNA minor groove binders acting as modulators of transcription and interfering with DNA repair mechanisms. They cause selective depletion of tumor-associated macrophages and circulating monocytes, activating caspase-8-dependent apoptosis and TRAIL receptors (TRAIL-Rs) expression. These findings offer strong proof-of-concept evidence for monocyte targeting in humans and provide the rational for testing these two drugs in myelomonocytic leukemias. Material and Methods: Patient samples (20 CMML; 12 JMML) were collected from peripheral blood. The drugs cytotoxicity was evaluated by growth inhibition; apoptosis (Annexin-V/P.I), TRAIL-Rs and cleaved caspase-8 expression were investigated by flow cytometric assay. In vivo experiments were performed using athymic nude mice transplanted with MV-4−11 cells. Results: Both trabectedin and lurbinectedin showed a strong cytotoxic effect on malignant CD14+ monocytes in vitro and were able to induce marked apoptosis, at nanomolar concentrations, much more effective than azacitidine (5-AZA), used at micromolar concentrations as positive control. In addition, trabectedin and lurbinectedin were found to efficiently inhibit the in vitro growth of bone marrow hematopoietic precursors (CFU-GM) of CMML and JMML patients. In a CMML cellular model, the MV-4−11 cell line, we found an increased TRAIL-Rs and cleaved caspase-8 expression after trabectedin or lurbinectedin exposure suggesting that apoptosis induced by these drugs followed the extrinsic pathway. Preliminary in vivo experiments, in MV4−11 model, showed a marked antitumor activity of both trabectedin and lurbinectedin that was much higher than that of 5-AZA. Conclusions: Our data suggest that trabectedin and lurbinectedin exert a more specific cytotoxic effect on malignant CMML and JMML monocytes than other drugs commonly used in MDS/MPN diseases and this makes these two drugs good candidates for clinical studies in CMML and JMML. Studies are in progress to elucidate the molecular mechanisms behind these therapeutically antitumor effects of these drugs. 49 POSTER (Board P043) siRNA targeting of mitochondrial thymidine kinase 2 (TK2) sensitizes cancer cells to gemcitabine and increases mitochondrial toxicity C. Di Cresce1 , P. Ferguson2 , R. Figueredo2 , M. Rytelewski1 , S. Maleki Vareki1 , M.D. Vincent3 , J. Koropatnick1 . 1 Western University, Microbiology and Immunology, London, Canada; 2 London Regional Cancer Centre, Cancer Research Laboratories, London, Canada; 3 Western University, Oncology, London, Canada Background: Mitochondrial thymidine kinase 2 (TK2) preferentially phosphorylates thymidine to generate thymidine monophosphate (dTMP). Wednesday 19 November 2014 21 TK2 also phosphorylates deoxycytidine to generate dCMP, a precursor for dCTP. dCTP negatively regulates deoxycytidine kinase (dCK), which primarily phosphorylates deoxycytidine as well as the anticancer drug gemcitabine. Because phosphorylation by dCK is required to activate the drug, there is a therapeutic advantage to high dCK in tumour cells treated with gemcitabine. Antisense knockdown of TK2 could reduce TK2-produced dCMP, thus decreasing dCTP levels and its inhibition of dCK, and lead to increased dCK activity, gemcitabine activation, and anticancer effectiveness. Importantly, gemcitabine is a poor substrate for phosphorylation by TK2. Given the ability of TK2 to phosphorylate deoxycytidine and thus down-regulate dCK activity, we hypothesized that: (1) TK2 can mediate human tumour cell resistance to gemcitabine, and (2) antisense (siRNA) downregulation of TK2 can inhibit this mechanism of resistance. We also hypothesized that anti-TK2 siRNA-induced drug sensitization is mediated by mitochondrial damage. Materials and Methods: siRNA downregulation of TK2 followed by gemcitabine treatment of MCF7, HeLa and A549 human tumour cell lines (which express high, medium, and low levels of TK2, respectively). Cell lines were analyzed for proliferation (alamarBlue viability staining), levels of various mRNAs (qPCR) and proteins (immunoblotting), mitochondrial to nuclear DNA ratio (mtDNA:nDNA) (qPCR), and mitochondrial membrane potential (MitoTracker CMXROS and flow cytometry). Results: Downregulation of TK2 using siRNA sensitized MCF7 and HeLa cells (high and medium TK2 expressers, respectively) to gemcitabine, but did not sensitize A549 cells (low TK2 expresser). siRNA knockdown of TK1 and/or thymidylate synthase (TS) in combination with TK2-siRNA and gemcitabine did not cause further sensitization; this phenomenon is specific to targeting of TK2. The combined treatment with TK2 siRNA and gemcitabine increased dCK enzyme levels in TK2 high- and medium-expressing cell lines. The addition of TK2 siRNA treatment to gemcitabine treatment of TK2-expressing tumour cells specifically decreased mitochondrial DNA (mtDNA:nDNA) and mitochondrial activity. Conclusions: This is the first demonstration of a direct role for TK2 in resistance to gemcitabine or any other anticancer drug, and distinguishes TK2 from other dTMP-producing enzymes (cytosolic TK1 and TS). Decreased mitochondrial function is related to TK2 siRNA-induced sensitization to gemcitabine. 50 POSTER (Board P044) The effect of esomeprazole, a proton pump inhibitor, on the pharmacokinetics of the investigational Aurora A kinase inhibitor alisertib (MLN8237) in patients with advanced solid tumors or lymphomas X. Zhou1 , J. Nemunaitis2 , S. Pant3 , T. Bauer4 , A. Lockhart5 , M. Patel6 , B. Zhang7 , V. Kelly8 , C.D. Ullmann8 , M. Bargfrede9 , K. Venkatakrishnan9 . 1 Millennium: The Takeda Oncology Company, Clinical Pharmacology, Cambridge, USA; 2 Mary Crowley Medical Research Center, Oncology, Dallas, USA; 3 Oklahoma University Medical Center, Hematology/Oncology, Oklahoma City, USA; 4 Sarah Cannon Research Insitute, Tennessee Oncology, Nashville, USA; 5 Washington University, Dept of Med. Oncology Div. Med Onc Section, St. Louis, USA; 6 Florida Cancer Specialists, Sarasota Cattlemen, Sarasota, USA; 7 Takeda Pharmaceuticals International Co, Statistics, Cambridge, USA; 8 Takeda Pharmaceuticals International Co, Oncology Clinical Research, Cambridge, USA; 9 Takeda Pharmaceuticals International Co, Clinical Pharmacology, Cambridge, USA Background: Alisertib is an investigational, orally available, selective Aurora A kinase inhibitor currently in clinical development for multiple oncology indications. Alisertib enteric-coated tablets are designed to bypass the acidic gastric pH and delay dissolution until entry into the upper small intestine. Alisertib exhibits pH-dependent solubility. This study characterized the effects of esomeprazole, a proton pump inhibitor (PPI) on the pharmacokinetics of single-dose alisertib in advanced cancer patients (pts). Materials and Methods: Eligible pts were 18 years of age with ECOG PS 0−1. In this fixed-sequence, 2-cycle, open-label study, a single oral dose of alisertib 50 mg was administered on cycle 1, day 1 (C1D1) and cycle 2, day 8 (C2D8). Cycle 1 was 24 days, and cycle 2 was 31 days. Esomeprazole 40 mg (delayed release) was given once daily in cycle 2 from days 1−10. Plasma pharmacokinetic samples were collected predose and up to 72 hours post alisertib on C1D1 and C2D8. Ratios of geometric mean Cmax , AUC0−last , and AUC0−inf in the presence of esomeprazole (C2D8) versus in its absence (C1D1) were calculated and 90% confidence intervals (CI) were estimated. Secondary endpoints were safety and tolerability. Results: Of 25 pts enrolled (male, 44%; white, 88%; median age, 61 years; and mean weight, 82 kg), 18 pts were evaluable. Following a single, oral dose of alisertib, median Tmax was 3 and 4 hours in the presence and absence of esomeprazole, respectively. The geometric mean AUC0−inf of alisertib in the presence of esomeprazole was 129% of that in its absence (90% CI, 107–156; N = 17). The geometric mean Cmax in the presence of 22 Wednesday 19 November 2014 esomeprazole was 114% of that in its absence (90% CI, 96–136; N = 18). At data cutoff, treatment-related adverse events (AE) were reported in 24 pts (96%); the most common AEs were diarrhea (52%), alopecia (52%), neutropenia (36%), and fatigue (36%). Treatment-related grade 3/4 AEs were reported in 15 pts (60%); the most common (>10%) were neutropenia (36%) and leukopenia (12%). The observed AEs and their incidence were generally consistent with the alisertib safety profile observed to date. Conclusions: Esomeprazole produced an approximately 30% increase in alisertib systemic exposure. These results support the recommendation that gastric acid-reducing agents (e.g., PPIs, H2 receptor antagonists) be avoided in pts receiving alisertib. 51 POSTER (Board P045) Development of rational combination therapy strategies to optimize treatment for GPNMB expressing Her2+ and triple negative breast cancer A. Rose1 , G. Maric2 , M.G. Annis2 , H. Smith2 , W.J. Muller2 , P.M. Siegel2 . 1 McGill University Department of Medicine, Goodman Cancer Research Centre, Montréal, Canada; 2 McGill University, Goodman Cancer Research Centre, Montréal, Canada Background: Glycoprotein NMB (GPNMB) is a cell surface protein that promotes tumor growth and metastasis in murine breast cancer (BC) models. CDX011 is a GPNMB-targeted antibody drug conjugate that has shown robust clinical activity and is being investigated in late stage clinical trials for BC. Data from early clinical trials with CDX011 reveals that response rate is directly linked to tumoral GPNMB expression levels. The goal of this project is to define the prognostic and functional relevance of GPNMB in basal/triple-negative (TN)/Her2-positive BC, and to devise combination therapy strategies, which could improve CDX011 efficacy for the treatment of BC. Methods: GPNMB was ectopically expressed in breast cancer cells. Cell invasion was assessed by boyden chamber assays and tumor growth and spontaneous metastasis were assessed with in vivo mouse models. The Cancer Genome Atlas (TCGA) human breast cancer gene expression data (n = 1160) was interrogated for associations between GPNMB levels and intrinsic subtype and overall survival. Lapatinib-resistant cells were generated from several Her2+ cell lines. GPNMB mRNA levels were determined by qPCR and protein by immunoblot and FACS. Results: Ectopic GPNMB enhanced invasion by 2−4 fold, and in vivo tumor growth was enhanced ~2-fold in both Hs578T and NIC-Her2 models. NIC cells expressing GPNMB displayed a 4-fold increase in spontaneous lung metastases. In the TCGA data set GPNMB expression was significantly higher in basal and Her2 than it was in the luminal A and B subtypes. Tumors with high GPNMB expression were associated with significantly shorter overall survival (HR = 2.0295, 95% CI = 1.3476 to 3.0567. Treatment with kinase inhibitors (KI) EGFR/Her2-family inhibitors (gefitinib, lapatinib) led to significantly up-regulated GPNMB in basal-like BC cells: MDA-468, MDA-436, MDA-157, and Her2+ cells: SkBR3, HCC1954, BT474, MDA361. Moreover, Mek inhibition with trametinib led to increased GPNMB expression in both basal and Her2+ BC. This induction was transcriptionally mediated, and led to increased GPNMB protein at the cell surface. Moreover, 34 Lapatinib-resistant cells expressed higher levels of GPNMB than corresponding parental cells. Finally, CDX011 as a single agent caused a significant reduction in MDA-468 tumor growth. Conclusions: GPNMB is highly expressed in Her2+ and Basal breast cancer − it promotes tumor growth, invasion and metastasis and correlates with poor survival. As such it represents a promising therapeutic target. GPNMB is up-regulated by many KI that are currently used to treat BC. Our data suggest that combination of KI with CDX011 will lead to improved tumor regression; our efforts to test these combinations in vivo will be discussed. 52 POSTER (Board P046) Platinum(IV) derivatives of oxaliplatin: Cellular effects and in vivo potency S. Göschl1 , V. Pichler1 , E. Brynzak1 , P. Heffeter2 , U. Jungwirth2 , M.A. Jakupec1 , W. Berger2 , M. Galanski1 , B.K. Keppler1 . 1 University of Vienna, Institute of Inorganic Chemistry, Vienna, Austria; 2 Medical University of Vienna, Institute of Cancer Research, Vienna, Austria Platinum(IV) complexes are an attractive way to overcome some disadvantages of platinum(II)-based anticancer drugs such as severe side effects or resistances, because they are kinetically more inert to ligand substitution and their higher lipophilicity may improve the cellular uptake. Four platinum(IV) complexes derived from oxaliplatin reported herein have shown activity in the colorimetric MTT assay in vitro in HCT15, HCT116 and HCT116oxR cells (all colon carcinoma). The extent of induced apoptosis (AnnexinV-FITC/PI staining) and the influence of the complexes on the Poster Session – Cytotoxics cell cycle were measured by flow cytometry. Two of the complexes (1 and 2) were tested in vivo in murine L1210 leukemia, and 2 was tested in a colon tumor (CT26) mouse model. The platinum levels in the organs were determined by ICP-MS measurements. These platinum(IV) compounds, mostly yielding IC50 values in the micromolar range, are up to 25 times more active in HCT116 cells than in the oxaliplatin resistant subline, whereas oxaliplatin is 66 times less potent in HCT116oxR cells. After 24 h incubation with 2 a strong increase of the G2 /M phase fraction and a decrease of the S phase fraction was found in HCT15 cells, whereas the effects were somewhat less pronounced in HCT116 cells. After 24 h incubation with 1 an up to 5-fold increase of apoptosis was found in HCT116 but not in HCT15 and HCT116oxR cells. 48 h incubation of 1 or 2 resulted in a total increase of up to 50% and 15% apoptosis in HCT15 and 50% and 25% in HCT116 cells, respectively. In L1210 murine leukemia an increase in life span up to 60% was observed. 2 was tested in immuno-competent and immunodeficient mice to determine whether it is active in a solid tumor model and whether the immune system has an influence on the efficiency as found for oxaliplatin. The immune system seems to be relevant for activity because 2 was found to be active in Balb/c but not in SCID mice, although the tumor platinum levels in both mouse models are the same. Overall, these results demonstrate the high potency of modified platinum(IV) compounds. For a deeper insight into their suitability as prodrugs activated by reduction, their reduction properties and their activity under hypoxic conditions in 2D and 3D cell culture will be studied. 53 POSTER (Board P047) Adeno-associated virus (AAV) carrying diphtheria toxin a gene for pancreatic cancer therapy M. Chen1 , C.Y. Ho1 , M. Teng1 , H. Chen1 . 1 Virovek Incorporation, R&D, Hayward, USA Pancreatic cancer is an aggressive malignancy with morbidity rates almost equal to mortality rates because of the current lack of effective treatment options. Here, we describe a DNA-based therapy for pancreatic cancer using the AAV vector that expresses the diphtheria toxin A chain (DT-A) under the control of the survivin gene regulatory sequences. We produced the AAV vectors carrying DT-A coding sequence that was disrupted by the human growth hormone intron so that its expression was abolished during AAV vector production in insect cells and used these vectors for the study. In vitro experiments showed that the AAV vector was effective in inhibiting protein synthesis in pancreatic carcinoma cell lines but not in normal cell line. In vivo experiment results demonstrated tumor growth arrest in a xenograft mouse model for pancreatic cancer in a dose-dependent manner. Differences in tumor size between the control and high dose group were significant (P = 0.015). These AAV vectors provide a new option for cancer gene therapy. The protocol and any amendment(s) or procedures involving the care and use of animals in this study were reviewed and approved by the Institutional Animal Care and Use Committee (IACUC) of CrownBio prior to conduct. During the study, the care and use of animals were conducted in accordance with the regulations of the Association for Assessment and Accreditation of Laboratory Animal Care (AAALAC). Table 1. Antitumor activity of test article AAV6-DTA in the treatment of subcutaneous PANC-1 human pancreatic cancer xenograft model T/C (%) T-C (days) at 786 mm3 P valueb Group 1. AAV6-SURV-GFP 1.5×1012 vg/mouse 1720±258 Group 2. AAV6-SURV-DTA 1.5×1012 vg/mouse 786±234 Group 3. AAV6-SURV-DTA 1.5×1011 vg/mouse 808±218 − − − 45.72 12.5 0.015 46.98 10.5 0.017 Group 4. AAV6-SURV-DTA 1.5×1010 vg/mouse 60.84 6 0.072 Treatment a Mean±SEM; b vs. vehicle control. Tumor size (mm3 )a on day 48 1046±301 Poster Session – Cytotoxics 54 POSTER (Board P048) MGMT methylation assessed by methyl-BEAMing technique is a prognostic and predictive biomarker in glioblastoma and metastatic colorectal cancer patients L. Barault1 , A. Amatu2 , F.E. Bleeker3 , C. Moutinho4 , A. Cassingena2 , F. Tosi2 , T. Venesio5 , M. Esteller4 , A. Bardelli6 , S. Siena2 , A. Sartore-Bianchi2 , F. Di Nicolantonio6 . 1 Candiolo Cancer Institute − FPO IRCCS, Experimental Clinical Molecular Oncology, Candiolo, Italy; 2 Ospedale Niguarda Ca’ Granda, Department of Hematology and Oncology, Milan, Italy; 3 Academic Medical Center University of Amsterdam, Department of Clinical Genetics, Amsterdam, Netherlands; 4 Bellvitge Biomedical Research Institute (IDIBELL), Cancer Epigenetics and Biology Program (PEBC), Barcelona, Spain; 5 Candiolo Cancer Institute − FPO IRCCS, Investigational Clinical Oncology, Candiolo, Italy; 6 University of Torino, Department of Oncology, Candiolo, Italy Background: O6-methylguanine DNA methyltransferase (MGMT ) silencing by promoter methylation is a common alteration found in different cancer types. This has been shown to be both a prognostic and a predictive marker of sensitivity to alkylating agent-based therapy like dacarbazine and temozolomide in glioblastoma. However in other malignancies its value remains controversial. This might be due to sampling issues, tumor heterogeneity or to the use of inadequate detection methods. In this study, we present a new assay to reliably measure MGMT methylation both in tumor and plasma samples. Material and Methods: Methylation of MGMT has been assessed by an ultra-sensitive digital PCR technique, in which a two-step PCR is followed by detection via fluorocytometer (Methyl-BEAMing). Results were compared to two other commonly used techniques (Methylation Specific PCR, MSP and pyrosequencing). Two samples datasets have been evaluated: tumors from a cohort of 98 newly diagnosed glioblastoma patients from the pre-temozolomide era, and specimens from a cohort of 68 metastatic colorectal cancer patients treated with dacarbazine in a phase II clinical trial (DETECT-01 trial, EUDRACT number 2011–002080−21). The prognostic and/or predictive value of MGMT methylation has also been evaluated. As a proof of concept, the three methods were assessed in a subset of colorectal cancer patients’ plasma derived DNA to evaluate their performance as a liquid biopsy test. Results: Methyl-BEAMing showed high reproducibility across independent experiments, as well as high sensitivity (up to 0.09% methylation detected) and specificity. In the glioblastoma cohort, Methyl-BEAMing methylated status (>50%) was associated with a decreased hazard ratio for death (HR = 0.35; p < 0.0001) compared to MSP (HR = 0.54; p = 0.006) or pyrosequencing (HR = 0.61; p = 0.059). In mCRC, tissue where tumor heterogeneity is possibly higher, both Methyl-Beaming and pyrosequecing assays provided better prediction of objective response to dacarbazine than MSP. Progression free survival was also improved in metastatic colorectal cancer with methylated status when samples were assessed with Methyl-BEAMing (p = 0.0012) or pyrosequencing (p = 0.0005). Quantitative evaluation of MGMT methylation in circulating tumor DNA was effective with Methyl-BEAMing. Conclusions: MGMT methylation testing based on BEAMing technology outperforms commonly used methods and might allow the non-invasive follow-up of patients, upon alkylating agent treatments using blood circulating DNA. 55 POSTER (Board P049) Low, frequent doses of PM060184 induce remarkable in vivo antitumor activity P. Aviles1 , M.J. Guillen1 , P.P. Lopez-Casas2 , F. Sarno3 , O. Cataluña4 , P. Nuñez4 , C. Cuevas4 , M. Hidalgo3 . 1 PharmaMar S.A., Preclinical, Colmenar Viejo (Madrid), Spain; 2 Centro Nacional de Investigaciones Oncológicas and Hospital de Madrid, Colmenar Viejo (Madrid), Spain; 3 Centro Nacional de Investigaciones Oncológicas and Hospital de Madrid, Madrid, Spain; 4 Pharmamar S.A., Preclı́nica, Colmenar Viejo (Madrid), Spain Background: PM060184 is a synthetic marine-derived compound originally isolated from the marine sponge Lithoplocamia lithistoides. PM060184 induces disorganization and disruption of the microtubule network as well as aberrant mitotic spindle multipolarization and chromosome missegregation. These effects give rise to prometaphase arrest and formation of multinucleated cells. Then, cells enter to caspase-driven apoptosis or are arrested in a pseudo-senescent state. PM060184 is currently under evaluation in Phase I clinical studies in patients with advanced cancer diseases. The objective of the present work was to explore the in vivo anticancer efficacy of PM060184 administered at low daily doses (0.5 to 2 mg/kg). Wednesday 19 November 2014 23 Material and Methods: Athymic female nu/nu mice were subcutaneously implanted with different tumors: MDA-MB-231 (breast), H460 (NSCLC) and several pancreas patient-derived (AVATAR) tumors, namely JH010, JH-015, Panc-291, and Panc-039. Tumor (ca. 300 mm3 ) bearing animals (N = 6−10/group) were randomly allocated to receive PM060184 or placebo. Treatments (0.5 to 2 mg/kg, iv) were administered daily for 20 consecutive days. Antitumor effect was calculated using DT/DC (%), defined as a percentage of the change in tumor size for treated (T) and placebo (C) groups during the placebo-treated survival time (D). Complete tumor regression (CR) was defined when tumor volume <63 mm3 for 2 or more consecutive measurements. Results: The treatment with PM060184 produced lowest DT/DC values as summarized in the table. Tumor Breast MDA-MB-231 NSCLC H460 Pancreas JH-024 JH-010 JH-015 Panc-291 Panc-039 Daily dose (mg/kg) Minimal DT/DC (%) On Day 2.0 1.0 0.5 2.0 1.0 0.5 2.0 2.0 2.0 2.0 2.0 7.3 14.1 24.0 5.5 7.8 17.7 19.7 14.8 38.9 12.0 6.1 21 21 21 11 11 11 21 21 28 24 28 Conclusion: The treatment with PM060184 at low, frequently given doses demonstrated significant in vivo antitumor activity in breast, NSCLC and pancreas xenografted tumors. 56 POSTER (Board P050) Radiosensitizing effect of sodium metaarsenite in a metastatic brain tumor model W.Y. Kang1 , Y.M. Park2 , S.J. Kim2 . 1 Institute for refractory cancer research Samsung medical center, Samsung Biomedical Research Institute, Seoul, South Korea; 2 Komipharm International Inc. Co., Pharmaceutical Division, Seoul, South Korea Background: Brain metastases are found in about 10% of lung cancer patients at the time of diagnosis, and about 40% of all lung cancer patients develop brain metastases during their disease progression. The chemotherapy is limited because of little or no effectiveness due to the blood–brain barrier. The radiation therapy is the most frequently used, and sensitizing agents, which synergize with radiation, can improve the efficacy of the therapy. Material and Methods: Sodium metaarsenite (KML001® ) is an orally bioavailable arsenic compound that has entered phase I/II clinical trials in solid tumors and hematopoietic malignancies. In this study, we elucidated the radio-sensitizing effect of sodium metaarsenite (KML001® ) in an animal model of metastasis of lung cancer to the brain. Results: The clonogenic assay showed that treatment with sodium metaarsenite (KML001® ) inhibited clone formation in radio-sensitive (H23) and radio-resistant lung cancer cells (A549 and PC14PE6) in a concentration-dependent manner. The combined irradiation and sodium metaarsenite (KML001® ) treatment significantly reduced colony formation in H23 (p < 0.01), A549 (p < 0.05) and PC14PE6 lung cancer cells (p < 0.05), compared with the radiation alone group. In the metastatic brain cancer model with H23 cells, sodium metaarsenite (KML001® ) treatment (5 mg/kg/day) and radiation therapy (5 Gy) showed 54.5% and 67.6% reduction in tumor volume, respectively, compared with control group (p < 0.001 vs. control). The combined irradiation and sodium metaarsenite (KML001® ) treatment induced 88.1% decrease in tumor volume (p < 0.001 vs. control). In the metastatic brain cancer model with PC14PE6 cells, the single irradiation (15 Gy) and the combined irradiation (15 Gy) and sodium metaarsenite (KML001® ) treatment (7 mg/kg/day) significantly increased median survival day of the mice to 22 and 26 days, respectively, compared to control group (median survival day = 19) (p < 0.001). The combination improved survival significantly with regard to the radiation only group (p < 0.001). Conclusions: This study demonstrated that sodium metaarsenite (KML001® ) may have potential as an alternative therapeutic agent, 24 Wednesday 19 November 2014 Poster Session – Cytotoxics especially in combination with radiation therapy in lung cancer patients with brain metastases and provide a rationale for testing the combination of sodium metaarsenite (KML001® ) and radiotherapy in the clinic. 59 POSTER (Board P053) Discovery of novel inhibitor of FOXO nuclear–cytoplasmic shuttling from natural products of marine origin 57 POSTER (Board P051) Differential antitumor activity of trabectedin, lurbinectedin, Zalypsis and PM00128 against a panel of human cells deficient in transcription and NER factors F.J. Castillo Correa1 , N. De Pedro1 , L. Rodriguez Quesada1 , D. Oves Costales1 , J.R. Tormo1 , J. Martin1 , F. Reyes1 , O. Genilloud1 , F. Vicente1 , W. Link2 , B. Cautain1 . 1 Fundacion Medina, Screening and Target Validation, Granada, Spain; 2 Universidad do Algarave, Ciencias Biomedicas e Medicina, Faro, Portugal V. Moneo1 , S. Avila1 , P. Martı́nez1 , B. de Castro1 , S. Cascajares1 , C. Cuevas1 , L.F. Garcia-Fernandez1 , C.M. Galmarini1 . 1 PharmaMar S.A.U., Cell Biology Department, Colmenar Viejo (Madrid), Spain Trabectedin, lurbinectedin, Zalypsis and PM00128 are synthetic marinederived anticancer drugs that covalently bind to the minor groove of DNA through via a common pentacyclic skeleton. The compounds differ in an additional chemical moiety attached to the pentacyclic skeleton that protrudes out from the double helix. Trabectedin, lurbinectedin and Zalypsis present a tetrahydroisoquinole, a tetrahydro b-carboline and a trifluorocinnamic group, respectively, while PM00128 lacks such additional moiety. To gain insight into how the presence of those different chemical groups contribute to the selectivity of the four compounds, we tested their cytotoxicity profiles against a panel of 43 fibroblast cell lines derived from patients with genetic diseases caused by mutations in transcription/NER factors, including CSA, CSB, XPC, XPA, XPE, XPB, XPD, XPG. In general, trabectedin and lurbinectedin presented a similar, although not identical, response pattern against the cell panel. However, these two compounds have a different behavior when compared to Zalypsis and PM00128. Four out of seven fibroblast cells lines carrying truncations in the XPG endonuclease gene were more resistant to trabectedin than normal fibroblasts, with RI values ranging from 3.4 to 6.7. Also interesting, a cell line (GM15754) carrying a missense mutation (R112H) in the XPD helicase gene, showed a significant resistance to both trabectedin and lurbinectedin, showing a RI of 41.0. Thus, the proper functionality of XPG and XPD factors in transcription and/or DNA repair processes may be important for the antiproliferative action of these compounds Remarkably, the sensitivity profiles obtained with standard DNA binders, such as cisplatin and mitomycin C, were completely divergent to those of trabectedin and lurbinectedin. On the other hand, no significant differences in the sensitivity of these cell lines were observed against Zalypsis and PM00128, suggesting that the repair of the DNA damage generated by these compounds is not exclusively dependent on the NER pathway. In summary, the differences in the chemical moieties attached to the common DNA binding scaffold in these compounds, seemed to correlate with the differential biological activity found against different tumoral cells. 58 POSTER (Board P052) Pipecolidepsin A, Stellatolide A and Irvalec: New cyclodepsipeptides of marine origin with antitumor activity J.M. Molina-Guijarro1 , V. Moneo1 , J.F. Martinez-Leal1 , C. Cuevas1 , L.F. Garcia-Fernandez1 , C.M. Galmarini1 . 1 PharmaMar S.A.U., Cell Biology Department, Colmenar Viejo (Madrid), Spain Pipecolidepsin A and Stellatolide A, along with Irvalec, are three synthetic marine-derived cyclic depsipeptides that show antitumor activity in vitro against a wide variety of human tumor cell lines. In dose–response curves against a panel of 24 human cancer cell lines, representative of 11 different tissues, the compounds showed GI50 values in the low micromolar range. Using the mechanism of action of Irvalec as a model, the cellular effects of Pipecolidepsin A and Stellatolide A were evaluated. Preliminary studies with these compounds were conducted in A549 (NSCLC) and HCT-116 (colon adenocarcinoma) cell lines as tumor models. The results pointed out that all of them share a common set of cellular effects. Phase contrast and fluorescence microscopy as well as plate fluorimetry analyses, showed that the compounds caused very rapid cell membrane destabilization, causing rapid and dramatic morphological changes, including cell blebbing, severe swelling, and plasma membrane permeabilization (as detected by propidium iodide) that irrevocably lead to cell lysis and necrotic cell death. Interestingly, membrane damage was observed only after reaching a threshold concentration, variable depending on the compound, in the culture medium. Strikingly, all the compounds caused a notable inhibition of cell viability after 30 min exposure, indicating that their cellular effects were produced very rapidly upon treatment. The efficacy of Pipecolidepsin A and Stellatolide A is currently being evaluated in in vivo models. In summary, these results indicate that the compounds Pipecolidepsin A, Stellatolide A as well as Irvalec, exert their potent antitumor activity by inducing rapid and severe membrane damage in tumor cells. The nucleo-cytoplasmic transport of certain tumor suppressor and oncoproteins is disrupted in cancer cells resulting in their aberrant subcellular localization and their respective inactivation or over-activation. This subcellular localization occurs actively via the nuclear pore complex that spans the nuclear envelope and is mediated by transport receptors. Regulation of the FoxO (forkhead box O) factors is receiving increasing attention as their activation in the nucleus has been linked to cell-cycle arrest and apoptosis, acting as tumor suppressors. Microbial natural metabolites have played a major role as one of the most important sources for the discovery of novel drugs. In this work, we applied a previously established high-throughput and high-content cellular-imaging assay that monitors the nuclear–cytoplasmic translocation of a GFP–FOXO3a fusion protein in U2OS cells to screen a library of extract from marine actinobacteria, one of the most efficient groups of secondary metabolite producers. A total of 3,300 extract, fractions and pure compounds were screened. The nuclear accumulation of fluorescence triggered by the pan-PI3K inhibitor, LY294002 (at 250 mM), was defined as 100% activity and used as a reference to define primary hits in U2foxRELOC assay. A final hit rate of 0.04% (13/3,300) was achieved; defining hits as non-toxic, specific FoxO Relocators. Two news FOXO relocators were isolated as pure compounds. MDN-XX is an alkaloid that has been previously described as a compound with antifungal activity. The other one is a new structure actually under characterization. As a general result, we validate the strategy used to identify activators of FoxO based on the screening of a collection of natural products, such as marine actinomycetes using the U2foxRELOC assay. Furthermore, the discovery of MDN-XX, with an IC50 of 10 nM, proves that marine actinomycetes can be used as an attractive and unexplored source of FoxO activators. 60 POSTER (Board P054) Sodium metaarsenite cytotoxic activity is associated with telomere length and many types of arsenic transporters in non-small cell lung cancer Y.M. Park1 , S.J. Kim1 . 1 Komipharm International Co. Ltd., Pharmaceutical Division, Shiheung, South Korea Background: Sodium metaarsenite (KML001® ) is an orally bioavailable arsenic compound that has entered phase I/II clinical trials in solid tumors and hematopoietic malignancies. The underlying mechanisms of anticancer effects of KML001® have been shown to be telomere poisoning. Because arsenic resistance could limit the efficacy of KML001® in patients with nonsmall cell lung cancers (NSCLC), expression of membrane pore proteins involved in arsenic influx into cells, energy-dependent transporters that detect and eject arsenic from cells, and arsenic-detoxifying machinery proteins need to be evaluated to predict the sensitivity and resistance of human non-small cell lung cancers to KML001® . Material and Methods: In this study, we characterized six NSCLC cells with regards to the cytotoxicity by KML001® and expression of arsenic influx/efflux machinery proteins. We profiled expression of human aquaglyceroporin (AQP) 1−9, glucose transporter(GLUT) 1−4, LRP and MRP1−3 in six NSCLC cell lines. In addition, the telomere restriction fragment (TRF) lengths were measured and compared among six NSCLC cell lines. Finally we examined in vivo antitumor activity of KML001® in two human NSCLC xenografts transplanted with H292 cells with a low IC50 and PC14PE6 cells with a high IC50 for KML001® . Results: MTT assay revealed that H292, H23, and H2009 were sensitive to KML001® (IC50 = 2.2, 2.4, and 9.8, respectively), whereas A549, PC14PE6, and H1792 were resistant to KML001® (IC50 = 29.6, 31, and 35, respectively). Arsenic influx activity for arsenic-sensitive cell lines was higher than that for arsenic-resistant cell lines. However, compared to arsenic-sensitive cell, arsenic-resistant cells showed a rapid reduction in arsenic accumulation over 24 h coupled with a increase in the rate of arsenic efflux. TRF length analysis demonstrated that the resistant A549, H1792, and PC14PE6 cells displayed longer telomeres compared to the sensitive H2009, H292 and H23 cells. H23 and H292 with higher expression levels of AQP9, AQP2, AQP3, GLUT3 and GLUT4 showed significantly enhanced arsenic uptake in compared to A549 and PC14PE6 cell lines with lower expression levels of these membrane pore proteins. Arsenic contents were significantly low in PC14PE6 and A549 cell lines with increased Poster Session – Cytotoxics MRPs and LRP expression. In H292 and PC14PE6 NSCLC xenograft models, administration of 3.5 and 7 mg/kg KML001® significantly reduced tumor volume and tumor weight without additional toxicity to the mice. The combination with cisplatin and KML001® showed synergic inhibitory effects on the growth of H292 and PC14PE6 xenografts. Conclusions: These results suggest that telomere length, membrane pore proteins and drug transporters responsible for arsenic influx/efflux, such as AQPs, glucose transporters, LRP and MRPs may be used to predict the sensitivity and/or resistance of human NSCLC cells to KML001® and sodium metaarsenite (KML001® ) may have potential as an alternative therapeutic agent, especially in combination with cisplatin in NSCLC patients. 61 POSTER (Board P055) A panel of pediatric liver cancer patient-derived xenografts to improve stratification of children with hepatoblastoma M. Fabre1 , D. Nicolle2 , A. Gorse2 , O. Déas2 , C. Mussini3 , L. Brugières4 , M.R. Ghigna5 , E. Fadel6 , L. Galmiche-Rolland7 , C. Chardot8 , C. Armengol9 , J.G. Judde2 , S. Branchereau10 , S. Cairo2 . 1 Institut Gustave Roussy, Biology and Medical Pathology Department, Villejuif, France; 2 Xentech, R&D, Evry, France; 3 Bicêtre Hospital, Pathology Department, Le Kremlin Bicêtre, France; 4 Institut Gustave Roussy, Pediatric Oncology Department, Villejuif, France; 5 Marie Lannelongue Hospital, Pathology Department, Le Plessis Robinson, France; 6 Marie Lannelongue Hospital, Surgery Department, Le Plessis Robinson, France; 7 Necker Hospital, Pathology Department, Paris, France; 8 Necker Hospital, Pediatric Surgery Department, Paris, France; 9 Health Sciences Research Institute Germans Trias i Pujol (IGTP), Translational Liver Oncology, Badalona, Spain; 10 Bicêtre Hospital, Pediatric Surgery Department, Le Kremlin Bicêtre, France Despite being the predominant type of pediatric liver malignancies, hepatoblastoma (HB), with a world-wide incidence of 1 case per million persons per year, is a rare tumor. The high rate (>60%) of b-catenin activating mutations places HB as one of the human tumors most tightly associated with activation of the Wnt/b-catenin pathway. Evidence for (epi)genetic origin of HB is provided by its association with congenital anomalies, Beckwith–Wiedemann syndrome, and familial adenomatous polyposis, a disorder caused by germline mutation of APC, involved in b-catenin degradation. Like other rare diseases, rare cancers are particular challenging due to their low incidence, particularly for the identification of novel therapies. The rarity and the heterogeneity of childhood liver cancers hamper the development of reliable research tools that recapitulate each disease. To tackle this issue, we have launched a program aimed at the constitution of liver cancer patient-derived xenografts (PDXs). At present, 13 HBs and 2 HB/hepatocellular carcinoma (HCC) transitional liver cell tumors (TLCTs) have been successfully grown in immunocompromised mice out of 48 tumors grafted. HB and TLCT PDXs maintain the histological features of primary human tumors, and the heterogeneity of AFP levels in mouse blood correlate with that observed in patients. Comparative analysis of the clinical parameters associated to tumors from which PDX could or could not be established has been performed. This analysis clearly shows that tumor take is associated with high AFP level post-chemotherapy, with low % of treatment-induced necrotic/fibrotic area in the resected tumor, and, most important, with poor prognosis. Among HB PDXs models that have been established several are, in accordance with the clinical history, resistant to cis platinum and doxorubicin-based standard of care. In vivo anti-cancer screening in histologically different HB/TLCT PDX subtypes show unique profiles of response to the drugs tested, and identified the combination irinotecan/ temozolomide as a promising second line combination for a subset of HB PDXs. The identification of molecular biomarkers predictive of HB response to irinotecan/temozolomide combination will be discussed. Development of a panel of childhood liver tumor PDXs will endow the scientific community with an innovative and versatile research tool that will decisively contribute to improve our understandings on pediatric liver malignancies. These models constitute an unperishable reservoir of biological samples that strongly recapitulate the human tumor biology, and they can be used in several research domains such as functional genomics, cancer stem cell biology and pharmacogenomics, notably for the identification of Wnt/b-catenin inhibitors. In the long run, improved knowledge in all these research fields will be translated in improved cures for kids. Wednesday 19 November 2014 25 62 POSTER (Board P056) Antitumor and temozolomide-sensitizing effects of sodium metaarsenite in an orthotopic glioblastoma xenograft model W.Y. Kang1 , Y.M. Park2 , S.J. Kim2 . 1 Institute For Refractory Cancer Research Samsung Medical Center, Samsung Biomedical Research Institute, Seoul, South Korea; 2 Komipharm International Inc. Co., Pharmaceutical Division, Shiheung, South Korea Background: Glioblastoma is one of the most malignant types of primary brain tumors and the treatment of glioblastomas remains difficult in that no contemporary treatments are curative. Temozolomide (TMZ) was approved and has been used for the treatment of glioblastoma as adjuvant or concomitant therapy with radiotherapy. Material and Methods: Sodium metaarsenite (NaAsO2 , KML001® ) is an orally available arsenic compound that has entered phase I/II clinical trials in solid tumors and hematologic malignancies. In this study, we investigated the antitumor activity and TMZ-sensitizing effects of KML001® in glioblastoma cell lines and a glioblastoma orthotopic xenograft mice model. Results: KML001® inhibited colony formation in TMZ-sensitive (U87MG, U373MG) and TMZ-resistant (U138MG and U251MG) glioblastoma cells in a concentration-dependent manner. The combined KML001® and TMZ treatment significantly decreased clonogenecity of glioblastoma cells, compared with TMZ treatment only (p < 0.05 or less). The combinational treatment of KML001® and TMZ increased the amount of cleaved PARP and caspase-3 that occur at the onset of apoptosis, in U87MG- and U251MG-glioblastoma cells, when compared with TMZ treatment only. Immunocytochemistry (ICC) assay showed that the combinational treatment increased g-H2AX levels which is a DNA damage response factor in U87MG and U251MG-glioblastoma cells, compared with KML001® and TMZ treatment only. The administration of 5 mg/kg of KML001® inhibited tumor growth (46%) and induced apoptosis (p < 0.05 vs. Control) in the U87MG-glioblastoma orthotopic xenograft mice model. And the combination therapy of KML001® and TXM significantly reduced tumor mass volume in the U87MG-glioblastoma orthotopic xenograft model, compared with KML001® monotherapy (p < 0.05). In the U251MGglioblastoma orthotopic xenograft mice model, the combination significantly decreased tumor volume, compared with KML001® treatment only group (p < 0.05) and TMZ treatment only group (p < 0.05). Conclusions: In conclusion, KML001® showed similar or more potent antitumor effect than TMZ. The combinational treatment of KML001® and TMZ was synergistic or additive in a glioblastoma orthotopic xenograft mice model. These results provide a rationale for clinical testing of the combination therapy of KML001® and TMZ. 63 POSTER (Board P057) Radium-223 dichloride − Efficacy and mode-of-action in a mouse model of prostate cancer bone metastasis M.I. Suominen1 , K.M. Fagerlund1 , J.P. Rissanen1 , Y. Konkol1 , E. Alhoniemi1 , D. Mumberg2 , K. Ziegelbauer2 , S.M. Käkönen3 , J.M. Halleen1 , R.L. Vessella4 , A. Scholz2 . 1 Pharmatest Services Ltd, Turku, Finland; 2 Bayer Healthcare, Global Drug Discovery TRG-Onc/GT, Berlin, Germany; 3 University of Turku, Department of Cell Biology and Anatomy, Turku, Finland; 4 University of Washington, Departments of Urology and Microbiology, Seattle, USA Background: Radium-223 dichloride (Xofigo® ) is an alpha-emitting calcium mimetic that improves overall survival in prostate cancer patients with bone metastases (ALSYMPCA trial, NCT00699751, Parker et al. NEJM 18:213−33, 2014). Here, we clarified radium-223 dichloride modeof-action in an osteoblastic prostate cancer mouse model mimicking the devastating bone metastasis seen in prostate cancer patients. Material and Methods: The therapeutic effects of radium-223 dichloride were investigated in a clinically relevant patient-derived prostate cancer xenograft model exhibiting PSA expression, osteoblastic growth and systemic metastasis when inoculated into the bone marrow cavity. Human LuCaP 58 prostate cancer cells were inoculated into a tibia of 6−8-week-old male SCID mice (n = 17−18/group) and radium-223 dichloride (300 kBq/kg, iv injection) or vehicle control were administered once serum PSA levels reached 1 ng/ml and again 4 weeks later. X-rays and serum samples were obtained biweekly and at sacrifice 6 weeks after the first dose. Micro-CT measurements were performed on the tibiae (n = 8−11 mice/group) prior to preparation of decalcified paraffin sections for histomorphometry and immunohistochemistry. Soft tissues were collected for histology to observe visceral tumors, followed by macroscopical evaluation. Results: The inhibitory effect of radium-223 dichloride on tumor-induced osteoblastic bone growth was clearly visible in x-rays and in tibial weight 26 Wednesday 19 November 2014 measurement. Radium-223-treated mice exhibited reduced bone volume and surface in addition to decreased tumor volume compared to untreated animals. Metastatic spread to visceral organs was evident in 53% and 33% of vehicle- or radium-223 dichloride-treated mice, respectively. Importantly, both serum PSA and a bone formation marker PINP were reduced in radium-223 dichloride-treated mice. Moreover, the significantly lower PSA values were apparent as early as two weeks following the first dose, indicating that in addition to reducing osteoblastic bone growth, radium223 dichloride constrains tumor growth in metastatic prostate cancer. Conclusions: In conclusion, radium-223 dichloride (Xofigo® ) therapy exhibits a dual mode-of-action that impacts on tumor cells and on tumorinduced bone reaction, both important players in the destructive vicious cycle of osteoblastic bone metastasis in prostate cancer. 64 POSTER (Board P058) Nifuroxazide halogenic derivatives induce ROS-mediated apoptosis and display antitumor activity against metastatic melanoma C. Fernandez de Farias1 , M.H. Massaoka1 , N. Girola1 , C.R. Figueiredo1 , R.A. Azevedo2 , L.C. Tavares3 , L.R. Travassos1 . 1 Federal University of São Paulo, Department of Microbiology Immunology and Parasitology, São Paulo, Brazil; 2 Butantan Institute, Department of Biochemistry and Biophysics, São Paulo, Brazil; 3 University of São Paulo, Department of Biochemical and Pharmaceutical Technology, São Paulo, Brazil Background: Metastatic melanoma is a highly aggressive and therapyresistant malignancy. At the metastatic stage the disease is highly resistant to conventional therapy, and the 5-year survival is rather low. Therefore, novel therapeutic interventions are stimulated. Nifuroxazide is a widely used antibiotic, and its mechanism of action depends on ROS production. In this work we report on the antimelanoma activity of two halogenic derivatives of nifuroxazide. Material and Methods: Cell viability was examined by MTT assay on B16F10-Nex2 murine melanoma cells after treatment with N-Br and N-I. Superoxide anion production was evaluated by dihydroethidium (DHE) assay in B16F10-Nex2 cells co-incubated or not with N-acetylcysteine (Nac). Chromatin condensation was analyzed by Hoescht 33342 staining. DNA degradation was evaluated in B16F10-Nex2 cells lysed in TELT buffer and subjected to electrophoresis in 1% Agarose gel. Apoptosis, in B16F10-Nex2 cells, was evaluated by annexin V-positive cells, measured by FACS. Mitochondrial membrane permeability of melanoma cells, coincubated with Nac and treated with N-Br and N-I, was assessed using the fluorescent probe tetramethylrhodamine ethyl ester (TMRE), and then analyzed by FACS. Therapeutic efficacy was examined in a syngeneic model of metastatic melanoma using C57BL/6 mice endovenously injected with B16F10-Nex2 cells and treated i.p. with N-Br and N-I. After 14 days, animals were sacrificed and the lungs were examined for metastatic colonization. Results: Both derivatives induced cell death in vitro in a dose-dependent manner. The IC50 values were 16mM and 12mM for N-Br and N-I, respectively, against murine melanoma cells. In the presence of Nac cytotoxicity of both compounds decreased. Furthermore, treatment with N-Br and N-I increased superoxide anion production by 87.5% and 55.65%, respectively. Co-incubation with Nac completely inhibited ROS production upon treatment with both compounds. Apoptosis cell death was suggested by a ladder pattern of DNA fragmentation and a drug concentration-dependent phosphatidyl serine surface translocation. Moreover, TMRE staining showed that N-B and N-I were able to induce the loss of mitochondrial membrane potential in a time-dependent manner, which was inhibited by Nac within 6 h of treatment. Hoescht staining confirmed that cells treated with both compounds exhibited chromatin condensation as in apoptotic nuclei. Remarkably, i.p. doses of N-Br and N-I were protective against metastatic melanoma, raised by endovenous injection of B16F10-Nex2 tumor cells. Conclusion: Nifuroxazide halogenic derivatives induce apoptosis in melanoma cells in a ROS-dependent manner at micromolar doses. Both N-Br and N-I were protective against metastatic B16F10-Nex2 melanoma in a syngeneic model. Supported by Fapesp no. 2014/05107-8. Poster Session – Cytotoxics 65 POSTER (Board P059) Phase II drug metabolism UGT1A enzyme affects cellular response of colon cancer cells to antitumor triazoloacridinone C-1305 treatment E. Augustin1 , E. Bartusik1 , A. Theus1 , B. Borowa-Mazgaj1 , Z. Mazerska1 . 1 Gdansk University of Technology, Pharmaceutical Technology and Biochemistry, Gdansk, Poland Background: The essential limitation of a drug’s effectiveness in a living organism is the individual’s level of enzymes, which catalyze drug metabolism. Furthermore, the expression level of metabolic enzymes in tumor tissues (in vivo) or tumor cells (in vitro) may affect the final effect of the drug treatment. C-1305 is a promising antitumor agent with high activity against many experimental cellular and tumor models. Studies on C-1305 metabolism indicated that the compound is conjugated by several uridine diphosphate-glucuronyltransferase (UGT) isoforms, the most active being extrahepatic UGT1A10. Here, we investigated whether and how UGT1A isoenzyme affects the cellular response of colon cancer cells following C-1305 treatment. Materials and Methods: C-1305 activity was evaluated in two human colon carcinoma cell lines, HT29 (UGT1A positive) and HCT116 (UGT1A negative). To determine whether UGT1A expression affects the final cellular response upon C-1305 treatment, HT29 and HCT116 cells were exposed to EC50 concentration for 24 h to 120 h. DAPI staining was used to analyze cellular morphology. Flow cytometry for annexin V/PI assay and subG1 DNA fraction was applied to identify apoptosis. Analysis of cellular morphology and expression of SA-b-galactosidase were performed to identify cells with senescence-like phenotype. Acridine orange staining was performed to detect acidic vesicular organelles (AVOs) as a marker of autophagy. Results: Treatment of colon cancer cells with C-1305 for 72 h suppressed cell proliferation with EC50 concentration equal to 0.5 mM for HT29 and 0.8 mM for HCT116 cells, respectively. C-1305 induced apoptosis, necrosis and mitotic catastrophe in both cell lines as evidence by chromatin condensation, the presence of multinucleated cells, phosphatydilserine externalization and presence of sub-G1 fraction. In all tests, the number of apoptotic cells was low and increased in a time-dependent manner and reached ~23% after 120 h of drug exposure in both cell lines. Starting from 72 h, HCT116 cells which did not die by apoptosis or necrosis, underwent cellular senescence, preceded by autophagy. Interestingly, pharmacological inhibition of autophagy by chloroquine (10 mM) sensitized HCT116 cells to C-1305 and profoundly intensified the senescence phenotype. HT29 cells did not undergo cellular senescence. Moreover, rapid autophagy observed in those cells after 24 h decreased following prolonged drug treatment. Conclusions: Our results indicate that in colon cancer cells treated with C-1305, the lack of UGT1A expression promotes autophagy followed by cellular senescence. UGT1A status had no effect on apoptosis, mitotic catastrophe or necrosis induced by C-1305. 66 POSTER (Board P060) Clinical validity of new genetic biomarkers of irinotecan neutropenia: An independent replication study F. Innocenti1 , J. Ramirez2 , W. Qiao3 , A.J. de Graan4 , M.J. Ratain2 , R.H.N. van Schaik4 , R.H.J. Mathijssen4 , G.L. Rosner5 , D.J. Crona6 . 1 University of North Carolina at Chapel Hill, Linberger Comprehensive Cancer Center & Center for Pharmacogenomics and Individualized Therapy Eshelman School of Pharmacy, Chapel Hill NC, USA; 2 University of Chicago, Department of Medicine, Chicago IL, USA; 3 MD Anderson Cancer Center University of Texas, Houston TX, USA; 4 Erasmus University Medical Center, Erasmus MC Cancer Institute, Rotterdam, Netherlands; 5 Johns Hopkins University, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore MD, USA; 6 University of North Carolina at Chapel Hill, Center for Pharmacogenomics and Individualized Therapy Eshelman School of Pharmacy, Chapel Hill NC, USA Purpose: This study aimed to provide evidence for the clinical validity of germline genetic variants previously associated with irinotecan neutropenia and pharmacokinetics. Methods: Ten germline variants from six genes, whichassociated with absolute neutrophil count (ANC) nadir and/or irinotecan pharmacokinetics in a discovery cohort of 78 cancer patients, were genotyped in an independent replication cohort of 108 cancer patients. Patients from both cohorts received single-agent irinotecan every three weeks. Pharmacokinetic data and neutrophil counts were collected during cycle 1 of treatment. Associations between the germline variants and ANC nadir or irinotecan pharmacokinetics were analyzed using linear regression. Univariate and multivariate models adjusted for sex, age, irinotecan dose, and ANC nadir models also adjusted for baseline ANC. Poster Session – Drug Resistance and Modifiers Results: For ANC nadir, we replicated UGT1A1*93, UGT1A1*28, and SLCO1B1*1b. In both univariate and multivariate models, SLCO1B1*1b had a protective effect against neutropenia, independent of the effect of either UGT1A1*28 or UGT1A1*93. For irinotecan AUC0−24 , we replicated ABCC2 −24C>T and HNF1a 79A>C; however ABCC2 −24C>T predicted only a small fraction of the interindividual variability in irinotecan exposure, and HNF1a 79A>C had a 75% lower estimate of effect compared to the discovery cohort. For SN-38 AUC0−24 and the glucuronidation ratio, we replicated UGT1A1*28, UGT1A1*93, and ABCC1 1684T>C; however ABCC1 1684T>C had an 85% lower estimate of effect compared to the discovery cohort. Conclusion: In addition to UGT1A1*28, this study independently validated UGT1A1*93 and SLCO1B1*1b as new predictors of irinotecan neutropenia. Further demonstration of the clinical utility of SLCO1B1*1b and UGT1A1*93 will help further optimize irinotecan therapy for cancer patients. 67 POSTER (Board P061) Cytotoxic response as a result of the cross-talk between UGT mediated metabolism and modulation of UGT activity by C-1311 and C-1305 acridinone antitumor agents in selected solid tumor cell lines Z. Mazerska1 , M. Pawlowska1 , A. Bejrowska1 , M. Szydlowska1 , B. Fedejko1 , E. Augustin1 . 1 Gdansk University of Technology, Department of Pharmaceutical Technology and Biochemistry, Gdansk, Poland Background: UDP-glucuronyltransferases (UGTs, EC 2.4.1.17) transform nearly 35% drugs to metabolites, which are usually of lower toxicity or limited therapeutic effects. Anticancer agents are of special interest in this respect, because the glucuronidation may represent a mechanism of intrinsic drug resistance and there were reported the differences in UGT expression between normal and tumour tissues. Moreover, the UGT level and activity in normal and tumour cells can be modulated by other chemotherapeutics, what is crucial in antitumor multidrug therapy. Considering above we aimed here to know whether antitumor acridinone derivatives C-1305 and C-1311 are glucuronidated in selected solid tumour cell lines and what is the impact of UGT1A10 overexpression on cytotoxicity of these compounds. We also answered whether C-1305 and C-1311 are able to influence UGT enzymatic activity. Materials and Methods: The studied compounds, 5-diethylamino-8hydroxyimidazoacridinone, C-1311, and 5-dimethylamino-8-hydroxytriazoloacridinone, C-1305, were developed in our laboratory, and C-1311 was selected for II phase of clinical studies. Cell lines of human hepatoma, HepG2, colon tumours, HCT116 and HT29 and breast cancer, MCF-7, were studied and they (except HT29) were tranfected with UGT1A10 vector by electroporation. UGT1A10 was selected as the most effective UGT isoenzyme towards studied compounds in vitro. Metabolic glucuronidation in tumour cells was followed by HPLC analysis. The concentration of standard UGT substrates 7-hydroxy-4-(trifluoromethyl)coumarin (7-TFK) and 7-ethyl10-hydroxycamptothecin (SN-38) were the markers of UGT activity. Results indicated that both compounds were metabolized in HT-29 wild type cells (natural UGT expression) and in UGT1A10 overexpressed tumour cells to O-glucuronides on 8-hydroxyl group. Cytotoxicity of C-1311 in MCF-7 cells overexpressed with UGT was lower than in MCF-7 wild type, whereas it was not changed in HepG2 and HCT116. At the same time the activity of C-1305 was slightly, but significantly, higher in the presence of higher level of UGT in HepG2 and MCF-7 cells. Compounds C-1305 and C-1311 were similar in the profile of UGT modulation. They activated UGT only at low concentration and after short time of incubation, whereas higher concentration and long time resulted in the inhibition of UGT mediated metabolism. Conclusions: The cross-talk between the glucuronidation and UGT induction/inhibition demonstrated here seems to be responsible for the fact that the final influence of UGT on cytotoxicresponse depended on the type of tumor cells and the type of compound. Nevertheless, the results showed that glucuronidation of C-1305 antitumor agent in MCF-7 cells did not result in lower cytotoxicity, as is usually observed for majority of drugs, but we even observed the activation effect of C-1305 glucuronide toward tumour cells. 68 POSTER (Board P062) Can the P53 status predict the outcome of Polo-like kinase 1 inhibition in non-small cell lung cancer cell lines? J. Van den Bossche1 , A. Wouters1 , C. Deben2 , V. Deschoolmeester2 , P. Specenier3 , P. Pauwels4 , M. Peeters3 , F. Lardon1 . 1 Antwerp University, Oncology, Antwerp, Belgium; 2 Antwerp University, Pathology, Antwerp, Belgium; 3 Antwerp University Hospital, Oncology, Antwerp, Belgium; 4 Antwerp University Hospital, Pathology, Antwerp, Belgium Introduction: Polo-like kinase 1 (Plk1), a key regulator of multiple steps during mitosis, is considered as one of the most promising therapeutic Wednesday 19 November 2014 27 targets for mitotic intervention due to its overexpression in a number of human malignancies, including non-small cell lung cancer (NSCLC). TP53 is the most frequently mutated gene in human cancer and plays a role in many cellular processes including cell growth and response to DNA damage. Previous studies suggest a negative interplay between Plk1 and P53, leading to the hypothesis that P53 status might be a predictive biomarker for response to Plk1 inhibition. As such, we investigated the cytotoxic effect of the small molecule inhibitor BI6727 (volasertib) in a series of NSCLC cell lines differing in P53 status. Material and Methods: Three isogenic NSCLC cell lines (A549 (P53 wt), A549-NTC (empty vector control, p53 wt) and A549–920 (P53 deficient)) were generated using a P53 GIPZ shRNA lentiviral vector. The CRL5908 NSCLC cell line, harboring a P53 mutation (R273H), was included too. All cell lines were treated with BI6727 (0−85nM) for 24 or 72 hours. Treated cells were incubated under both normal and reduced oxygen conditions (hypoxia, <0.1% O2 ). Cell survival was assessed using the sulphorhodamine B (SRB) assay and IC50 values were calculated using WinNonlin software. The effect of Plk1 inhibition (0−10nM) on cell cycle distribution of A549 cells was determined flow cytometrically using the Vindelov method. Results: Treatment with BI6726 established a dose-dependent growth inhibition under both normoxic and hypoxic conditions. As shown in Table 1, a significantly reduced sensitivity to volasertib was observed in P53 deficient cells compared to p53 wt cell lines (p < 0.001). For example, in A549–920 cells, 24 hours of Plk1 inhibition (normoxia) resulted in an IC50 value of 27.59±5.77 nM in contrast to 17.87±0.40 nM for A549-NTC cells. Table 1 demonstrates also a decreased effect of BI6727 under hypoxic conditions (p < 0.001). However, this could not be observed in the P53 mutant cell line. Considering the cell cycle distribution under normoxic conditions after treatment with 10nM volasertib, a significant G2 /M phase block was induced in the A549 cell line (p < 0.022). Furthermore, a sub-G1 peak could be observed when treated with high concentrations of BI6727, suggesting induction of apoptosis. Similar experiments will be performed in the cell lines lacking functional P53 in order to detect possible differences in cell fate after Plk1 inhibition. Conclusion: Our results show that A549 NSCLC cells with functional P53 seem to be more sensitive to Plk1 inhibition compared to isogenic P53 deficient cells. Further experiments are warranted to further clarify this observation. In addition, combination studies of volasertib with conventional chemotherapeutics and radiotherapy will be initiated. Table 1. IC50 values ± standard deviations after 24 and 72 hours of treatment with volasertib under both normoxic and hypoxic conditions Cell line A549 NTC 920 5908 Normoxia 24 h 72 h Hypoxia 24 h 72h 15.44±2.49 17.87±0.40 27.59±5.77 61.90±3.94 18.44±1.83 17.33±1.32 28.00±6.32 72.38±9.87 79.91±15.41 66.39±14.31 115.46±27.60 76.43±10.83 54.46±5.58 63.89±22.30 112.52±34.19 68.66±9.83 Drug Resistance and Modifiers 69 POSTER (Board P063) AKT3 activation mediates resistance to HER2-targeted therapies in HER2-amplified breast cancer F. Carmona Sanz1 , F. Montemurro2 , V. Rossi2 , C. Verma3 , M. Berger1 , J. Baselga1 , M. Scaltriti1 . 1 Memorial Sloan-Kettering Cancer Center, New York City, USA; 2 Institute for Cancer Research and Treatment, Candiolo, Italy; 3 A STAR’s Bioinformatics Institute (BII), Singapore, Singapore Background: HER2 targeted therapies have improved the clinical benefit of HER2-amplified breast cancer when diagnosed before metastatic spread. Nevertheless, a substantial percentage of patients with advanced HER2 positive disease are intrinsically refractory to these agents, and many initially responding patients acquire resistance over time. Activation of PI3K/AKT pathway via mutation of PIK3CA or loss of PTEN has been associated with resistance to anti-HER2 therapy, and combination regimes with PI3K inhibitors are now under investigation in the clinical setting. We hypothesize that also aberrations in AKT3 concur in limiting the sensitivity to anti-HER2 agents. Material and Methods: We used targeted exome-sequencing to analyze clinical specimens obtained from HER2-amplified breast cancer patients 28 Wednesday 19 November 2014 Poster Session – Drug Resistance and Modifiers treated with trastuzumab and/or lapatinib monotherapy. Further protein modeling studies and functional in vitro and in vivo assays were used to validate our findings. Genetically engineered AKT 1/2 null cells were also used to assess the contribution of AKT3 activation in the context of drug resistance. Results: We have identified gain-of-function genomic alterations in AKT3 associated with therapy refractoriness in HER2-amplified breast cancer patients treated with anti-HER2 agents in a chemotherapy-free setting. Specifically, copy-gain and genomic mutation were associated with intrinsic resistance to trastuzumab or lapatinib. Protein modeling predicts an activating role for the mutation identified, providing a mechanism for pathway activation beyond those previously described. Treatment combination with specific AKT inhibitors might improve treatment efficacy and overcome resistance to HER2-directed therapy. Conclusions: Genomic analyses of selected patient biopsies provide relevant biomarkers that can be used for clinical decision making. The involvement of AKT3 in the development of resistance to anti-HER2 agents provides an actionable target for efficient therapeutic intervention. Moreover, the confirmation of AKT3 as a reliable prognostic biomarker would improve patient stratification beyond the assessment of routinely assayed pathway alterations. 70 POSTER (Board P064) Antitumor activity of S116836, a novel tyrosine kinase inhibitor, against imatinib-resistant FIP1L1-PDGFRa-expressing cells J. Pan1 , Y. Shen2 , K. Ding3 . 1 Sun Yat-sen University Zhongshan Ophthalmic Center, State Key Laboratory of Ophthalmology, Guangzhou, China; 2 Sun Yat-sen University Zhongshan School of Medicine, Department of Pathophysiology, Guangzhou, China; 3 Guangzhou Institute of Biomedicine and Health Chinese Academy of Sciences, Key Laboratory of Regenerative Biology and Institute of Chemical Biology, Guangzhou, China The FIP1-like-1-platelet-derived growth factor receptor alpha (FIP1L1PDGFRa) fusion oncogene is the driver factor in a subset of patients with hypereosinophilic syndrome (HES)/chronic eosinophilic leukemia (CEL). Most FIP1L1-PDGFRa-positive patients respond well to the tyrosine kinase inhibitor (TKI) imatinib. Resistance to imatinib in HES/CEL has been described mainly due to the T674I mutation in FIP1L1-PDGFRa, which is homologous to the imatinib-resistant T315I mutation in BCR−ABL. Development of novel TKIs is imperative to overcome resistance to imatinib. We synthesized S116836, a novel TKI. In this study, we evaluated the antitumor activity of S116836 in FIP1L1-PDGFRa-expressing cells. The results showed that S116836 potently inhibited PDGFRa and its downstream signaling molecules such as STAT3, AKT, and ERK1/2. S116836 effectively inhibited the growth of the WT and T674I FIP1L1PDGFRa-expressing neoplastic cells in vitro and in nude mouse xenografts. Moreover, S116836 induced intrinsic pathway of apoptosis as well as the death receptor pathway, coincided with up-regulation of the proapoptotic BH3-only protein Bim-EL through the Erk1/2 pathway. In conclusion, S116836 is active against WT and T674I FIP1L1-PDGFRaexpressing cells, and may be a prospective agent for the treatment of HES/CEL. 71 POSTER (Board P065) Novel regulation of estrogen receptor transcription by the PI3K pathway 1 1 1 1 1 1 E. Toska , M. Elkabets , A. Bosch , O. Litvin , M. Scaltriti , J. Baselga . 1 MSKCC, New York, USA Background: Alterations in the PI3K/Akt/mTOR pathway occur in up to 50% of estrogen receptor (ER) positive breast tumors. Clinical data showed that dual inhibition of the ER and mTOR pathways results in greater disease control. Although previous work has pointed to the existence of crosstalk between ER and certain nodes of the PI3K pathway, the mechanism by which both pathways regulate each other remains to be elucidated. Thus, we aim to investigate the mechanisms by which ER-dependent transcriptional program is regulated by the PI3K pathway. Material and Methods: ER-positive cell lines with different genomic alterations in the PI3K pathway were treated in vitro with the p110a-specific PI3K inhibitor BYL719. RNA expression was evaluated by gene expression microarray analysis and RT-PCR. Promoter occupancy of ER to its target genes was assessed by chromatin immunoprecipitation (ChIP) assay. A transposon activation mutagenesis screen was developed to identify modulators of resistance to PI3K inhibitors in ER-positive breast cancer cells. This approach employs the transfection of transposon containing CMV promoters that are randomly integrated in the genome and drive activation of nearby gene expression. Results: We observed that inhibition of the PI3K pathway by BYL719 triggers ER gene expression, which in turn results in increased ERdependent transcriptional activity accompanied by an ER-driven re-wiring of the cell transcriptome. The transposon activation mutagenesis screen followed by high throughput sequencing successfully identified genes that regulate ER expression/activity and putatively cause resistance to PI3K inhibitors in ER+ breast cancer cell lines. Interestingly, among the genes identified we found a number of key transcription factors known to modulate ER expression. Importantly, these results were confirmed in breast cancer patients treated with BYL719. Conclusions: Our findings suggest that PI3K inhibition activates the ER pathway by modulating ER expression levels. Moreover, we have developed a transposon activation mutagenesis screen that identified a number of ER co-factors as possible responsible for resistance to PI3K inhibition. The molecular mechanisms by which these factors enter into play upon PI3K inhibition are currently being investigated. 72 POSTER (Board P066) Nrf2 as a molecular target in overwhelming chemoresistance in breast cancer therapy N. Samadi1 , F. Ramezani1 , M. Sabzichi1 . 1 RCPN, Clinical Biochimestry, Tabriz, Iran Background: Nuclear factor erythroid 2-related factor 2 (Nrf2) has been recognized as a transcription factor that control mechanisms of cellular defense response by regulation of three classes of genes, including, endogenous antioxidants, phase II detoxifying enzymes and transporters. Previous studies have revealed the role of Nrf2 in resistance to chemotherapeutic agents and high level expression of Nrf2 have found in many types of cancer. At physiological concentrations, luteolin as a flavonoid compound can inhibit Nrf2 and sensitized cancer cells to chemotherapeutic agents. We reported luteolin loaded in phytosome as an advanced nanoparticles carrier sensitized MDA-MB 231 cells to doxorubicin. Material and Methods: Luteolin-loaded phytosome was prepared by thin film hydration technique. Cell culture/cytotoxicity studies of luteolin, doxorubicin, and phytosome were performed by means of MDA-MB231 human cancer cells and MTT assay. Determination of the gene expression levels of Nrf2, HO1, NQO1 and MDR1, used by Real-Time polymerase chain reaction (RT-PCR). Results: In this study, we prepared nano phytosoms of luteolin to enhance the bioavailability of luteolin and improve passive targeting in breast cancer cells. Our results showed that co-treatment of the cells with nano particles containing luteolin and doxorubicin has the highest percentage of cell death in MDA-MB 231cells (p < 0.05). Furthermore, luteolin-loaded nanoparticles reduced Nrf2 gene expression at mRNA level in the cells higher than luteolin alone (p < 0.05). Similarly, expression of downstream genes for Nrf2 including Ho1 and MDR1 were reduced significantly (p < 0.05). Inhibition of Nrf-2 expression caused a marked increase in cancer cell death (p < 0.05). Conclusions: Taken together, these results suggest that phytosome technology can improve the efficacy of chemotherapy by overcoming resistance and enhances permeability cancer cells to chemical treatment and may thus be considered as a potential delivery system to increase the therapeutic protocols in cancer patients. 73 POSTER (Board P067) Differential pathway resiliency in response to MAPK inhibition in BRAF-mutant cancer M. Sos1 , R.S. Levin1 , J.D. Gordan1 , J.A. Oses-Prieto2 , J.T. Webber3 , M. Salt4 , B. Hann4 , A.L. Burlingame2 , F. McCormick4 , S. Bandyopadhyay3 , K.M. Shokat1 . 1 UCSF, Howard Hughes Medical Institute and Department of Cellular and Molecular Pharmacology University of California San Francisco, San Francisco CA, USA; 2 UCSF, Department of Pharmaceutical Chemistry University of California San Francisco California USA, San Francisco CA, USA; 3 UCSF, Department of Bioengineering and Therapeutic Sciences University of California San Francisco, San Francisco CA, USA; 4 UCSF, Helen Diller Family Comprehensive Cancer Center Department of Medicine University of California San Francisco San Francisco, San Francisco CA, USA Background: Despite the development of potent RAS-RAF pathway inhibitors, only a fraction of BRAF-mutant patients responds to the treatment with these drugs. Materials and Methods: Here, we applied a combined chemo-genomics and chemo-proteomics approach to gain insights into the dynamics of primary resistance signaling and to define novel cancer vulnerabilities in these tumors. Poster Session – Drug Resistance and Modifiers Results: These analyses uncovered differential pathway resiliency in response to MAPK inhibition in BRAF-mutant cancer cells and identified how high-dose MEK inhibition as a viable strategy to overcome this source of resistance signaling. Mapping of global phosphorylation dynamics using orthogonal mass-spectrometry based methods revealed multi-layered MAPK pathway feedback-loop release and autocrine cytokine secretion as complementary drivers of adaptive signaling in these tumors. Conclusions: Overall, our data provide a kinome- and phosphoproteomewide view of the adaptive process of primary resistance to MAPK inhibitors in BRAF-mutant tumors that may be of importance for future clinical trials involving these targeted drugs. 74 POSTER (Board P068) Increased EDN1 expression mediates acquired resistance to the combination therapy of PI3K and MEK inhibitors for colorectal cancer B. Bhattacharya1 , S.H.H. Low1 , T. Benoukraf1 , M.L. Chong1 , K.X. Koh1 , R. Soong1 . 1 National University of Singapore, Cancer Science Institute, Singapore, Singapore Background: Previously we reported that acquired resistance (AQR) to the combination of BKM120 (PI3K inhibitor) and AZD6244 (MEK inhibitor) can be generated in PIK3CA and KRAS mutant HCT116 colorectal cancer (CRC) cells, in addition to AQR to the individual agents. Using gene expression analysis we demonstrated that the differentially expressed genes in the combination AQR cells are distinctly different to those expressed in single agent AQR and parental cells, with EDN1 (endothelin-1) gene being the most highly expressed (~33-fold). Currently, we generated AQR to the same combination in LoVo CRC cell line and explored determinants of resistance. Methods: LoVo CRC cells with KRAS mutation were exposed continuously with combined (1 IC50 dose of each agent) or single agent (2 doses of IC25 ) concentrations of MEK (AZD6244) and PI3K (BKM120) inhibitors, or DMSO (parental). Combination Indices (CI) was calculated by the method of Chou and Talalay. Differentially expressed genes were determined using Affymetrix Gene 1.0ST analysis. Results: LoVo cells with AQR to combination treatment were obtained after 12 months (CI@fu0.5 of ‘LoVoCR’ cells 2.5±0.3 vs parental 0.19±006, p = 0.03). LoVo cells with AQR to single agent treatment with AZD6244 (IC50 of ‘LoVoAR’ 67.1±0.02mM vs parental 5.1±0.01mM; p = 0.02) and BKM120 (IC50 of ‘LoVoBR’ 5.2±0.11mM vs parental 0.9±0.21mM; p = 0.002) were also generated. Consistent with our previous findings LoVoCR cells were resistant to apoptosis, wound healing response and cell cycle arrest compared with parental cells. Furthermore, these cells also displayed resistance to the combination of an alternative PI3K inhibitor (BYL719) and MEK inhibitor (GDC0973). No cross-resistance was observed with 5-FU or carboplatin in LoVoCR cells, arguing against a multi-drug resistance phenotype. Consistent with our gene expression data in HCT116 cells AQR to the combination (HCT116CR) cells a 7-fold overexpression of EDN1 was also observed in LoVoCR cells. Both HCT116CR and LoVoCR cells displayed significantly elevated phosphorylation levels of AKT and ERK compared to parental cells, suggesting some feedback mechanism. Silencing EDN1 by siRNA significantly reduced the proliferation rates of HCT116CR and LoVoCR cells compared to control siRNA, which was accompanied by a decrease in phosphorylation of AKT and ERK. Both the combination AQR cells were significantly sensitive to bosentan (endothelin receptor antagonist) induced growth inhibition (HCT116 IC50 = 67.4±0.9mM vs HCT116CR IC50 = 39.2±1.2mM; p = 0.01: LoVo IC50 = 83.2±2.5mM vs LoVoCR IC50 = 41.1±3.4mM; p = 0.03). Furthermore, in HCT116CR and LoVoCR cells the antagonism was converted to synergy in the presence of a non-growth inhibitory concentration (1/5th IC50 ) of bosentan. Finally, pre-stimulation with exogenous endothelin-1 conferred resistance to the combination in both parental HCT116 and LoVo cells, along with an increase in AKT and ERK phosphorylation. Current work aims to uncover the mechanism of transcriptional regulation of endothelin in AQR. Conclusions: EDN1 is a specific mediator of AQR to the use of the PI3K and MEK inhibitor combination in CRC, irrespective of the genetic lesions involved. Endothelin receptor antagonists can potentially circumvent such resistance. Wednesday 19 November 2014 29 75 POSTER (Board P069) Loss of PTEN leads to acquired resistance to the PI3Ka inhibitor BYL719: a case of convergent evolution under selective therapeutic pressure P. Castel1 , D. Juric2 , M. Griffith3 , O.L. Griffith4 , H.H. Won1 , B. Ainscough5 , H. Ellis1 , S. Ebbesen6 , I. Gopakumar1 , C. Quadt7 , M. Peters7 , D. Solit1 , S.W. Lowe6 , E.R. Mardis5 , M.F. Berger1 , M. Scaltriti1 , J. Baselga1 . 1 Memorial Sloan Kettering Cancer Center, HOPP, New York, USA; 2 Massachusetts General Hospital, Cancer Center, Boston, USA; 3 Washington University School of Medicine, Department of Genetics, St Louis, USA; 4 Washington University School of Medicine, Department of Medicine, St Louis, USA; 5 Washington University School of Medicine, The Genome Institute, St Louis, USA; 6 Memorial Sloan Kettering Cancer Center, Cancer Biology and Genetics, New York, USA; 7 Novartis Pharma AG, Basel, Switzerland Background: Activating mutations of PIK3CA, the gene encoding the p110a subunit of PI3K, are frequent in breast cancer and selective inhibitors of this enzyme have shown promising clinical activity in breast tumors harboring these mutations. Material and Methods: We studied the case of a patient with metastatic breast cancer harboring a PIK3CA mutation that was treated in a clinical trial with BYL719, a highly selective PI3Ka inhibitor. The treatment resulted in partial tumor regression that lasted 9.5 months followed by progression and rapid death of the patient. A rapid autopsy was performed with collection of tissue samples from 16 different metastatic sites. We compared by whole genome and exome sequencing the original primary tumor, a rapidly progressing lung metastasis and a periaortic lesion that was still responding to BYL719 at time of death. Besides several common alterations, PTEN loss and a missense mutation were detected only in the lung metastasis. Using targeted exome sequencing we analyzed all the other available samples. Results: Strikingly, we observed a consistent loss in PTEN (via different mechanisms such as deletion, splice site mutation and frameshift mutations) in all the lesions refractory to BYL719 but not in the responding ones. We were able to build a dendrogram showing the phylogenetic evolution of the lesions and the evolutionary convergence of the PTEN alterations. To validate PTEN loss as a possible mechanism of acquired resistance to selective PI3Ka inhibition, we generated inducible PTEN shRNA clones starting from three different BYL719-sensitive cell lines. In all the studied models, induction of PTEN shRNA resulted in resistance to BYL719. Since PTEN deficient genetic models have been shown to rely on the b subunit of the PI3K holoenzyme, we tested whether the concomitant inhibition of both p110a and p110b was sufficient to revert the resistant phenotype. BKM120 (a pan-PI3K inhibitor) or the addition of AZD6482 (p110b inhibitor) to BYL719 re-sensitized the cells to BYL719. To expand our findings in vivo, we used a patient-derived xenograft (PDX) model generated from a lung PTEN-null non-responding lesion. Consistently, this PDX model was refractory to the antitumor activity of BYL719 but conserved sensitivity to BKM120 or the combination of AZD6482 and BYL719. In both cases, IHC analysis revealed a decrease in PI3K/AKT downstream effectors pAKT (473) and pS6 (240/4) staining with BKM120 or AZD6482+BYL719, but not with BYL719 alone. Preliminary analyses of other specimens collected from patients treated with BYL719 showed homozygous PTEN loss in another sample upon therapy progression. Conclusion: Taken together, the different mechanisms that inactivate PTEN in the tumor treated with BYL719 can be explained by convergent phenotypic evolution in a heterogeneous tumor and highlight the importance of PTEN and PI3Kb in acquired resistance to PI3Ka inhibitors. 76 POSTER (Board P070) Mixed lineage kinases activate MEK independently of RAF to mediate resistance to RAF inhibitors A.A. Marusiak1 , Z.C. Edwards1 , W. Hugo2 , E.W. Trotter1 , M.R. Girotti3 , N.L. Stephenson1 , X. Kong2 , M.G. Gartside4 , S. Fawdar1 , A. Hudson1 , W. Breitwieser5 , N.K. Hayward4 , R. Marais3 , R.S. Lo2 , J. Brognard1 . 1 Cancer Research UK Manchester Institute, Signalling Networks in Cancer, Manchester, United Kingdom; 2 Jonsson Comprehensive Cancer Center, Division of Dermatology, Los Angeles, USA; 3 Cancer Research UK Manchester Institute, Molecular Oncology, Manchester, United Kingdom; 4 QIMR Berghofer Medical Research Institute, Oncogenomics Research, Brisbane, Australia; 5 Cancer Research UK Manchester Institute, Cell Regulation, Manchester, United Kingdom Melanoma is a form of skin cancer that displays a particularly aggressive and malignant phenotype. Over 50% of melanoma cases involve mutation 30 Wednesday 19 November 2014 of the BRAF protein, and of these more than 90% carry the amino acid substitution V600E. This is an activating mutation that constitutively activates the ERK pathway, promoting survival and proliferation. BRAF inhibitors such as vemurafenib initially give good results, with a high rate of objective response and improved survival rates; however, resistance develops after around six months. We have identified a novel mechanism of resistance to BRAF inhibition, mediated by the mixed lineage kinase (MLK) family of proteins. MLKs are MAP3Ks, which are known to activate the JNK pathway. We observed that MLK1−4 can directly phosphorylate MEK in vitro and activate the ERK pathway in cells. Expression of MLK1−4 in melanoma cell lines harbouring BRAFV600E reactivates the ERK pathway and promotes cell survival despite treatment with BRAF inhibitors. Furthermore, MLKs are found to be upregulated in 9 of 21 melanoma patients with acquired drug resistance. Consistent with this observation, MLKs promote resistance to RAF inhibitors in mouse models, and contribute to acquired resistance in a cell line model. Lastly, we observe that a majority of MLK1 mutations identified in patients are gain-of-function mutations. In conclusion these results suggest a role for MLKs as direct activators of the MEK/ERK pathway with implications for melanomagenesis and resistance to RAF inhibitors. 77 POSTER (Board P071) Tumor suppressive roles of miR-221 and miR-222 in lung cancer M. Sato1 , R. Yamashita1 , T. Kakumu1 , T. Hase1 , E. Maruyama1 , Y. Sekido2 , M. Kondo1 , Y. Hasegawa1 . 1 Nagoya University Graduate School of Medicine, Department of Respiratory Medicine, Nagoya, Japan; 2 Aichi Cancer Center Research Institute, Division of Molecular Oncology, Nagoya, Japan Background: Bimodal roles of miR-221 and miR-222 microRNAs are reported in several types of human cancers. A previous study suggested their oncogenic role in invasiveness in lung cancer, albeit only one cell line (H460) was used. Material and Methods: To further evaluate involvement of miR-221 and miR-222 in lung cancer, we investigated the effects of miR-221 and miR222 overexpression on six lung cancer cell lines, including H460, as well as one immortalized normal human bronchial epithelial cell line, HBEC4. Results: miR-221 and miR-222 overexpression induced epithelial-tomesenchymal transition (EMT)-like changes in morphology as well as expression levels of EMT-associated genes in HBEC4 but did not confer EMT-associated oncogenic phenotypes, anchorage-independent growth and invasiveness. Consistent with the prior report, miR-221 and miR222 promoted growth in H460; however, miR-221 suppressed growth in four other cell lines with no effects in one, and miR-222 suppressed growth in three cell lines but promoted growth in two. Cell cycle and apoptosis analyses revealed that growth suppression by miR-221 and miR-222 occurred through intra-S-phase arrest and/or apoptosis resulting from DNA double strand breaks. Microarray analysis suggested that the JAK/STAT signaling pathway is involved in the apoptosis-induced by miR221 and miR-222. Finally, lung cancer cell lines transfected with miR-221 or miR-222 became more sensitive to the S-phase targeting drugs, possibly due to an increased S-phase population. Conclusions: Our data are the first to show tumor-suppressive effects of miR-221 and miR-222 on lung cancer, suggesting their potential as therapeutics for the disease. 78 POSTER (Board P072) A comprehensive in vitro screen to identify therapeutic candidates for inclusion with etoposide/platin combinations to improve treatment of SCLC D. Evans1 , R. Delosh1 , J. Laudeman1 , C. Ogle1 , R. Reinhart1 , M. Selby1 , T. Silvers1 , A. Monks1 , E. Polley2 , G. Kaur2 , J. Morris2 , B.A. Teicher2 . 1 Frederick National Laboratory for Cancer Research, MPB/DCTD, Frederick MD, USA; 2 NCI, DCTD, Rockville MD, USA Background: SCLC initially shows a good response to first line chemotherapeutic regimens but recurrent disease is highly resistant to treatment. Consequently, the SCLC 5-year survival rate is only 5−10%. In an attempt to improve therapeutic efficacy for SCLC, various combination treatments have been tested; however, the two-drug combination of etoposide and a platinum drug (carboplatin or cisplatin), with equivalent clinical activity, has remained the standard of care for 30 years. Improving the activity of the platin/etoposide backbone in SCLC, by adding a third, non-cross-resistant agent, has had little success. Empirical approaches in the clinic have not been able to evaluate the many investigational and approved agents that could serve as the third drug to make an efficacious triplet regimen. Materials and Methods: We established a panel of 67 human SCLC cell lines for use in single agent and combination screens. In phase 1, the Poster Session – Drug Resistance and Modifiers SCLC lines were screened with ~100 approved anticancer drugs and 433 investigational agents. The single agent data were used to select agents for the combination screen seeking a third drug to add to the platin/etoposide backbone. The screen used fixed concentrations of carboplatin (3.7uM) and etoposide (0.3uM) and exposure time (96 h). The effect of simultaneously adding a third agent (from the approved and investigational small molecule collection), at varying concentrations, on the viability of each of the SCLC lines was examined. Results: Based on single agent activity in the primary screen of 67 SCLC lines, ~180 compounds from the Approved and Investigational Oncology Agent libraries were examined in the combination screen. The third agents were tested from a maximum concentration corresponding to the clinical CMax concentration with 3-fold serial dilutions over 8 dilutions. The in vitro screening data were analyzed using two methods: the Combination Index Method and the Bliss Independence model. Conclusions: The goal was to identify compounds producing greater-thanadditive cytotoxicity in the majority of SCLC lines. The results suggest that compounds targeting BCL2 and the JAK pathway improve the efficacy of the triplet across a number of cell lines. Combined with the gene expression and miRNA expression data for the lines, the data obtained will help identify novel therapeutic combinations, may help in matching patients with treatments and may identify novel molecular targets in SCLC. Funded by NCI Contract No. HHSN261200800001E. This research was supported in part by the Developmental Therapeutics Program in the Division of Cancer Treatment and Diagnosis of the National Cancer Institute. 79 POSTER (Board P073) Quantitative proteomics as a tool to identify resistance mechanisms in erlotinib-resistant subclones of the non-small cell lung cancer cell line HCC827 K. Jacobsen1 , R.R. Lund1 , H.C. Beck2 , H.J. Ditzel1 . 1 Molecular medicine, Cancer & Inflammation, Odense, Denmark; 2 Center for Clinical Proteomics, Clinical Biochemistry and Pharmacology, Odense, Denmark Background: Erlotinib (Tarceva® , Roche) has significantly changed the treatment of non-small cell lung cancer (NSCLC) as approximately 70% of patients show significant tumor regression when treated. However, all patients relapse due to development of acquired resistance, which in 43−50% of cases are caused by a secondary mutation (T790M) in EGFR. Importantly, a majority of resistance cases are still unexplained. Our aim is to identify novel resistance mechanisms − and potentially new drug targets − in erlotinib-resistant subclones of the NSCLC cell line HCC827. Materials and Methods: We established 3 erlotinib-resistant subclones (resistant to 10, 20, 30 mM erlotinib, respectively), and performed comparative quantitative proteomic analysis of these and the parental HCC827 cell line. The resistant subclones were examined both in absence and presence of erlotinib, and in biological triplicates on a Q-Exactive mass spectrometer. Only proteins identified with minimum 2 unique peptides and in minimum 2 of 3 replicates were used for further analysis. Results: Importantly, the resistant clones did not acquire the T790M mutation or other EGFR or KRAS mutations, potentiating the identification of novel resistance mechanisms in these subclones. We identified 2875 cytoplasmic proteins present in all 4 cell lines. Of these 87, 56 and 23 were upregulated >1.5 fold; and 117, 72 and 32 were downregulated >1.5 fold, respectively, in the 3 resistant clones compared to the parental cell line. By network analysis, we found cell survival, proliferation and migration to be induced, and apoptosis and adhesion to be repressed across the 3 resistant clones vs the parental cell line. Furthermore, networks involved in DNA repair and adherens junction signaling were inconsistently repressed in the 3 cell lines. More specifically, EGFR was consistently downregulated, indicating a bypass signaling mechanism to achieve resistance, and mitogen-activated protein kinase 1 (MAPK1) and synovial apoptosis inhibitor 1 (SYNV1) were upregulated. Conclusions: In conclusion, cancer-related networks such as proliferation and apoptosis were found to be regulated, supporting the validity of the model. EGFR was consistently downregulated and MAPK1 activated, indicating a bypass resistance mechanism, likely leading to activation of downstream proteins obviating EGFR. Generally, the overlap of regulated proteins between the 3 subclones was low, indicating the subclones have become resistant by different mechanisms. Poster Session – Drug Resistance and Modifiers 80 POSTER (Board P074) Determination of an oxidative stress gene signature in inflammatory breast cancer patient tumors and development of a novel redox modulatory strategy in overcoming chemotherapy resistance and mediating anti-tumor efficacy G.R. Devi1 , J.L. Allensworth2 , M. Evans2 , N. Ueno3 , D. McDonnell4 , F. Bertucci5 , S. Van Laere6 . 1 Duke University, Surgery and Duke Cancer Institute, Durham NC, USA; 2 Duke University, Surgery, Durham NC, USA; 3 University of Texas MD Anderson, Oncology, Houston, USA; 4 Duke University, Pharmacology, Durham NC, USA; 5 Institut Paoli-Calmettes, Oncology, Marsellie, France; 6 General Hospital Sint-Augustinus, Oncology, Antwerp, Belgium Background: Cancer cells often have increased levels of reactive oxygen species (ROS); however, acquisition of redox adaptive mechanisms allows for evasion of ROS-mediated cell death. Chemotherapies including the anthracyclines, taxanes, alkylating agents, platinum compounds as well as radiation therapy all rely heavily on the induction of oxidative stress-induced apoptosis for their anti-tumor activities; thus, redox adaptation can confer resistance to many breast cancer therapies. Inflammatory breast cancer (IBC) is an advanced and distinct breast cancer subtype characterized by high rates of residual disease and regional recurrence despite advances in multimodality treatment. We hypothesize that the poor response of IBC tumors to common treatment strategies, many of which rely heavily on ROS induction, is the result of redox adaptation. Experimental Design: Metagene analysis was conducted to identify an oxidative stress response (OSR) gene signature in IBC cells treated with an acute dose of a strong ROS inducer and then allowed to recover. This OSR signature was applied to normal breast samples, pre-treatment IBC and nonIBC patient tumor samples to assess their oxidative stress response (OSR). A dithiocarbamate, disulfiram (DSF), currently approved as an antialcoholism drug was applied to therapeutically resistant IBC cells alone or in combination with copper (Cu); effects on viability, antioxidants, survival factors, and tumor progression were assessed. Results: Analysis of patient samples using the unique OSR metagene generated revealed significantly higher OSR scores in IBC tumor samples compared to normal or non-IBC tissue. In addition, we have identified a novel mechanism of DSF to act as a Cu ionophore in a Cu-transporter Ctr1-independent manner, target the Cu signaling redox axis in inducing oxidative stress-mediated apoptosis. This resulted in a potent inhibition of NF-úB signaling, aldehyde dehydrogenase activity, 3D mammosphere formation, in vivo orthotopic mammary tumor growth in murine IBC models and in overcoming chemotherapy resistance. Conclusions: These results indicate that IBC tumors are highly redox adapted, which may render them resistant to ROS-inducing therapies. DSF, through redox modulation, may be a useful approach to enhance chemoand/or radio-sensitivity for advanced BC subtypes where therapeutic resistance is a major challenge to durable responses to current standard of care. 81 POSTER (Board P075) Sensitization of triple-negative breast cancer to PI3K inhibition by cotargeting IGF1R K. de Lint1 , J.B. Poell1 , J. Vidal Rodriguez1 , H. Soueidan1 , W. Nijkamp1 , L.F. Wessels1 , R.L. Beijersbergen1 . 1 Netherlands Cancer Institute − Antoni van Leeuwenhoek, Molecular Carcinogenesis, Amsterdam, Netherlands Background: Targeted therapies have proven invaluable in the treatment of breast cancer, as exemplified by tamoxifen treatment for hormone receptorpositive tumors and trastuzumab treatment for HER2-positive tumors. In contrast, a subset of breast cancer negative for these markers (triplenegative breast cancer) has met very limited success with pathwaytargeted therapies. A large fraction of triple negative breast cancers depend on the PI3K pathway for proliferation and survival, however, inhibition of PI3K alone generally has limited clinical benefit. It is of interest to identify potential combination therapies that can enhance the response and thereby improve clinical outcome for triple-negative breast cancer. Materials and Methods: We have analyzed the response of a panel of triple-negative breast cancer cell lines to the PI3K inhibitor GDC-0941. We have generated a breast cancer cell line resistant to PI3K inhibition due to an adaptive response. We have applied large-scale pooled shRNA screening for the identification of genes required for cell proliferation under PI3K inhibition in the adapted triple-negative cell line. Results: We have identified IGF1R as crucial component of the adaptive response to PI3K inhibition. Knock-down of IGF1R potently restores the sensitivity of these cells to the PI3K inhibitor GDC-0941. Pharmacological inhibition of IGF1R prevents colony outgrowth of adapted cells. In treatment-naive cells IGF1R inhibition sensitizes cells to PI3K inhibition and induces apoptosis. In a subset of triple-negative breast cancer cell lines, Wednesday 19 November 2014 31 IGF1R inhibition shifts the dose–response curve of GDC-041 up to 5-fold. In particular we find that breast cancer cell lines with high expression of IGF2-processing and signaling genes are responsive to the combination of PI3K and IGF1R inhibitors, whereas high expression of ERBB3 or mutated RAS are associated with a limited benefit of IGF1R inhibition. Conclusions: Our results suggest that combination treatment with PI3K and IGF1R inhibitors may prove beneficial over monotherapy in a subset of triple-negative breast cancers. 82 POSTER (Board P076) Regorafenib resistance in colorectal carcinoma is associated with enhanced expression of type II interleukin 1 receptor and reversed by MEK/ERK inhibitor A.C. Mar1 , C.H. Chu2 , C.W. Shiau3 , T.C. Lee1 . 1 Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan; 2 Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan; 3 Institute of Biopharmaceutical Science, National Yang-Ming University, Taipei, Taiwan Targeted therapy initially shows promising tumor regression but the development of drug resistance quickly results in failure of treatment. Among a batch of colorectal cancer (CRC) cell lines, we have preliminarily found that the expression levels of type II interleukin 1 receptor (IL1R2), an IL-1 decoy receptor, were closely associated with Regorafenib resistance. In addition, IL1R2 expression was associated with poor prognosis of patients with CRC cancer. Regorafenib was the newly approved multikinase inhibitor used for treatment of late-stage metastatic CRC by US FDA. In this study, we conducted experiments to elucidate the mechanism underlying which IL1R2 is involved in Regorafenib resistance. We first demonstrated that silencing of IL1R2 in HT29 cells overcame its resistance to Regorafenib, whereas ectopic expression of IL1R2 in HCT116 cells reduced its sensitivity to Regorafenib in both in vitro and in vivo systems. In addition, enhanced expression of IL1R2 was observed in Regorafenib-resistant DLD-1 colon cancer cells (DLD-1-R), which were established by growing DLD-1 cells in the presence of Regorafenib. In IL1R2 overexpressing cells, such as HT29, IL1R2-overexpressing HCT116, and DLD-1-R cells, Regorafenib treatment significantly resulted in activation of MEK/ERK signaling, which is crucial for survival. We also revealed that increased p-ERK levels in Regorafenib treated IL1R2overexpressing cells were likely due to decreased expression of MKP-3, one of the phosphatases of ERK. Furthermore, pretreatment of HT29, IL1R2-overexpressing HCT116, and DLD-1-R cells with MEK/ERK inhibitor U0126 significantly reversed their Regorafenib resistance in in vitro and in vivo systems. Taken together, our present study suggested that enhanced IL1R2 plays certain roles on Regorafenib resistance and the combination of Regorafenib and MEK/ERK inhibitor is a rationale regime to overcome Regorafenib resistance in CRC patients. 83 POSTER (Board P077) Acquired resistance to BET bromodomain inhibitors is associated with modulation of the apoptotic signaling network P. Sandy1 , S. Nerle1 , A. Conery2 , C. Hatton3 , B. Bryant3 , R. Sims2 , E. Normant1 . 1 Constellation Pharmaceuticals, Pharmacology, Cambridge, USA; 2 Constellation Pharmaceuticals, Biology, Cambridge, USA; 3 Constellation Pharmaceuticals, Bioinformatics, Cambridge, USA Background: Bromodomain and extraterminal (BET) family proteins function as chromatin readers that recognize and bind acetylated lysine residues on histones and play an essential role in the regulation of transcription of key oncogenes, including c-Myc and Bcl-2. Potent and selective small molecule inhibitors of BET bromodomains (BETi) induce growth arrest and apoptosis in a wide range of tumor types, in both in vitro and in vivo models, and are currently being evaluated in Phase I clinical trials. In this study we sought to model acquired resistance to long term BETi treatment and elucidate the underlying mechanisms in different tumor types. Materials and Methods: We used two orthogonal approaches to generate cell lines with reduced phenotypic sensitivity to BET bromodomain inhibition. In one, A375 melanoma cells were treated in culture with a BETi at a concentration where the majority of cells were eliminated by apoptosis. After several months, colonies able to proliferate in the presence of the inhibitor were obtained. In parallel experiments, mice inoculated with MV4−11 acute myeloid leukemia cells were dosed with a BETi at its maximum tolerated dose and the surviving tumors were serially transplanted into similarly treated recipient animals. Two BETi-resistant clones maintained decreased sensitivity to BETi in vitro when compared to parental cells in a 72-hour viability assay. Results: Detailed phenotypic analysis revealed an attenuated apoptotic response to high-dose BETi in the resistant clones as compared to parental cells. Transcriptional profiling and proteomic analysis revealed altered 32 Wednesday 19 November 2014 expression of Bcl-2 family members in both models, suggesting that two vastly different tumor types have converged upon the apoptotic signaling network as a mechanism of modulating the phenotypic response to BET bromodomain inhibition. Functional experiments demonstrated that these transcriptional changes are relevant in dictating the response to BETi. Conclusions: As BETi advance toward clinical use, it becomes increasingly important to understand potential mechanisms of acquired resistance and use this information to identify predictive biomarkers for maximal therapeutic benefit in patients. We will discuss strategies for stratifying patients based on the activity of the apoptotic signaling network, and present data on the use of pharmacological inhibition of the apoptotic response as a way to modify the phenotypic response to BETi. 84 POSTER (Board P078) Src family kinase activation is a compensatory survival mechanism for acquired resistance to EGFR-TKIs in lung cancer cells M. Ono1 , K. Sonoda1 , K. Azuma2 , K. Watari1 , M. Molina3 , R. Rosell4 , M. Kuwano5 . 1 Kyushu University, Dept. of Pharmaceutical Oncology Graduate Sch. of Pharmaceutical Sci., Fukuoka, Japan; 2 Kurume University School of Medicine, Dept. of Internal Medicine Div. of Respirology Neurology and Rheumatology, Kurume, Japan; 3 Pangaea Biotech, Barcelona, Spain; 4 Catalan Institute of Oncology, Barcelona, Spain; 5 Kyushu University, Lab. of Molecular Cancer Biology, Fukuoka, Japan Background: Most NSCLC patients harboring activating EGFR mutations benefit from treatment with EGFR-TKIs, but the clinical efficacy of EGFRTKIs is limited by the appearance of tumor drug resistance. Multiple kinase inhibitors of EGFR family proteins have been developed to overcome such drug resistance. To develop further personalized therapeutics and drug resistance modifiers, we should understand how drug resistance to EGFRTKIs including multiple kinase inhibitors is acquired at molecular basis. In our present study, we present a novel finding that Src family kinase activation is alternatively responsible for acquired drug resistance to afatinib in lung cancer cells harboring activating EGFR mutation. Our afatinibresistant clones does not harbor T790M, Ras mutation, PTEN loss, mutant EGFR loss, IGFIR activation, BIM and others. Materials and Methods: We have established afatinib-resistant subclones from human lung cancer cell lines, HCC827, harboring activating EGFR mutations after stepwise exposure to afatinib. We have characterized biochemical properties of drug-resistant subclones as compared with their drug-sensitive counterparts by Western blot, RT-PCR and microarray analysis. Results: We characterized two independent afatinib-resistant subclones isolated from HCC827. (1) Afatinib-resistant subclones, BR1−8 and BR2−3, showed markedly decreased expression of EGFR, HER2, HER3, c-Met and PDGFRb as compared with HCC827, and Akt phosphorylation was highly resistant to afatinib; (2) the activation of Src family kinase (SFK) was augmented in resistant subclones, and combination of afatinib with c-Src siRNA or with dasatinib suppressed cell growth and Akt phosphorylation; (3) among SFK, expression of Fyn was also upregulated in resistant subclones, and treatment with Fyn siRNA with afatinib partially suppressed Akt phosphorylation. In addition to above results, our recent relevant study showed that activation of Src along with enhanced expression of integrin b1, a2 and a5 was observed in erlotinib-resistant subclones derived from PC9. And also Src silencing or SFK inhibitor (dasatinib) restored erlotinib sensitivity through reduced activation of Akt. Conclusions: Together, our present study strongly support the novel finding that SFK activation including Src and/or Fyn could be one key mechanism responsible for acquired resistance to afatinib, and also that combination with SFK-targeted drug could be useful to overcome drug resistance to afatinib. 85 POSTER (Board P079) Wnt secretion is required to maintain Wnt activity in colon cancer O. Voloshanenko1 , G. Erdmann1 , T.D. Dubash2 , I. Augustin1 , M. Metzig1 , C.R. Ball2 , H. Glimm2 , R. Spang3 , M. Boutros1 . 1 Deutsches Krebsforschungszentrum, Division Signaling and Functional Genomics/B110, Heidelberg, Germany; 2 National Center for Tumor Diseases (NCT) and German Cancer Research Center (DKFZ), Department of Translational Oncology, Heidelberg, Germany; 3 University of Regensburg, Computational Diagnostics Group, Regensburg, Germany Aberrant activation of the canonical Wnt/b-catenin pathway occurs in almost all colorectal cancers (CRCs) and contributes to their growth, invasion and survival. It is widely believed that mutations in APC or b-catenin aberrantly activate Wnt signalling, independent of upstream ligands. Yet, several recent experimental findings have challenged this notion, for example Poster Session – Drug Resistance and Modifiers secreted inhibitory proteins of the SFRP family are still able to attenuate Wnt signalling in colon cancer cells. Still the direct role of canonical Wnts in CRCs has never been studied. Surprisingly, we found that the Wnt cargo receptor Evi/Wls is highly expressed in CRCs as well as Wnt3 protein. We show that independent of the mutations in APC or b-catenin Wnt pathway activation is still responsive to stimulation by Wnt secretion and receptor-proximal signalling. Silencing of Evi leads to inhibition of clonal capacity of colon cancer cells and their proliferation. To identify pathways, which are synthetically lethal upon silenced Evi we performed the genome-targeted siRNA screen upon three different conditions − Wnt signalling high (shAPC), Wnt signalling normal for CRCs (shCtrl) and downregulated Wnt signalling (shEvi). We could not identify any pathways, which are synthetically lethal upon downregulation of APC but we found several pathways, which are synthetically lethal upon silencing of Evi. These results were confirmed by downregulation of Evi or b-catenin by siRNA and treatment with the drugs, which inhibits identified pathways. To conclude we showed that even in the presence of APC or b-catenin mutations CRCs are still dependent on upstream canonical Wnt signalling regulation. These findings potentially open new avenues for therapeutic interventions by targeting Wnt secretion via Evi/Wls. We identified several pathways, which are targeted by the drugs and are synthetically lethal upon inhibition of Wnt secretion in CRCs. 86 POSTER (Board P080) Influence of EGFR exon 19 mutation subtypes on survival outcomes in advanced stage Asian non-small cell lung cancer patients receiving TKI therapy B. Chowbay1 , O. Singh1 , N. Sutiman2 , D.S.W. Tan3 , W.T. Lim3 , E.H. Tan3 . 1 National Cancer Centre, Laboratory of Clinical Pharmacology Division of Medical Sciences, Singapore, Singapore; 2 The Academia SingHealth, Clinical Pharmacology Core, Singapore, Singapore; 3 National Cancer Centre, Department of Medical Oncology, Singapore, Singapore Background: Mutations in epidermal growth factor receptor (EGFR) gene have been shown to affect the treatment outcomes in patients. In this study we aimed to explore the influence of EGFR exon 19 mutation subtypes on survival outcomes in advanced stage Asian non-small cell lung cancer (NSCLC) patients receiving tyrosine-kinase inhibitor (TKI) treatment as 1st line therapy. Material and Methods: Of 937 Asian NSCLC patients, 148 patients with stage IIIB or IV, harboring EGFR exon 19 mutations and receiving TKI as 1st line treatment, were selected. The majority of the patients were of Chinese descent (83.1%), followed by Malays (10.8%), Indians (3.4%) and others (2.7%). The median age of patients was 60 years (range: 29−86 years). Kaplan–Meier analysis, log-rank test and Cox regression methods were implemented to evaluate the survival outcomes between groups Results: The EGFR exon 19 mutation subtype 15-nucleotide deletion (c.2236_2250del, ELREA) was observed most frequently (62.8%) followed by mixed insertion/substitution/deletion (23%), 18-nucleotide deletion (c.2240_2257del, 7.4%) and 15-nucleotide deletion (non-ELREA, 6.8%). Patients harboring exon 19 ELREA deletion and mixed insertion/substitution/deletion had significantly longer median overall survival (37.1 months), compared to those with c.2240_2257del [18 months; hazard ratio, 2.5; 95% CI (1.1−5.6); p = 0.027] and non-ELREA deletion [13 months; hazard ratio, 4.08; 95% CI (1.9−8.8); p < 0.001]. Similar trends were observed for progression free survival (PFS) outcomes. Patients harboring exon 19 ELREA deletion and mixed insertion/substitution/deletion had the longest median PFS (14.9 months) compared to those with c.2240_2257del [9.13 months; hazard ratio, 2.01; 95% CI (0.91−4.4); p = 0.08] and non-ELREA deletion [6.87 months; hazard ratio, 3.12; 95% CI (1.39–6.98); p = 0.006]. Conclusions: EGFR exon 19 mutation subtypes showed significantly different survival outcomes after 1st line TKI treatment in advanced stage NSCLC patients. Further studies are recommended in larger cohort of advanced stage NSCLC patients to improve the personalized therapy based on patients’ EGFR mutation status. 87 POSTER (Board P081) Critical difference in development of acquired resistance to MDM2 inhibitor SAR405838 in vitro and in vivo G. Hoffman-Luca1 , C.Y. Yang1 , J. Lu1 , D. Ziazadeh1 , D. McEachern1 , L. Debussche2 , S. Wang1 . 1 University of Michigan, Pharmacology, Ann Arbor MI, USA; 2 Sanofi, Oncology, Vitry/Seine, France SAR405838 is a potent and specific MDM2 inhibitor currently being evaluated in Phase I clinical trials for the treatment of human cancer as a single agent and in combination. In the present study, we investigated the acquired resistant mechanisms for SAR405838 using the SJSA-1 Poster Session – Drug Resistance and Modifiers osteosarcoma cell line in vitro and in vivo. The SJSA-1 cell line possesses an amplified MDM2 gene and wild-type p53 and is sensitive to SAR405838 and other MDM2 inhibitors in vitro and in vivo. In vitro treatment of the SJSA-1 cells with SAR405838 using two different treatment protocols resulted in acquired resistance to the drug. Analysis of these resistant cells showed that p53 is mutated in the DNA binding domain and cannot be activated by SAR405838. Treatment of mice bearing the parental SJSA-1 xenograft tumors with SAR405838 led to rapid tumor regression, but tumors eventually returned after treatment cessation. A number of cell lines were established by culturing the regrown tumors and, surprisingly, these sublines showed minimal loss of sensitivity to SAR405838 as compared to the parental SJSA-1 cell line. Consistently, analysis of thesesublines showed that p53 retains its wild-type status, with the exception of one subline, that harbored a single heterozygous mutation C176F. Computational modeling suggested that the p53 C176F mutant may still be capable of binding to target DNA to elicit gene transcription, which was confirmed by in vitro treatment with SAR405838. Xenografts of representative sublines lacking p53 C176F mutation obtained from regrown tumors treated with one-round SAR405838 were still responsive to SAR405838 treatment. Interestingly, after a second round of in vivo treatment with SAR405838, all sublines established from harvested tumors uniformly harbored a heterozygous C176F p53 mutation, which were still responsive to SAR405838, albeit with reduced sensitivity. Our study showed that the SJSA-1 tumor cells acquired profound resistance to MDM2 inhibitor SAR405838 in vitro and developed inactivating p53 mutations in its DNA binding domain. But in vivo, SJSA-1 tumor cells only acquired minimal or modest resistance when treated with either one- or two-rounds of SAR405838. Our study suggests that tumor cells respond differently to drug treatment under in vitro and in vivo environments and consequently develop different types of resistance. 88 POSTER (Board P082) Genome-wide drug sensitivity screens in haploid mouse embryonic stem cells S.J. Pettitt1 , D. Krastev1 , H. Pemberton1 , Y. Fontebasso1 , I. Bajrami1 , I. Kozarewa1 , J. Frankum1 , R. Rafiq1 , J. Campbell1 , R. Brough1 , A. Ashworth1 , C.J. Lord1 . 1 Institute of Cancer Research, Division of Breast Cancer, London, United Kingdom Background: We have screened a genome wide collection of mutants induced by transposon insertion in haploid cells with a variety of targeted agents and chemotherapies in order to find new genetic determinants of sensitivity. Materials and Methods: Haploid mouse embryonic stem cells were mutagenised with a piggyBac gene trap transposon. To enable accurate counting of mutants, a random 25-nt barcode was inserted into the transposon donor plasmid. This can be amplified in a minimal PCR step and the products analysed by next-generation sequencing, in a manner similar to pooled shRNA screens. Barcodes were associated with genomic insertion sites by inverse PCR. We generated a library of approximately 100,000 mutants and treated with DMSO (solvent control) or drug at SF50 dose. The mappings for barcodes showing significant change in abundance between treated and control arms were analysed and hits called based on the criteria of multiple insertions in a gene showing a phenotype. Results: In a screen for poly(ADP-ribose) polymerase (PARP) inhibitor sensitivity using the clinical agents olaparib and BMN 673, we detected known determinants of sensitivity including Brca2 and Cdk12. We identified loss of Ewsr1 as a novel determinant of PARP inhibitor sensitivity and showed that knockdown of EWSR1 in MCF7 breast cancer cells also sensitises to BMN 673. Since Ewing’s sarcoma cells with EWSR1-ETS fusions are reported to be PARP inhibitor sensitive, we are investigating a possible contribution of loss of wild type EWS function to this effect. We have also screened this library against 25 other drugs and will report our latest results. Conclusions: Pooled haploid mutant libraries can be used to identify genetic determinants of sensitivity at a genome-wide scale without prior assumptions of the mechanism. 89 POSTER (Board P083) Tie-2 regulates the stemness of prostate cancer cells K. Tang1 , M. Ling1 . 1 Institute of Health and Biomedical Innovation, Brisbane Qld, Australia Background: Prostate cancer (PCa) is the most commonly diagnosed male cancer in Western countries. Patients with advanced PCa are normally treated with hormone ablation therapy. This therapy is effective initially as PCa cells require androgen to grow and survive; however, the cancer cells eventually become androgen independent and develop metastatic, castration-resistant tumors. At this stage, chemotherapy and Wednesday 19 November 2014 33 radiotherapy exhibit only small benefits. Ample evidence supports the idea that a rare population of cancer cells known as cancer stem cells (CSCs) is responsible for the development of treatment resistant and disease relapse. Unfortunately, little is known about the identity of these cells, making it difficult to target them. Here we reported that a rare population of PCa cells expresses the Tie-2 protein, a tyrosine kinase receptor that regulates the stemness and bone homing of hematopoietic stem cells. Material and Methods: Here, using fluorescence-activated cell sorting (FACS), we have isolated the Tie-2+ population from the PCa cell line PC-3. cDNA microarray analysis was then performed to characterize the gene expression profile of these cells. Meanwhile, cell adhesion assay was performed to examine the ability of the Tie-2+ cells to adhere to osteoblasts and endothelial cells. Furthermore, quiescent staining and drug sensitivity assay was carried out to examine whether Tie-2+ cells are more quiescent, and thus become resistant to chemotherapeutic drug. Finally, we have injected both Tie-2+ and Tie-2− PC-3 cells intracardiacly into the NOD-SCID mice to determine if Tie-2 expression promote prostate tumor metastasis under in vivo condition. Results: Characterization of Tie-2+ PCa cells revealed that these cells express higher level of prostate CSC markers when compared to the Tie-2− population. Meanwhile, Tie-2+ cells are highly adhesive to osteoblasts and endothelial cells, a characteristic necessary for the development of tumor metastasis. We also found that Tie-2+ cells are more quiescent and resistant to the chemotherapeutic drug cabazitaxel, further support that these cells possess CSC-like characteristics. More importantly, we found that Tie-2+ cells, but not the Tie-2− cells population, developed metastatic tumor in vivo. Conclusions: Our data suggested that Tie-2+ population represent the PCa stem cells population which play an importantly role in the development of drug resistance and prostate tumor metastasis. Thus, Tie-2 might be a novel therapeutic target for treatment of advanced PCa patients. 90 POSTER (Board P084) Tumor infiltrating leukocyte subpopulations as a biomarker of response and resistance to targeted therapy in patients with BRAF mutation-positive metastatic melanoma M.C. Kelley1 , D.B. Doxie2 , A.R. Greenplate2 , H. Crandall1 , J.A. Sosman3 , J.M. Irish2 . 1 Vanderbilt University, Surgical Oncology, Nashville TN, USA; 2 Vanderbilt University, Cancer Biology, Nashville TN, USA; 3 Vanderbilt University, Hematology-Oncology, Nashville TN, USA BRAF mutation-positive metastatic melanoma responds to BRAF and MEK targeted therapy, then progresses within 6−9 months. Many resistance mechanisms have been identified in tumor cells, but little is known about changes ocurring in the tumor microenvironment during resistance. Dysfunctional immune responses are linked to tumor progression, so we evaluated the tumor infiltrating leukocyte profile in melanoma metastases responding and progressing on targeted therapy. Samples were obtained during surgical excision of soft tissue metastases in a patient with BRAF V600E mutation-positive melanoma receiving therapy with a BRAF inhibitor (dabrafenib) and MEK inhibitor (trametinib). Responding lesions were defined by: stable reduction in tumor volume during therapy and the physical characteristics of the lesion. Novel high dimensional mass cytometry (CyToF) panels were used to characterize tumor and immune cell subsets. Machine learning tools (visNE) classified individual cells according to a multidimensional signature of 30+ proteins with roles in melanoma biology, immune regulation, and metastasis. Key biomarkers of melanoma and immune cell subsets included melanoma cell adhesion molecule (MCAM), NGFR, KIT, nestin, CD3, CD4, CD8, CD14, CD16, CD33, CD34, CD44, CD45, CD49F, MHC class II (HLA-DR), and chemokine receptors (CCRs & CXCRs) known to play a role in metastasis. Intracellular signaling (pERK, pAKT, pSTAT-1, 3, 5 and 6, pCREB), proliferation (Ki67) and apoptosis (cleaved caspease3) were also evaluated. Live cells were identified by length and DNA content and gated into melanoma cell (CD45−, MCAM+) and leukocyte (CD45+, MCAM−) populations. The abundance and phenotype of subpopulations of immune cells were compared in responding and progressing lesions. Responding lesions contained nearly 3 fold more T-cells than progressing lesions, and 63% of these cells were CD8+ effector T cells compared to 14% in progressing lesions. In contrast, progressing lesions contained almost 3 fold more MMHC-II expressing cells, including a nearly 2 fold increase in CD14−, CD33+, HLA-DR+ myeloid-derived suppressor cells (Table 1). In depth analysis of leukocyte subpopulations in additional melanoma metastases responding and progressing on therapy is underway. These preliminary findings confirm that maladaptive immune responses, including reduced CD8+ T-cell and increased myeloid subpopulations, are present in melanoma metastases progressing on BRAF targeted therapy. It is unclear if these changes occur in response to resistance developing within the tumor or are directly responsible for tumor progression. Further investigation of combinations of targeted therapy and immunotherapy 34 Wednesday 19 November 2014 Poster Session – Drug Resistance and Modifiers are supported by these findings. Analysis of tumor infiltrating leukocyte subpopulations may be a useful biomarker for monitoring response to targeted therapy. Table 1. % CD45+ cells % MHC+ cells % CD3+ cells CD3+/MHC-II− CD3−/MHC-II+ CD14− CD14−/CD33+ CD8+ Responding 74* Progressing 27* 26* 73* 41 49 3.8 6.2 63* 14* *p < 0.05. 91 POSTER (Board P085) 4E-BP1 expression levels determine sensitivity of triple negative breast cancer cells to mTOR inhibitors K. Jastrzebski1 , B. Thijssen1 , J. Vidal Rodriguez1 , K. de Lint1 , C. Lieftink1 , L.F. Wessels1 , R.L. Beijersbergen1 . 1 NKI-AvL, Molecular Carcinogenesis, Amsterdam, Netherlands Background: In contrast to other breast cancer subtypes, triple negative breast cancers are characterized by an absence of recurrent genetic alterations. However, alterations in the PI3K pathway are frequently observed, either through mutation or amplification of PIK3CA or the loss of the negative regulator PTEN. As a result, inhibitors of this pathway, including inhibitors of mTOR, the downstream target of the PI3K pathway, have been explored in the clinic. It has been found that mutational activation of PI3K represents an important determinant of sensitivity to mTOR inhibitors. Nevertheless, a number of PI3K wild-type cell lines also show sensitivity to these inhibitors, although the regulators of this response are still unknown. We set out to find such modulators of response to mTOR inhibitors in a panel of triple negative breast cancer cell lines initially using high throughput approaches. Material and Methods: We determined the sensitivity of a panel of triple negative breast cancer cell lines to AZD8055 (mTOR inhibitor) and BEZ235 (mTOR/PI3K dual inhibitor). This data was then used together with additional datasets generated for this panel, including RNA expression (by RNA-seq), (phospho-)protein levels (by Reverse Phase Protein Arrays) and mutational status (by post-capture DNA-seq), to carry out regression analysis to identify features correlated with response. Results: We found that the protein expression levels of 4E-BP1, a downstream target of mTOR involved in regulating cap-dependent protein synthesis, correlated with response to both inhibitors. In poorly responding cell lines expressing low levels of 4E-BP1, overexpression of the protein increased sensitivity. Conversely, in sensitive cell lines expressing high levels of 4E-BP1, knock-down of 4E-BP1 led to reduced sensitivity to mTOR inhibition. Conclusions: These results indicate that effective inhibition of protein synthesis downstream of PI3K/mTOR is an important determinant of mTOR inhibitor activity. Given that approximately 20% of breast cancer tumors annotated in The Cancer Genome Atlas show an amplification of the 4E-BP1 locus, such patients would likely benefit from mTOR inhibitor treatment. Furthermore, we hypothesize that mTOR inhibitor response can be improved even in patients expressing low 4E-BP1 by co-treating with agents that induce its expression. To this end, we are currently screening for genes and drugs that modulate 4E-BP1 levels. 92 POSTER (Board P086) Role of ERK nuclear translocation in cisplatin-sensitive and -resistant ovarian cancer cells S. Dilruba1 , G.V. Kalayda1 , U. Jaehde1 . 1 Institute of Pharmacy, Clinical Pharmacy, Bonn, Germany Background: The clinical use of the anti-cancer drug cisplatin is limited due to the rapid development of resistance against this drug. However, the mechanisms of resistance are not completely understood yet. Extracellular signal regulated kinase1/2 (ERK1/2) is activated in response to cisplatin treatment in ovarian cancer cells. Activated ERK1/2 induces the expression of survival genes upon translocation to nucleus, which may confer resistance to this drug. Objectives: This projects aims at investigating the importance of ERK1/2 nuclear translocation for cisplatin resistance in ovarian cancer cells. Methods: EFO27 and A2780 ovarian carcinoma cells and their corresponding cisplatin-resistant variants (EFO27/CDDP and A2780cis) were investigated. The cytotoxicity of cisplatin was estimated using the MTT assay. Phosphorylated ERK1/2 translocation to the nucleus was confirmed by immunofluorescence staining. Selected proteins were overexpressed by lipofectamine-mediated transfection. Phosphorylation of ERK1 (T202/Y204) and ERK2 (T185/Y187) and transfected protein expression were detected by Western blot. Results: Cytotoxicity of cisplatin was assessed with and without inhibition of ERK1/2 by U0126. Whereas U0126 increased cisplatin sensitivity of EFO27 and EFO27/CDDP cells, the opposite effect was found in A2780 and A2780cis cells. Translocation of ERK1/2 to the nucleus in response to cisplatin was detected in both EFO27 cells, but not in A2780 cells. Further, PEA-15, a small protein which inhibits ERK1/2 translocation to the nucleus was used to investigate the relevance of ERK1/2 cytoplasmic sequestration for cisplatin resistance. PEA-15 was overexpressed in A2780cis cells and the cytotoxicity of cisplatin in transfected cells was measured. The pEC50 values obtained were 5.15±0.21, 5.04±0.15, 5.00±0.09 in A2780cis, A2780cis-HA (empty vector), and A2780cis-PEA-15wt (n = 4−6) respectively. Conclusion: ERK1/2 nuclear translocation differs between the ovarian cancer cell lines. Further studies will reveal the most suitable cell line pair to study the association between ERK1/2 nuclear translocation and cisplatin resistance. 93 POSTER (Board P087) A stress induced early innate response causes multi-drug tolerance in melanoma D.R. Menon1 , S. Das2 , C. Krepler3 , A. Vultur3 , B. Rinner4 , S. Schauer2 , K. Kashofer2 , K. Wagner4 , G. Zhang3 , E. Bonyadi Rad5 , H.P. Soyer1 , B. Gabrielli6 , R. Somasundaram3 , G. Hoefler2 , M. Herlyn3 , H. Schaider1 . 1 Translational Research Institute, Dermatology Research Centre, Woolloongabba, Australia; 2 Medical University of Graz, Institute of Pathology, Graz, Austria; 3 The Wistar Institute, Molecular Oncogenesis, Philadelphia, USA; 4 Medical University of Graz, Center for Medical Research, Graz, Austria; 5 Medical University of Graz, Dermatology, Graz, Austria; 6 Translational Research Institute, Diamantina Institute, Woolloongabba, Australia Background: Acquired drug resistance constitutes a major challenge for effective cancer therapies with melanoma being no exception. The dynamics of early drug resistance leading to permanent resistance are poorly understood. Material and Methods: Melanoma cell lines were exposed to molecular targeted inhibitors like BRAF or MEK inhibitors or chemotherapy at sublethal drug concentrations for over 90 days. Alternatively melanoma cells were exposed to hypoxic conditions or low glucose media. Cells surviving drug exposure, hypoxia or nutrient starvation were monitored for the expression of CD271, ALDH activity, differentiation markers, ABCB5, chromatin remodeling, histone demethylases and markers for angiogenesis to characterize cells exposed for a minimum of 12 days. Further gene expression analyses, RPPA analyses and in vivo tumorigenicity were performed in these cells. Results: Drug exposure, hypoxia or nutrient starvation leads to an early innate cell response in melanoma cells resulting in multi-drug resistance, termed induced drug tolerant cells (IDTC). Transition into the IDTC state seems to be an inherent stress reaction for survival towards unfavorable environmental conditions or drug exposure independent of any subpopulation or cancer stem cell. The response comprises chromatin remodeling, activation of signaling cascades, and markers proposed to be stem cell markers with higher angiogenic potential and tumorigenicity. These changes are characterized by a common increase in CD271 expression concomitantly with loss of differentiation markers such as melan-A and tyrosinase, enhanced ALDH activity and upregulation of histone demethylases. Accordingly, IDTCs show a loss of H3K4me3, H3K27me3 and gain of H3K9me3 suggesting activation and repression of differential genes. Drug holidays at the IDTC state allow for reversion into parental cells re-sensitizing them to the drug they were primarily exposed to. However, upon continuous drug exposure IDTCs eventually transform into permanent and irreversible drug resistant cells. Knockdown of CD271 or KDM5B decreases transition into the IDTC state substantially but does not prevent it. Conclusions: Our results suggest a phenotypic shift of parental cells to the induced drug tolerant cell (IDTC) state irrespective of a given subpopulation thus not representing cancer stem cells. Targeting IDTCs would be crucial for sustainable disease management and prevention of acquired drug resistance. Poster Session – Drug Screening 94 POSTER (Board P088) Elucidating mechanisms of resistance to FGFR inhibitors in endometrial cancer L. Packer1 , S. Byron2 , C. Mahon1 , D. Loch3 , A. Wortmann1 , K. Nones4 , S. Grimmond4 , J. Pearson5 , N. Waddell4 , P. Pollock1 . 1 Translational Research Institute, Queensland University of Technology, Brisbane Qld, Australia; 2 Translational Genomics Research Institute, Phoenix, USA; 3 Queensland University of Technology, Brisbane Qld, Australia; 4 Institute of Molecular Biology, University of Queensland, Brisbane Qld, Australia; 5 QIMR Berghofer Medical Research Institute, Brisbane Qld, Australia Background: Fibroblast Growth Factor Receptor 2 (FGFR2) is mutated in 10−20% of endometrial cancer patients and is associated with a higher risk of recurrence. Preclinical studies by our lab and others have demonstrated FGFR2 inhibition is a viable therapeutic strategy in FGFR2mutant endometrial cancer. A significant clinical issue that we aim to address is that of acquired resistance to anti-FGFR therapies in the context of endometrial cancer. Materials and Methods: The endometrial cancer cell lines AN3CA and JHUEM-2 express mutant FGFR2 and are sensitive to FGFR inhibitors. We have generated subclones of AN3CA and JHUEM-2 cells resistant to the FGFR inhibitors PD173074 and NVP-BGJ398, respectively. Phosphoprotein arrays, gene expression profiling, exome sequencing and SNP analysis were performed to identify genes and signalling pathways that mediate resistance to FGFR inhibitors. Results: Loss of FGFR2 protein expression was identified in one resistant subclone, but the remaining subclones retain FGFR2 expression. Upregulation of downstream survival pathways such as pERK and pAKT was observed in some of the JHUEM-2resistant and AN3CAresistant subclones. To further characterise these subclones we are currently analysing data from exome sequencing, expression arrays and copy number analysis, to determine the molecular mechanisms of resistance in these cell lines. Like most endometrial cancer cells, AN3CA and JHUEM-2 cells have constitutive activation of the PI3K pathway, due to mutations in PIK3R1, PTEN or PIK3CA. Our results show that combined inhibition of the PI3K pathway and the MEK/ERK pathway by trametinib or an FGFR inhibitor causes cell death in these cells. Conclusions: This research will provide insight into possible combination therapies that may combat drug resistance in FGFR-mutant endometrial cancer. Drug Screening 95 POSTER (Board P089) Identification of synthetic lethality compounds from natural products for cancers K.W. Ng1 , K.S. Lee1 , V. Patel2 , E. Sundaramoorthy3 , N. Ayoub3 , X. Su3 , A. Venkitaraman3 , S.H. Teo4 . 1 Cancer Research Initiatives Foundation, Drug Discovery Research Group, Selangor, Malaysia; 2 Cancer Research Initiatives Foundation, Nasopharyngeal Cancer Research Group, Selangor, Malaysia; 3 University of Cambridge, The Medical Research Council Cancer Cell Unit, Cambridge, United Kingdom; 4 Cancer Research Initiatives Foundation, Breast Cancer Research Group, Selangor, Malaysia Background: Many cancers, such as basal breast and serous ovarian cancers, are characterized by genomic instability, through the loss of function of TP53 and BRCA2. Until recently, there have been limited successes in developing efficient targeted therapies for these forms of solid cancers. In 2005, two research groups independently demonstrated that inhibition of Poly-(ADP-ribose)-polymerase (PARP) can selectively kill BRCA2-deficient cancer cells through synthetic lethality. However, no study has hitherto explored natural products that are synthetic lethal to the BRCA2-deficient cancers. Here, we describe the development of a cell-based assay to search for natural products with synthetic lethality properties. Methods: We have developed a cell-based assay using an isogenic pair of BRCA2-proficient and deficient cell lines. The sensitivity of the assay was evaluated using Olaparib, Mitomycin C and Irinotecan, either in isolation or in combination as ‘spike-in’ controls with natural product extracts, to investigate their inhibitory activities in the presence of potential interfering compounds. The assay was then used to screen for our in-house natural product library of plant, microbial and fungus extracts. Results: We report that this assay format is able to detect the selective cytotoxic effects of Mitomycin C, Olaparib and Irinotecan with 22, 17 and 16 fold difference of EC50 in BRCA proficient cells compared to that of BRCA deficient cells. When added as spike-in controls with natural product Wednesday 19 November 2014 35 extracts, the detection limits were 1% (w/w) for Olaparib and Irinotecan and 0.1% (w/w) for Mitomycin C. Screening of our in-house library of 454 plant, 305 microbial and 62 fungus extracts, identified 2 plants, 1microbial, 6 fungus extracts with EC50 less than 5 mg/mL on the BRCA2 deficient cells and fold difference of >6. Conclusion: Our data represents the first systematic identification of potential synthetic lethal natural products using a cell based assay. We anticipate from our on-going work to unravel and identify the key chemical components of the 9 extracts conferring synthetic lethality properties. 96 POSTER (Board P090) Evaluation of hormone therapies in a panel of breast PDX models: Relevance of ER status on sensitivity to letrozole and tamoxifen M.J. Wick1 , T. Vaught1 , L. Gamez1 , J. Meade1 , A. Diaz1 , K.P. Papadopoulos1 , D.W. Rasco1 , A. Patnaik1 , M. Beeram2 , A. Lang2 , A.W. Tolcher1 . 1 South Texas Accelerated Research Therapeutics, (START), San Antonio TX, USA; 2 START Center for Cancer Care, San Antonio TX, USA Background: Breast cancer classification and treatment strategy is currently based on immunohistochemical staining and pathological scoring for the estrogen (ER), progesterone (PR) and ERBB2 (HER2) receptors. Based on threshold ER scores, breast cancers are designated hormonereceptor positive and treated with endocrine therapy including ER antagonists and aromatase inhibitors (AI). However, whether breast cancers with ER scores below threshold would benefit from endocrine therapy is unclear. To better understand the role of endocrine therapy in breast cancer, we stratified a panel of breast PDX models using ER percentage (ER%): ER<10% and ER10%. Drug sensitivity studies were performed evaluating models response to letrozole and tamoxifen and efficacy compared to the ER% for each model. Methods: Breast PDX models were developed in immune-deficient mice from primary or metastatic patient tissue and established models confirmed by histologic comparative analysis and linked with patient treatment and outcome data. Each model was assigned an ER% from the clinical biopsy score at the time of sample collection and engraftment. Drug sensitivity studies were performed evaluating models response to chronic dosing of letrozole or tamoxifen; study endpoints included tumor volume and time from treatment initiation as study endpoints. T/C values, growth delay and regressions were reported for each model. Results: Letrozole treatment resulted in statistically significant (p < 0.05) tumor growth inhibition in several ER<10% models including ST518 and ST1077 (ER = 0%) while several ER 10% models including ST565 (ER = 100%), developed from a chemo naı̈ve patient, was insensitive to therapy. Letrozole tested in HER2 (3+) models was inactive in ST1339 (ER = 0%) model but efficacious in ST340 (ER = 20%). Activity of tamoxifen was similar to letrozole in evaluated models. Conclusion: We evaluated a panel of breast patient-derived xenografts and compared model sensitivity to letrozole and tamoxifen with ER% in each model. Overall sensitivity of either agent did not correlate with higher ER% values, suggesting patients with ER% below threshold may benefit from these therapies in combination with novel targeted agents or approved standards of care. 97 POSTER (Board P091) Utilization of low passage adenoid cystic carcinoma PDX models to identify novel combination therapies M.J. Wick1 , J. Meade1 , T. Vaught1 , M. Nehls1 , J. Flores1 , J. Kaufman2 , A.W. Tolcher1 , D.W. Rasco1 , A. Patnaik1 , C.A. Moskaluk3 , K.P. Papadopoulos1 . 1 South Texas Accelerated Research Therapeutics, (START), San Antonio TX, USA; 2 Adenoid Cystic Carcinoma Research Foundation, (ACCRF), Needham MA, USA; 3 University of Virginia, Charlottesville VA, USA Background: Adenoid Cystic Carcinoma (ACC) is an uncommon cancer of the head and neck which typically originates in the salivary glands with limited treatment options and once metastatic no approved standard of care. To identify potentially useful therapies we utilize a panel of low passage ACC xenograft models for in vivo screening of FDA-approved and investigational therapies with potential benefit towards ACC. Based on these results, combination treatments are evaluated looking for additive or synergistic effects. Previously we reported activity of the multi-tyrosine kinase inhibitor dovitinib in models of ACC. However, whether combination with other targeted therapies would result in additive or synergistic activity was unclear. To test this we evaluated dovitinib in combination with two classes of agents with anecdotal clinical activity, an HDAC inhibitor and IGF-1R inhibitor; for these studies we utilized vorinostat and linsitinib. RNA and DNA-based sequence analysis was also performed on the ACC panel models to correlate sensitivity or resistance with molecular markers. 36 Wednesday 19 November 2014 Poster Session – Drug Screening Methods: Low passage ACC models were established in immune-deficient mice from primary or metastatic patient tissue and once established were confirmed by histologic comparative analysis. Drug sensitivity studies were performed evaluating dovitinib, vorinostat and linsitinib. Study endpoints included tumor volume and time from treatment initiation with tumor growth inhibition, delay and regression reported at study completion. Results: To date over eighty FDA-approved and investigational therapies have been evaluated. In the current study additive effects were reported in dovitinib/vorinostat and dovitinib/linsitinib combination groups compared with single agents. Statistically significant (p < 0.05) tumor growth inhibition was reported in two models comparing the combination to single agents using a submaximal dovitinib concentration. Sequence based analysis is currently underway to correlate sensitivity and resistance to these and other therapies. Conclusion: Low passage ACC models have been used to identify agents potentially useful in the treatment of ACC. Currently we have identified preclinical combination benefit with dovitinib/vorinostat and dovitinib/ linsitinib combinations and RNA and DNA sequence based analysis is currently underway to correlate sensitivity and resistance to these and other therapies. mechanisms of action produced supra-additive activity with the same compounds in the ‘Combo Set’. Examples of these interactions included: (1) ‘Test Agents’ inhibiting DNA damage repair checkpoints (p53, ATR, or GSK3-b) that all produced similar patterns of combination activity when combined with ‘Combo Set’ alkylating agents, and to a lesser extent with Topoisomerase poisons; (2) Wee 1 and Chk1 inhibitors that demonstrated optimal therapeutic benefit when combined with gemcitabine; this result was striking because gemcitabine, a member of the ‘Combo Set’, was an infrequent combination hit with other ‘Test Agents’; (3) EGFR inhibitors, when combined with dacarbazine, were all supra-additive in a single cell line: PC-3. We also found multiple antagonistic interactions, including: (1) Src inhibitors were antagonistic with ATRA and oxaliplatin in all three tested cell lines; (2) HDAC inhibitors were antagonistic with many antimetabolites in the ‘Combo Set‘. These results may aid in selection of combinations for further preclinical investigation, leading to clinical studies. 98 POSTER (Board P092) Synergistic inhibition of HER2 positive breast cancer by triptolide and lapatinib J. Sakoff1 , J. Gilbert2 , A. McCluskey3 . 1 Calvary Mater Newcastle, Medical Oncology, Newcastle NSW, Australia; 2 Calvary Mater Newcastle Hospital, Medical Oncology, Newcastle NSW, Australia; 3 The University of Newcastle, Chemistry, Newcastle NSW, Australia P. Chalugun1 , J.S. Shim1 , P. Korangath1 , S. Sukumar1 , J.O. Liu1 . 1 Johns Hopkins University, Pharmacology, Baltimore MD, USA HER2 positive breast cancers are poorly differentiated and have a higher potential for metastasis. Although trastuzumab and lapatinib have been used for the treatment of HER2 positive breast cancer, resistance of both drugs has dampened the long-term benefit of those drugs. As cancer has multiple genetic aberrations and can readily develop resistance to individual drugs with specific targets, we employed synergistic drug combination as a strategy to overcome drug resistance and to enhance to efficacy of existing drugs. From a screen of the Johns Hopkins Drug Library, we identified triptolide as a strong synergistic hit with lapatnib in HCC1954, a drug-resistant HER2-positive breast cancer cell line. The combination of lapatinib and non-toxic doses of triptolide synergistically inhibited the HER2 signaling pathway. We found that lapatinib increased both mRNA expression and the half-life of HER2 protein, whereas triptolide countered the effects of lapatinib by downregulating the expression of HER2, leading to the synergistic inhibition of HER2 signaling pathway. The synergy in cell proliferation was observed in all HER2-positive breast cancer cell lines regardless of drug resistance status, but was absent in HER2-negative ones. In mouse xenograft models, the combination of lapatinib and triptolide at their minimum effective doses almost completely inhibited the growth of the drug-resistant HER2-positive breast cancer cells. Together, these findings suggest that the combination of triptolide and lapatinib could be a promising new therapeutic regimen for drug-resistant HER2-positive breast cencer. 99 POSTER (Board P093) Combination screening of investigational oncology agents S. Holbeck1 , J.M. Collins2 , J.D. Doroshow3 . 1 National Cancer Institute, Rockville, USA; 2 National Cancer Institute, DCTD, Rockville, USA; 3 National Cancer Institute, DCTD, Bethesda, USA Treatment with combinations of drugs forms the backbone of most cancer treatment regimens. With the advent of newer therapies targeting specific drivers or molecular defects present in tumor cells come new opportunities and challenges in developing drug combinations. Many molecularly targeted drugs elicit profound responses in patients as single agents, but it is common for resistance to arise in a matter of months. There is thus an urgent need for strategies to develop combinations that incorporate these new agents. We have previously reported on our systematic approach to the screening of all pair-wise combinations of approved small molecule oncology drugs (~5000 drug pairs) in a panel of 60 human tumor cell lines, the NCI-60. Our combination screening has now been expanded to include ~9000 drug pairs, including many investigational agents, initially screened against a small panel of cell lines (3−5 lines). With some overlap between the 2 screens, a total of 12,660 unique drug pairs has been tested. In the current screen, we established a ‘Combo Set’ panel of ~70 approved and investigational drugs. Agents of interest (‘Test Agents’) were then evaluated in combination with each of the drugs in the ‘Combo Set’ in each of 3−5 cell lines. Additional testing in the NCI-60, and/or xenografts, was performed for 55 combinations with greater than additive activity in the smaller cell line panel. By examining multiple representatives of a mechanistic class as ‘Test Agents’, we identified interactions wherein ‘Test Agents’ with similar 100 POSTER (Board P094) Small molecules selectively targeting breast cancer cells Breast cancer is one of the most common cancers among women. Despite advances in therapy, drug resistance is often induced, tumour selectivity is poor and drug off-targets culminate in limited efficacy. Indeed metastatic advanced breast cancer is deemed incurable. Better, more effective treatments for this disease are clearly needed. We have discovered a structurally distinct class of small molecules that target breast cancer cell lines while having little to no effect on normal breast cancer cells or on cell lines derived from other tumour types including colon, ovarian, lung, skin, prostate and pancreatic carcinomas, neuroblastoma and glioblastoma. Indeed these molecules show more than 500-fold selectivity towards breast cancer cells compared with other tumour types, while maintaining nM potency, as determined by the MTT growth inhibition (GI50 ) assay with GI50 values of 0.1−0.7uM (72 h exposure). Moreover, the sensitive breast cancer cell lines represent tumour types from the four main breast cancer classifications including ER+ luminal A (MCF-7, T47-D and ZR-75−1 cells), ER+ luminal B (BT-474), HER2+ (SKBR-3), and most importantly the Basal (triple negative MDA-MB-468 cells) classification which traditionally carries a very poor prognosis. Our novel class of molecules also retain activity in MCF-7/VP16 cells (GI50 0.2uM) which overexpresses the drug resistance ABCC1 gene. Only one breast cancer cell line has shown insensitivity, MDA-MB-231 (Basal triple negative), which unlike all of the other breast cell types has amplifying mutations in KRas and BRaf activity, a genotype found in less than 5% of breast cancer tumours. Furthermore, our novel compounds induce minimal effects on the growth of normal MCF10A breast cells. Cell cycle analysis in the most sensitive breast cancer cell line, MDAMB-468, shows an increase in the proportion of cells in the S-phase of the cell cycle within 24 h of exposure, concomitant with a decrease in the proportion of cells in the G1 -phase, and preceding an increase in the subG1 cell death population. The ability to specifically target breast tumours, while having little or no effect on normal breast cells, or other tumour types is a unique finding. Elucidating the mechanism controlling this phenomenon is now the focus of our research efforts. 101 POSTER (Board P095) PIK3CA mutation-targeting compounds analyses using NCI60 cell line panel H. Bando1 , J. Lih2 , E.C. Polley3 , S.L. Holbeck4 , B. Das2 , D. Sims2 , T. Doi5 , A. Ohtsu5 , M. Williams2 , N. Takebe1 . 1 National Cancer Institute National Institute of Health, Cancer Therapy Evaluation Program Division of Cancer Treatment and Diagnosis, Rockville, USA; 2 National Cancer Institute National Institute of Health, The Frederick National Laboratory for Cancer Research, Frederick, USA; 3 National Cancer Institute National Institute of Health, Biometric Research Branch Division of Cancer Treatment and Diagnosis, Rockville, USA; 4 National Cancer Institute National Institute of Health, Developmental Therapeutics Program Division of Cancer Treatment and Diagnosis, Rockville, USA; 5 National Cancer Center Hospital East, Department of Gastroenterology and Gastrointestinal Oncology, Kashiwa, Japan Background: The US National Cancer Institute 60 (NCI-60) human tumor cell line panel was developed as an in vitro drug-discovery tool, and it is a unique publicly accessible platform of various datasets. Through the CellMiner website, we could access genomic datasets of NCI-60. We could Poster Session – Drug Screening also obtain the activities of various test compounds to the NCI-60 cell line panel from NCI Developmental Therapeutics Program (DTP) website. Using this capability, we screened for therapeutic agents against the cell lines with PIK3CA mutation, the second most frequently mutated actionable oncogene among various types of tumors. Material and Methods: Utilizing NCI-60 cell line GI50 (50% growthinhibitory levels) data of PI3K/AKT/mTOR pathway compounds, we calculated the differences in mean log GI50 between the PIK3CA mutated cell lines and non-mutated cell lines (delta log GI50) to investigate promising compounds. The volcano plot (the x-axis depicts delta log GI50 and the y-axis depicts statistical significance level) was used to search for the promising test compounds. Results: Seven cell lines had PIK3CA mutation (3 p.E545K, 3 p.H1047R, and 1 p.R38C mutation). We could collect GI50 data on 35 PI3K/AKT/mTOR targeting compounds (7 pan-class PI3K inhibitors, 7 isoform-selective PI3K inhibitors, 5 rapalogs, 3 mTOR kinase inhibitors, 6 panPI3K/mTOR inhibitors, and 7 AKT inhibitors). In our analysis, 1 panclass PI3K inhibitor, 2 isoform-selective PI3K inhibitors, 1 rapalog and 1 AKT inhibitor showed promising trends by both delta log GI50 and statistical significance. Conclusions: NCI-60 cell line panel may be a valuable tool to identify various actionable mutation–drug relationships and to discover promising drug candidates. 102 POSTER (Board P096) Comparison of platinum/taxane and anthracycline-based therapies in ovarian PDX models: Correlating stage of biopsy collection and engrafting with in vivo drug sensitivity J. Meade1 , M.J. Wick1 , T. Vaught1 , L. Gamez1 , M. Farley1 , A. Moriarty1 , A.W. Tolcher1 , A. Patnaik1 , D.W. Rasco1 , A.J. White2 , K.P. Papadopoulos1 . 1 South Texas Accelerated Research Therapeutics, (START), San Antonio TX, USA; 2 START Center for Cancer Care, San Antonio TX, USA Background: Standard first-line treatment for ovarian cancer is a platinumbased therapy often including a taxane, with various salvage therapies for recurrent disease. We and others have established and validated low passage ovary patient-derived xenograft (PDX) models from biopsies obtained at diagnosis and following clinical treatment progression; however, whether drug sensitivity to each model correlates to the clinical context was unclear. To test this we stratified thirty-nine ovary PDX models using clinical outcome data at the time of biopsy collection into four groups: chemo naı̈ve, first-line platinum responding, first-line platinum refractory and anthracycline pretreated. Drug sensitivity studies were performed, evaluating model response to platinum, platinum plus taxane and liposomal doxorubicin and results compared between each group. Methods: Ovary PDX models were developed inimmune-deficient mice from primary or metastatic patient tissue and established models confirmed by histologic comparative analysis and linked with patient treatment and outcome data. Drug sensitivity studies were performed evaluating models response to three regimens with tumor volume and time from treatment initiation as study endpoints. T/C values, growth delay and regressions were reported for each model. Results: For the thirty-nine models evaluated: 18/39 were from chemonaı̈ve patients, 6/39 from first-line platinum responding, 10/39 from firstline platinum refractory and 5/39 from anthracycline pretreated patients. In these studies chemo-naı̈ve and first-line platinum responding models were sensitive to the platinum based regimens with few exceptions including ST036 which harbors known AKT and KRAS mutations. Most first-line platinum refractory models including ST419 and ST884 were resistant to platinum alone and platinum/taxane combination. Interestingly sensitivity to liposomal doxorubicin did not correlate with clinical pretreatment as several models from chemo-naı̈ve patients including ST024 and ST511 were insensitive while some models established from anthracycline pretreated patients including ST255B and ST467 were sensitive to the therapy. Conclusion: We have established a panel of ovary patient-derived xenografts and correlated model sensitivity to platinum and anthracyclinebased treatments to the clinical context at the time of biopsy collection and engraftment. Overall platinum sensitivity in models from chemo-naı̈ve and first-line platinum responding patients, with few exceptions, correlated with clinical response, irrespective of activating mutations. Preclinical response to anthracyclines was less predictive and not predicated on the clinical context. Wednesday 19 November 2014 37 103 POSTER (Board P097) The use of next generation sequencing (NGS) in the management of metastatic breast cancer (MBC): Defining a model for genomic-driven therapies L. Austin1 , M. Gooptu1 , T. Avery1 , R. Jaslow1 , J. Palazzo2 , M. Cristofanilli1 . 1 Thomas Jefferson University Hospital, Medical Oncology, Philadelphia PA, USA; 2 Thomas Jefferson University Hospital, Pathology, Philadelphia PA, USA Background: Metastatic breast cancer is an incurable disease treated with palliative intent. The limited benefit from standard therapies could be related to the fact that the disease is biologically heterogeneous and not properly managed by current treatments. Increased understanding of the molecular complexity using next generation sequencing (NGS) allows for individual tumor mutation analysis which provides better selection of treatments based on genomic abnormalities driving the disease. Methods: We retrospectively analyzed 33 patients with advanced or metastatic breast cancer treated at Thomas Jefferson University, diagnosed between 2003–2013, on whom next generation sequencing (NGS) by Foundation One™ was sent for genomic analysis. Immediately actionable mutations for this analysis were considered those for which FDA-approved agents for breast cancer were identified. We also reported potentially actionable mutations which were defined as mutations with investigationaltherapeutic agents. Results: The majority of patients (88%) had inflammatory breast cancer (IBC). According to disease subtype, 36% were ER+/HER− (Luminal A), 18% ER+/HER+ (Luminal B), 15% ER−/HER+ (HER2+), and 30% were ER−/HER− (triple negative). NGS genomic analysis revealed a total of 78 unique mutations with a total of 178 mutational events. The five most commonly mutated genes in order of frequency were TP53 (55% of patients), MYC amplification (39%), PIK3CA mutations (36%), ERBB2 amplification (30%) and PTEN loss or mutation (15%). Eleven of 78 mutations (14%) were immediately actionable (based on our definition) and comprised of PIK3CA mutations/amplifications, ERBB2 amplifications, AKT mutations and PTEN loss/mutations. In total, 21 of 33 patients (64%) had at least one immediately actionable mutation and 97% (32) of patients had either an immediately actionable or potentially actionable mutation. The most common potentially actionable mutations were TP53, MYC amplification, FGFR1 amplification and MDM2 amplification. All but one of the HER2+ patients (IHC/FISH) had ERBB2 amplification on NGS. Interestingly, of the 10 patients that had ERBB2 amplification, 70% had a concomitant PIK3CA mutation and all had IBC. Two patients with ERBB2 amplification and PIK3CA mutations who had progressed on trastuzumab ((Herceptin® ) combinations were started on everolimus (Afinitor® ), Trastuzumab and vinorelbine (Navelbine). Conclusion: In conclusion, in this cohort of 33 patients, the Foundation One™ panel detected unique mutations of which 14% were immediately actionable and 97% of patients had at least one mutation that was immediately or potentially actionable. Actionable mutations were detected across all receptor groups and there was a high incidence on concomitant ERBB2 amplification and PIK3CA mutation. The Foundation One™ panel is a useful tool which can be utilized for tailoring targeted therapy for breast cancer patients. This warrants further investigation with a prospective trial to evaluate the clinical impact of this added information and its effect on decision making and clinical outcomes. 104 POSTER (Board P098) Identification of inhibitors of tryptophan metabolizing enzymes for cancer immunotherapy by high-throughput screening G. Zaman1 , J.C.M. Uitdehaag1 , S. van Gerwen1 , N. Seegers1 , A.M. van Doornmalen1 , J. de Man1 , R.C. Buijsman1 . 1 Netherlands Translational Research Center B.V., Oss, Netherlands Background: The amino acid tryptophan is an important regulator of the immune system by regulating the activation of T cells. Tumor cells express enzymes that oxidize tryptophan, thereby dampening the local T cell immune response against cancer cells. These enzymes are indoleamine 2,3-dioxygenase (IDO1) and tryptophan 2,3-dioxygenase (TDO). Despite the substantial evidence of the importance of IDO1 and TDO as small molecule drug targets, only a handful of different chemical scaffolds have been reported. The lack of chemical matter is explained by the lack of robust assays for high-throughput screening. We have developed new assays for IDO1 and TDO, which we have used to screen a compound library, and to characterize the selectivity of reference inhibitors. Materials and Methods: NFK Green™ is a chemical probe that specifically reacts with N-formyl kynurine, the reaction product of the enzymatic conversion of tryptophan by IDO1 and TDO. The reaction is quantified by measuring fluorescence on a 384-well plate multimode reader. Biochemical assays were developed for IDO1 and TDO using recombinantly expressed 38 Wednesday 19 November 2014 proteins, and a library of 87,000 diverse lead-like molecules was screened. NFK Green™ was also used to determine the tryptophan metabolizing activity in a collection of human cancer cell lines and was related to the expression levels of IDO1 and TDO by western blot analysis. Results: Biochemical and cell-based screening assays were developed for IDO1 and TDO using a new fluorescent read-out. High-throughput screening of libraries of small chemical compound libraries yielded novel selective inhibitors of either IDO1 or TDO. Side-by-side comparison of published reference compounds revealed significant, previously unnoted cross-reactivity of a widely used hydroxyamidine-based inhibitor of IDO1 (Compound 5l) with TDO. The selectivity of other reference IDO1 or TDO inhibitors was confirmed, leading to definition of a new tool compound set. Biochemical selectivity of compounds correlated with inhibition of cellular tryptophan metabolizing activity and expression of IDO1 or TDO. Conclusions: We have developed new biochemical and cell-based assays for IDO1 and TDO, to enable the identification of novel small molecule inhibitors and to support lead optimization. Side-by-side comparison of published inhibitors revealed novel, unanticipated cross-reactivity of IDO1 inhibitor scaffolds with TDO. 105 POSTER (Board P099) A platform to test multiple therapy options simultaneously in a patient’s own tumor N. Caffo1 , R. Klinghoffer1 . 1 Presage Biosciences Inc., Seattle, USA While investigational cancer drugs must ultimately be validated in clinical trials, most early drug discovery is performed under in vitro conditions in cell-based models that poorly represent the disease they are intended to represent. To enable in vivo analysis of anti-cancer agent efficacy at earlier stages of drug development, and to potentially enable toxicity-sparing assessment of novel agents in the oncology clinic, we have developed a technology platform called CIVOTM . CIVOTM allows for simultaneous assessment of up to eight drugs or drug combinations in a single solid tumor. Controlled microinjection-based delivery of doxorubicin, docetaxel, mafosfamide, and gemcitabine both as single agents and combinations was tested in the canine sarcoma clinic. Drugs were co-injected in a columnar array with UV fluorescent beads resulting in easy-to-identify bands of drug, each at a distinct position of the patient’s tumor. Tumors were resected 72 h following microinjection and were examined for responses using standard histology methods. The CIVO introduced drug microdoses induced spatially defined, graded, and mechanism-specific cellular changes around sites of drug exposure in a patient-specific manner. Consistent with the use of doxorubicin as first line therapy in the soft tissue sarcoma clinic, the frequency and extent of response of localized responses to doxorubicin exceeded those of all other agents tested. This preclinical data, along with early responses observed in the human clinic, set the stage for clinical application of this technology to identify which novel agents are likely to succeed or fail in subsequent clinical trials. Immunotherapy (Immunecheckpoints, Vaccination, Oncolytic viruses, Cytokines) 106 POSTER (Board P100) Beta-3 integrin inhibition reduces inflammatory cytokine release but not anti-cancer activity of oncolytic adenovirus in ovarian cancer A.K. Browne1 , L.A. Tookman1 , C.K. Ingemarsdotter1 , R. Bouwman1 , K. Pirlo1 , Y. Wang1 , K.M. Hodivala-Dilke2 , I.A. McNeish3 , M. Lockley1 . 1 Barts Cancer Institute, Centre For Molecular Oncology, London, United Kingdom; 2 Barts Cancer Institute, Centre For Tumour Biology, London, United Kingdom; 3 University of Glasgow, Institute of Cancer Services, Glasgow, United Kingdom Background/Introduction: The potential of oncolytic adenoviruses as anti-cancer therapy has repeatedly been demonstrated. A consistent and worrying feature of adenoviral gene therapy is the rapid cytokine release that occurs after viral administration. These cytokines give rise to dose limiting inflammatory toxicities, which can be severe and have hindered further investigation and clinical development of these promising anti-cancer therapies. Using primary ovarian cancer cells and genetically modified mice, we show that the E1A-CR2 deleted replicating oncolytic adenovirus, dl922–947, induces cytokines via beta-3 integrin in macrophage-rich tissues. We present new evidence that co-administration of a Cilengitidelike integrin inhibitor controls the inflammatory cytokines and hepatic toxicity Poster Session – Immunotherapy induced by dl922–947 in tumour bearing mice. Importantly, although alphav/beta-3integrin functions as a secondary adenoviral receptor, we found no evidence that beta-3 inhibition compromised viral infectivity and oncolysis in vitro or anti-cancer efficacy in vivo. Material and Methods: We quantified production of cytokine mRNA (qRTPCR) and protein (Mesoscale Discovery System) following dl922–947 in ovarian cancer cells lines, tumour cells harvested from the ascites of women with ovarian cancer and in murine tissues, peritoneal cells and serum. Murine models included nude mice bearing intraperitoneal ovarian cancer xenografts and non-tumour bearing, immunocompetent beta-3 null mice. Pharmacological inhibition of beta-3 integrin was achieved using H2574, a cyclic RGD mimetic inhibitor of alpha-v/beta-3andalpha-v/beta-5 integrins. Results: Primary and established ovarian cancer cell lines in vitro did not release inflammatory cytokines in response to adenovirus. In contrast, intraperitoneal delivery of dl922–947 caused rapid, systemic cytokine induction in ovarian cancer xenografts. Cytokines originated predominantly in macrophage-rich murine tissues (liver, spleen and peritoneal macrophages), rather than the injected malignant cells, and was independent of viral replication. Adenoviruses are known to induce cytokine release via beta-3 integrin-expressing macrophages. We found that co-administration of the integrin inhibitor, H2574, controlled production of inflammatory cytokines in the circulation of tumour-bearing mice. Cotreatment also reduced pathological features of viral hepatic toxicity such as eosinophilic degeneration and liver enzyme elevation. Importantly, combining dl922–947 with H2574 did not compromise anti-cancer activity in vitro or in vivo. Conclusions: Combining oncolytic adenoviruses with pharmacological inhibition of beta-3 integrin enables safe systemic delivery of replicating adenoviruses, without compromising anti-cancer activity. This novel approach could have a major impact on the future development of these effective anti-cancer agents. 107 POSTER (Board P101) CIGB-247: Anti-VEGF therapeutic vaccine in patients with advanced solid tumors F. Hernández-Bernal1 , J.V. Gavilondo2 , M. Ayala Ávila2 , A.V. de la Torre3 , J. de la Torre4 , K.H. Selman-Housein4 , Y. Morera2 , M. Bequet-Romero2 , C.M. Valenzuela1 , Y. Martin5 . 1 Center for Genetic Engineering and Biotechnology (CIGB), Clinical Trials, Havana City, Cuba; 2 Center for Genetic Engineering and Biotechnology (CIGB), Pharmaceuticals, Havana City, Cuba; 3 “Celestino Hernández” Hospital, Oncology, Santa Clara, Cuba; 4 Medical and Surgical Research (CIMEQ), Oncology, Havana City, Cuba; 5 “Celestino Hernández” Hospital, Oncology, Havana City, Cuba Background: The CIGB-247 is a vaccine preparation for the therapy of cancer that combines the recombinant antigen p64K-hVEGFKDR− , produced in Escherichia coli and the VSSP adjuvant. This antigen is a representative molecule of the human Vascular Endothelium Growth Factor (VEGF-A), in its isoform 121. Vaccination with CIGB-247 in experimental animal models has been safe, with anti-tumor and anti-metastatic effects. Material and Methods: A non-controlled, dose up scaling phase I clinical trial was performed in patients with advanced solid tumors, which previously received the best onco-specific treatment available without response. The general objective of the trial was to study the safety profile of the vaccine at three antigen dose levels. A maximum of 10 patients per group were planned. Individuals were subcutaneously immunized for 8 consecutive weeks with 50, 100 or 400 mg of antigen (all in the same amount of VSSP adjuvant), and re-immunized on week 12. On week 16, evaluations of safety, tolerance, clinical status, and immunogenicity (seroconversion for anti-VEGF IgG, serum VEGF/KDR-Fc blocking ability, and gamma-IFN ELISPOT with blood cells stimulated in vitro with mutated VEGF) were done. Results: Vaccination was shown to be safe at the three dose levels, with only grade 1−2 adverse events. CIGB-247 was immunogenic and higher numbers of individuals positive to the three immune response tests were seen with increasing antigen dose. Conclusions: This is the first clinical testing report of a cancer therapeutic vaccine based on a human VEGF related molecule as antigen. The CIGB247 vaccine is safe, immunogenic, and merits further clinical development. Poster Session – Immunotherapy 108 POSTER (Board P102) CD70 (TNFSF7), a receptor involved in acute immune modulation of viral infection, is frequently overexpressed in solid and hematological malignancies J. Jacobs1 , K. Zwaenepoel1 , P. Aftimos2 , C. Rolfo3 , S. Rottey4 , L. Ysebrant de Lendonck2 , K. Silence5 , A. Awada2 , A. Thibault5 , P. Pauwels1 . 1 Universitair Ziekenhuis Antwerpen, Pathology, Antwerp, Belgium; 2 Institut Jules Bordet, Oncology, Brussels, Belgium; 3 Universitair Ziekenhuis Antwerpen, Oncology, Antwerp, Belgium; 4 Ghent University Hospital, Oncology, Ghent, Belgium; 5 arGEN-X BVBA, Research, Zwijnaarde, Belgium Tissue expression of CD70 (TNFSF7), a receptor of the TNF superfamily normally involved in transient, rapid-onset immune response, is highly restricted to small subsets of T-, B-, and dendritic cells. It is often chronically over-expressed in patients with hematological and solid malignancies in whom it mediates tumor cell growth and immune escape. To date, the incidence of CD70 positivity has not been systematically characterized in patients with advanced malignancies. We developed an immunohistochemistry (IHC) method to detect CD70 on paraffin-embedded tumor biopsies in support of a Phase 1 trial of ARGX110, a monoclonal IgG1 SIMPLE Antibody™ endowed with enhanced ADCC properties (POTELLIGENT® ). A total of 182 samples (120 solid tumors and 62 hematological malignancies) were selected at random from a university hospital tissue bank and tested for CD70 expression. Samples were considered positive for CD70 (cut-off: 10% cells staining) in 33% and 58% of cases, respectively. As of March 2014, CD70 positivity has also been documented in 147 of 296 patients (50%) who underwent IHC screening as an eligibility requirement for study participation (ClinicalTrials.gov Identifier: NCT01813539). EBV-induced malignancies (e.g.: Hodgkin’s and Burkitt’s lymphoma, nasopharyngeal carcinoma) consistently overexpressed CD70. A high incidence of CD70 positivity was observed in T- and B-cell lymphomas (64%), as well as renal cell carcinoma (90%) and esophageal cancer (64%). Consistent with the intracellular trafficking of CD70, staining patterns in malignant cells included membranous, cytoplasmic and perinuclear distribution. In conclusion, the expression of CD70 is commonly increased in a wide variety of solid and hematological malignancies. 109 POSTER (Board P103) Functional activity, but not PD-1 expression level, differentiates primary CLL from healthy PD1+ T cells using SCNP S. Liang1 , L. Leung1 , S. Putta1 , D. Hotson1 , D. Rosen1 , R.E. Hawtin1 . Nodality Inc., Research, So San Francisco CA, USA 1 Background: Drugs inhibiting PD-1 signaling have demonstrated clinical efficacy in the treatment of cancer. To increase understanding of PD-1+ T cell biology, PD-1 expression was profiled across CD4/CD8 T cell subsets in peripheral blood mononuclear cells (PBMC) of CLL and healthy donors (HD), and the functional responsiveness of these PD-1+/− subsets to cytokine modulation or T cell receptor (TCR) modulation +/− PD-1 blockade was interrogated. Materials and Methods: Single Cell Network Profiling (SCNP) is a multiparametric flow cytometry based technology that enables simultaneous analysis of signaling networks in multiple immune cell subsets. CLL (n = 9) and HD (n = 8) PBMC were profiled by SCNP to interrogate CD4/CD8 +/− T cell subsets for PD-1 expression, cell subset specific signaling following modulation with IL-2, IL-7, IL-15, IL-21 or TCR (a-CD3/a-CD28), and proliferation following TCR modulation +/− PD-1 blockade. CLL and HD data were compared to identify dysfunctional signaling associated with disease and PD-1 expression. Results: CLL and HD did not differ significantly in median PD-1 expression, although CLL samples were more heterogeneous. Significant differences were detected in signaling capacity in CLL vs HD, particularly in PD-1+ CD8 T cells. Unmodulated p-STAT5 was elevated in CLL in PD-1+ and PD-1− CD8 T cells and in PD-1+ CD4−/CD8− T cells. IL-2, IL-7 and IL-15 induced lower p-STAT5 levels in PD-1+ CD8 T cells and PD-1+ CD4−/CD8− T cells of CLL donors, indicating dysfunctional signaling through these common g-chain cytokines in these PD-1+ subsets. In contrast to reduced cytokine responsiveness, increased TCR modulation of p-ERK was observed in PD-1+ CD8 T cells in CLL vs HD. Conversely, CLL T cells demonstrated decreased proliferation in response to TCR modulation, which was partially reversed with PD-1 blockade. Conclusions: The dysregulated cytokine signaling, elevated TCR responsiveness and reduced proliferation observed in CD8, but not CD4, PD-1+ T cell subsets in CLL is consistent with the reported ‘pseudo-exhausted state’. These data establish the application of SCNP to interrogate PD-1+ T cell subset signaling and the functional consequences of tumor– Wednesday 19 November 2014 39 microenvironment interactions. Building upon and verifying these data, SCNP will be applied to both developing predictive and prognostic markers of response in hematologic and solid tumor indications, and interrogating the efficacy of therapeutics to restore T cell function. 110 POSTER (Board P104) IL-6/STAT3/Fra-1 signaling axis promotes colorectal cancer aggressiveness through epithelial–mesenchymal transition J. Shao1 , H. Liu1 . 1 Zhejiang University School of Medicine, Pathology and Pathophysiology, Hangzhou City, China Fos-related antigen-1 (Fra-1), a member of the Fos family, is aberrantly expressed in several types of human cancer, but its functional roles in cancer development and the regulatory mechanisms are still not well understood. In this study, we investigated the significance of Fra-1 expression in human colorectal cancer (CRC). Fra-1 levels were positively correlated with the local invasion depth as well as lymph node and liver metastasis in a total of 229 CRC patients. Intense immunohistochemical staining of Fra-1 was observed at the tumor invasive front adjacent to inflammatory cells and in parallel with secretion of the pro-inflammatory cytokine interleukin-6 (IL-6) in the CRC tissues. Exogenous IL-6 administration to CRC cell lines significantly upregulated Fra-1 expression in a manner dependent on signal transducer and activator of transcription 3 (STAT3), during which both phosphorylated and acetylated post-translational modifications were required for STAT3 activation to promote the transcription of Fra-1 gene by directly binding to its promoter. Importantly, Fra-1 upregulated by IL-6/STAT3 signaling endowed the CRC cells with properties of epithelial– mesenchymal transition (EMT), an essential step for tumor progression and metastasis. RNA interference-based attenuation of STAT3 or Fra-1 prevented IL-6-induced EMT, cell migration and invasion, whereas ectopic expression of Fra-1 markedly reversed the inhibitory effect of STAT3knockdown on the EMT process. Collectively, this study uncovered the existence of an aberrant IL-6/STAT3/Fra-1 signaling axis leading to EMT and aggressiveness in colorectal cancer and suggested novel therapeutic opportunities for the treatment of malignant disease. 111 POSTER (Board P105) Identification of peptides which could block PD-1 checkpoint for NSCLC immunotherapy Y. Zhu1 , C. Li1 . 1 Suzhou Institute of Nano-tech and Nano-bionics CAS, Nanobiomedicine, Suzhou, China Background: Non-small cell lung cancer (NSCLC) has been reported responding to programmed death-1 (PD-1) immune checkpoint blockade, thus inhibitory peptides blocking PD-1/programmed death ligand-1 (PDL-1) pathway may contribute the effective therapy to NSCLC patients. Materials and Methods: X15 bacteria peptide library was used to screening and selecting binding peptides to PDL-1 and PD-1. Focused library was designed and constructed according to the peptide screening results from X15 random bacteria peptide library. Affinity and specificity of binding peptides for PDL-1 and PD-1 were examined with methods of SPR and competition experiments. In vitro assessment of peptides for blocking the PD-1/PDL-1 pathway was performed with MDA-MB-231 cell lines. Metastatic mice model of A549 cells were constructed with nude mice after 2 months since A549 cells were injected into the lung position of mice. The evaluation of peptides for their anti-tumor effect was done via measuring and comparing tumor sizes and life spans of mice injected either with binding peptides or scramble peptides. Immunohistology were performed with anti-CD31 antibody and blood of mice was collected for circulating tumor cells detection. Results: 1. Mice model with metastatic lung cancer was established; 2. Peptides binding with PDL-1 were obtained from random X15 library; 3. Conserved sequences for peptides binding with PDL-1 were identified and their physiochemical properties were examined roughly; 4. Focused library was established according to the conserved binding peptide sequences; 5. Peptides interacted with PDL-1 could block proliferation of MDA-MB-231; 6. Life span of tumor mice got elongated and tumor size was decreased after mice injected with binding peptides; 7. The amount of CTC was alleviated and CD-31 positive signals got decreased in binding peptides-treated mice group. Conclusion: Peptides binding to PDL-1 could behave as potential drugs for metastatic lung cancer therapy since they can block signal pathway initiated by PD-1/PDL-1 interaction, inhibit angiogenesis and metastasis of tumor cells. 40 Wednesday 19 November 2014 Poster Session – Immunotherapy 112 POSTER (Board P106) A novel primary human tumor explant platform provides a preclinical translational link from tissue culture to the clinic G. Juan1 , K. Paweletz1 , E. Trueblood2 , J. Rossi1 , M. Damore1 , A. Anderson1 , R. Loberg1 . 1 Amgen, Medical Sciences, Thousand Oaks CA, USA; 2 Amgen, Pathology, Seattle WA, USA Background: To explore a candidate immunotherapeutic (BiTE® ), a translational explant platform was developed consisting of cultures of thinly sectioned tissues from freshly resected solid tumors. The tumor explants are being used to study treatment responses in a model system that preserves the tumor architecture and microenvironment, including immune effector populations. Material and Methods: 18 freshly resected epithelial tumors were sectioned and treated in culture for 48 or 72 h with increasing concentrations (0, 5, 50 and 500 pM) of an EGFR-BiTE® or a MEC14-BiTE® (negative control). The culture supernatant was then collected to quantitate cytokines released as a measure of T-cell activation using Myriad’s CytokineMAP® A v1.0 panel. CD25 and CD3 enumeration to demonstrate in situ T-cell activation was performed by IHC in FFPE tissues derived from the treated explants. In addition, the parental tumors were profiled by IHC to characterize the EGFR target levels together with the initial tumor T-cell infiltrate. Finally, gene expression profiles of the parental tumors were generated to explore potential resistance mechanisms. Results: Tumor resident T-cells are activated ex vivo by BiTE® . A dose dependent increase of several cytokines including IFN-g, IL-2 and TNF-a was observed in conditioned media harvested from EGFR-BiTE® treated but not in MEC14-BiTE® treated explants. In addition, a dose dependent increase of granzyme B into media as measured by ELISA was observed. Importantly, a dose dependent increase of total CD25 counts and the %CD3CD25 is observed in the EGFR-BiTE® explants vs. those treated with the control BiTE® . EGFR-BiTE® (N = 18) 0 pM IFN-g (pg/mL) IL-2 (pg/mL) TNF-a (pg/mL) %CD3CD25 5.6±0.9 6.8±0.7 24.4±4.2 28.5±15 5 pM 28.9±9.8 55.9±23 43.6±7.3 41.2±17.7 50 pM 101±37 114.4±43.5 88±23.6 57.9±26.2 mode of action, its activity in selected pre-clinical models, and to identify pharmacodynamic biomarkers for response monitoring. In vitro functional tests using lymphocytes from various species were conducted. A series of in vivo syngenic mouse tumor models were selected based on immune checkpoint ligand expression. Immune-related biomarkers and drug concentrations were assessed from circulating blood and tumor samples from those models. Results: A first-in-class therapeutic peptide, designated W014A (formerly AUR-012), was characterized. W014A is a 29-amino acid branched peptide designed as a PD-1 decoy using selected portions of the human PD-1 receptor. W014A displayed equipotent antagonism towards PD-L1 and PDL2-mediated T cell exhaustion. Robust activity in rescue of proliferation and effector functions (IFN-g secretion) from mouse, non-human primate and human lymphocytes was demonstrated. W014A also prevented the interaction of PD-L1 with B7.1. A complete rescue of CD4+ and CD8+ T cells and suppression of regulatory T cells were observed using proliferation assays of immune cells stimulated with anti-CD3/anti-CD-28. Different in vivo models, including melanoma, colon, breast and kidney cancers (B16, CT26, 4T1 and Renca) demonstrated the potent effects of W014A on both primary tumor growth and metastasis. Active drug concentration levels in tumour (Renca model), as well as intratumoral recruitment (CT26 model) of CD4+ and CD8+ T cells, and a reduction in PD-1+ T cells (both CD4+ & CD8+ ) were observed concomitantly with antitumoral activity. Conclusions: Altogether, the unique mechanism of action and preclinical activity of W014A support the set-up of clinical trials in the near future and suggest potential pharmacodynamic biomarkers for use in the clinic. The synergy with other treatments that enhance endogenous antitumor immunity will also be investigated. 114 POSTER (Board P108) Toll-like receptor 5 agonist entolimod as a potential anticancer immunotherapeutic agent L. Burdelya1 , C. Brackett1 , B. Kojouharov1 , J. Veith1 , A. Gudkov1 . 1 Roswell Park Cancer Institute, Cell Stress Biology, Buffalo NY, USA 500 pM 455.3±118.8 605.8±207.7 272.9±61.8 94.9±51.3 Conclusions: Infiltrating T cells can be activated by BiTE® molecules, as demonstrated by cytokine secretion and T-cell activation in the explant culture system. Using a novel preclinical ex vivo model of human primary tumors, the explants provide mechanistic insights into the modulation of the tumor immunoresponse upon administration of a BiTE® . 113 POSTER (Board P107) Preclinical activity and pharmacodynamic biomarkers of W014A, a PD-1 decoy peptide blocking both PD-1 immune checkpoint ligands, PD-L1 and PD-L2 C. Bailly1 , M. Broussas2 , M. Ramachandra3 , P.G. Sasikumar3 , K. Shrimali3 , S. Adurthi3 , M. Ramachandra3 , L.K. Satyam3 , A.A. Dhudashia3 , S. Dhodheri3 , K.B. Sunilkumar3 , N. Corvaı̈a4 , P. Ferre5 . 1 Institut de Recherche Pierre Fabre, Head of Research IRPF, Toulouse Cedex 1, France; 2 Institut de Recherche Pierre Fabre, Experimental Oncology Department, Saint-Julien en Genevios, France; 3 Aurigene Discovery Technologies Ltd, Bangalore, India; 4 Institut de Recherche Pierre Fabre, Saint-Julien en Genevois, France; 5 Institut de Recherche Pierre Fabre, Toulouse, France Background: Cancer immunotherapy is starting to change the way cancer is treated. The goal is to re-activate patient’s immune system to specifically destroy tumor cells. Recent clinical trials in various settings have confirmed that several monoclonal antibodies blocking either the programmed cell death-1 (PD-1) receptor on infiltrating T cells, or its ligand PD-L1 re-activate tumor-specific T cell cytotoxicity, and induce impressive and durable clinical responses. However, the immune evasion of tumor cells cannot be restricted to the sole interaction between PD-1 and PD-L1. PD-1 also interacts with a higher binding affinity with PD-L2, and PD-L1 is capable of binding to B7.1 (CD80) on the T cell surface. Similarly as PD-1/PD-L1, both PD-1/PD-L2 and PD-L1/B7.1 interactions result in deactivation of T cells. Antagonizing those 3 interactions might induce a more robust anti-tumor activity. Materials and Methods: A novel drug candidate was designed to antagonize both PD-L1 and PD-L2. Our goal was to characterize its Mobilization of innate immunity by Toll-like receptor (TLR) agonists and the subsequent development of adaptive immunity have been considered as an attractive approach to cancer immunotherapy. Unfortunately, the majority of TLR agonists induce prohibitive acute inflammatory responses limiting their clinical use. In this regard, TLR5 stands alone since the TLR5 agonist, bacterial flagellin, induces much less severe systemic inflammation than agonists of other TLRs. Entolimod is a flagellin derivative and a clinical stage experimental drug initially developed as a candidate radiation antidote capable of protection from and mitigation of radiation injury in mice and non-human primates. We found that entolimod, in addition to its radioprotective properties, had anticancer effects in a variety of TLR5-positive tumors in mice. We hypothesized that entolimod can induce antitumor defense if tumors are located in a TLR5-responsive microenvironment such as the liver independently of the TLR5 status of tumor cells. This hypothesis was tested in three syngeneic spontaneous and experimental liver metastasis models: CT26 and MC38 colorectal and 4T1 breast adenocarcinomas. The results demonstrate that entolimod treatment was efficient in suppressing metastatic disease when injected systemically either before or after surgical removal of primary tumors in all tested mouse models of metastatic colon, breast, and melanoma cancers. This effect was mediated by mobilization of immune effectors to the liver, the major primary target organ for TLR5 agonists, and did not depend on the TLR5 status of the tumors. Rapid and massive recruitment of neutrophils, NK, CD4/CD8 T cells and other types of immune cells to the liver was followed by eradication of dormant tumor cells and micrometastases and development of protective T cell memory. Importantly, entolimod has passed through two Phase I clinical trials in 150 healthy volunteers and is currently undergoing a Phase I trial in cancer patients with advanced solid tumor liver metastases with the expectation to be used in adjuvant or neoadjuvant settings for prevention of metastatic disease. 115 POSTER (Board P109) Anti-metastatic activity via co-blockade of PD-1 and adenosine A2A receptor D. Mittal1 , A. Young1 , K. Stannard1 , M.W. Teng1 , B. Allard2 , J. Stagg2 , M.J. Smyth3 . 1 QIMR Berghofer Medical Research Institute, Immunology in Cancer and Infection, Brisabane, Australia; 2 Faculté de Pharmacie et Institut du Cancer de Montréal Montréal Québec Canada, Centre de Recherche du Centre Hospitalier de l’Université de Montréal, Montreal, Canada; 3 QIMR Berghofer Medical Research Institute, Immunology in Cancer and Infection, Brisbane, Australia Adenosine targeting is an attractive new approach to cancer treatment, but no clinical study has yet examined adenosine inhibition in oncology despite Poster Session – Immunotherapy the safe clinical profile of adenosine A2A receptor inhibitors (A2ARi) in Parkinson’s disease. Monoclonal antibodies (mAb) that block programmed death (PD)-1 or cytotoxic T lymphocyte antigen (CTLA-4) receptors have been associated with durable clinical responses against a variety of cancer types and hold great potential as novel cancer therapeutics. Metastasis is the main cause of cancer related deaths worldwide, and therefore we have studied experimental and spontaneous mouse models of melanoma and breast cancer metastasis to demonstrate the efficacy and mechanism of a combination of A2A receptor inhibitor in combination with various immune check point inhibitors. The combination of anti-PD-1 and A2A receptor inhibitor significantly reduces metastatic burden and prolongs the life of mice compared with either monotherapy alone. Importantly, the combination was only effective when the tumor expressed high levels of CD73, suggesting a tumor biomarker that at a minimum could be used to stratify patients that might receive this combination. The mechanism of the combination therapy was critically dependent on NK cells and interferon gamma, and to a lesser extent, CD8+ T cells and the effector molecule, perforin. Consistent with the anti-metastatic role of NK cells, we observed significantly high number of NK cells in the lungs of tumor bearing mice after combination immunotherapy. Overall, our preclinical data provide a strong rationale to use A2ARi with anti-PD-1 mAb for the treatment of minimal residual and metastatic disease. 116 POSTER (Board P110) Novel targets for antibody–drug conjugate therapy A.G. Grandi1 , S.C. Campagnoli1 , M.P. Parri1 , E.D.C. De Camilli2 , B.J. Jin3 , P.S. Sarmientos1 , G.G. Grandi4 , L.T. Terracciano5 , P.P. Pileri1 , G.V. Viale2 , R. Grifantini6 . 1 Externautics, R&D, Siena, Italy; 2 European Institute of Oncology, Pathology, Milan, Italy; 3 Fourth Military University, Immunology, XI’an, China; 4 Novartis Vaccines, R&D, Siena, Italy; 5 Basel Medical University, Pathology, Basel, Switzerland; 6 Externautics, Siena, Italy The study focuses on two novel potential therapeutic targets identified by a systematic immune-histochemistry (IHC) screening with a large collection of polyclonal antibodies (approximately 1600) raised against marginally characterized human proteins. Here we describe the molecular characterization of two surface-associated proteins (EXN36 and EXN91) associated to different cancer types. EXN36 is mainly over-expressed in ovary and breast cancers (frequency of approximately 30−40%). Interestingly, it is also over-expressed in triple negative breast cancer. The protein is involved in cell proliferation, migration and invasiveness. Concerning EXN91, it is an adhesion molecule and it acts as a signaling receptor, likely to be important in developmental processes and cell communication. The protein is mainly detected in colon cancer with high frequency (more than 80%), both in early and advanced stages, in high and low grade cancers. Interestingly, EXN91 is over-expressed in KRAS and BRAF mutant colon cancers with significant frequency (approximately 50%). Finally, it is also detected in esophagous SCC and ccRCC (10−20%). Murine monoclonal antibodies able to recognize EXN36 and EXN91 on the surface of cancer cells have been selected and characterized to assess their potential for specific therapeutic indications. In particular, five antiEXN36 mAbs are able to recognize the target protein in breast (Her2+ ,Er+ and triple negative cells) and ovary cell lines. A murine monoclonal antibody is able to recognize EXN91 on the surface of colon cancer cells. This antibody also shows the ability to inhibit growth of colon cancer in xenograft mouse models. Finally, it specifically binds cancer tissues by IHC, suggesting that it could be also developed as companion diagnostic tool for EXN91-based therapies. EXN36 and EXN91 monoclonal antibodies show a high number of binding sites on the cancer cell surface, ranging from 10,000 to 100,000 sites per cells. The antibody specificity has been confirmed in different immunoassays (Western blot, FACS, IHC) by gene silencing experiments and/or competition with peptides containing the antibody epitopes. Thes eantibodies have high affinity for their target epitopes (KD : 10−9 ,10−10 nM). Moreover, they show limited IHC reactivity in normal tissues (FDA tissue panel). Some antibodies are efficiently internalized by cancer cells, suggesting that they can be exploited for the development of Antibody–Drug Conjugate (ADC). The analysis of their potential for ADC is ongoing. Initial results from in vitro studies show that these antibodies, indirectly linked to commercially available drugs (e.g. auristatin-based, DM1, and duocarmycin), show significant anti-tumor activity with specific drugs and linker chemistry. Overall, the results indicate that EXN36, EXN91 and their specific monoclonal antibodies could be developed for the targeted therapy of cancer indications at high medical need, either alone or in combinatorial strategies. Wednesday 19 November 2014 41 117 POSTER (Board P111) “Arming” the chimeric oncolytic adenovirus enadenotucirev to deliver checkpoint inhibitors and other therapeutics directly to tumours B. Champion1 , P. Kodialbail1 , S. Illingworth1 , N. Rasiah1 , D. Cochrane1 , J. Beadle1 , K. Fisher1 , A.C.N. Brown1 . 1 PsiOxus Therapeutics Ltd, Abingdon Oxford, United Kingdom Enadenotucirev (EnAd; formerly called ColoAd1) is a potent, chimeric Ad11p/Ad3 adenovirus active against a range of epithelial cancer cells, with a shorter time-to-lysis than either wild type Ad11p, Ad3 or Ad5. In normal cells, EnAd is attenuated and shows little or no activity by either cytotoxicity or by qPCR. In vivo, EnAd shows efficacy in a range of xenograft human tumour models following intra-tumoural, intravenous and intra-peritoneal injection, and is currently being evaluated clinically for treatment of several different epithelial cancers. Data from an ongoing clinical mechanism of action study have shown that i.v. dosed EnAd infects and replicates in tumour cells, producing significant amounts of viral protein (hexon), indicating that transgene encoded proteins will also be made in significant amounts by tumours following i.v. delivery of an armed EnAd virus. To develop ‘armed’ variants for delivery of therapeutic agents that enhance EnAd’s anti-tumour activity, we have developed a system for rapid generation of modified viruses that can be dosed systemically to deliver immunomodulatory antibodies into tumours. We chose to first encode antiVEGF antibodies since, unlike immunomodulators, they could be readily evaluated in vivo in immunodeficient mouse human tumour xenograft models. We have successfully produced EnAd variants encoding fulllength (NG-135) and ScFv (NG-76) forms of anti-human VEGF antibodies which have similar virus activity profiles to EnAd in cancer cell lines in vitro (virus replication, gene expression and oncolytic action), but also express and release the respective anti-VEGF antibody forms into the culture supernatant. Using either HCT-116 or DLD human colon carcinoma xenograft models we have shown that the virus infection profile following intra-tumoural injection is similar to the parental EnAd virus (virus replication and Hexon gene expression). Anti-VEGF antibody expression by these tumours could be detected in the tissue as both mRNA and functional antibody. Antibodies were detectable early (within 3 days of infection) and expression was sustained over several weeks. Furthermore, low levels of anti-VEGF antibody were detectable in the blood. Production and evaluation of viruses similarly expressing checkpoint inhibitor antibodies is now in progress, together with evaluation of anti-VEGF armed oncolytic viruses for their impact on the growth and microenvironment of tumour xenografts. 118 POSTER (Board P112) Major synergy between Coxsackievirus A21 (CAVATAK™) and radiotherapy or chemotherapy in bladder cancer G.R. Simpson1 , N. Annels1 , M. Ajaz1 , F. Launchbury1 , G. Bolton1 , A.A. Melcher2 , K.J. Harrington3 , G. Au4 , D. Shafren4 , H. Pandha1 . 1 The University of Surrey, Faculty of Health and Medical Sciences, Guildford, United Kingdom; 2 St James’s University Hospital Leeds, Institute of Molecular Medicine, Leeds, United Kingdom; 3 Institute of Cancer Research, Targeted Therapy Team, London, United Kingdom; 4 Viralytics Ltd & The University of Newcastle, Viralytics Ltd & The University of Newcastle, Newcastle, Australia Introduction: There are still no treatments for superficial bladder cancer (SBC) which alter its natural progression, where 20% of patients develop metastatic disease. SBC is often multifocal, has high recurrences after surgical resection and recurs after intravesical live BCG.As this is a clinical setting in which local live biological therapy is already well established, it presents intriguing opportunities for oncolytic virotherapy. Coxsackievirus A21 (CVA21) has recently been shown to be an efficient oncolytic agent that specifically targets and rapidly lyses human malignant melanoma, multiple myeloma, prostate and breast tumours, which express high levels of the CVA21 cellular uptake receptors both in vitro and in vivo. In addition, a Phase I clinical trial in late stage melanoma patients has recently been completed, and has demonstrated that intratumorally administered CVA21 is well tolerated in humans, and that 55.55% of patients experienced stabilization or reduction in injected tumour volumes. Materials and Methods: Infection Radio- & Chemotherapy Synergy assays, Combination index analyses, QPCR and IHC for ICAM-1/DAF, Culture of SBC. Results: Characterization of CVA21 cytotoxicity in a panel of cell lines yielded a range of sensitivities. CVA21 cytotoxicity seems to correlate expression of viral receptors ICAM-1 & DAF. The addition of radiotherapy or chemotherapy resulted in significantly increased cytotoxicity over CVA21 alone. When 5637 or T24 cells were irradiated (4−10 Gy) then 24 hours 42 Wednesday 19 November 2014 later exposed to CVA21 (multiplicities of infection 0.961–12.6), clear synergy was seen. Dose matrix analysis showed that combination indices reached minima of approximately 0.4. Similar analyses showed synergy between Mitomycin C (1.4–0.021ug/ml) and CVA21 at multiplicities of infection between 0.78 and 50 on 5637 cells, which was confirmed on T24 cells. Crucially exposure to Mitomycin C or radiotherapy up-regulates the expression of viral receptors ICAM-1 & DAF in bladder cancer cell lines at both the RNA and protein level. Ru19−19 cells showed low ICAM-1 expression and almost no cytotoxicity when infected with CVA21. Exposure to Mitomycin C increased Ru19−19 ICAM-1/DAF expression, resulting in enhanced cytotoxicity killing, higher than each agent alone. Changing the sequence of treatment with CVA21 and Mitomycin C on bladder cancer cell lines does not appear to change the cytotoxicity killing. Patient derived primary bladder cancer cell lines appear to be highly susceptible to CVA21 infection. Conclusions: Combining CVA21 with either radiotherapy or chemotherapy synergistically enhances cytotoxicity in bladder cancer cell lines. Radiation and chemotherapy enhanced CVA21 oncolysis, likely by increased viral receptors ICAM-1 and DAF expression. These results offer strong support for translational clinical trials of CVA21 plus chemotherapy or radiotherapy that have been initiated in the clinic 119 POSTER (Board P113) 3-Bromopyruvate as an inducer of immunogenic cell death in colon cancer cells K.H. Jung1 , J.H. Lee1 , J.W. Park1 , C. Quach1 , K.H. Lee1 . 1 Samsung Medical Center Sungkyunkwan University School of Medicine, Nuclear Medicine, Seoul, South Korea Background: As cancer cells tend to resist cell death and evade immune surveillance, there is a need to develop therapeutic strategies that induce apoptosis and immune-mediated clearance of cancer cells. 3-Bromopyruvate (3-BrPA) is a halogenated alkylating analog of pyruvic acid that has been shown to inhibit tumor proliferation. The anti-cancer effect is presumed to occur by compromised ATP synthesis through inhibition of glycolysis and mitochondrial complex II activity. In this study, we evaluated the ability of 3-BrPA to induce immunogenic cell death (ICD) in colon cancer cells. Materials and Methods: CT26 murine colon cancer cells were treated with 10 to 20 mM of 3-BrPA for 24 h. Well-known ICD inducers including doxorubicin (DX; 20 mM) and combined mitomycinC/tautomycin (MitoC; 30 mM/TTM; 150 nM) were used as positive controls. Cell surface exposed calreticulin (CRT) was detected by confocal microscopy and fluorescenceactivated cell sorting (FACS) analysis using alexa488 anti-CRT antibody. The magnitude of CRT exposure was measured by binding of 125 I labeled anti-CRT antibody prepared by the iodogen-method. Apoptotic and necrotic cells were identified by FACS using FITC-annexinV and PI staining. Results: Confocal microscopy showed increased binding of alexa488 antiCRT antibodies to the surface of CT26 cells treated with 3-BrPA, in magnitudes comparable to that by DX and MitoC/TTM. FACS analysis confirmed a significant right-shift of fluorescent signals in cells treated with 3-BrPA, in a fashion similar to that by DX and MitoC/TTM. Hence, 3-BrPA treatment increased fluorescent signal-positive cells from 2.7±0.8% to 16.9±0.9%. The amount of cell bound 125 I-labeled anti-CRT antibody increased to 246.1±109.4 % of control level by 3-BrPA treatment. Furthermore, FITC-annexinV and PI staining of 3-BrPA-treated cells showed that CRT was exposed on early apoptotic (AnnexinV+ PI− ) but not secondary necrotic (AnnexinV+ PI+ ) cells. Conclusion: This study provides evidence that, in addition to its glycolysis inhibiting property, 3-BrPA induces early apoptotic CRT exposure on the surface of cancer cells, indicating a potential role of ICD in its anti-cancer effects. 120 POSTER (Board P114) Density of CD 8 +ve T cells & CD 56 +ve NK cells in follicular adenoma & papillary carcinoma of thyroid in Pakistani population J. Varda1 , N. Naseem1 , A.H. Nagi1 . 1 University of Health Sciences Lahore, Morbid Anatomy & Histopathology, Lahore, Pakistan Background: In Pakistan, papillary thyroid carcinoma (PTC) is the commonest (69−71%) of all thyroid malignancies, while follicular adenoma is the most common variety of benign lesions accounting for 60% of all thyroid nodules. In tumour microenvironment, CD 8 +ve cytotoxic T lymphocytes (CTLs) & CD 56 +ve natural killer (NK) cells play a key role in progression from benign to malignant neoplasm as well as in the metastatic potential of tumour. Objectives: To determine the density of CD 8 +ve CTLs & CD 56 +ve NK cells in biopsies of patients with follicular adenoma and papillary thyroid carcinoma Poster Session – Immunotherapy Material and Methods: A total of 50 patients presenting with various histological subtypes of follicular adenoma and different grades of PTC were recruited through non-probability convenient sampling during study period of January–December 2013 from different clinical centers of Lahore, Pakistan. Relevant clinical data was recorded and morphological findings including subtypes of follicular adenoma and histological grades of PTC was ascertained microscopically. Density of CD 8 +ve CTLs & CD 56 +ve NK cells was determined immunohistochemically and related with other histological parameters. Results: The mean age of the patients with thyroid lesions was 36.72±14.04 years (Age range: 14−84 years) with 74% females and 26% males and a female to male ratio of 2.8: 1. Among n = 25 cases each of follicular adenoma and PTC, 76.0% and 72.0% were females and 24.0% and 28.0% were males with a female to male ratio being 3.1: 1 and 2.1:1 respectively (p = 1.0). The ages of patients were divided into three age groups; Group 1 (10−34 years), Group 2 (35−59 years) & Group 3 (60−84 years). Among n = 25 cases each of follicular adenoma and PTC 64.0% and 56.0% cases were present in Group 1, 32.0% and 16.0% cases were present in Group 2 while 4.0% and 28.0% cases were seen in Group 3 respectively (p = 0.046). The density of CD 8 +ve CTLs was scored from 1−5 where increased frequency of score 3 (56%) and score 5 (40%) were observed in cases of follicular adenoma and PTC respectively (p = 0.01). Whereas when the density of CD 56 +ve NK cells was related to the total number of follicular adenoma and PTC, increased frequency of score 3 (96%) was observed in cases of follicular adenoma as compared to PTC (52%) (p = 0.000). Score 3 for CD 8 +ve CTLs and CD 56 +ve NK cells was most frequent among the microfollicular variety of follicular adenoma while this density increased with the increasing histological grades of PTC. Conclusion: The density of CD 8 +ve CTLs and CD 56 +ve NK cells was related strongly with the microfollicular subtype of follicular adenoma and grade II of PTC. Hence, the lymphocytic infiltrate in tumour microenvironment might be an independent prognostic factor if studied on a comparatively larger sample size with follow up of the patients. 121 POSTER (Board P115) A modified double-deleted vaccinia virus combining viral oncolysis and potential gene therapy as a novel therapeutic for atypical teratoid/rhabdoid tumors Y. Ruan1 , A. Narendran2 . 1 Alberta Children’s Hospital, Calgary Alberta, Canada; 2 Alberta Children’s Hospital, Pediatrics and Oncology, Calgary Alberta, Canada Background: AT/RT is a highly malignant brain tumour of infancy that has a poor outcome. The tumor is characterized by the loss of tumor suppressor gene SNF5, a core subunit of the SWI/SNF chromatin remodeling complex, which consequently leads to substantial epigenetic changes and tumorigenesis. Due to the unacceptable toxicity of current chemotherapy on children, safe and effective novel therapies are urgently needed. Oncolytic virotherapy has emerged as a promising approach that uses replication-competent virus to provide anti-neoplastic activity, through the action of direct killing via cell lysis and the additional effect via the activation of the host anti-tumour immune response. We have previously demonstrated the efficacy of double-deleted vaccinia virus (vvDD), a virus with improved safety and tumor specificity, in the ability of homing to and killing AT/RT xenografts. Vaccinia virus, in particular, has the additional advantage of having non-essential genes on its genome that can be replaced with foreign DNA to enhance cytotoxicity. We therefore generated a modified vvDD that expresses wild-type SNF5 gene and tested whether this virus possesses better efficacy against AT/RT cells. Methods: Modified virus, vvDD-hSNF5, was generated by cloning wild type human SNF5 gene into shuttle vector pSC65-mCherry. This construct was transfected and co-infected with vvDD-GFP to HEK293 cells to generate recombined viral particles. Successfully recombined viruses, in which the mCherry and hSNF5 genes replaced GFP in the TK locus, were selected by FACS (sorting of mCherry+ GFP− cells). Viral titre was determined by plaque assay and cytotoxicity against AT/RT cells was determined by crystal violet staining. The ability of vvDD-hSNF5 to express SNF5 gene in AT/RT cells was determined by western blotting. Results: We successfully generated the modified vvDD-hSNF5 that expresses high levels of SNF5 protein in AT/RT cells. Arming of vvDDhSNF5 does not affect the replication of the virus. SNF5 protein is primarily localized to the cell nucleus but is also present in the cytoplasm. vvDDhSNF5 is capable of decrease cell cycle progression in AT/RT cells, in contrast to control virus (vvDD). The ability to cause effective cytotoxicity remains unchanged in vvDD-hSNF5 virus. Conclusions: We generated a modified oncolytic virus that can potentially combine oncolytic virotherapy with gene therapy. As a proof-of-concept, Poster Session – Immunotherapy Wednesday 19 November 2014 we demonstrated that vvDD-hSNF5 possesses similar replication potency and in vitro cytotoxicity. The expression of SNF5 can induce cycle arrest in AT/RT cells. These preliminary observations grant further investigation of vvDD-hSNF5 in in vivo testing. 122 POSTER (Board P116) Analysis of immune-response markers in resectable NSCLC M. Usó1 , E. Jantus-Lewintre1 , R. Sirera2 , S. Calabuig-Fariñas1 , S. Gallach1 , E. Escorihuela1 , A. Blasco3 , R. Guijarro4 , C. Camps5 . 1 Fundación de Investigación Hospital General de Valencia, Molecular Oncology, Valencia, Spain; 2 Universitat Politècnica de València, Biotechnology, Valencia, Spain; 3 Hospital General de Valencia, Oncology, Valencia, Spain; 4 Hospital General de Valencia, Thoracic Surgery, Valencia, Spain; 5 Universitat de València, Medicine, Valencia, Spain Background: Several markers have been indentified to be involved in pro- and anti-tumor immune responses, and some of them may have a prognostic impact. In this study we have analyzed gene expression of a set of markers related to different immune responses in samples from resectable NSCLC patients. Material and Methods: RNA was isolated from fresh-frozen lung specimens (tumor and normal lung) from resectable NSCLC patients (n = 178). RTqPCR was performed to analyze the expression of CCL2, CCL22, CD1C, CD209, CTLA4, IL10, IL23A, LGALS1, LGALS2, and TGFB1 by the use of hydrolysis probes. Relative gene expression was assessed by Pfaffl formula and normalized by the use of CDKN1B, GUS and ACTB as endogenous genes (selected by GeNorm algorithm). Statistical analyses were considered significant at p < 0.05. Results: Patient’s median age was of 65 [26−85], 86.5% were male, 47.2% with squamous (SCC) histology and 11.2% presented a mutation in KRAS gene. Mann-Whitney test revealed significant differences between histology and TGFB1 expression (p = 0.020), being higher in patients with SCC. Moreover, higher levels of LGALS2 (p = 0.023) were found to be associated with absence of lymph node involvement and higher IL23A expression was associated with KRAS WT status (p = 0.026). Survival analyses revealed that higher levels of IL23A and LGALS2 were associated with longer overall survival (OS) (p < 0.001 and 0.007, respectively) and progression free survival (PFS) (p = 0.003 and p = 0.002, respectively) (Table 1). Furthermore, survival analyses restricted to adenocarcinoma (ADC) patients revealed that higher levels of IL10 and CTLA4 were both correlated with longer OS (p = 0.017 and 0.028, respectively) and PFS (p = 0.015 and p = 0.006), as well as IL23A and LGALS2 (Table 1). Table 1. Marker NSCLC (n = 178) IL23A Low High LGALS2 Low High ADC (n = 74) IL10 Low High CLTA4 Low High IL23A Low High LGALS2 Low High OS Median (months) p PFS Median (months) 0.001* 42.6 NR 0.003* 23.4 81.23 0.007* 46.6 NR 0.002* 26.2 NR 0.017* 37 81.2 0.015* 17.8 49.3 0.028* 37.5 NR 0.006* 18.8 81.2 0.025* 42.9 NR 0.015* 19.2 81.2 0.001* 37.4 NR p 0.005* 19.2 NR Gene expression levels were dichotomized as high (median or higher) and low (less than the median). Conclusions: Our data indicated that the expression of certain immuneresponse markers could be associated with better outcome in resectable NSCLC patients. Supported by grants PS09/01149, RD06/0020/1024 and RD12/0036/0025 from RTICC, and Instituto de Salud Carlos III. 43 123 POSTER (Board P117) Targeting tryptophan metabolism in human lung cancer J. Deshane1 , C. Schafer1 , Y. Wang1 , A. Sawant2 , T.H. Jin1 , D. Zhi3 , S. Ponnazhagan2 , S. Grant4 . 1 UAB (University of Alabama Birmingham) Cancer Center, Medicine/Pulmonary, Birmingham AL, USA; 2 UAB (University of Alabama Birmingham) Cancer Center, Pathology, Birmingham AL, USA; 3 UAB (University of Alabama Birmingham) Cancer Center, Biostatistics, Birmingham AL, USA; 4 UAB (University of Alabama Birmingham) Cancer Center, Medicine-Hematology Oncology, Birmingham AL, USA Background: The purpose of the study is to determine whether combination chemotherapy-mediated targeting of tryptophan (Trp) metabolism by inhibition of indoleamine 2,3-dioxygenase (IDO) enzyme activity in immunosuppressive myeloid-derived suppressor cells (MDSCs) predicts improved clinical outcome in lung cancer patients. Methods: Percentages of circulating MDSCs were determined using CD33+ myeloid cells enriched from peripheral blood samples collected from Stage III−IV Non-Small Cell Lung Cancer (NSCLC) patients and their normal healthy relatives. Quantitation of L-Kynurenine (L-kyn), a read out for IDO enzymatic activity, was performed in serum and purified circulating MDSCs. Results: Serum IDO activity (levels of L-kyn) was found to be significantly correlated (P = 3.0×10−5 ) with disease status of patients (n = 11) and their normal relatives (n = 8) using a linear mixed model with family ID as random effect. The percentages of circulating granulocytic (G-MDSCs) and monocytic-MDSCs (Mo-MDSCs) immunosuppressive subsets are significantly associated with disease status. Using linear mixed model, we found G-MDSCs (P = 0.004) and Mo-MDSCs (P = 3.7×10−5 ) are both higher in cancer patients compared to normal healthy subjects. Following the second cycle of treatment with combination chemotherapies, serum L-Kyn was reduced significantly (n = 5, p = 0.026, paired t test). Mean effect of chemo is −55.0 nmol kynurenine/hour, suggesting response to combination chemotherapy strategies. Percentages of subsets of MDSCs are also significantly reduced after chemotherapy treatments (n = 5, p = 0.030 for G-MDSCs, p = 0.026 for Mo-MDSCs, paired t test). Mean effects of chemotherapy treatments are −2.9% for G-MDSCs and −12.4% for Mo-MDSCs. Ongoing studies will determine correlations of change in IDO activity in MDSCs with reduction in tumor burden and overall survival of lung cancer patients. Conclusions: These preliminary studies suggest that the IDO enzymatic pathway and tryptophan metabolism may serve as important therapeutic targets and diagnostic markers in predicting clinical outcomes of combination chemotherapies in the treatment of NSCLC in humans. Supported by ACS-IRG-60–001−53. 124 POSTER (Board P118) A WT1-derived peptide protects against metastatic melanoma in a syngeneic model by in vivo immunomodulatory effects on dendritic cells M.H. Massaoka1 , C.R. Figueiredo1 , N. Girola1 , R.A. Azevedo2 , L.R. Travassos1 . 1 Experimental Oncology Unit, Department of Microbiology Immunology and Parasitology, São Paulo SP, Brazil; 2 Butantan Institute, Department of Biochemistry and Biophysics, São Paulo SP, Brazil Background: The cell-penetrating peptide, WT1-pTj, derived from a zinc finger domain of the Wilms Tumor Protein 1 (WT1), displays antimelanoma activity in vitro by suppression of cell growth and induction of cellular senescence. We now report that WT1-pTj-mediated antitumor effects in vivo rather depend on the immune system primarily involving dendritic cells (DCs). Materials and Methods: In vivo protection experiments with WT1-pTj were made in mice challenged endovenously with B16F10-Nex2 melanoma cells. Syngeneic C57Bl/6 or immune deficient animals were used. The peptide significantly reduced lung metastatic nodules in syngeneic animals when injected i.p. In the present work: (a) The same protocol was used in immune deficient NOD/Scid/IL-2rgnull mice; (b) To investigate the role of DCs, the syngeneic melanoma model was used. Mice were injected e.v. with B16F10-Nex2 melanoma cells to induce lung metastasis, and seven days after tumor inoculation animals received a single dose of syngeneic bone-marrow DCs primed with melanoma lysate and treated ex vivo with WT1-pTj for two days. Lung nodules were counted and compared with the untreated control; c) CD11c+ DCs from the cervical lymph nodes of WT1-pTj-treated metastatic melanoma-bearing mice were examined for the expression of co-stimulatory molecules by FACS and production of cytokines by ELISA. Additionally, the levels of CD8+ and CD4+ T lymphocytes and NK1.1+ cells in the lung and spleen of treated and untreated mice with metastatic disease were determined. 44 Wednesday 19 November 2014 Results: Systemic WT1-pTj treatment protected against metastatic melanoma in immune competent but not in immune deficient animals. Remarkably, peptide-activated syngeneic DCs ex vivo protected against metastatic melanoma, even in animals with established pulmonary nodules. By culturing CD11c+ cells isolated from cervical lymph nodes of WT1pTj-treated animals developing metastatic melanoma, we found that the peptide induced phenotypic maturation of DCs (e.g. upregulation of CD40, MHC-II and CD86) and enhanced production of type-1 cytokines, such as IL-6 and IL-12. Simultaneously, a marked decrease in TGF-b1 production was observed in DCs retrieved from WT1-pTj-treated mice. Moreover, the WT1-pTj-mediated antitumor activity was associated with significantly augmented frequency of tumor-infiltrating lymphocytes (CD8+ and CD4+) and NK1.1+ cells, and down-regulation of splenic CD4+ FoxP3+ regulatory T cells. Conclusions: The present results show the immunomodulatory role of WT1-pTj and indicate that the WT1-derived peptide may act as a potent adjuvant in cancer immunotherapy. Supported by FAPESP no. 2010/51423-0 and the Brazilian National Research Council (CNPq). 125 POSTER (Board P119) Critical issues in the clinical development of oncolytic viruses − A regulatory perspective M. Schuessler-Lenz1 . 1 Paul-Ehrlich-Institute, Langen, Germany Oncolytic viruses are claimed to replicate selectively and preferentially in tumor tissue, without causing excessive damage to normal tissues. In Europe there has been a steady increase in the number of clinical trials performed with oncolytic viruses, and some development candidates have reached the pivotal stage of clinical development. As oncolytic viruses are replication competent there is a need to balance the therapeutic promises linked to this new treatment concept against the risks that may be associated with replication competent viruses. Most of the oncolytic viruses are classified as gene therapy medicinal products, based on genetic modifications to change the viral tissue tropism and to increase tumor specificity. From a European regulatory perspective, gene therapy medicinal products are in the scope of the Advanced Therapy Medicinal Product (ATMP) regulation. This implies that for the development of oncolytic viruses towards marketing authorisation, both national and European regulatory and legal requirements apply, based on the different key players for clinical trial authorisation and central marketing authorisation. At the European Medicines Agency the Committee for Advanced Therapies formulates the draft opinion on quality, safety and efficacy of oncolytic viruses for final approval by the Committee for Human Medicinal Products. In Germany clinical trial authorisations with oncolytic viruses are approved by the Paul-Ehrlich Institute. A review of clinical trials shows that oncolytic viruses are at different stages of clinical development. They constitute one of the main innovative treatment concepts in cancer therapy, as can be seen from the number of clinical trials submitted to the Paul-Ehrlich Institute. We review the main issues in early clinical development, based on our experience with clinical trial assessment and national advice. We also review the interaction between the national competent authority and the Committee for Advanced Therapies. 126 POSTER (Board P120) IMCgp100: A novel bi-specific biologic for the treatment of malignant melanoma W. Shingler1 , J. Harper2 , G. Bossi2 , D. Barker2 , J. Dukes2 , N. Liddy3 , S. Paston2 , T. Mahon3 , P. Molloy3 , M. Sami1 , E. Baston3 , B. Cameron3 , A. Johnson1 , A. Vuidepot3 , N. Hassan1 , Y. McGrath1 , B. Jakobsen1 . 1 Immunocore Ltd, Development, Abingdon Oxford, United Kingdom; 2 Immunocore Ltd, Cell Biology, Abingdon Oxford, United Kingdom; 3 Immunocore Ltd, Protein Science, Abingdon Oxford, United Kingdom Background: Despite significant advances in the treatment of metastatic melanoma, long-term remission for the majority of patients remains elusive. Kinase inhibitors provide potent but short-term responses for a significant proportion of patients and immunotherapy elicits long-term responses with the prospect of cure, but only in a minority. IMCgp100 comprises an affinity-enhanced T cell receptor (TCR) specific for the HLAA2 restricted melanoma gp100 peptide (YLEPGPVTA) fused to an anti-CD3 antibody fragment. Binding of IMCgp100 to melanoma cells redirects T cell cytotoxicity allowing them to kill even HLA down-regulated melanoma cells otherwise invisible to cancer specific T cells. Materials and Methods: Preclinical efficacy and safety testing of IMCgp100 has been performed using a range of in vitro assays of immunological activity against human tissue, including ELISpot, cytotoxicity Poster Session – Immunotherapy assay and Incucyte. A Phase I clinical study is currently underway to determine the safety and tolerability of IMCgp100 in patients with metastatic melanoma, with extensive laboratory testing accompanying this first in human study to try to identify pharmacodynamic markers. Results: Here, we present data which provides the foundation for the clinical observations. In vitro, IMCgp100 is demonstrated to potently redirect T cells from late stage cancer patients to target melanoma tumours exhibiting HLA down-regulation, even in the presence of high numbers of regulatory T cells. Target cell killing is observed within hours and is specific for gp100. In addition killing is associated with the release of various proinflammatory cytokines and chemokines as well as cross-presentation of gp100 and other melanoma-associated antigens by dendritic cells. Thus, IMCgp100 demonstrates the potential to elicit potent short-term responses and trigger longer-term anti melanoma activity in vivo. Maximum tolerated dose has been established for weekly dosing with the drug being well tolerated and showing evidence of tumour shrinkage. Analyses of trial patient samples provide evidence for drug mediated T cell mobilisation and transient cytokine and chemokine release, including those reported to play a key role in anti-melanoma responses. Conclusion: These data support the potential of IMCgp100 as a new immunotherapy against advanced melanoma. In-vitro data demonstrate the drug is specific for melanoma cells, and preliminary early phase clinical data suggest acceptable toxicity and promising durable efficacy. 127 POSTER (Board P121) Correlation of clinical activity of pembrolizumab (MK-3475) with immunohistochemical staining for programmed death-1 ligand (PD-L1) in 50% of tumor cells in a prospective non-small cell lung cancer (NSCLC) validation population E.G. Garon1 , N.A. Rizvi2 , N.B. Leighl3 , R. Hui4 , J.P. Eder5 , A. Patnaik6 , C. Aggarwal7 , L. Horn8 , A.S. Balmanoukian9 , M.A. Gubens10 , E. Felip-Font11 , E. Carceny Costa12 , J.C. Soria13 , M.J. Ahn14 , H.T. Arkenau15 , J.S. Lee16 , G. Robinet17 , G.M. Lubiniecki18 , J. Zhang19 , K. Emancipator21 , R. Rutledge22 , M. Dolled-Filhart23 , L. Gandhi20 . 1 David Geffen School of Medicine at UCLA, Dicision of Hematology/Oncology, Los Angeles, USA; 2 Memorial Sloan Kettering Cancer Cente, Department of medicine, New York, USA; 3 Princess Margaret Cancer Centre, Department of Medicine, Toronto, Canada; 4 Westmead Hospital University of Sydney, Department of Medical oncology, Sydney, Australia; 5 Yale University, Department of medical oncology, New Haven, USA; 6 South Texas Accelerated Research Therapeutics, Clinical research, San Antonio, USA; 7 Abramson Cancer Center of the University of Pennsylvania, Department of medicine, Division of Hematology/Oncology, Philadelphia, USA; 8 Vanderbilt Ingram Cancer Center, Department of Medicine, Nashville, USA; 9 The Angeles Clinic and Research Institute, Department Lung and Thoracic cancer, Los Angeles, USA; 10 University of California San Francisco, Thoracic Tumours Group, San Francisco, USA; 11 Hospital General Universitari Vall d’Hebron, Department of medical oncology, Barcelona, Spain; 12 Catalan Institut of Oncology − Badalona, Badalona, Spain; 13 Gustave Roussy, Drug Development Department (DITEP), Villejuif, France; 14 Samsung Medical Center, Department of Internal Medicine, Samsung, South Korea; 15 Sarah Cannon Research UK, Oncology, London, United Kingdom; 16 Seoul National University Bundang Hospital, Department of Hematology/Oncology, Seongnam-si, South Korea; 17 Hopital Morvan, Institute de Cancerologie, Brest, France; 18 Merck & Co. Inc., Clinical Research, North Wales, USA; 19 Merck & Co. Inc., BARDS, North Wales, USA; 20 Dana-Farber Cancer Institute, Medical Oncology, Boston, USA; 21 Merck & Co., Inc., Molecular Biomarkers and Diagnostics, Whitehouse Station, NJ, USA; 22 Merck & Co., Inc., Oncology Clinical Researchs, Whitehouse Station, NJ, USA; 23 Merck & Co., Inc., Molecular Biomarkers and Diagnostics, Whitehouse Station, NJ, USA Background: The phase I KEYNOTE-001 study evaluated the safety, tolerability, and clinical activity of pembrolizumab, a selective anti-PD-1 antibody that blocks the interaction between programmed death-1 (PD-1) on T cells and its ligands PD-L1 and PD-L2 on tumor cells. Of those patients (pts) with tumor tissue evaluable for PD-L1 status by immunohistochemistry (IHC) in the initial 38-pt NSCLC cohort, all pts with clinical response by immune-related response criteria (irRC) were in the group with the highest PD-L1 expression. Tissue from these pts and an additional 119 pts were evaluated to generate a formalized training set. Among the 129 pts with tumor evaluable for PD-L1 expression and measurable disease at baseline per RECIST v1.1 as assessed by independent central review, a highly significant correlation between strong PD-L1 expression (i.e., staining in 50% of tumor cells) and the overall response rate (ORR) and progressionfree survival (PFS) was observed. Materials and Methods: 92 treatment-naı̈ve and 216 previously treated pts with measurable NSCLC whose tumors expressed detectable PD-L1 Poster Session – Immunotherapy (1% cutoff) using a prototype IHC assay using the 22C3 antibody were randomized to receive pembrolizumab at 10 mg/kg every 2 or 3 weeks; 2 pts were never treated. A new tumor biopsy 60 days prior to or, with Amendment 8, any time after the most recent therapy before the first pembrolizumab dose was required. Tumor response was assessed every 9 weeks by RECIST v1.1 by independent central review. All pts will have a minimum of 6 mo of follow-up. PD-L1 expression was subsequently evaluated in the study eligibility tumor samples by a clinical trial IHC assay using the 22C3 antibody for assessment of the relationship with outcomes with a goal of validating the utility of IHC staining in 50% of tumor cells as a biomarker to predict the efficacy of pembrolizumab. Results: After selection of the training set population, over 500 additional pts signed consent between 20 May 2013 and 12 May 2014 and provided tissue for PD-L1 assessment. Based on PD-L1 staining using the prototype IHC assay and other study eligibility criteria, 306 pts received pembrolizumab. Conclusions: At the meeting, we will present data evaluating whether the cutoff of PD-L1 staining by IHC in 50% of tumor cells that was selected based on our training set correctly predicts ORR and PFS in the validation set of 306 pts with advanced NSCLC treated with pembrolizumab. 128 POSTER (Board P122) T cell-mediated cancer immunotherapy through OX40 agonism M. Huseni1 , C. Du2 , J. Zhu2 , P. Pacheco-Sanchez3 , M. Moskalenko3 , H. Chiu4 , K. Dalpozzo1 , K. Totpal3 , L. Damico-Beyer5 , J. Kim2 . 1 Genentech, Oncology Biomarkers, South San Francisco CA, USA; 2 Genentech, Cancer Immunology, South San Francisco CA, USA; 3 Genentech, Translational Oncology, South San Francisco CA, USA; 4 Genentech, Biochemical and Cellular Pharmacology, South San Francisco CA, USA; 5 Genentech, Portfolio Management and Operations, South San Francisco CA, USA Background: Productive immune responses to tumors are hypothesized to require T cell costimulation. OX40 is a costimulatory molecule that is expressed on activated effector (Teff) and regulatory T cells (Treg). Agonistic antibodies targeting OX40 are predicted to counteract the immunosuppressive tumor microenvironment and promote T cell dependent anti-tumor immunity via two distinct mechanisms − activation and expansion of antigen experienced T cells and inhibition of T cell suppression. An anti-human OX40 antibody MOXR0916, and a surrogate anti-mouse OX40 antibody were tested for their ability to costimulate effector T cells and inhibit Treg function in vitro and in vivo, respectively. Materials and Methods: MOXR0916 is a humanized agonist OX40 antibody, which binds to human OX40 with subnanomolar affinity. Due to sequence divergence between human and mouse OX40, a murine agonist OX40 antibody was employed to assess anti-tumor efficacy, Teff costimulation and Treg dynamics in murine syngeneic tumor models. The role of Fc effector function was determined utilizing Fc receptor knockout mice and isotype variants of anti-mouse OX40. In vitro analysis of MOXR0916 and isotype variants of MOXR0916 in Teff costimulation and Treg suppression assays were conducted with sorted peripheral blood T cell populations from healthy donors. Results: In syngeneic mouse tumor models, anti-mouse OX40 treatment induced durable tumor regression which were associated with intratumoral Treg depletion and CD8+ T cell infiltration, and enhancement of interferon gamma (IFN-g) production. Tumor regression and pharmacodynamic modulation of Teff and Tregs required antibody crosslinking via Fc receptors. MOXR0916 costimulated CD4+ memory T cell proliferation and IFN-g production following T cell receptor engagement in a dose dependent manner. Additionally, MOXR0916 impaired the suppressive function of Tregs in naı̈ve T cell coculture assays. Memory CD4+ T cell costimulation was dependent on MOXR0916 effector function. In in vitro T cell activation assays, MOXR0916 costimulated Teff production of IFN-g at comparable levels as anti-mouse OX40. Conclusions: Anti-mouse OX40 antibody induced durable anti-tumor immunity in multiple syngeneic tumor models. Potent single agent activity correlated with Teff costimulation and modulation of Treg dynamics. MOXR0916 and anti-mouse OX40 induced comparable levels of IFN-g production, supporting the clinical investigation of MOXR0916 as a T cell directed therapy for advanced malignancies. 129 POSTER (Board P123) Characterization of PD-L1 expression in circulating tumor cells (CTCs) of non-small cell lung cancer (NSCLC) patients R. Krupa1 , D. Lu1 , M. Harvey1 , J. Louw1 , A. Jendrisak1 , D. Marrinucci1 , R. Dittamore1 . 1 Epic Sciences Inc., San Diego CA, USA Background: Novel PD-1 and PD-L1 targeting immunotherapies are demonstrating efficacy in multiple tumor types. Recent data have suggested Wednesday 19 November 2014 45 that increased progression free survival (PFS) is observed in patients whith higher expression of the PD-L1 protein in tumor tissue. However, many NSCLC patients have insufficient tumor sample or have high co-morbidities preventing access to tissue IHC to determine PD-L1 expression and potential benefit to novel PD-1/PD-L1 immunotherapies. We developed a protein assay for PD-L1 protein and examined CTCs and CTC subpopulation incidence and molecular characterization in blood samples from newly diagnosed NSCLC patients. Material and Methods: 16 samples from newly diagnosed NSCLC patients prior to therapy were recruited and blood specimens were collected and shipped to Epic Sciences. All nucleated cells were plated onto glass slides and subjected to immunofluorescent (IF) staining and CTC identification by fluorescent scanners and algorithmic analysis. CTCs, defined as traditional (CK+, CD45− with intact and morphologically distinct DAPI+ nuclei), apoptotic (CK+, CD45−, non-intact nuclei) and CK− (CK−, CD45−, intact and distinct nuclei). CTC subtypes were characterized with PD-L1 IF to assess expression. Results: Assays for the PD-L1 protein were developed and specificity confirmed utilizing Colo205, SU-DHL-1 and A549 cells spiked into donor blood and run through the Epic Assay. Additionally, expression analysis of Colo205, SU-DHL-1 and A549 cell lines show increased differential PD-L1 expression when cells were exposed to interferon gamma. PD-L1 positive CTCs were detected in 8/16 (50%) of NSCLC patients. PD-L1 positivity was seen in traditional and CK− CTCs, as well as apoptotic and CTC clusters. Conclusion: PD-L1 protein assessment of CTCs and CTC subpopulations from NSCLC patients at diagnosis is feasible on the Epic CTC platform. This test demonstrates sensitivity and specificity and may aid in the identification of patients suitable for clinical trial studies with novel PD-1 or PD-L1 therapies. The identification of PD-L1 positive CTC subpopulations identifies unique tumor cell morphology and suggests evidence of epithelial plasticity in some patients. Further analysis of pharmacodynamics of CTCs and PD-L1 expression on CTCs in the setting of PD-1/PD-L1 therapies is warranted. 130 POSTER (Board P124) Preclinical results of ProCervix, a first in class, first in indication therapeutic vaccine targeting HPV16/18 infected women M. Esquerre1 , M. Bouillette-Marussig1 , A. Goubier1 , M. Momot1 , H. Keller1 , M. Bissery1 . 1 Genticel, Labege, France With the availability of HPV diagnostic tests, it is now possible to identify HPV infected women and to develop treatment in order to clear the infection and prevent the onset of neoplasia and cancer. ProCervix is a bivalent therapeutic vaccine consisting of two adenylate cyclase (CyaA) recombinant proteins originating from Bordetella pertussis into which HPV16 E7 and HPV18 E7 have been inserted. The CyaA targets CD11b expressed by Antigen Presenting Cells (APC). It delivers the vaccine antigens to both MHC-I and MHC-II pathways in the APC for presentation to CD4+ and CD8+ T cells. We report here on the preclinical properties of ProCervix therapeutic vaccine designed to treat women infected with HPV16 and/or 18 before they develop high grade cervical lesions. ProCervix binding to CD11b was performed using a cell line expressing human CD11b in a competition assay using biotinylated-CyaA HPV16 E7. The immunogenicity was evaluated in C57BL/6 mice vaccinated i.d. with ProCervix adjuvanted with Imiquimod 5% cream. E7-specific T cell responses were measured using IFN-g ELISpot and TH 1/TH 2 cytokines, using Cytometric Bead Array and FACS analysis. Cytotoxic T lymphocytes (CTL) were evaluated by in vivo killing assays. Therapeutic efficacy was evaluated in mice bearing 106 HPV16 E7-expressing tumour cells implanted s.c. and vaccinated on day 11 and 39. Tumour growth was measured with a caliper twice a week. Results obtained with an in vitro functional cell-based assay demonstrated that ProCervix binds to human CD11b-expressing cells. In vivo, using C57BL/6 mice, intradermal administration of ProCervix in combination with a TLR7 agonist, resulted in the development of both HPV16 E7-specific and HPV18 E7-specific T cell responses with a clear TH 1 cytokine profile. Using an in vivo killing assay, we demonstrated that ProCervix-induced CD8+ T cells are functional CTLs. Using syngeneic TC-1 tumour cells, our results demonstrated that these CTLs were able to eradicate HPV16-E7expressing cells. Finally, using this tumour-rejection model, we showed that even a low dose of E7 antigens lead to strong therapy when it delivered via ProCervix. These preclinical data prompted a phase I clinical study in HPV16/18 infected women with normal cytology which indicated that ProCervix was well tolerated, and exhibited a higher frequency of peripheral HPV-specific interferon-gamma associated T-cells and a higher viral clearance in the treated group compared to the placebo group. 46 Wednesday 19 November 2014 131 POSTER (Board P125) Zfra activates novel Hyal2+ CD3− CD19− memory spleen cells to block cancer growth, stemness, and metastasis in vivo N. Chang1 . 1 National Cheng Kung University, Tainan City, Taiwan Zfra is a 31-amino-acid zinc finger-like protein, which participates in tumor necrosis factor signaling. Here, we determined that synthetic full-length Zfra1−31 peptide selfpolymerized in degassed buffers without catalytic enzymes. When nude mice and BALB/c mice were pre-injected with micromolar levels of Zfra1−31 or truncated Zfra4−10 via tail veins, these mice became resistant to the growth, metastasis and stemness of prostate, breast, and lung cancer cells, melanoma cells, and many malignant cancer cells. Alteration of the Ser8 phosphorylation site to Gly8 abolished Zfra polymerization and cancer suppression in vivo. Injected Zfra was deposited mainly in the spleen. Transfer of Zfra-stimulated spleen cells to naı̈ve mice conferred resistance to cancer growth. Mechanistically, Zfra bound membrane hyaluronidase Hyal-2 and suppressed the TGF-b/Hyal-2/WWOX/Smad4 signaling, via down-regulation of Hyal-2 and activated WWOX (with Y33 phosphorylation), in the spleen for generating novel non-T/non-B memory cells, designated Hyal2+ CD3− CD19− cells. Transfer of these cells to naı̈ve mice also induced anticancer response. Similarly, agonist anti-Hyal-2 antibody mimicked the effect of Zfra in causing cancer suppression. In conclusion, Zfra self-polymerizes in the spleen to activate Hyal2+ CD3− CD19− cells for blocking cancer growth, stemness and metastasis in vivo. Supported in part by NSC and NHRI, Taiwan, and DoD, USA 132 POSTER (Board P126) A novel anti-PDL1 antibody-based bifunctional protein with enhanced immunological activity Y. Wu1 , S. Martomo1 , Z. Zhong1 , D. Lu1 , Z. Polonskaya1 , X. Luna1 , Z. Zhang1 , H. Zhang1 , L. Witte1 , S. Waksal1 , Z. Zhu1 . 1 Kadmon Corporation LLC, NYC, USA Preclinical and clinical evidence suggest that immunotherapies based on immunomodulating agents that inhibit immunosuppressive pathways (e.g., PD-1/PD-L1), or that stimulate the immunity of T-cells and NK cells (e.g., by cytokines such as IL-12, IL-15, IL-21), hold great potential for the effective treatment of cancer. The anti-PD1/PDL1 approach, via attenuation of inhibitory checkpoints, has shown success in certain clinical settings across multiple cancer types. Its full potential may be limited however by impaired overall immunity within the tumor micro-environment. The broad clinical application of immune-stimulating cytokines has been greatly hindered by their limited bioavailability, short half-life and systemic toxicities due to their lack of target specificity. It is therefore desirable to develop biotherapeutic agents that are capable of both inhibiting immunosuppressive pathways and simultaneously stimulating and expanding immune effector cells thereby increasing both innate and adaptive immune responses within the tumor environment for greater antitumor activity. To this end, we engineered a panel of recombinant bifunctional proteins that combine an anti-PD1 antibody with an immune-stimulating cytokine. These bifunctional proteins were genetically constructed and produced by mammalian cell cultures. One of the bifunctional proteins, KD-033, was efficiently expressed in mammalian cells and was fully stable when incubated in serum samples. The bifunctional protein retained binding and functional activity of both its parental components as tested by ELISA and cell-based assays. Poster Session – Immunotherapy Further, KD-033 showed strong activity in relieving PD1/PDL1-meditated suppressive effect on CD4 T cell proliferation and cytokine (IL-2, IFN) production, and simultaneously showed significant enhancement of the killing activity of CD8 T cells and NK cells. 133 POSTER (Board P127) Analysis of immune microenvironment in resectable NSCLC: Prognostic value of regulatory and conventional T cell markers proportion M. Usó1 , R. Sirera2 , S. Calabuig-Fariñas1 , A. Blasco3 , E. Pastor4 , R. Guijarro4 , E. Jantus-Lewintre1 , J. Forteza5 , C. Camps6 . 1 Fundación de Investigación Hospital General de Valencia, Molecular Oncology, Valencia, Spain; 2 Universitat Politècnica de València, Biotechnology, Valencia, Spain; 3 Hospital General de Valencia, Oncology, Valencia, Spain; 4 Hospital General de Valencia, Thoracic Surgery, Valencia, Spain; 5 Instituto Valenciano de Patologı́a, Valencia, Spain; 6 Universitat de València, Medicine, Valencia, Spain Background: Immune cells present in tumor microenvironment have been demonstrated to play an important role in tumor progression, and therefore, in patient’s outcome. Methods: FFPE samples from 117 early-stage NSCLC patients of primary tumor tissue were used. We assessed the mRNA expression levels of 11 genes (CD127, CD25, FOXP3, CTLA-4, IL-10, TGFB-1, LAG-3, GITR and TNFA as well as CD4 and CD8) in microdisected tumor and tumor stroma areas by RTqPCR. The presence of CD4+, CD8+ and FOXP3+ (+ = positive) lymphocytes was also assessed in 84 of these FFPE samples by immunohistochemistry (IHC). All statistical analysis were considered significant at p < 0.05. Results: Survival analyses revealed that patients with lower expression levels of CD8 in tumor areas have worse overall survival (OS) and progression free survival (PFS). Lower expression levels were also associated with worse OS for CD4 and LAG-3 in tumor. We also found that those patients with higher levels of FOXP3 stroma/FOXP3 tumor ratio had worse OS and the same was observed for FOXP3 stroma/CD4 tumor ratio and for FOXP3 stroma/CD8 tumor ratio. Furthermore, the presence of FOXP3+ and CD8+ lymphocytes assessed by IHC was associated with prognosis (Table 1). Gene expression levels were dichotomized according to the median in high and low. Infiltration of FOXP3+ lymphocytes was defined as high (10% of total lymphocytes) and low (<10%). Infiltration of CD8+ lymphocytes was dichotomized in high and low according to the median of the absolute number of CD8+ lymphocytes (X400). Conclusion: The presence of immune biomarkers in tumor microenvironment have a prognostic impact in resectable NSCLC patients. Supported by grants PS09–01149 and RD12/0036/0025 from ISCIII. Table 1 (abstract 133). Survival analysis (log-rank test). Analyzed by RTqPCR CD8 in tumor, low vs high CD4 in tumor, low vs high LAG3 in tumor, low vs high FOXP3 stroma/FOXP3 tumor ratio, low vs high FOXP3 stroma/CD4 tumor ratio, low vs high FOXP3 stroma/CD8 tumor ratio, low vs high Analyzed by IHC CD8+ lymphocytes in tumor, low vs high High FOXP3+ lymphocytes stroma/Low FOXP3+ lymphocytes tumor, vs others High FOXP3+ lymphocytes stroma/Low CD8+ lymphocytes tumor, vs others OS Median (months) p PFS Median (months) p 37.2 vs 81.23 42.9 vs 81.23 36.2 vs 69 NR vs 42.9 81.23 vs 46.66 74.33 vs 46.43 <0.001* 0.026* 0.017* 0.002* 0.025* 0.017* 19.43 vs 81.23 23 vs 37.8 22.1 vs 30.1 NR vs 19.43 37.8 vs 22.13 37.8 vs 22.13 0.002* 0.058 0.085 <0.001* 0.027* 0.022* 40.4 vs 73.98 36.2 vs 69 17.43 vs 68.8 0.021* 0.020* 0.011* 23 vs 58.83 17.49 vs 35 15.3 vs 35.9 0.026* 0.16 0.035* Poster Session – Immunotherapy 134 POSTER (Board P128) Epigenetic immunomodulation by SGI-110 combined with immune checkpoint blockade for new therapeutic strategies A. Covre1 , C. Fazio1 , H.J.M.G. Nicolay2 , P.G. Natali3 , P. Taverna4 , M. Azab4 , S. Coral2 , M. Maio1 . 1 University Hospital of Siena, Medical Oncology and Immunotherapy, Siena, Italy; 2 Epigen Therapeutics s.r.l., Pordenone, Italy; 3 University of Chieti, Lab CINBO, Chieti, Italy; 4 ASTEX Pharmaceuticals Inc., Dublin, USA Background: SGI-110 is a dinucleotide of decitabine (DAC) and deoxyguanosine formulated as a low volume SQ injection that extends DAC exposure compared to DAC IV. Our in vitro and in vivo evidences identified a strong immunomodulatory activity of SGI-110 on human cancer cells of different histotype and on human melanoma xenografts, and showed a remarkable anti-tumor effect once combined with anti-CTLA-4 mAb in a syngeneic mouse model. In this study we evaluated the contribution of anti-tumor immune responses in the reduction of tumor growth achieved by this therapeutic combination. Materials and Methods: The mammary carcinoma cells TS/A (2×105 ) were implanted SQ in Balb/c mice. Animals bearing palpable tumors were treated with 3 mg/kg of SGI-110 (days 1−5), alone or combined with 100 mg of anti-murine CTLA-4 mAb (days 8, 11 and 14). The immunomodulatory effects of treatment were studied on tumor and normal tissues by RTPCR and by quantitative RT-PCR analysis of murine CTA expression. Immunohistochemical evaluation of tumor infiltrating immune cells was also performed. P1A-promoter methylation was tested by quantitative Methylation-Specific PCR (qMSP) on genomic DNA from tumor tissues. Results: The expression of P1A and Mage-a family members was induced in tumor tissues from animals treated with SGI-110, either alone or in combination with anti-CTLA-4 mAb, but not from mice treated with antiCTLA-4 mAb alone. Levels of P1A-specific mRNA were similar in tumors from mice treated with SGI-110 alone (3.18×10−04 P1A/b-actin molecules) or combined with anti-CTLA-4 mAb (1.18×10−04 P1A/b-actin molecules). The DNA hypomethylating effect of SGI-110 was sustained by the reduction of P1A promoter methylation in cancer tissues from SGI-110- (16%) and combination- (7%) treated mice vs control. Epigenetic remodelling was restricted to tumor tissue leaving almost unaltered normal ones. The contribution of immune cells in the therapeutic effectiveness of treatment was supported by the increased frequency of tumor infiltrating CD3+ cells in the combination arm (11±1.9) vs control (3.7±1.4) or single agent, antiCTLA-4 mAb (3±1.1) and SGI-110 (4.1±1.7), treated mice. Conclusion: These data highlight the involvement of the immune system in the anti-tumor effect of SGI-110 combined with CTLA-4 blockade. Based on these experimental evidences, an exploratory phase I trial to evaluate safety and immunobiologic activities of the combination is being activated in advanced melanoma patients. 135 POSTER (Board P129) AD-O64.3: IFN-g–TRAIL fusion protein. Use of two independent signaling pathways for a strong synergistic antitumor effect B. Zerek1 , J.S. Pieczykolan1 , S.D. Pawlak1 , P.K. Rozga1 , A. Pieczykolan1 , M. Szymanik1 , A. Jaworski1 , M. Galazka1 , K. Bukato1 , K. Poleszak1 , M. Teska-Kaminska1 , W. Strozek1 . 1 Adamed Sp. z.o.o., Drug Discovery, Warsaw, Poland Background: Interferon gamma (IFN-g) is a dimeric soluble cytokine, an representative of Type II interferons group. Secreted by NK, NKT, Th1, Tc and dendritic cells IFN-g ligand binds to two types of receptors and acts by activation the JAK-STAT pathway. Generally IFN-g antitumor action is mediated through the immunomodulatory function which results from the expression and action of many different classes of IFN-stimulated genes (ISGs) responsible for antigen processing, leukocyte trafficking and tumor cytotoxicity. IFN-g stimulates antibody-dependent toxicity and potentiates the process of connecting the cells with tumor cells. Additionally, it is able to induce an anti-proliferative effects and activates caspases, thereby inducing apoptosis in many cancer cell lines. IFN-g may cause Bak upregulation, cytochrome C secrection and Bax translocation. In many tumor lines showing resistance to TRAILstimulated apoptosis, interferon gamma acted synergistically, contributing to their sensitivity to TRAIL. Additionally, one of IFN-g effects is an intense stimulation of human monocytes to produce TRAIL protein. We developed the novel fusion protein AD-O64.3 consists of artificial dimer of IFN-g, recombinant variant of human TRAIL fragment and sequences recognized by tumor-specific proteases (MMP’s, uPa) in between. Materials and Methods: AD-O64.3 protein was expressed in E. coli and purified by IEC. Obtained protein was characterized biochemically and biophysically using CD spectroscopy, SEC-HPLC, protease cleavage and MTT cell cytotoxicity assays. Interaction with the respective receptors was Wednesday 19 November 2014 47 confirmed with SPR method. The proapoptotic effect was tested using active caspase 3 staining. For in vivo potential we examined the efficacy on mice xenograft models of human renal cell carcinoma (ACHN), human colon adenocarcinoma (SW620) and human hapatoma (PLC/PRF/5) cell lines. Results: Obtained protein has well-defined secondary and quarternary structure and partially verified mechanism of action. The molecule showed in vitro specific cytotoxic effect on various cancer cell lines (IC50 below 0.1 ng/ml). New protein showed very low activity on normal cells. In vivo scINFTR3.0 showed promising effect displaying significant tumor volume inhibition. Conclusions: We developed very promising molecule with high antitumor activity showing synergistic effect with TRAIL. 136 POSTER (Board P130) Tumor-infiltrating lymphocytes (TILs) following intratumoral administration of ONCOS-102 are associated with prolonged overall survival in last line solid tumor patients S. Pesonen1 , T. Joensuu2 , E. Jager3 , J. Karbach3 , C. Wahle4 , K. Kairemo2 , K. Partanen2 , R. Turkki5 , A. Hemminki6 , C. Backman1 , M. von Euler1 , T. Hakonen1 , T. Ranki1 , L. Vassilev1 , A. Vuolanto1 , M. Jaderberg1 . 1 Oncos Therapeutics Ltd., Helsinki, Finland; 2 Docrates Cancer Center, Helsinki, Finland; 3 Krankenhaus Nordwest, Hämatologie-Onkologie, Frankfurt, Germany; 4 Krankenhaus Nordwest, Hämatologie-Onkologie, Helsinki, Finland; 5 Institute for Molecular Medicine Finland, Helsinki, Finland; 6 University of Helsinki, Cancer Gene Therapy Group Haartman Institute, Helsinki, Finland Intratumoral administration of adenovirus activates Toll-like receptor signalling leading to production of pro-inflammatory cytokines and activation of the innate immune system. Adenovirus causes immunogenic cancer cell death and the subsequent release of tumor antigens in the presence of danger signal results in the priming of a potent adaptive anti-tumor immune response. This effect may be further enhanced by immune-stimulating transgenes expressed by the virus. We present immunomonitoring results from a phase I study with ONCOS-102, a chimeric oncolytic adenovirus coding for GMCSF, in 12 patients with refractory injectable solid tumors. A total of 9 intratumoral injections were given at three different dose levels. Peripheral blood mononuclear cells (PBMCs) were collected at baseline and during the study to assess the antigen specificity of CD8+ T cells by IFN-gamma ELISPOT (analysis ongoing). The presence of tumor-infiltrating lymphocytes (TILs) were analyzed at baseline and 1 and 2 months after treatment initiation by immunohistochemistry (IHC). A computer assisted quantification of IHC samples was performed by calculating the fraction of a positively stained cellular region in the whole biopsy. In an exploratory analysis, a correlation between the post-treatment increase in different subpopulations of TILs and overall survival (OS) was assessed by Spearman’s rank correlation analysis. Intratumoral ONCOS-102 triggered an innate immune response in every patient as measured by a transient increase in systemic pro-inflammatory cytokines and induction of fever within 6 to 10 hours post administration. Infiltration of innate immune cells into tumors post-treatment was detected in 11 out of 12 patients. Concomitant infiltration of T cells was detected in 11 out of 12 patients with the most prominent increase seen in CD8+ T cells. Two patients showing the most robust increase in tumor-infiltrating CD8+ T cells post-treatment showed a prominent induction of tumor specific CD8+ T cells in peripheral blood. Biopsies from a non-injected distant tumor were obtained from one patient and a 2.5-fold increase in CD8+ T cells following ONCOS-102 treatment was detected. The correlation between OS and increase in TILs was analyzed. Among all sub-populations, CD8+ T cells (correlation coefficient (r) 0.74, p = 0.008) and CD68+ cells (r = 0.84, p = 0.001) showed the most significant correlation with OS. A correlation between post-treatment changes in CD8+ and CD68+ cells in tumors was also detected (r = 0.59, p = 0.046). Concomitant trafficking of innate and adaptive immune cells to the tumors and the induction of tumor specific CD8+ T cells suggest that ONCOS102 is able to induce de novo anti-tumor immune responses in advanced cancer patients. Correlation between TILs following treatment and OS, as well as CD8+ T cell infiltration into a non-injected distant lesion, suggest an involvement of a systemic immune activation. 48 Wednesday 19 November 2014 137 POSTER (Board P131) Immune checkpoint blockade enhances measles virotherapy C.E. Engeland1 , R. Veinalde1 , C. Grossardt1 , S. Bossow1 , I. Shevchenko2 , V. Umansky2 , D.M. Nettelbeck3 , D. Jäger4 , C. von Kalle1 , G. Ungerechts5 . 1 National Center for Tumor Diseases (NCT), Translational Oncology, Heidelberg, Germany; 2 German Cancer Research Center (DKFZ), Clincal Cooperation Unit Dermato-Oncology, Heidelberg, Germany; 3 German Cancer Research Center (DKFZ), Heidelberg, Germany; 4 National Center for Tumor Diseases (NCT), Medical Oncology, Heidelberg, Germany; 5 National Center for Tumor Diseases (NCT), Translational Oncology and Medical Oncology, Heidelberg, Germany Poster Session – Immunotherapy 139 POSTER (Board P133) GBR1302: a BEAT® bispecific antibody for the treatment of HER2 positive cancers A. Croset1 , J. Macoin1 , R. Ollier1 , M. Pluess1 , C. Delon1 , D. Skegro1 , S. Blein1 , S. Hou1 , J. Back1 . 1 Glenmark Pharmaceuticals S.A., R&D, La Chaux de Fonds, Switzerland Background: We hypothesized that combining oncolytic Measles virus (MV) with immune checkpoint blockade using antibodies against CTLA-4 and PD-L1 can provide synergistic anti-tumor effects. Material and Methods: Targeted immunomodulatory MV vectors encoding anti-CTLA-4 and anti-PD-L1 antibodies were cloned and characterized in vitro. Oncolytic efficacy was addressed in human melanoma xenografts. Immunotherapeutic efficacy was evaluated in a fully immunocompetent murine model of subcutaneous syngeneic malignant melanoma (B16CD20) and compared to parental MV with or without systemic administration of anti-CTLA-4 and anti-PD-L1. Results: Viral replication and oncolysis of MV anti-CTLA-4 and MV antiPD-L1 were not impaired. In the B16-CD20 model, treatment with MV antiCTLA-4 and MV anti-PD-L1 led to an increase in tumor-infiltrating cytotoxic T cells as well as a decrease in regulatory T cells. Therapeutic benefits in terms of delayed tumor growth and prolonged median overall survival were observed for animals treated with MV anti-CTLA-4 and MV anti-PD-L1, respectively. Further investigations in preparation of a Phase I trial are currently ongoing. Conclusions: Combining oncolytic MV with immune checkpoint modulation is a promising approach with direct implications for future clinical application. Background: Human epidermal growth factor receptor 2 (HER2) is highly expressed in a significant proportion of breast, ovarian and gastric cancers. Since the discovery of its role in tumorigenesis and metastasis, HER2 has received great attention in cancer research over the past two decades. HER targeting therapies (such as Herceptin) have demonstrated efficacy but are limited by several resistance mechanisms. Targeting, recruiting, redirecting or bridging the cytotoxic T cells to HER2 tumor cells has the potency to trigger a more efficient elimination of tumor cells. Using the Glenmark BEAT® platform, we have produced a bispecific antibody, GBR1302, targeting human CD3e and HER2 which is designed to recruit cytotoxic T lymphocytes against HER2 positive cancer cells. Material and Methods: Re-directed lysis (RDL) in vitro killing assays using non-activated human peripheral blood mononuclear cells (PBMC) as effector cells and multiple carcinoma cell lines over-expressing HER2 at different levels were performed to determine the potency of GBR1302. In vivo, the potency of GBR1302 was evaluated using tumor models, in which a mixture of human HER2 expressing tumor cells and human PBMCs were xenografted subcutaneously in immuno-deficient mice (NOD-SCID). Results: GBR1302 was able to bridge cytotoxic T lymphocytes to HER2 tumor cells and trigger killing of the tumor cells at a very low concentration. A clear correlation between GBR1302 killing and HER2 expression levels on target cells was demonstrated. In in vivo xenograft experiments, GBR1302 induced a strong antitumor effect which was also dependent on HER2 expression levels. Conclusion: These data highlight a very good potency of GBR1302 for HER2 overexpressing cancers and warrant further clinical studies with this antibody. 138 POSTER (Board P132) Preclinical activity and safety of MGD006, a CD123xCD3 Bispecific DART® molecule for the treatment of hematological malignancies 140 POSTER (Board P134) Relationship between programmed death ligand 1 (PD-L1) expression and clinical outcome in patients (pts) with melanoma (MEL) treated with pembrolizumab (pembro; MK-3475) P. Moore1 , G.R. Chichili1 , L. Huang1 , H. Li1 , S. Burke1 , F. Chen2 , L. He1 , Q. Tang1 , L. Jin1 , S. Gorlatov1 , V. Ciccarone1 , S. Koenig1 , M. Shannon1 , R. Alderson1 , S. Johnson1 , E. Bonvini1 . 1 MacroGenics, Rockville MD, USA; 2 MacroGenics, South San Francisco CA, USA T-cell directed killing of tumor cells using bispecific molecules may hold promise for cancer treatment. MGD006 (also encoded as S80880 and known as CD3xCD123-DART) is a bispecific diabody-based molecule consisting of two polypeptides, each composed of the VH of one antibody in tandem with the VL of the second antibody and covalently linked at the COOH termini via a disulfide bridge. MGD006 simultaneously binds T lymphocytes and cells expressing CD123(IL3RA), an antigen up-regulated in several hematological malignancies and differentially expressed in AML blasts compared to normal hematopoietic stem and progenitor cells. MGD006 mediates dose-dependent T-cell redirected killing of CD123-positive cell lines as well as primary AML blasts. Furthermore, MGD006 demonstrates potent activity in tumor-bearing mice engrafted with human peripheral blood mononuclear cells or when tumors were coinoculated with human T lymphocytes. MGD006 binds to both human and cynomolgus monkey antigens and can redirect T cells from either species to kill CD123-expressing cells. Preclinical safety and pharmacology was therefore assessed in monkeys that were infused with escalating doses of MGD006 on continuous or intermittent schedules over a period of 4 weeks. Monkeys infused with MGD006 showed depletion of circulating CD123positive cells, an activity biomarker, as early as 72 h after treatment initiation and persisting throughout the 4-week treatment period. Furthermore, T cells from treated monkeys exhibited efficient ex vivo redirected target cell lysis, indicating no functional exhaustion. Transient release of cytokines, particularly IL-6, was observed following the first MGD006 infusion, but not after subsequent administrations even when the dose was escalated. A reversible, decrease in red cell mass with concomitant reduction in CD123-positive progenitors in the bone marrow was also observed. No significant changes in circulating platelets or neutrophil levels were observed. The preclinical safety and efficacy profile of MGD006 supports advancement to clinical evaluation. A phase 1 safety study of MGD006 in relapse/refractory AML is currently recruiting patients (http://clinicaltrials.gov/ ct2/show/NCT02152956?term=mgd006&rank=1). Note: Studies involving animal subjects were performed following institutional IACUC approval. A. Daud1 , O. Hamid2 , C. Robert3 , F.S. Hodi4 , J.D. Wolchok5 , W.J. Hwu6 , J.S. Weber7 , R. Kefford8 , P. Hersey9 , A.M. Joshua10 , R. Joseph11 , T.C. Gangadhar12 , R. Dronca13 , A. Patnaik14 , H. Zarour15 , K. Gerigich16 , J. Lunceford16 , K. Emancipator16 , M. Dolled-Filhart16 , X. Li16 , P. Kang16 , S. Ebbinghaus16 , A. Ribas17 . 1 University of California San Francisco, Medicine Division of Hematology and Medical Oncology, San Francisco CA, USA; 2 The Angeles Clinic and Research Institute, Melanoma Center, Los Angeles CA, USA; 3 Gustave Roussy and INSERM U 981, Medical Oncology, Villejuif Paris-Sud, France; 4 Dana-Farber Cancer Institute, Medicine, Boston MA, USA; 5 Memorial Sloan-Kettering Cancer Center, Medicine, New York NY, USA; 6 The University of Texas MD Anderson Cancer Center, Melanoma Medical Oncology, Houston TX, USA; 7 H. Lee Moffitt Cancer Center, Cutaneous Oncology, Tampa FL, USA; 8 Crown Princess Mary Cancer Centre Westmead Hospital and Melanoma Institute Australia University of Sydney, Medicine, Sydney, Australia; 9 University of Sydney, Medicine, Sydney, Australia; 10 Princess Margaret Cancer Centre, Medical Oncology, Toronto, Canada; 11 Mayo Clinic, Medical Oncology, Jacksonville FL, USA; 12 Abramson Cancer Center of the University of Pennsylvania, Medicine, Philadelphia PA, USA; 13 Mayo Clinic, Oncology, Rochester MN, USA; 14 South Texas Accelerated Research Therapeutics, Phase I Research, San Antonio TX, USA; 15 University of Pittsburgh, Medicine, Pittsburgh PA, USA; 16 Merck & Co. Inc., Molecular Biomarkers and Diagnostics, Whitehouse Station NJ, USA; 17 University of California Los Angeles, Hematology/Oncology, Los Angeles CA, USA Background: In an initial analysis of the relationship between PD-L1 expression and efficacy of the anti-PD-1 monoclonal antibody pembro (training set; n = 125), the preliminary cutpoint for PD-L1 positivity was an Allred proportion score (APS) 2 (ie, staining in 1% of tumor cells). Using this cutpoint, the PD-L1+ pts (71%) had a significantly higher ORR (P = 0.0007) and longer PFS (P = 0.0051) than PD-L1− pts. We report the results of an independent validation set to confirm the cutpoint and provide pooled results of the training and validation sets. Methods: The validation set included 150 PD-L1-evaluable pts with ipilimumab naı̈ve and treated MEL treated with pembro 10 mg/kg Q3W or 2 mg/kg Q3W in KEYNOTE-001. Response was assessed every 12 wk by RECIST 1.1 by independent central review. PD-L1 expression was assessed in pretreatment tumor biopsies by IHC using the 22C3 Poster Session – Preclinical Models Wednesday 19 November 2014 49 Table (abstract 140): Relationship between tumor PD-L1 expression and clinical activity Measurable disease and interpretable PD-L1 IHC N Validation Set PD-L1+ (APS 2) PD-L1− (APS <2) HR (95% CI), PD-L1+ vs PD-L1− 2-sided P c Pooled Set PD-L1+ (APS 2) PD-L1− (APS <2) HR (95% CI), PD-L1+ vs PD-L1− 2-sided P a b c ORRa , n (%) Interpretable PD-L1 IHC N PFSa 24-wk, % Median (range), wk OSb 12-mo, % Median (range), mo 111 24 − − 40 (36) 1 (4) − 0.002 123 27 − − 45 19 − − 24 12 0.43 (0.27–0.69) 0.0002 67 43 − − NR 8 0.43 (0.24–0.78) 0.0042 194 54 − − 81 (42) 5 (9) − <0.0001 212 63 − − 51 29 − − 24 12 0.50 (0.36–0.69) <0.0001 72 53 − − NR 13 0.49 (0.33–0.74) 0.0005 Analysis cutoff: Oct 18, 2013. Analysis cutoff: May 6, 2014. PD-L1 association test. antibody. APS included staining in tumor cells. Response rate, PFS, and OS were compared between PD-L1+ and PD-L1− pts using Miettinen and Nurminen’s method (ORR) and Cox regression (PFS, OS). Results: 82% of validation set pts were PD-L1+ (APS2). There was a significantly higher response rate and significantly longer PFS and OS for PD-L1+ pts in the validation set (Table). The positive (PPV) and negative (NPV) predictive values for ORR in the validation set were 36% and 96%. 77% of pooled set pts were PD-L1+ (Table). PPV and NPV for the pooled set were 42% and 91%. Conclusions: Tumor PD-L1 expression was associated with higher ORR and prolonged PFS and OS in advanced MEL pts treated with pembro. Although NPV is >90%, the high prevalence of PD-L1 positivity, durable responses in PD-L1− pts, and unknown prognostic value and dynamic nature of tumor PD-L1 expression in MEL suggest PD-L1 expression may not be useful for selecting MEL pts for pembro treatment. 141 POSTER (Board P135) Phase I study of ipilimumab with stereotactic radiosurgery for melanoma patients with brain metastases W. Shi1 , E. Wuthrick2 , K. Feeney3 , M. Werner-Wasik4 , D.W. Andrews5 , J.J. Evans5 , K. Judy5 , C. Farrell5 , A.P. Dicker4 . 1 Thomas Jefferson University Hospital, Radiation Oncology, Philadelphia PA, USA; 2 Ohio State University, Radiation Oncology, Philadelphia PA, USA; 3 Thomas Jefferson University, Medical Oncology, Philadelphia PA, USA; 4 Thomas Jefferson University, Radiation Oncology, Philadelphia PA, USA; 5 Thomas Jefferson University, Neurological surgery, Philadelphia PA, USA Background: Brain metastases (BM) occur in more than half of patients with advanced melanoma. Stereotactic radiosurgery (SRS) is an effective treatment for symptom palliation and provides a benefit in local control for patients with limited BM. Ipilimumab (Bristol-Myers Squibb) is a human monoclonal antibody targeted to cytotoxic T-lymphocyte Antigen 4 antibody (CTLA-4) receptor with survival benefit in patients with metastatic melanoma. We hypothesize that combining SRS with Ipilimumab will yield a synergistic effect. However, the toxicities of this combined therapy are unknown. This is a phase I study is to assess the safety profile of combining escalating doses of Ipilimumab with standard dose SRS. Methods: Eligible patients had 4 BM with the largest lesion 4 cm, or resection cavity 4 cm. Ipilimumab starting dose was 3 mg/kg once on weeks 1, 4, 7, and 10. SRS was 15−24 Gy, based on the size, delivered on day 1 of week 1. The primary endpoint is maximum tolerated dose (MTD) assessed 30 days following SRS. Secondary endpoints include the rate of new BM, extra-cranial disease response, overall survival (OS), progression free survival (PFS), and adverse events. Results: Nine patients with a median 1 BM (range, 1−3) were enrolled from November 2011 to March 2014. Eight (89%) patients had extra-cranial metastases. Five received ipilimumab 3 mg/kg and four patients received 10 mg/kg. The median follow up was 4 months (range, 2−19) and no doselimiting toxicities have been observed. All patients have local control of treated index lesins, 80% of assessable patients have developed new BM, and 80% of assessable patients have stable extra-cranial disease. Median OS was not reached. Intracranial PFS at 4 months was 38.9%. PFS of any site was 22% at 4 months. Adverse events were mild, grade 1−2 and grade 3 in six (66%) and one (11%) patient, respectively. Conclusions: Concurrent ipilimumab and SRS is well tolerated in patients with BM from melanoma. This phase I study will continue to assess the MTD of ipilimumab for future phase II trials. 142 POSTER (Board P136) IL-17 as a novel molecular target for prostate cancer prevention A. De Angulo1 , R. Faris2 , C. Jolly1 , L. deGraffenried1 . 1 University of Texas at Austin, Nutritional Sciences, Austin, USA; 2 Texas A&M University Health Science, Microbial Pathogenesis and Immunology, Bryan, USA Background: Prostate cancer represents 14% of all new cancer cases in the US and is the fifth leading cause of cancer death. Incidence is closely associated with aging, but the mechanisms by which aging promotes prostate cancer development are unclear, limiting the development of effective preventive interventions. Aging is accompanied by immune dysfunction and a progressive increase in pro-inflammatory cytokines, including interleukin 17 (IL-17). Aging-associated increases in circulating IL-17 promotes pro-inflammatory signaling in prostate epithelial cells, possibly contributing to tumorigenesis. Methods: Serum and splenic CD4+ T-lymphocytes from young T cell aging-mimic mice as well as young and aged wild-type mice were collected. Surface markers and intracellular levels of IL-17, IFN-g and IL-4 in isolated CD4+ T-cells were measured using flow-cytometry. shRNA was used to knock down the IL-17 receptor in LNCaP prostate cancer cells and RWPE-1 non-transformed prostate epithelial cells, which were then exposed to mouse sera or conditioned media from stimulated T-lymphocytes. NFkB and STAT3 activation, NF-kB and STAT3 target gene expression, and epithelial cell transformation were all measured in prostate epithelial cells. Results: T cells from aging and aging-mimic mice secrete elevated levels of IL-17, possibly due to an imbalance in the TH17/TH1 and TH17/TH2 cell ratios. T-lymphocyte-secreted IL-17 from aging-mimic mice induced NF-kB and STAT3 activity and target gene expression in LNCaP and RWPE-1 cells. Importantly, IL-17 also promoted pro-tumorigenic changes in RWPE-1 cells, leading to a pre-transformed phenotype. Inhibition of IL-17 signaling blocked age-induced changes in both the cancer and non-transformed prostate epithelial cells. Conclusion: Aging of the immune system is associated with increased levels of IL-17, which stimulates the pro-inflammatory NF-kB and STAT3 pathways in prostate epithelial cells and activates programming associated with cellular transformation. Inhibition of IL-17 signaling blocks the protumorigenic activity induced by aging T cells. These findings provide evidence that the dysregulation of IL-17 production in aged T-cells may directly contribute to the increased risk for prostate cancer. Future novel immunotherapies for prostate cancer could target the increase production of IL-17 associated with aging. Preclinical Models 143 POSTER (Board P137) Regional bias of intratumoral genetic heterogeneity of nucleotide repeats in colon cancers with microsatellite instability C. An1 , Y. Choi2 , M. Kim2 , J. Lee1 , N. Yoo2 , S. Lee2 . 1 Uijongbu St. Mary’s Hospital, Surgery, Uijongbu City, Korea; 2 Catholic University of Korea, Pathology, Seoul, Korea Background: Intratumoral heterogeneity (ITH) may produce regional biases in genotype and phenotype evaluation in a single tumor and may impede proper cancer diagnosis. 50 Wednesday 19 November 2014 Material and Methods: To evaluate the extent of ITH in colorectal cancer (CRC) with microsatellite instability (MSI), we obtained 4−7 biopsies from 39 CRCs followed by MSI analysis either using the Bethesda MSI evaluation system or Promega system with 5 mononucleotide markers. Results: We found decreased prevalence of MSI (+) by the Promega system compared to the Bethesda system. The overall discordance between the two systems was 54%. In contrast to the previous studies that had shown discordance only in low MSI (MSI-L), our results showed the discordance not only in MSI-L, but also in high MSI (MSI-H) cases. Among the MSI (+) CRCs, ITH of MSI status was identified in 41.7% of CRC by the Bethesda system and 22.2% by the Promega system. In terms of MSI markers, the ITH originated from dinucleotide markers in most cases (69%), but it originated from mononucleotide markers (31%) as well. Pooling of DNA from a regional biopsy with MSI (+) with additional biopsies from stable MSI (MSS) showed that this approach was beneficial to increase the sensitivity of MSI detection. Conclusions: Our results indicate that ITH of MSI phenotype by the Bethesda system is more overestimated than previously identified. However, because there was considerable ITH of MSI subtypes and markers even by the Promega system, our data suggest that analysis of MSI status in multiple regional biopsies is needed for a better evaluation of MSI status in CRC. 144 POSTER (Board P138) Association between interleukin 17/interleukin 17 receptor gene polymorphism and papillary thyroid cancer Y. Eun1 , H. Chung1 , Y.C. Lee1 . 1 Kyung Hee University, Otolaryngology, Seoul, South Korea Background: Interleukin 17 (IL17) is an important cytokine for inflammatory and autoimmune disease. Recently, although numerous studies have been suggested the role of IL17 in tumor development, the mechanism remains to be unknown. The aim of this study is to determine whether single nucleotide polymorphisms (SNPs) in IL17 and IL17R contribute the development of papillary thyroid cancer (PTC) and assess the relationship between IL17 and IL17R SNPs and the clinicopathologic characteristics of PTC. Material and Methods: Eight SNPs located within the three genes of IL17A, IL17RA and IL17RB were genotyped using direct sequencing in 94 patients with PTC and 213 patients without PTC (controls). Genetic data were analyzed using commercially available software. And, the statistical analyses were performed according to clinicopathologic characteristics of PTC. Results: Genotyping analysis demonstrated that the SNP rs4819554 of IL17RA (codominant model 1, OR = 0.39, P = 0.001; and dominant model, OR = 0.45, 95% CI, P = 0.002) and the SNP rs1025689 of IL17RB (dominant model, OR = 0.59, P = 0.043) were significantly associated with the development of PTC. The SNP rs2275913 of IL17A (codominant model 2, OR = 0.19, P = 0.034; dominant model, OR = 0.34, P = 0.033) was significantly associated with multifocality. Furthermore, IL17RA SNP rs4819554 (dominant model, OR = 0.25, P = 0.010) was significantly associated with bilaterality of cancers. Conclusion: In our case–control study of SNPs in the IL17 and IL17R gene in patients with PTC, we demonstrated that IL17RA polymorphism have the possibilities of developing PTC and can influence the bilaterality of PTC. 145 POSTER (Board P139) ARQ 087, a novel pan FGFR-inhibitor crosses the BBB (blood–brain barrier) and distributes to the brain of rats R. Savage1 , T. Hall1 , B. Schwartz1 . 1 ArQule Inc., Woburn, USA Background: ARQ 087 is a potent multi-kinase inhibitor with pan-FGFR activity against FGFR1, FGFR2, FGFR3 and FGFR4 kinases. Preclinical data from human cell lines and xenograft models support the exploration of its anti-tumor activity across a broad range of human solid and hematological malignancies. Material and Methods: QWBA (Quantitative Whole Body Autoradiography) and metabolite profiling studies were conducted with 14 C-ARQ 087 in rats. Free concentrations of 14 C-ARQ 087 related radioactivity were determined in rat brain via microdialysis. The brain regions sampled by microdialysis were the right striatum and left ventricle. The concentrations sampled in the brain were compared to those obtained in peripheral blood sampled from the right jugular vein. Results: From QWBA studies, 14 C-ARQ 087 derived radioactivity was found to distribute to the cerebellum, cerebrum, choroid plexus, corpus callosum, lateral ventricle, meninges and spinal cord (as well as broadly distributing to the rest of the body) after 5-Day repeat dosing in SpragueDawley rats. At 24 hours post dose on Day 5, 14 C-ARQ087 derived Poster Session – Preclinical Models radioactivity ranged from 0.540 mg equiv./g (cerebellum) to 4.12 mg equiv./g (choroid plexus) versus 0.756 mg equiv./g in plasma. In brain tissues AUC(0−24 h) ranged from 12.4 (cerebellum) to 408 (choroid plexus) mg equiv.·hr/g versus 34.2 mg equiv.·hr/g in plasma. Metabolite profiling data in rat brain showed that ARQ 087 is present primarily as parent drug. Preliminary microdialysis data in rat brain showed that free unbound ARQ 087 (based on AUC) is present in the striatum (17.45%) and in the left ventricle (16.30%) compared to that in systemic circulation. Conclusions: ARQ 087 distributes to the brain of rats as well as broadly to the rest of the body. Metabolite profiling and preliminary microdialysis studies confirmed that in brain primarily parent ARQ 087 is present and available in part as free ARQ 087. 146 POSTER (Board P140) Establishment of patient-derived xenografts (PDX) models for triple negative breast cancer (TNBC) as a pre-clinical platform for drug development J. Thatte1 , M. Meza1 , J. Ricono1 , T. Broudy1 , C. Mirsaidi1 , P. Nair1 . 1 Molecular Response, San Diego California, USA TNBC comprises 15−20% of breast cancers in the United States. TNBC lacks expression of estrogen receptor, progesterone receptor and receptor tyrosine protein kinase ERBB2 or Her-2/neu oncogene amplification. As a result, this type of breast cancer is difficult to treat as most of the chemotherapies target these 3 receptors. TNBC is an aggressive form of cancer associated with high morbidity, mortality and shorter diseasefree survival. Prognosis and management of TNBC is complicated due to its heterogeneous clinical presentation, histology and response to therapy. PDX models in immune compromised mice have become a valuable tool for preclinical drug development in recent years. Here, we report development and characterization of the TNBC PDX model. We used patient derived TNBC tissues to generate 5 new TNBC models in NOD-SCID mice. Patient tumors were pre-screened for their ER, PR and Her-2/Neu expression by IHC, prior to inoculation in mice. We report efficacy of two standard of care drugs, cisplatin and vinorelbine, in the TNBC PDX model which demonstrates the potential utility of the TNBC model in drug discovery effort in oncology for treatment of TNBC. 147 POSTER (Board P141) An integrated approach for identifying E-cadherin synthetic lethality networks I. Bajrami1 , S.J. Pettitt1 , R. Brough1 , H. Pemberton1 , D. Kastrev1 , Y. Fontebasso1 , J. Frankum1 , J. Campbell1 , A. Ashworth1 , C.J. Lord1 . 1 Institute of Cancer Research, Division of Breast Cancer, London, United Kingdom The E-cadherin (CDH1) tumour suppressor gene encodes a calciumdependent cell–cell adhesion glycoprotein, which has roles in maintaining cell polarity, differentiation, cell migration and survival. E-cadherin dysfunction is a feature common to many epithelial tumours, with the highest incidence occurring in diffuse gastric cancer (50%) and lobular breast cancer (56%) and can occur via CDH1 mutation, deletion or epigenetic silencing. Although E-cadherin dysfunction is relatively common, approaches to target this pathogenic alteration do not as yet exist. We have taken an integrated functional genomics approach to identifying E-cadherin synthetic lethality effects that exploits siRNA. Using a combination of Achilles’ Heel siRNA and small molecule inhibitor screens in histologically and genetically diverse tumour cell line panels, we have identified a compendium of genes whose disruption selectively targets E-cadherin deficient cells. Alongside the Achilles’ Heel screens in tumour cell models, complementary screens in isogenic systems with shRNA and CRISPR-engineered E-Cadherin defects will also be presented. As an orthogonal approach, we have also exploited piggyBac transposonbased mutagenesis in haploid ES cells to generate a diverse mutant library consisting of 100,000 mutants which are now being used in E-cadherin synthetic lethal screens. Together, these systems provide a framework for identifying candidate synthetic lethal effects suitable for mechanistic dissection and subsequent validation. The results from these complementary approaches and subsequent validation of selected effects will be presented. Poster Session – Preclinical Models 148 POSTER (Board P142) RAS synthetic lethal interactions from yeast to human cells S. van Wageningen1 , A. Prahallad1 , G. Heynen1 , R. Rothstein2 , R. Bernards1 . 1 Netherlands Cancer Institute Antoni van Leeuwenhoek hospital, Molecular Carcinogenesis, Amsterdam, Netherlands; 2 Columbia University, Genetics Department, New York, USA Background: Synthetic lethal (SL) interactions are used to develop targeted cancer therapy. However, novel SL interactions discovered in mammalian cell cultures are often cell type specific and are therefore only relevant to a small, or difficult to define, subset of patients. We developed a strategy in which we prioritize potential SL drug targets using the genetically tractable model system Saccharomyces cerevisiae. Material and Methods: Weperformed a SL screen by expressing a constitutively active RAS allele, RAS2(V19), in ~4800 S. cerevisiae strains in which each individual gene is deleted. Next we tested if SL interactions were conserved in human cancer cell lines. Results: The yeast screen yielded a hit list highly enriched for mutants with a defect in ‘endoplasmic reticulum (ER)-to-Golgi-to-vacuole’ transport. Moreover, we found that this list had a significant overlap with strains sensitive to b-mercaptoethanol, DTT and tunicamycin. We hypothesized that ER homeostasis was disturbed in these cells. The two gene deletion mutants most sensitive to ER stress are IRE1 and HAC1. These genes make up the unfolded protein response (UPR) in yeast; the signaling pathway that restores ER homeostasis. Both UPR genes were SL with RAS2(V19). Next we asked if we could detect a SL interaction between oncogenic RAS and the UPR in human cells. We find that a SL interaction between oncogenic RAS and the UPR is dependent on specific RAS effector pathways in human cell cultures. Conclusions: The UPR is conserved in evolution. However, signaling pathways downstream of RAS have diverged over time. We will present how the interaction between oncogenic RAS and the UPR has evolved in human cells and how this interaction can be exploited for therapeutic intervention. 149 POSTER (Board P143) Quantitative mutational assessment of circulating tumor DNA using massively parallel deep sequencing in plasma and urine from advanced colorectal cancer patients J.C. Poole1 , C.R.T. Vibat1 , L. Benesova2 , B. Belsanova2 , S. Hancock1 , T.L. Lu1 , M.G. Erlander1 , M. Minarik2 . 1 Trovagene Inc., R&D, San Diego, USA; 2 Genomac Research Institute, Center for Applied Genomics of Solid Tumors, Prague, Czech Republic Background: Technologies enabling the assessment of circulating tumor DNA (ctDNA) in biofluids expand the clinical utility to detect and monitor cancer patient oncogenic mutations by minimally invasive and non-invasive liquid biopsy methods. Mutational tumor load quantification with high clinical sensitivity is vital for robust individualized assessment of systemic therapeutic responsiveness and resistance. A quantitative ctDNA assay using a massively parallel deep sequencing approach was developed to determine patient ctDNA mutational status. Material and Methods: Initial assay development was for the simultaneous detection of 13 known (7 reported) oncogenic mutations in KRAS codons 12/13. An ultrashort 31bp region encompassing KRAS codons 12/13 was PCR amplified; G12A/C/D/R/S/V, and G13D mutations were enriched by suppressing wild-type (WT) sequence amplification with a WT blocking oligo. Barcoded adaptor primers were added for compatibility with massively parallel deep sequencing. Limits of detection (LOD) were independently determined for each of the 7 KRAS mutations by spiking 5–500 copies of each mutant into 60 ng of a WT genomic background. Limits of quantitation (LOQ) were confirmed with 7 copies of each mutation in an increasing WT genomic DNA background of 60–360 ng. Archived, matched plasma and urine samples (stored between 3−5 years prior to ctDNA extraction) from 20 treatment naı̈ve, advanced cancer patients with known tumor tissue KRAS mutations determined by an accredited clinical laboratory, were used in a retrospective setting for a blinded pilot study. These samples were used to compare KRAS status in urine and plasma to tumor tissue, and assess clinical sensitivity of the ctDNA assay. Results: LOD data for 5–500 KRAS G12A/C/D/R/S/V, and G13D mutant copies in 60 ng WT DNA showed a highly correlative response with an average R2 of 0.90 for the 7 mutations evaluated. LOQ assessed for each mutation in an increasing WT DNA background, revealed a robust signal for each mutation versus WT alone; an estimated analytical LOD of 7 copies per ~100,000 genome equivalents (0.007%) was observed. Of 20 blinded retrospective plasma ctDNA samples evaluated, 19 (95%) displayed the KRAS mutation concordant with tumor tissue. Of 20 matched urine samples tested, 16 were deemed evaluable; 15 (94%) had a significant sequence call consistent to tumor and to plasma. Wednesday 19 November 2014 51 Conclusion: The developed method for quantitative massively parallel deep sequencing of ctDNA for KRAS mutational assessment has reported high clinical sensitivity in plasma and urine. This technical approach is scalable and has the potential for detecting and quantifying a multitude of genomic alterations indicative of therapeutic responsiveness and resistance. Expansion of retrospective colorectal patient cohort described herein will be reported. Partially supported by the Czech Ministry of Health grant NT 13660. 150 POSTER (Board P144) Pirin downregulates E-cadherin gene expression and contributes to EMT K. Komai1 , Y. Niwa1 , Y. Sasazawa1 , S. Simizu1 . 1 Keio University, Faculty of Science and Technology, Yokohama, Japan Background: Downregulation of E-cadherin, a cell–cell adhesion protein, induces epithelial–mesenchymal transition (EMT), which plays crucial roles in metastatic progression. A nuclear protein pirin enhances NF-úB related transcription by binding to Bcl3-p50 complex, which is important for the SLUG expression and melanoma migration. Additionally, proteomics analysis indicated that pirin expression was decreased in metastatic adenoid cystic carcinoma cells. Although these reports suggest that pirin may be involved in tumor metastasis, there are no reports which directly demonstrate the contribution of pirin to metastasis. Here, we investigated the effects of pirin on EMT which associates with metastasis, and its mechanisms. Material and Methods: Pirin was overexpressed or silenced in HeLa cells, and then EMT-related genes and protein expressions were detected. The morphological changes of pirin stably-expressing HeLa cells were measured by employing parameter of ‘circularity’, [4p(area)/(perimeter)2 ]×100, which decreases by morphological changes from cobblestone-like epithelial cells to spindle-like mesenchymal cells. The effect of pirin on cell migration and anticancer drug resistance was measured by wound healing assay and MTT assay, respectively. The binding of wild-type pirin or its mutant to Bcl3 was confirmed by GST pull-down assay using recombinant GST-Bcl3. Results: Knockdown of pirin increased E-cadherin gene expression whereas overexpression of pirin decreased its level. Pirin stably-expressing HeLa cells exhibited spindle-like morphology and loss of cell–cell adhesion, which are reminiscent of EMT. From the result of MTT assay, we demonstrated that pirin contributed to acquire anticancer drug resistance. Furthermore, RNAi experiment revealed that pirin positively regulated A549 cell migration. Next, we examined whether Bcl3, a binding partner of pirin, is involved in EMT induction by pirin overexpression. GST pull-down analysis indicated that Pirin/E103A mutant was decreased its binding ability to Bcl3; however, as with wild-type pirin, this mutant also downregulated E-cadherin gene expression, suggesting that pirin decreases E-cadherin expression in Bcl3-SLUG-axis-independent manner. Conclusions: Pirin downregulates E-cadherin gene expression in Bcl3 independent manner, and contributes to EMT and cancer malignancy. These data provide evidence that pirin may be a potent target toward cancer therapy. 151 POSTER (Board P145) Impact of EGFR amplification pattern on the expression of miRNA-200c in primary glioblastoma multiforme L. Muñoz Hidalgo1 , C. López Gines2 , E. Serna3 , D. Monleon1 , R. Callaghan2 , R. Gil Benso2 , H. Martinetto4 , A. Gregori Romero2 , J. Gonzalez Darder5 , M. Cerda Nicolas2 . 1 Fundation HCU-INCLIVA, Pathology, Valencia, Spain; 2 University of Valencia, Pathology, Valencia, Spain; 3 University of Valencia, UCIM, Valencia, Spain; 4 Institute FLENI, Neurological, Buenos Aires, Argentina; 5 Clinical Hospital, Neurosurgery, Valencia, Spain Glioblastoma Multiforme (GBM) is the most common tumor in the primary tumors of the central nervous system, accounting for 60% of neoplasms in this location. It is a highly aggressive tumor with a median survival of twelve months. Heterogeneity in the biological behavior of this neoplasm of astrocytic glial origin is expressed in the infiltrative nature, this is a critical feature in glioblastoma. Several miRNAs have been related with different types of cancer, some of them related with ability of modulation behavior neoplastic cells expressed epithelial/mesenchymal changes. In this regard, miRNA expression is deregulated in most, if not all, types of cancer. Based on the literature the most common dysregulation of miRNAs in GBM is over-expression; more than two hundred miRNAs have been found to be significantly overexpressed. We have evaluated whole-genome miRNA expression profiling associated with different EGFR amplification patterns in primary glioblastoma multiforme, whose clinicopathological and immunohistochemical features have 52 Wednesday 19 November 2014 also been analyzed. All samples used for histopathological examination were fixed in neutral-buffered formalin, embedded in paraffin, sectioned and stained with hematoxylin-eosin. The immunohistochemical study was performed on paraffin-embedded sections using the avidin–biotin peroxidase method. To evaluate EGFR gene status, dual-color FISH analysis was performed on paraffin tissue arrays from 30 samples. Epigenetic analysis study of miRNAs and mRNA in 30 samples was performed using miRNA and mRNA Genechip Array (Affymetrix, Santa Clara, CA, USA). Expression levels of the selected miRNA (mir-200c) and mRNAs (CDH1, EGFR and ZEB1) were quantified using real-time reverse transcription-PCR (RT-PCR) analysis. MirRNA-200c showed a very significant difference between tumors having or not EGFR amplification. With respect to EGFR status our cases were categorized into three groups: high level EGFR amplification, low level EGFR amplification, and no EGFR amplification. Our results showed that microRNA-200c and E-cadherin expression are down-regulated, while ZEB1 is up-regulated, when tumors showed a high level of EGFR amplification. Conversely, ZEB1 mRNA expression levels were significantly lower in the group of tumors without EGFR amplification. Tumors with a low level of EGFR amplification showed ZEB1 expression levels comparable to those detected in the group with a high level of amplification. In this study we provide what is to our knowledge the first report of association between mirRNA-200c and EGFR amplification in glioblastomas. The mirRNA-200c plays an important role in epithelial–mesenchymal transition, but its implication in the behavior of glioblastoma is largely unknown, and we suggest that microRNA-200c may act as a potential regulator of glioblastoma migration and invasion by targeting ZEB1 mRNA. 152 POSTER (Board P146) Preclinical characterization of MM-151, an oligoclonal antibody therapeutic that targets EGFR by three distinct mechanisms of action A. King1 , M. Sevecka1 , N. Gerami-Moayed1 , O. Burenkova1 , J. Kearns1 , G. Tan1 , C. Sloss1 , R. Bukhalid1 , U. Nielsen1 , B. Wolf1 . 1 Merrimack Pharmaceuticals, Cambridge, USA Background: EGFR is a well-documented driver of solid tumor growth and a validated therapeutic target. However, currently approved EGFRtargeting monoclonal antibodies have limited clinical benefit, indicating the need for improved antibody therapeutics. We hypothesized that sub-optimal inhibition of the EGFR network and engagement of the immune system may limit the activity of current monoclonal antibody therapeutics, such as cetuximab and panitumumab. MM-151, an oligoclonal combination of three fully human IgG1s with subnanomolar affinities and non-overlapping epitopes, was developed using a systems biology approach to address these unmet needs. Methods: Preclinical characterization studies were performed, including signaling, proliferation, and immune effector assays to elucidate the mechanisms of action of MM-151 and to differentiate it from current monoclonal antibody therapeutics. Results: Our characterization assays demonstrate that MM-151 has three distinct mechanisms of action: ligand antagonism, receptor downregulation, and the pathway extrinsic activities of complement-dependent cytotoxicity and antibody-dependent cellular cytotoxicity. MM-151 displayed an advantage over cetuximab for all three mechanisms in the preclinical assays. Seven redundant ligands with a wide range of affinities can activate EGFR. We therefore examined the ability of MM-151 to antagonize ligand-driven signaling and proliferation in detail. Initially, we compared MM-151 with cetuximab and observed similar inhibition of signaling and proliferation driven by each of the three low-affinity ligands, but MM-151 showed increased inhibition against each of the four high-affinity ligands. A bioinformatics analysis using primary tumor data from The Cancer Genome Atlas revealed expression of distinct ligand mixtures comprised of both low- and high-affinity ligands across indications. MM-151 provided superior inhibition of proliferation with indication-specific ligand mixtures. MM-151 was also active against a cetuximab-resistant cancer cell line with upregulated expression of high-affinity ligands. Conclusions: MM-151 is a EGFR-targeting antibody combination designed using systems biology to overcome ligand redundancy and signal amplification within the EGFR network. MM-151’s novel oligoclonal composition enables enhanced antagonism of EGFR ligands, EGFR downregulation and immune effector function. These preclinical studies provide a rationale for clinical study of MM-151. Poster Session – Preclinical Models 153 POSTER (Board P147) Moving beyond in vitro models and addressing the challenges of pooled RNAi screens in mouse xenografts D. Tedesco1 , K. Bonneau1 , M. Makhanov1 , D. Deng1 , P. Sun2 , A. Chenchik1 . 1 Cellecta Inc., Mountain View CA, USA; 2 The Scripps Research Institute, La Jolla CA, USA RNAi loss-of-function screening with pooled shRNA expression libraries has proven to be a useful tool to identify essential cancer genes and drug resistance mechanisms in numerous cell lines in vitro. The effects of knocking down large numbers of genes on cancer cell growth and viability can be measured simultaneously using this approach. Now there is considerable interest to adapt RNAi viability screens to ex vivo xenograft mouse models. However, small take rates, growth rate variance of cells, and differing cell microenvironments in these more complex tumor models impose significant challenges to this sort of assay. We have developed a novel approach based on the use of pooled shRNA libraries with clonal barcodes that enables proliferation measurements of clonal populations produced by the individual shRNA-expressing founder cells that produce the tumor. This RNAi clonal analysis provides a basis to separate, across large cell populations, the external parameters that strongly influence cell growth rates from shRNA-induced growth inhibition in these systems. We will present in vivo RNAi screening validation data for several cancer models. 154 POSTER (Board P148) Drug response database with PDX tumor models in biomarker-driven multi-drug multi-arm clinical trial settings J. Jiang1 , T.F. Yu1 , Y. Yan1 , W. Du1 , T.T. Tan1 , L. Hua1 , J.L. Gu1 , X.Q. Yang1 , Z.H. Liu1 , X.K. Ye1 , Z. Gu1 . 1 GenenDesign, Oncology, Shanghai, China Recent advances in affordable genome sequencing and molecular profiling provide opportunities to better understand the complexity and heterogeneity of cancer, and perform multi-biomarker diagnosis in a single comprehensive test for personalized clinical treatment. A new biomarker-driven multi-drug multi-arm clinical trial in lung squamous cell carcinoma (Lung-MAP) uses cutting-edge genomic profiling to match patients with investigational treatments targeting their unique tumor mutations. However, there are still difficulties in enrolling enough patients with specific parameters, comparing different regimes on same clinical tumor and validating predictive biomarkers, especially those for drugs in early development stage. Patient derived xenograft (PDX) tumor models have been proved to recapitulate the complexity and heterogeneity of their corresponding human tumors by phenotypic and genomic characterization, and thus become to be widely used in recent years in preclinical setting to facilitate drug discovery, translational studies and clinical trials support. To further meet the increasing needs and complement the current clinical practice for precision medicine, better characterized PDX models with genomic profiles and drug response information to multiple chemo/targeted therapies are in demand. GenenDesign has established over 700 PDX tumor models and derived around 100 resistance models to drugs of interest. Through our in-house efforts, PDX models of different tumor types were tested with related SOCs and clinical candidates in biomarker-driven multi-drug multi-arm clinical trial settings. So far, more than 800 data sets have been generated, including responses to chemotherapy drugs, targeted inhibitors against HER2, EGFR, FGFRs, c-Met, MEK and Ras/Raf pathway, as well as PI3K/Akt pathway etc. Moreover, genomic profiling data of many PDX model have also been acquired at hot-spot mutation, gene expression, gene copy number and RNA/Exome sequence levels. The combination of functional and molecular information will help to design and support clinical trials, discover predictive biomarkers and unravel underlying drug resistance mechanisms. 155 POSTER (Board P149) SNIPER(TACC3) degrades TACC3 protein via the ubiquitin– proteasome pathway and induces apoptosis in cancer cells expressing a large amount of TACC3 N. Ohoka1 , K. Nagai2 , K. Okuhira1 , N. Shibata1 , T. Hattori1 , N. Cho2 , M. Naito1 . 1 National Institute of Health Sciences, Division of Biochemistry and Molecular Biology, Tokyo, Japan; 2 Takeda Pharmaceutical Co. Ltd., Medicinal Chemistry Research Laboratories Pharmaceutical Research Division, Fujisawa, Japan Microtubule inhibitors are widely used as anti-cancer drugs. They arrest cancer cells and often induce mitotic catastrophe and cell death. However, they also affect microtubule function in non-dividing cells, which limit their Poster Session – Preclinical Models utility. Recently, inhibitors of spindle-regulatory proteins have attracted considerable attention, and transforming acidic coiled-coil-3 (TACC3) is a spindle-regulatory protein overexpressed in many human cancers. We have developed a protein knockdown system to induce degradation of target proteins via the ubiquitin–proteasome system in cells with hybrid molecules named SNIPER (Specific and Non-genetic IAP-dependent Protein ERaser). In this study, we designed and synthesized novel SNIPER(TACC3)s that target TACC3 for degradation, and evaluated their activity in vitro. SNIPER(TACC3)s induce poly-ubiquitylation and proteasomal degradation of TACC3, and reduce the TACC3 protein level in cells. Mechanistic analysis indicated that the ubiquitin ligase APC/CCDH1 mediates the SNIPER(TACC3)-induced degradation of TACC3. Cancer cells express larger amount of TACC3 than do normal fibroblasts, and SNIPER(TACC3) selectively induced cell death in cancer cells. These results suggest protein knockdown of TACC3 by SNIPER(TACC3) is a potential strategy to treat cancers overexpressing the TACC3 protein. 156 POSTER (Board P150) Behaviour of platinum(IV) complexes with prodrug function in different models of hypoxia E. Brynzak1 , P. Heffeter2 , V. Pichler1 , M.A. Jakupec1 , B.K. Keppler1 . 1 University of Vienna, Institute of Inorganic Chemistry, Wien, Austria; 2 Medical University of Vienna, Institute of Cancer Research, Wien, Austria Background: Solid tumours frequently contain regions of low oxygen concentration, which have been identified as important component for drug modification, therapy resistance and metastasis formation. Selective targeting of this tumour hypoxia might be a proper strategy to overcome current therapeutic limits. Therefore platinum(IV) compounds with prodrug function, which require the reductive environment of tumor hypoxia for their biological activation, can be highly selective therapeutics. Material and Methods: To investigate the cytotoxicity of platinum(IV) compounds we used the AlamarBlue assay in hypoxic spheroid models of CH1 (ovarian carcinoma), HT1080 (fibrosarcoma) and HCT116 (colon carcinoma). Evidence of hypoxia has been provided by antibody staining of HIF-1alpha, and propidium iodide staining revealed necrotic regions in spheroid centres. Distribution of the drug within the spheroids has being determined by LA-ICP-MS. Further investigations of compound activity in an in vivo mouse model are ongoing. Results: Two test compounds were found to be at least 2−6 times more potent in hypoxic CH1 and HT1080 spheroid models than in monolayer culture, while satraplatin, another platinum(IV) compound, was 2 times less active. Furthermore platinum(II) complexes such as cis- and oxaliplatin were found to be 2−11 times less active in hypoxic models. Distribution studies showed adequate spheroid penetration for all tested compounds and give evidence of platinum(IV) accumulation within hypoxic regions. Conclusions: In this study we showed an advantage of platinum(IV) prodrugs over platinum(II) therapeutics currently used in the clinic and pointed out relevance of spheroid based in vitro models for drug screenings. 157 POSTER (Board P151) Sensitive and specific detection of 1p/19q codeletion in gliomas by next generation sequencing E. Dubbink1 , P.N. Atmodimedjo1 , R.M. van Marion1 , J.M. Kros1 , M.J. van den Bent2 , W.N.M. Dinjens1 . 1 Erasmus MC, Pathology, Rotterdam, Netherlands; 2 Erasmus MC Cancer Insitute, Neuro-oncology, Rotterdam, Netherlands Molecular subtyping of malignancies from the central nervous system becomes increasingly important to establish histological diagnosis and to predict differential treatment outcome of histologically similar tumors. One of these molecular markers is deletion of chromosomal arms 1p and 19q. Current methods to detect 1p/19q codeletion involve fluorescent in situ hybridisation (FISH) and loss of heterozygosity (LOH) analysis using polymorphic microsatellite markers. We will present a novel method to detect these aberrations based on single nucleotide polymorphism (SNP) analysis using next generation sequencing (NGS) on an Ion Torrent platform. We show that targeted NGS analysis of multiple heterozygous SNPs spread over the entire chromosomal arms 1p and 19q allows sensitive (down to 40% of tumor cells) and reliable detection of 1p and/or 19q deletion in gliomas. The strength of this method is that it accurately detects allelic imbalance in small amounts of suboptimal quality DNA derived from routine formalin-fixed, paraffin-embedded (FFPE) tissue in a fast turnaround time and that it can be easily adapted to perform additional mutational analysis of genes of interest. The test is therefore perfectly suited to become standard practice for routine glioma diagnostics. Wednesday 19 November 2014 53 158 POSTER (Board P152) The development of a series of orthotopic solid tumour models of prostate, lung and ovarian cancer using optical and X ray imaging M. Batey1 , M. Brown1 , E. Bowden1 . 1 Epistem Ltd, Manchester, United Kingdom Background: One of the most important aspects in anti cancer drug development is the availability of robust preclinical models which allow the efficacy of novel therapies to be examined. Several orthotopic models have been described where cancer cells are grown at clinically relevant sites. The objective is that these models, compared to more conventional subcutaneous models, will provide a more realistic environment, and will be superior models for therapeutic evaluation. A major difficulty with such techniques however is assessment of disease burden, with deep lying or metastatic tumours not being amenable to the usual methods of measurement. The introduction of non invasive small animal imaging has opened up the possibility of using such models in preclinical drug development programs, and in time the prospect of lower drug attrition rates in human trials. Here we discuss the development of three preclinical imaging models of solid human cancers, using the prostate line LnCAP, the ovarian line A2780, and the lung line A549. Materials and Methods: Following stable lentiviral transduction of these cell lines with a vector expressing firefly luciferase and GFP, LnCAP cells were implanted directly into the testis of male SCID mice, A2780 cells were implanted into the intraperitoneal space of female CD-1 nude mice, and A549 cells were implanted into the left lung of female CD-1 nude mice. Using the Bruker In Vivo Xtreme System, animals were monitored following initial transplantation, and disease burden quantified longitudinally over several weeks using co-registered 2D and 3D bioluminescent and X-ray detection. Results: Establishment of disease can be measured in each individual animal prior to commencement of therapy, and can be tracked in each animal throughout the duration of the study, with sites of metastasis readily visualised. In untreated animals the A2780 model runs over approximately 8 weeks, with multiple sites of solid tumour formation and frequent associated tumour ascites. Control mice in the A549 model are viable for approximately 6 weeks, with metastatic tumour development common in the model and a third of mice developing a pleural effusion. The LnCAP model runs over approximately 10 weeks, with the local development of dense, highly vascularised tumours, which show some invasion into the surrounding tissues. In all models visualisation of engrafted disease by imaging is possible at an early stage, and all show consistently high take rates. Conclusion: The ability to quickly identify engrafted animals, and the predictable development of disease demonstrated allows for improved randomisation based on disease signal, early therapeutic intervention, and extension of the treatment window. Efficacy of treatment can be easily followed by optical imaging, and as such, these models provide an attractive, clinically relevant environment for the preclinical assessment of novel therapeutics and combination treatment regimens. 159 POSTER (Board P153) Neoadjuvant chemotherapy in breast cancer patients induces expression of miR-34a and miR-122 P. Freres1 , C. Josse1 , N. Bovy2 , M. Boukerroucha3 , I. Struman2 , V. Bours3 , G. Jerusalem1 . 1 C.H.U. Liege, Laboratory of Medical Oncology, Liège, Belgium; 2 GIGA-Research, Unit of Molecular Biology and Genetic Engineering, Liège, Belgium; 3 GIGA-Research, Human Genetics, Liège, Belgium Background: Circulating microRNAs (miRNAs) are extensively studied in cancer as biomarkers but little is known about the influence of anti-cancer drugs on their expression. In this article, we describe the modifications of circulating miRNAs profile under neoadjuvant chemotherapy (NAC) for breast cancer. Methods: The expression of 188 circulating miRNAs was assessed by RT-qPCR in plasma of 25 patients before and after NAC. 2 miRNAs significantly increased under NAC, miR-34a and miR-122, were measured in the tumor tissue before and after the chemotherapy for 7 patients with pathological partial response (pPR) to NAC. These 2 chemotherapyinduced miRNAs were further studied in the plasma of 22 patients with adjuvant chemotherapy (AC) as well as in 12 patients who did not receive any chemotherapy and 20 healthy women. Results: 25 plasma miRNAs are found significantly modified by NAC. Tumor suppressor miR-34a and miR-122 are highly upregulated at the end of the NAC, notably in pPR patients with aggressive breast cancers. Furthermore, miR-34a level is elevated in remaining tumor tissue after NAC treatment. Studying the kinetic of circulating miR-34a and miR-122 expression during NAC reveals that their levels are especially increased 54 Wednesday 19 November 2014 after anthracycline-based chemotherapy. AC induces lower levels of plasma miR-34a and doesn’t modify miR-122. The tumorectomy alone doesn’t deregulate miR-34a and miR-122. Circulating miR-34a and miR-122 are downregulated in NAC treated breast cancer patients compare to controls and normalized after treatments. Conclusion: This study demonstrates for the first time that NAC specifically induces expression of tumor suppressor miRNAs in plasma and tumor tissue that might be involved in the anti-tumor effect of the chemotherapy. 160 POSTER (Board P154) Identification of fusion genes through kinome-centered RNA sequencing in different types of solid tumors L. Mittempergher1 , C. Sun1 , F.H. Groenendijk1 , A.J. Bosma1 , S.M. Willems1 , T. Sustic1 , I.J. Majewski1 , W. Grernrum1 , N.M. Davidson2 , I. de Rink3 , H.M. Horlings1 , W. Theelen-Engelsman4 , S.F. Chin5 , A. Oshlack6 , B.W. van Rhijn7 , M. van den Heuvel4 , M.S. van der Heijden1 , C. Caldas5 , R. Bernards1 . 1 Antoni van Leeuwenhoek − Netherlands Cancer Institute, Molecular Carcinogenesis, Amsterdam, Netherlands; 2 Murdoch Childrens Research Institute Royal Children’s Hospital, Bioinformatics Division, Victoria, Australia; 3 Antoni van Leeuwenhoek − Netherlands Cancer Institute, Genomics Core Facility, Amsterdam, Netherlands; 4 Antoni van Leeuwenhoek − Netherlands Cancer Institute, Thoracic Oncology, Amsterdam, Netherlands; 5 University of Cambridge, Oncology, Cambridge, United Kingdom; 6 The Walter and Eliza Hall Institute, Cancer and Haematology, Victoria, Australia; 7 Antoni van Leeuwenhoek − Netherlands Cancer Institute, Urology, Amsterdam, Netherlands Background: Oncogenic fusion genes involving kinases are effective therapeutic targets in different tumor types. However, diagnostic screening for kinase fusion genes in solid tumors is particularly challenging, as many occur with a low frequency. To overcome this, we developed a capture enrichment strategy to enable high throughput transcript sequencing of the human kinome. Using this approach, we recently identified novel translocation events involving the FGFR3 and ALK genes in lung squamous cell and adenocarcinoma (Majewski IJ et al, 2013). Methods: To date we screened with this approach 192 non-small cell lung carcinomas, 480 breast cancers of different subtypes from the METABRIC cohort (Curtis C et al, 2012), 80 head and neck carcinomas and 80 muscle-invasive urothelial carcinomas. Patient material was available from frozen or formalin-fixed paraffin-embedded tissues. Sequencing libraries were constructed with a TruSeq mRNA library preparation kit using poly-A enriched RNA (Illumina). Capture enrichment was performed with the human kinome DNA capture baits (Agilent). Captured libraries were sequenced on an Illumina HiSeq2000 platform with a paired-end 51 base protocol. Sequences were aligned to the human genome (Hg19) with TopHat (Trapnell C et al, 2009). Two pipelines were used to identify and rank candidate fusion genes: TopHat-fusion (Kim D et al, 2012) and de novo transcript assembly with Trinity (Grabherr MG et al, 2011). In order to validate the fusion events, PCR primers were designed to amplify across the fusion breakpoints and fusion breakpoints were confirmed by PCR amplification from cDNA and subsequently by capillary sequencing. Results: About 90% of the fusion events predicted with TopHat and de novo assembly algorithm were validated by capillary sequencing. Intriguingly, a gene was found recurrently fused at the exact same breakpoint in the breast cancer set. Fusion genes identified in the discovery set will be screened in independent sets of samples in order to determine their frequency. In addition, association of genomic rearrangements with clinico-pathological parameters has been assessed. Detailed results and functional validations will be presented at the meeting. Conclusion: Our kinome capture enrichment strategy for systematically profiling kinase fusion genes across different cancer types can be reliably used to identify novel translocation events in any expressed kinase. 161 POSTER (Board P155) Leveraging a novel DNA barcoding platform for integrated profiling and pharmacodynamic readouts C. Castro1 , V. Peterson2 , A. Ullal2 , S. Agasti2 , S. Tuang2 , N. Miller2 , M. Birrer3 , R. Weissleder4 . 1 Massachusetts General Hospital Cancer Center, Medicine/Center for Systems Biology, Boston, USA; 2 Massachusetts General Hospital, Center for Systems Biology, Boston, USA; 3 Massachusetts General Hospital Cancer Center, Medicine, Boston, USA; 4 Massachusetts General Hospital, Center for Systems Biology/Radiology, Boston, USA Background: Studies cite modest overlap between DNA, RNA, and protein levels within tumor cells. Integrated testing could generate valuable and complementary mechanistic insight. We recently developed a DNA Poster Session – Preclinical Models barcoding platform to quantify ~100 protein markers using scant clinical trial samples down to a single cell. Here, we expand this tool to predict drug testing by enabling simultaneous testing of tumor DNA, RNA, and protein. Materials and Methods: We highlight two ovarian cancer cases with contrasting clinical characteristics (low and high grade). Besides profiling, biopsies were also treated ex-vivo with cytotoxic (carboplatin, paclitaxel) or targeted drugs (PKI-587 [PI3K/mTOR], selumetinib [MEK]). Antibodies conjugated to unique DNA barcodes were used for multiplexed proteomic measurements using one fine needle aspirate (FNA) pass. After labeling with Ab-DNA conjugates, cells were lysed and unique barcodes cleaved from antibodies. Lysates contained cellular DNA and mRNA along with cleaved DNA barcodes measurable by automated detection platforms with attendant high femtomolar sensitivity. Results: Integrative analyses and expanded drug testing were feasible on clinical specimens. Profiling: Subject 1 (low grade) had increased KRAS (~3 fold) and MYC (~5 fold) copy number suggesting MAPK pathway dysregulation. In contrast, Subject 2 (high grade) had increased copy number of PI3KCA (~3 fold) and AKT2 (~11 fold) genes suggesting PI3K pathway dysregulation. Concordant with DNA results, Subject 1 had multiple unregulated proteins in the MAPK pathway (p38 MAPK, MET) along with MAPK1 and MET mRNA levels. Subject 2 had high AKT expression, pS6, and MTOR at both protein and mRNA levels. Drug testing: Both subjects downregulated EpCAM, S6RP, and p44/42 MAPK protein levels following carboplatin, selumetinib, or paclitaxel. Subject 1 was very sensitive to selumetinib (IC50: ~20 nM), supporting our profile testing. While Subject 1 showed limited in vitro sensitivity to PKI-587, as predicted, we noted acquired sensitivity with HM30181 (MDR1 inhibitor) use; results were validated with cell line testing. Conclusion: Our novel platform’s potential for expanded ex-vivo target modulation testing using scant specimens and various drug dosages or combinations could render it a feasible preclinical drug screening tactic. Our data support recent ovarian cancer MEK inhibitor trial evidence and uncover potential synergism with MDR1, poised for further clinical exploration. 162 POSTER (Board P156) Drug–drug interaction predictions for MLN2480, an investigational pan-RAF inhibitor, based on nonclinical data S.K. Balani1 , A. Bulychev1 , L. Cohen1 , M. Liao1 , C.Q. Xia1 , F. Wang2 , P. Li3 , B. LeClair3 , T. Bohnert3 , L. Gan3 , X. Zhou4 , V. Bozon5 , S. Prakash6 . 1 Takeda Pharmaceuticals International Company, DMPK, Cambridge, USA; 2 Takeda Pharmaceuticals International Company, Cancer Pharmacology, Cambridge, USA; 3 Biogen Idec Inc, DMPK, Cambridge, USA; 4 Takeda Pharmaceuticals International Co., Clinical Pharmacology, Cambridge, USA; 5 Takeda Pharmaceuticals International Co., Oncology Clinical Research, Cambridge, USA; 6 Takeda Pharmaceuticals International Co., DMPK, Cambridge, USA Background: MLN2480 is an investigational small molecule pan-RAF inhibitor in clinical trials in patients with metastatic melanoma and other solid tumors. Non-clinical assessments were made to predict the potential for drug–drug interactions (DDIs), and pH and formulation effects in the clinic. Material and Methods: In vitro assessments of enzymes involved in metabolism, their quantitative phenotyping, and CYP inhibitions were carried out using human liver microsomes. Freshly isolated human hepatocytes were used to assess CYP induction and mRNA expression. Caco-2 cells were used to assess membrane permeability and transporters’ inhibition potential. Pharmacokinetic (PK) studies used mice to assess the effect of pH and cremophor on PK of MLN2480. Results: Studies with human liver microsomes indicated that MLN2480 is metabolized by multiple enzymes, with aldehyde oxidase and CYP2C8 playing predominant roles. Due to multiple metabolic enzymes involved in MLN2480 clearance, CYP2C8 inhibitor and inducer drugs are expected to have a low potential to alter exposure to MLN2480. Additionally, the compound is a significant inhibitor of CYP2C8, hence a potential to affect PK of CYP2C8 drugs. MLN2480 did not exhibit time-dependent inhibition of CYP3A, or induction of CYPs. The compound exhibits high membrane permeability in Caco-2 model and does not appear to be an efflux pump substrate, reducing any concerns of DDIs with efflux pump inhibitor drugs. Additionally, it is not an inhibitor of Pgp, but of BCRP. Thus, a DDI potential exists with BCRP substrate drugs. Physicochemical-based interactions also have been assessed in mice. Consistent with the fact that the solubility of MLN2480 is not pH dependent, there was no effect on exposure to MLN2480 in an alkaline formulation in rodents. Additionally, since paclitaxel would be tested as a combination agent, and Cremophor® EL (BASF SE) in Taxol is known to affect PK of some drugs, the effect of cremophor on MLN2480 PK was assessed Poster Session – Preclinical Models in mice. The results showed that with Cremophor concentration similar to that at the planned Taxol dose of 80 mg/m2 in the clinic, the increase in MLN2480 exposure (AUC) in mice was only 14%. Conclusions: Overall, based on nonclinical data, there is a DDI potential for MLN2480 with CYP2C8 substrates/inhibitors/inducers and BCRP substrate drugs in the clinic. The possible alteration of MLN2480 PK by Cremophor in Taxol (80 mg/m2 ) is likely to be minimal. 163 POSTER (Board P157) Interrogation of pharmacogenes in cancer patients using targeted DNA sequencing F. Innocenti1 , N. Gillis1 , J. Parker1 , N. Hayes1 , D. Eberhard1 , K. Richards1 , J.T. Auman1 , E. Seiser1 . 1 University of North Carolina at Chapel Hill, Chapel Hill NC, USA Background: Germline sequence variation and somatic alterations in genes associated with drug processing can generate individualized pharmacogenetic data for cancer patients that may aid in understanding therapeutic response. Material and Methods: Targeted sequencing of over 200 genes, including known druggable targets and genes relevant to cancer pathogenesis, was performed for matched germline and tumor DNA from over 200 patients representing many common cancer types. Aligned sequence data was used for genotype variant calling in both germline and tumor DNA and for mutation and copy number identification within tumors. Genotype data was used to determine genetic ancestry and to provide summary statistics for known pharmacogenetic variants in germline DNA. Additionally, somatic alterations within genes relevant to the pharmacology of anticancer agents were examined in the represented cancer types: brain/central nervous system, breast, gastrointestinal, genitourinary, gynecologic, head and neck, and hematologic. Results: The use of genetic markers to determine ancestry identified patients that were mainly Caucasian (78%) and African American (16%), and provided a means to correct for errors and ambiguity in self reporting for nine individuals. The most common cancer types included gastrointestinal (19%), genitourinary (18%), and breast (13%). A total of 38 pharmacogenetic variants in 18 genes, including cytochrome P450 genes, demonstrated similar minor allele frequencies when compared to 1000 Genomes data and were predominantly in Hardy-Weinberg equilibrium. Observed genotype concordance of these variants in matched germline and tumor DNA was greater than 95% for the majority of loci. Analysis of 16 genes associated with anticancer agents identified mutations 15 genes (22% of patients exhibited at least one mutation in one or more genes), including predicted non-synonymous coding changes and gains of stop codons in ABCB1 and DPYD. Aberrant tumor copy numbers were sporadically observed in most of these genes, although recurrent deletions of DPYD and SULT1A1 were present across tumor types. Conclusions: Next generation sequencing of pharmacogenes in both nonmalignant and tumor tissue from an individual provides a comprehensive catalog of germline variants and both known and novel somatic alterations. The integration of genetic data from germline and tumor may aid in the elucidating the pharmacology underlying therapeutic effect. Analysis of the effect of these variants and molecular alterations on drug response for a subset of individuals is ongoing and will be presented at the meeting. 164 POSTER (Board P158) Augmentation of NAD+ by NQO1 activation attenuates cisplatinmediated hearing impairment S. Yang1 , G.S. Oh2 , K.B. Kwon2 , R.K. Park2 , S.Y. Lee3 , S.R. Moon4 , H.S. So2 . 1 Wonkwang University School of Medicine, Department of Internal Medicine, Iksan-city Jeonbuk, South Korea; 2 Wonkwang University School of Medicine, Center for Metabolic Function Regulation, Iksan-city Jeonbuk, South Korea; 3 Wonkwang University School of Medicine, Department of Thoracic Surgery, Iksan-city Jeonbuk, South Korea; 4 Wonkwang University School of Medicine, Department of Radiation Oncology, Iksan-city Jeonbuk, South Korea Introduction: Cisplatin [cis-diaminedichloroplatinum-II] is an extensively used chemotherapeutic agent, and one of its most adverse effects is ototoxicity. A number of studies have demonstrated that these effects are related to oxidative stress and DNA damage. However, the precise mechanism underlying cisplatin-associated ototoxicity is still unclear. The cofactor nicotinamide adenine dinucleotide (NAD+ ) has emerged as a key regulator of cellular energy metabolism and homeostasis. Although a link between NAD+ -dependent molecular events and cellular metabolism is evident, it remains unclear whether modulation of NAD+ levels has an impact on cisplatin-induced hearing impairment. Wednesday 19 November 2014 55 Material and Methods: To investigate whether augmentation of NAD+ by NQO1 activation using b-Lapachone (b-Lap) attenuates cisplatinmediated hearing impairment, male C57BL/6mice and NQO1 knockout mice on a C57BL/6 background were used. For analysis of the auditory threshold, auditory brainstem response (ABR) was recorded. For biochemical analysis, we measured the enzymatic activity of SIRT1, PARP1, ROS production, NAD+/NADH ratio, mRNA levels of miR-34a and pro-inflammatory cytokines. Immunohistochemistry and western blot analysis were also performed. Results and Discussion: We have demonstrated for the first time that both the protein expression level and the activity of SIRT1 were suppressed by the reduction of intracellular NAD+ levels in cisplatin-treated cochlear tissue. We also found that the decrease in SIRT1 protein expression and its activity after cisplatin exposure were mediated by the increase in transcriptional activity of p53 for miR-34a expression and PARP-1 activation causing NAD+ -depletion, respectively. However, the increase in cellular NAD+ levels by NQO1 activation using b-Lap prevented mice from cisplatininduced cochlear damage and hearing impairment through the modulation of PARP-1, SIRT1, p53, and NF-kB. Conclusion: Considering that b-Lap itself did not attenuate the tumoricidal effect of cisplatin (Kidney International, 2014, in press), these results suggest that the direct modulation of the cellular NAD+ level by pharmacological agents could be a promising therapeutic strategy for enhancing the efficacy of cisplatin chemotherapy without its adverse effects. 165 POSTER (Board P159) Effect of zoledronic acid on the post-translational modification of activated leukocyte cell adhesion molecule (ALCAM) in cancer cells R. Toth1 , G. Trombino1 , V. Castronovo1 , A. Bellahcene1 . 1 C.H.U. Liège, Metastasis Research Laboratory, Liège, Belgium Background: Activated leukocyte adhesion molecule (ALCAM/CD166) is a 105kDa protein that is a member of the immunoglobulin superfamily. This family consists of proteins that are involved in recognition binding and adhesion processes of the cells. Zoledronic acid (ZA) is a bisphosphonate that has been extensively studied as an osteoclast inhibitor. ZA decreases bone turnover by inhibiting the mevalonate pathway in cells. This pathway has been notably implicated in post-translational protein modifications such as prenylation and N-linked glycosylation. Methods: MDA-MDA-231 cells have been treated with different concentrations of ZA for 48 h. Enzymatic digestion was performed with PNGaseF on protein extracts from treated and non-treated cells. Western blot analysis and cell aggregation assays have been performed upon ZA treatment. Results: We observed the appearance of a 95kDa form of ALCAM after 48 h of treatment with ZA in a dose dependent manner. MDA-MB-231 cytosolic/membrane protein fractionation showed that the 95kDa form of ALCAM was detectable in the membrane fraction. PNGaseF treatment of MDA-MB-231 cell extracts resulted in a single 68kDa band in both treated and non-treated conditions, indicating that the 95kDa form potentially represents an intermediate glycosylation form of ALCAM. We showed that ALCAM is crucial for MDA-MB-231 cell aggregation. Next, we observed that ZA treated-cells presented with a decreased aggregation capacity potentially linked to their expression of the 95kDa ALCAM form. Conclusion: Our results suggest for the first time that ZA affects the glycosylation of ALCAM in MDA-MB-231 cells in vitro, which will be further investigated in breast cancer tumor models in vivo. Reduced N-linked glycosylation of ALCAM was associated with a decreased aggregation potential in ZA-treated cancer cells. Cell aggregation is associated with anchorage independent growth and proliferation in MDA-MB-231 cells. Ongoing experiments will help to explore the potential implication of the 95kDa ALCAM form in these processes. 166 POSTER (Board P160) Pre-clinical and clinical activity of Anti-DLL4 (demcizumab) in combination with gemcitabine plus nab-paclitaxel in pancreatic cancer M. Hidalgo1 , A. Cubillo2 , R. Stagg3 , J. Dupont3 , Y. Wan-Ching3 , T. Hoey3 . 1 CNIO, Madrid, Spain; 2 CIOCC, Madrid, Spain; 3 Oncomed Pharmaceutical, California, USA DLL4-Notch signaling plays a key role in cancer stem cell (CSC) biology in numerous tumor types including pancreatic cancer. We have developed an anti-DLL4 antibody (demcizumab) that blocks Notch signaling and inhibits tumor growth though multiple mechanisms including a reduction of CSC frequency and the inhibition of productive angiogenesis. Previous studies have shown broad spectrum activity of anti-DLL4 & gemcitabine in a panel of patient derived pancreatic cancer xenografts. Data from a Phase 1b clinical study of demicizumb & gemcitabine in PDAC resulted in a 25% 56 Wednesday 19 November 2014 partial response rate in 16 evaluable patients. Based on the emergence of nab-paclitaxel & gemcitabine as a standard of care regimen for the treatment of pancreatic cancer, we have tested anti-DLL4, gemcitabine & nab-paclitaxel in PDAC PDX models, and observed enhanced antitumor activity in all seven pancreatic cancer xenografts tested. Based on serial transplantation experiments, the triple combination of anti-DLL4, gemcitabine, & nab-paclitaxel reduced CSC frequency whereas treatment with the chemothearpy agents alone did not. Interestingly, the combination activity of anti-DLL4 appeared to be greater with gemcitabine & nabpaclitaxel than with gemcitabine alone. In a co-clinical study, a PDX model derived from a Phase 1b patient who progressed rapidly on treatment with demcizumab & gemcitabine was, as expected, insensitive to gemcitabine or the combination of anti-DLL4 & gemcitabine, correlating well with the lack of clinical response. Notably, this tumor was more sensitive to nabpaclitaxel, gemcitabine & anti-DLL4 treatment. As a result of these data and the emergence of nab-paclitaxel & gemcitabine as a new standard of care for pancreatic cancer, the Phase 1b clinical study mentioned above was amended to test the triple combination of demcizumab, gemcitabine & nab-paclitaxel in patients with 1st line pancreatic cancer. Early data from the 1st 14 patients treated with this combination revealed a partial response in 6 (43%) patients and stable disease in another 6 (43% pts). Related AEs observed in 20% in the 38 patients in the Phase 1b study were nausea (37%), fatigue (34%), vomiting (32%), decreased appetite (24%) & hypertension (21%). Additional cohorts of patients are being treated with demcizumab, gemcitabine & nab-paclitaxel to further assess the preliminary safety, efficacy, pharmacokinetics and impact on biomarkers of this combination. 167 POSTER (Board P161) Genomic characterisation of 1003 cancer cell-lines G. Bignall1 , F. Iorio2 , P.A. Futreal3 , M.R. Stratton1 , P. Campbell1 , U. McDermott1 . 1 Wellcome Trust Sanger Institute, Cambridge, United Kingdom; 2 EMBL-EBI, Cambridge, United Kingdom; 3 MD Anderson Cancer Centre, Houston, USA Over the last twenty years there has been a paradigm shift in cancer treatment, moving away from the cytotoxic effects of chemicals targeting all cells going through cell division to a more targeted approach aimed at inactivating specific cellular components upon which the cancers rely to drive cell growth; a process termed oncogene addiction. The ‘poster child’ for such therapies is ‘imatinib’ a small molecule inhibitor of ABL kinase activity targeting the BCR−ABL fusion protein in CML. Here we present the genomic characterisation of 1003 cancer cell-lines currently being used as reagents in a high-throughput screen of anti-cancer agents. This screen is aimed at identifying novel biomarkers with which to stratify patients, identifying those most likely to respond to specific cancer therapies. To characterise the cell-lines we performed exome sequencing, copy number, expression and methylation analysis. Since most cell-lines are unmatched we screened out germline variants by comparison to ~8000 normal exomes. To further reduce the ‘genetic space’ for the subsequent downstream correlation to drug response data we included only ‘clinically relevant’ variants. The list of clinically relevant variants was identified by looking for recurrence across the ‘systematic screen data’ in COSMIC and by reducing the gene set to those genes identified as ‘frequently mutated’ across a series of >7000 clinical exomes/genomes from 29 cancer types using IntOGen, MutSigCV and dN/dS analysis. Tissue specific and pan cancer gene sets were identified for downstream analysis. In total we identified ~500,000 putative somatic non-synonymous variants across the set of 1003 cancer cell-lines, of which ~6000 were classed as clinically relevant. Analysis is currently on-going correlating this ‘clinically relevant’ variant data to the drug response. Comparison of the mutation frequencies between the clinical samples and the filtered variant data from the cancer cell-lines indicate that the cell-lines are likely to represent good model systems for downstream correlation to drug response. The variant data for the cancer cell-lines is available via the COSMIC web portal. 168 POSTER (Board P162) CDCP1 as a new marker of aggressiveness in triple-negative breast cancers M. Campiglio1 , F. Turdo1 , F. Bianchi1 , M. Sasso1 , L. De Cecco1 , P. Casalini1 , P. Gasparini1 , L. Forte1 , R. Agresti1 , I. Maugeri1 , G. Sozzi1 , E. Tagliabue1 . 1 Fondazione IRCCS Istituto Nazionale Tumori, Dept. Experimental Oncology and Mol. Med., Milano, Italy Background: Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype showing high recurrences and mortality rate, for which no therapies besides chemotherapy are available to date. Lacking specific markers for an effective targeted therapy, TNBCs still represent the most Poster Session – Preclinical Models important challenge for clinical oncologists. In an effort to identify specific markers responsible for aggressiveness of TNBCs that may serve as target(s) of therapy, we used post-surgery wound-healing fluids (WHFs) from breast cancer patients, known to be extremely enriched in growth factors and cytokines, as a tool mimicking the pro-tumorigenic post-surgery host microenvironment to stimulate TNBC cells lines. Material and Methods: Cell lines knock-down for CDCP1 by specific siRNA were analyzed for migration, invasion and proliferation in vitro. Immunohistochemistry on FFPE TNBC specimens were performed using a polyclonal antibody. Cases were classified as positive when plasmamembranes were stained in at least 10% of tumor cells. FISH analysis was performed using a pool of 3 BAC (bacterial artificial chromosome) clones that cover the CDCP1 gene at chromosome 3p21.31 and a commercial chromosome 3 enumeration probe. Kaplan–Meier methods were used to calculate the disease free survival (DFS) and distant DFS (DDFS) and differences in survival curves were evaluated with the log-rank test. Results: Gene expression profiling (GEP) on the Illumina platform using TNBC cell lines derived after stimulation with WHFs identified among the surface receptors the non-catalytic receptor CDCP1 (CUB domaincontaining protein 1) as the most significantly up-modulated gene. CDCP1 protein was found basally highly expressed in 6 of 8 TNBC cell lines. Its silencing in the most highly expressing TNBC lines (MDA-MB-231 and BT549) strongly impaired both their migration (~70%) and invasion (~50%) ability but did not affect their in vitro proliferation, suggesting a role for CDCP1 in TNBC dissemination. IHC analysis of CDCP1 in 126 human primary TNBC FFPE specimens revealed intense membrane staining in 60% of cases. CDCP1 expression was found to be a risk factor that significantly reduces both DFS (log-rank p = 0.0115) and DDFS (log-rank p = 0.0063) of TNBC patients. To evaluate whether the high expression level of CDCP1 in human TNBC specimens can depend on a genetic gain, FISH analysis of FFPE sections from 30 human TNBC cases (20 CDCP1positve and 10 CDCP1-negative in IHC) was performed, revealing that in more than 50% of CDCP1-positive cases CDCP1 gene was polysomic. Additionally, polysomy strongly correlated with CDCP1 protein expression levels. Conclusions: Our data identify CDCP1 as a marker of extremely aggressive TNBCs, suggesting its candidacy as a target of novel therapeutic strategies against this disease. Supported by AIRC 169 POSTER (Board P163) BRAF mutation testing in cell-free DNA from plasma of patients with advanced cancers using a novel, rapid, automated molecular diagnostics prototype platform (Idylla™) F. Janku1 , H.J. Huang1 , B. Claes2 , G.S. Falchook1 , A. Naing1 , S. Piha-Paul1 , A.M. Tsimberidou1 , R.G. Zinner1 , D.D. Karp1 , S. Fu1 , V. Subbiah1 , D.S. Hong1 , J.J. Wheler1 , R.G. Luthra3 , S.P. Patel4 , E.S. Kopetz5 , E. Sablon2 , G. Maertens2 , R. Kurzrock6 , F. Meric-Bernstam1 . 1 The University of Texas MD Anderson Cancer Center, Investigational Cancer Therapeutics (Phase I Clinical Trials Program), Houston, USA; 2 Biocartis, Mechelen, Belgium; 3 The University of Texas MD Anderson Cancer Center, Molecular Diagnostic Laboratory, Houston, USA; 4 The University of Texas MD Anderson Cancer Center, Melanoma Medical Oncology, Houston, USA; 5 The University of Texas MD Anderson Cancer Center, Gastrointestinal Medical Oncology, Houston, USA; 6 The University of California San Diego, Moores Cancer Center, La Jolla, USA Background: Cell-free (cf) DNA from the plasma of cancer patients offers an easily obtainable, low-risk, inexpensive and repeatedly applicable source of biologic material for mutation analysis of druggable targets and monitoring molecular changes in tumor(s) during and after therapeutic interventions. Novel, fast, and accurate diagnostic systems are needed for further development of plasma cfDNA testing in personalized therapy. Methods: cfDNA from plasma samples of patients with advanced cancers who progressed on systemic therapy was purified and 50– 100 ng DNA was used for testing for V600 BRAF mutations using the prototype molecular diagnostics (IdyllaTM ) fully integrated real-time PCRbased platform (Biocartis, Mechelen, Belgium) and BRAF V600 mutation prototype cartridges with a quick turnaround time (<60 minutes for cfDNA). The IdyllaTM platform and the BRAF V600 mutation prototype assay were used for research purposes only. Results were compared to mutation analysis of archival primary or metastatic tumor tissue obtained at different points of clinical care from a CLIA-certified laboratory if available. Results: cfDNA was extracted from plasma samples of 127 patients with advanced cancers (colorectal, n = 54; melanoma, n = 28; non-small cell lung, n = 12; breast, n = 6, Erdheim-Chester disease, n = 6; thyroid, n = 7; appendiceal, n = 3; ovarian, n = 3; endometrial, n = 3; other cancers, n = 5). BRAF mutations were detected in 29% (36/127) of plasma samples and in 43% (50/117) of available archival tumor samples, resulting in concordance Poster Session – Preclinical Models for 102 (87%) of 117 patients who had both plasma and tissue tested cases (kappa = 0.73, 95% confidence interval 0.61–0.85) with sensitivity 72%, specificity 99%, positive and negative predictive value 97% and 83%, respectively. In all 15 discrepant cases identical plasma cfDNA samples were tested using an alternative cfDNA BRAF mutation PCRbased method (BEAMing, Sysmex Inostics, Baltimore, MD), which yielded 100% agreement with the IdyllaTM platform. Longitudinally collected plasma samples were available in 13 patients (appendiceal, n = 2; colorectal, n = 2; melanoma, n = 4; papillary thyroid cancer, n = 2; other, n = 3) with plasma BRAF V600 mutations treated with predominantly BRAF targeting combinations and changes in the amount of BRAF-mutant cfDNA tracked changes in tumor markers and disease burden visualized via imaging. Conclusions: Detecting V600 BRAF mutations in cfDNA from plasma using the IdyllaTM platform and BRAF V600 mutation prototype cartridges is a fast and noninvasive alternative to mutation testing of tumor tissue with an acceptable level of concordance and sensitivity, and should be investigated further for testing and monitoring of BRAF mutation status in patients with cancer. Wednesday 19 November 2014 57 170 POSTER (Board P164) Novel, ultra-deep next-generation sequencing for BRAF mutation testing using small amount of cell-free DNA from plasma of patients with advanced cancers associated with sensitivity or resistance, and other cell line characteristics. EGR1 was identified as one of the top genes for which drug-induced changes in expression were associated with sensitivity to gemcitabine (gem; 32 cell lines up regulated >2-fold) and to erlotinib (17 cell lines down regulated >2-fold) in at least two treatment conditions. In the clinic, combinations of gem and erlotinib have been tested with mixed results. We hypothesized that divergent response of EGR1 to these two drugs might form the basis for antagonism. Treatment with the gem/erlotinib combination in 6 cell lines generated a range of antagonism in vitro, which depended on sensitivity to either the gem or erlotinib. Cell lines that were more sensitive to erlotinib, with greater EGR1 down regulation, demonstrated greater antagonism in response to the drug combination. In support of a role for EGR1, we found that transient down regulation of EGR1 in some gem-responsive cell lines led to decreased sensitivity to gem, while overexpression of the gene led to increased gem sensitivity. The measured antagonism was cell line dependent, but independent of drug scheduling. Sensitivity to gem appears mediated by EGR1 and can be antagonized by other pharmacologic effects on EGR1 as evidenced by the antagonism of growth inhibition between gem and erlotinib. These data may provide a rationale for the poor clinical response to this combination in some tumor types. Funded by NCI Contract No. HHSN261200800001E and supported in part by the Developmental Therapeutics Program in the Division of Cancer Treatment and Diagnosis, NCI. F. Janku1 , H.J. Huang1 , N.M. Ramzanali1 , X. Cai2 , R. Klausner2 , F. Meric-Bernstam1 , J.B. Fan2 . 1 MD Anderson Cancer Center, Investigational Cancer Therapeutics (Phase I Clinical Trials Program), Houston, USA; 2 Illumina, San Diego, USA 172 POSTER (Board P166) Modulation of estrogen-dependent transcription by cohesin in MCF7 human breast adenocarcinoma cells Background: Plasma cell-free (cf) DNA of cancer patients offers an easily obtainable and repeatedly applicable source of DNA for mutation analysis, which provides attractive alternative to tumor tissue testing. Novel ultrasensitive technologies using small amounts of DNA are needed for further development of plasma cfDNA testing in personalized therapy. Methods: We have developed a next-generation sequencing method for somatic BRAF mutation detection in cfDNA with high sensitivity and specificity. The protocol was designed specifically to utilize small DNA fragments, using a very low DNA input of 5 ng. Each cfDNA fragment was uniquely barcoded and amplified prior to Illumina target enrichment workflow, followed by ultra-deep sequencing (>10,000×). Proprietary data processing and analysis tools were developed to enable sensitive detection of rare mutant molecules over high wild-type background (i.e. detection of 1 in 1000 molecules). Results were compared to mutation analysis of archival primary or metastatic tumor tissue obtained at different points of clinical care from a CLIA-certified laboratory Results: cfDNA was extracted from plasma samples of 24 patients with advanced cancers (melanoma, n = 9; colorectal, n = 5; non-small cell lung, n = 2; papillary thyroid, n = 2; other cancers, n = 6) and 5 ng were used for BRAF mutation analysis. BRAF mutations were detected in 71% (17/24) of plasma samples and in 88% (21/24) of archival tumor samples, resulting in concordance in 87% (20/24) of cases. Conclusions: Detecting V600 BRAF mutations using ultra-deep sequencing of small amounts of cfDNA (5 ng) from plasma is feasible with an acceptable level of concordance with BRAF testing of tumor tissue obtained at different time points and should be investigated further for testing and monitoring of BRAF mutation status in patients with cancer. 171 POSTER (Board P165) Antagonistic interaction between gemcitabine and erlotinib is influenced by EGR1 (early growth response 1) transcription factor expression C.D. Hose1 , Y. Zhao2 , E.C. Polley2 , J. Fang2 , N.D. Fer1 , A. Rapisarda1 , B.A. Teicher2 , R.M. Simon2 , J.D. Doroshow2 , A. Monks1 . 1 Frederick National Laboratory for Cancer Research, Leidos Biomedical Research Inc., Frederick MD, USA; 2 National Cancer Institute, DCTD, Frederick MD, USA Drug-induced transcriptional changes may help to ascertain mechanisms of action and possible bystander effects, and can suggest potentially favorable or adverse drug combinations. We developed a database of gene expression changes that were observed following treatment with 15 commonly used anticancer agents in 60 human tumor cell lines, across 2 drug concentrations and 3 incubation times. Gene expression profiles were measured using Affymetrix HTA array plates 133A and 133B, and drug-induced fold-changes were calculated and compared to timematched controls. These dynamic transcriptional response data will be provided on a public website that can be facilely accessed and explored using the Transcriptional Pharmacology Workbench, a powerful web-based tool-set designed by the NCI for finding drug-modulated genes that are T. Dasgupta1 , J. Antony1 , J. Rhodes1 , M. McEwan1 , M. Eccles1 , J. Horsfield1 . 1 University of Otago, Pathology, Dunedin, New Zealand Background: RAD21, a component of the evolutionary conserved chromosome cohesion protein cohesin, is amplified in breast cancer. Amplification of RAD21 is correlated with poor prognosis and endocrine resistance in luminal breast cancers. However, the reasons for this correlation are not understood. Our lab discovered that depletion of RAD21 reduces estrogen induction of the proto-oncogene c-MYC, and impairs binding of estrogen receptor a (ERa) to its enhancers. Chromosome binding of RAD21 coincides with ERa in estrogen-induced breast cancer cells suggesting cohesin could modulate estrogen-dependent gene transcription. This study aimed to identify estrogen-sensitive genes that are dysregulated upon loss of cohesin, and determine the mechanisms of regulation mediated by cohesin. Material and Methods: To map global changes in gene expression, a microarray analysis was carried out in RAD21-depleted MCF7 cells in the presence/absence of estrogen. Chromatin immunoprecipitation (ChIP) and quantitative PCR (qPCR) was used to determine if RAD21 depletion influenced binding of ERa at selected altered genes (IL20 and SOX4). Results: Microarray analysis revealed that cohesin depletion affected transcription of not all, but a subset of estrogen-sensitive genes. Loss of cohesin resulted in bidirectional (up or down) regulation of ERa target genes. The most significantly regulated genes were co-bound by both ERa and cohesin and were over-represented in oncogenic pathways such as ErbB and PI3K/mTOR. Preliminary ChIP analysis suggests that depletion of RAD21 alters binding of ERa at sites previously identified3 for genes, SOX4 and IL20. Conclusion: Cohesin can promote or inhibit expression of estrogenresponsive genes in a context-specific manner. Ongoing experiments are aimed at confirming the ChIP findings, to further elucidate cohesin’s role in regulation of the ER transcription program. 173 POSTER (Board P167) Ras-mediated activation of mitogen-activated protein kinase pathway unleashes basement membrane damaging activity of serine protease hepsin T. Tervonen1 , S. Pant1 , D. Belitskin1 , J. Englund1 , K. Närhi2 , E. Verschuren2 , P. Kovanen3 , J. Klefström1 . 1 University of Helsinki, Translational Cancer Biology Research Program, Helsinki, Finland; 2 University of Helsinki, Institute for Molecular Medicine Finland, Helsinki, Finland; 3 University of Helsinki, Haartman Institute and Department of Immunology and Pathology, Helsinki, Finland Membrane-anchored serine proteases have emerged as novel players in invasion and metastasis of epithelial cancers. Among these, type II transmembrane serine protease hepsin is prominently upregulated in prostate and breast cancer both in mRNA and protein level. In agreement what was previously observed in ovarian cancer, normal human mammary gland expresses low levels of pericellularly and basally localized hepsin 58 Wednesday 19 November 2014 contrasting to diffuse, cytosolic expression observed in more than 80% (n = 49) of breast cancer specimens representing all major subtypes. Mutations in hepsin gene don’t explain widespread deregulation of hepsin protein in breast cancer, suggesting a critical role for upstream factors as culprits for hepsin deregulation. Hepsin expression in breast cancer was studied in paraffin sections and fresh tissue lysates from breast cancer patients. We also generated 2D and 3D human and mouse non-malignant mammary epithelial and cancer cell lines stably transduced with recombinant retro- or lentivirus vectors endowing cells with constitutive or inducible hepsin expression. Hepsin activity was probed with cell-based peptide substrate cleavage assay. We used lox-stop-lox (LSL)-KrasD12; p53−/− mice where sporadic lung tumors are induced with inhaled adeno-cre virus. Furthermore, mammary epithelial cells from LSL-KrasD12 mice were isolated and Kras activated ex vivo with adeno-cre virus to investigate pattern of 3D structure formation in Matrigel. To elucidate factors upstream of hepsin, we explored the effects of oncogenic Ras proteins, c-Myc, E2F-1, dominant negative p53 and Lkb1 silencing on hepsin protein expression levels in non-malignant mammary epithelial cells. We demonstrate that HrasV12, KrasV12, ectopic wildtype Kras, endogenous mutant LSL-KrasD12 and E2F-1 deregulate and enhance the proteolytic activity of hepsin. Oncogenic Ras proteins also reduced expression levels of HAI-1, the negative regulator of hepsin. Concomitantly, oncogenic Ras expression led to disappearance of desmoplakin and desmoglein from desmosomal junctions, which correlated with mislocalization of hepsin from its predominant localization in desmosomes to cytosol. shRNA-mediated silencing or function blocking Ab25 antibody for hepsin partially rescued HrasV12 induced transformation in 2D and 3D cultures of MCF10A cells and preserved the basal lamina integrity. Furthermore, MEK and Erk1/2 inhibitors prevented HrasV12dependent hepsin alterations as well as desmosomal and basement membrane defects. Our results couple Ras-MAPK pathway to deregulation of hepsin, revealing a possible role for hepsin in mediating Ras transformation of epithelial structures. 174 POSTER (Board P168) Combination of molecular and drug response data in patient-derived xenografts to assist patient stratification S. Cairo1 , O. Déas1 , A. Beurdeley1 , V. Yvonnet1 , M.F. Poupon1 , J.G. Judde1 . 1 Xentech, R&D, Evry, France Patient-derived xenografts (PDXs) are the preclinical models that most closely resemble tumors in patients. PDX and the tumor of origin show strikingly similar histological and molecular features, and when tested they possess very similar drug-response profile. Thanks to these characteristics, PDXs are potent surrogates of human tumor to investigate the impact of the genetic background of transformed cells on tumor response to treatment. Tumor heterogeneity is likely the reason why anticancer treatments fail to display the same efficacy in different patients. This diversity is probably due to the variability observed in tumor genetics, and in particular to the combination of genetic alterations in each tumor. In patients, the relationship between the degree of response to treatment and tumor genetic features is often loose. One of the difficulties in identifying genetic markers associated with anticancer treatment efficacy is that as each patient is subjected to only one therapeutic strategy, chosen as the best adapted based on the clinical parameters, it is impossible to know how this same patient would have responded to a different treatment. XenTech holds a large PDX collection, with more than 100 validated PDXs models characterized so far. These models represent tumors occurring in different tissues such as breast, lung, colon, prostate, liver and brain among others. Most of these modes have been subjected to standardof-care (SOC) treatments to characterize their response profile. As the studies are performed on the same tumor model, the genetic background heterogeneity that can bias molecular comparison of patient cohorts subjected to different therapeutic options is eliminated. The use of PDXs for this type of studies enables to investigate the response of the same tumor to different treatments by generating as many preclinical arms of xenografted mice as desired. These studies, besides providing a personalized profiling of tumor sensitivity to treatment, allow the investigation of the associated molecular features. In parallel, extensive molecular characterization has been performed, including gene expression array-CGH microarrays, and mutational profile of 73 genes most frequently mutated in the tumor types available in our PDX collection by microarray-based exon trapping coupled to high-throughput sequencing. For each model, mutational, gene expression and SNP/aCGH data of each PDX have been associated with treatment response profile in order to check for biomarkers associated with tumor sensitivity or resistance to treatment. The results obtained have been crossed with genomic data from patient cohorts with annotated response to SOC, and the results of these analyses will be discussed. Poster Session – Preclinical Models The use of each PDX as representative of a patient subset carrying the same overall genomic alteration could be the good compromise between the panel-driven and personalized use of PDXs to stratify patients. 175 POSTER (Board P169) Functional analysis of [methyl-3 H]choline uptake in glioblastoma cells: Influence of anti-cancer and central nervous system drugs M. Inazu1 , C. Taguchi2 , T. Yamanaka3 , H. Uchino2 . 1 Tokyo Medical University, Institute of Medical Science, Tokyo, Japan; 2 Tokyo Medical University, Department of Anesthesiology, Tokyo, Japan; 3 Tokyo Medical University, Department of Molecular Preventive Medicine, Tokyo, Japan Positron emission tomography (PET) and PET/computed tomography (PETCT) studies with 11 C- or 18 F-labeled choline derivatives are used to differentiate between malignant and benign lesions in various regions of the body, including the brain, head, bone, and soft tissue. Concerning glioma, choline PET may make it possible to differentiate between low-grade and high-grade gliomas. Moreover, untreated and recurrent high-grade gliomas can be visualized with sharp delineation, without any influence by reactive inflammatory changes caused by choline PET. Further, a recent in vitro study suggested that choline PET may be a useful indicator of the response to chemotherapy agents that act by inhibiting signal transduction. However, the nature of the choline transport system in glioblastoma is poorly understood. In this study, we performed a functional characterization of [methyl-3 H]choline uptake and sought to identify the transporters that mediate choline uptake in the human glioblastoma cell lines A-172 and U-251MG. In addition, we examined the influence of anti-cancer drugs and central nervous system drugs on the transport of [methyl-3 H]choline. High- and low-affinity choline transport systems were present in A-172 cells, U-251MG cells and astrocytes, and these were Na+ -independent and pH-dependent. Cell viability in A-172 cells was not affected by choline deficiency. However, cell viability in U-251MG cells was significantly inhibited by choline deficiency. Both A-172 and U-251MG cells have two different choline transporters, choline transporter-like protein 1 (CTL1) and CTL2. In A-172 cells, CTL1 is predominantly expressed, whereas in U-251MG cells, CTL2 is predominantly expressed. Treatment with anti-cancer drugs such as cisplatin, etoposide and vincristine influenced [methyl-3 H]choline uptake in U-251MG cells, but not A-172 cells. Central nervous system drugs such as imipramine, fluvoxamine, paroxetine, reboxetine, citalopram and donepezil did not affect cell viability or [methyl3 H]choline uptake. The data presented here suggest that CTL1 and CTL2 are functionally expressed in A-172 and U-251MG cells and are responsible for [methyl-3 H]choline uptake that relies on a directed H+ gradient as a driving force. Furthermore, while anti-cancer drugs altered [methyl3 H]choline uptake, central nervous system drugs did not affect [methyl3 H]choline uptake. 176 POSTER (Board P170) Resolvin D2 has mitogenic activity in estrogen receptor positive breast cancer cell lines via activation of estrogen receptor N. Al-Zaubai1 , C. Johnstone2 , M. Rizzacasa3 , A. Stewart1 . 1 University of Melbourne, Pharmacology and Therapeutics, Melbourne Victoria, Australia; 2 Peter Maccallum Cancer Centre, Research Division, Melbourne Victoria, Australia; 3 University of Melbourne, School of Chemistry, Melbourne Victoria, Australia Background: Inflammation has been implicated in tumour initiation, angiogenesis and metastasis and linked to the development of more aggressive, therapy-resistant estrogen receptor positive breast cancer. Resolvin D2 (RvD2) is a potent anti-inflammatory lipid mediator. As RvD2 is present in plasma at bioactive concentrations and may be synthesized within breast tumours by both tumour and stromal cells, we have characterized the impact of RvD2 on cell processes underlying breast tumour growth and spread. Materials and Methods: Viable cells were enumerated by Trypan-blue exclusion. Transactivation of estrogen response element was assessed by transient transfection with estrogen response element (ERE) reporter and pGL3 vector constructs. RT-qPCR was used to examine gene expression. Binding to the estrogen receptor was investigated by competitive radioligand binding assays. Western blotting and immunofluorescence were the techniques used to ascertain estrogen receptor a nuclear localization. Results: Unexpectedly, whilst RvD2 (10–1000 nM) supported the proliferation of the ER-positive breast tumour, MCF-7, cells, it did not affect the ER-negative, MDA-MB-231 cell number. The proliferative effect of RvD2 in MCF-7 cells was attenuated by the estrogen receptor antagonist ICI 182,780 (fulvestrant). Furthermore, RvD2 increased ERE transcriptional activity in a number of ER positive breast and ovarian tumour cell lines. Poster Session – Preclinical Models This activation was also inhibited by ICI 182,780. RvD2 altered the expression of a subset of estrogen-responsive genes. Prior exposure of MCF-7 cells to RvD2 resulted in a significant reduction in the apparent cytosolic ER density. However, binding experiments showed that RvD2 did not directly compete with 3 [H]-17b-estradiol (E2) for ER binding. Confocal immunocytochemistry and western blotting studies showed that RvD2 promoted nuclear localization of ERa with a corresponding decrease in cytosol ER density. Conclusions: These observations indicate that RvD2 displays significant but indirect estrogenic activities and that it has the potential to play a role in estrogen-dependent breast cancer progression. 177 POSTER (Board P171) Validation of 3D primary organoid cultures of colorectal carcinoma as discovery and validation platform for personalized cancer therapy P. Halonen1 , A. Kuijpers2 , B. Morris1 , B. Diosdado1 , S. Mainardi1 , R. Bernards1 , V. Verwaal2 , R. Beijersbergen1 . 1 Netherlands Cancer Institute − Antoni van Leeuwenhoek Hospital, Molecular Carcinogenesis, Amsterdam, Netherlands; 2 Netherlands Cancer Institute − Antoni van Leeuwenhoek Hospital, Colorectal Surgery, Amsterdam, Netherlands Background: Primary organoid cultures derived from patients’ tumors hold promise for the improvement of cancer therapy. For this, organoid cultures should accurately represent primary tumors with respect to their morphological and genomic characteristics. We have developed a 3D organoid culturing platform for primary and metastatic colorectal carcinoma derived from human tissues to conduct comparative studies of the primary tumors and the organoid culture counterparts. Material and Methods: Surgical specimens of primary and metastatic colorectal carcinoma were used to derive the primary tissue for culturing. 3D cultures were established based on the protocol by Sato et al. and adjusted for human colorectal cancer cells. Phenotypic comparison of primary tissue and organoids was done by immunohistochemistry. Genomic analysis consisted of copy number variation analysis by low-resolution full genome sequencing and exome sequencing by kinome capture; RNAseq was used to analyze gene expression. Signaling pathway status and drug responses were quantified using western blot analysis and Luminex technology combined with viability read-outs and fluorescence microscopy. Results: A high degree of similarity between the 3D cultures and original patient tissues was observed by immunohistochemistry using general and differentially expressed colorectal cancer markers. Genomic alterations identified in the primary tumor were also present in the organoid cultures derived thereof. Although some mutations were enriched in the organoids, we did not observe the appearance of specific mutations within the organoid panel. Comparison of short and long term organoid cultures indicated the preservation of the genomic alterations with some additional mutations indicative of the genomic instability of tumors. Gene expression analysis by RNAseq revealed clustering of organoids with the primary tissue and a concordance with subtype classification. Conclusions: This study shows that organoid cultures are highly representative of primary tumors and maintain these characteristics upon prolonged culturing. This establishes patient derived organoids as a discovery and validation platform for the prediction of drug response and a platform for the discovery of treatment options for personalized therapy. 178 POSTER (Board P172) Establishment of patient-derived xenografts (PDX) models for small cell lung (SCL) as a pre-clinical platform for drug development T. Broudy1 , J. Ricono1 , C. Mullins1 , C. Mirsaidi1 , P. Nair1 . 1 Molecular Response, San Diego, USA With over 150,000 deaths in 2012, lung cancer is the deadliest carcinoma in the United Sates. Small cell lung cancer, encompassing about 15−20% of all lung cancer cases, is more invasive and has a higher rate of proliferation with respect to non-small cell lung cancer, leading to a higher mortality rate. Most cases are responsive to chemotherapy, however there is a high rate of recurrence with treated patients and those in advanced stage of the disease often have a refractory response to treatment. Due to the fast growing nature of this cancer, the long term survival rate is low whilst advanced stage cancers typically will lead to expiry within 1 year of diagnosis. Preclinical PDX models have become valuable tools for novel drug development in recent years. Here, we used patient derived tissue to generate 8 new SCLC models in NOD-SCID mice. Patient tumors were pre-screened for their myc amplification status, before inoculating into immunocompromised animals. Once established as PDX models, cells were also grown in 3D cultures to compare morphology and to perform drug treatments to assess anti-proliferative potential of various compounds. Further characterization of the models were done by H&E, immunohistochemistry, and mutation analysis by next-generation Wednesday 19 November 2014 59 sequencing. Efficacy of standard of care drugs irinotecan, and cisplatin– etoposide combination was demonstrated in these models. Current studies are underway to derive correlations between in vivo drug response and mutational status of these models. Our data strongly suggests the potential utility of these unique PDX models in drug development efforts in oncology. 179 POSTER (Board P173) Effects of human breast cancer cells secreted factors on macrophage differentiation S. Coimbra de Sousa1 , R. Brion2 , J. Mönkkönen1 , H. Joensuu3 , D. Heymann2 , J. Määttä1 . 1 University of Eastern Finland, School of Pharmacy, Kuopio, Finland; 2 INSERM, UMR957, Nantes, France; 3 Helsinki University Central Hospital, Department of Oncology, Helsinki, Finland Background: Tumour associated macrophages (TAM) are a macrophage (Mf) population recruited and educated by tumour cells. Therefore, TAM exposed to IL-10, TGF-b, M-CSF and other immunosuppressive stimuli are more closely related to the M2 than M1 type macrophages. TAMs perform preferentially trophic tasks promoting epithelial outgrowth and invasion, common to the Mf role in development, rather than immune roles. The current study focuses on the in vitro differentiation of human Mfs in the presence of breast cancer conditioned medium (CM) and the differential expression of M1 and M2c markers by TAMs in tissue samples from breast cancer patients. Materials and Methods: CD14+ freshly isolated human monocytes were in vitro differentiated to M1 (IFN-g), M2a (IL-4) and M2c (IL-10) Mfs in the presence or absence of human breast cancer cell line CM (MCF-7, T47D and MDA-MB231). Differentiated cells were analysed by flow cytometry for the expression of CD14, CD16, CD64, CD86, CD200R and CD163. CD68, HLA-DRIIa and CD163 were analysed by immunohistochemistry in tissue microarray (TMA) samples from a large cohort of human breast cancer patients. Results: All the breast cancer CM enhanced M2a differentiation, by increasing the percentage of cells in the population of CD200Rhigh CD86med that normally results from IL-4 stimulus. Further, MDA-MB231 CM was sufficient to increase CD163 expression levels to the same extent as IL-10, the M2c inducing cytokine. In conjugation IL-10 and MDA-MB231 CM further increased CD163 expression. From the ongoing TMA analysis we expect to find out the effect of breast tumour Mf infiltration (assessed by CD68), M1 (HLA-DRIIa) and M2c differentiation (CD163) on recurrencefree survival of breast cancer patients treated in a randomised clinical trial (the FinXX trial). Conclusions: Breast cancer cell lines affect alternative Mf differentiation, inducing more matrix remodelling and immune-suppressive status, respectively M2a and M2c. Clinically this effect is relevant as human breast cancer TAM differentiation status may influence metastases formation, therapy efficacy and ultimately patient outcome. 180 POSTER (Board P174) Identifying and monitoring somatic mutations in cell free DNA of patients with metastatic melanoma J. Wisell1 , C.M. Amato2 , W.A. Robinson2 . 1 University of Colorado, Pathology, Aurora CO, USA; 2 University of Colorado, Medical Oncology, Aurora CO, USA Background: Within the last decade, significant advances have been made in understanding the molecular pathogenesis of melanoma, and several mutations such as those found in KIT, a tyrosine kinase receptor, and BRAF proto-oncogene, play a significant role in the disease. Patients with melanoma benefit from somatic mutation screening, particularly when it comes to predicting for therapeutic response. Such mutational analysis is performed on tumor samples, and with recent advancements in molecular biology, it is now possible to detect genetic changes, i.e. somatic mutations, in patient blood. In this study, our laboratory explored possible candidates for monitoring disease progression in patient blood samples. Material and Methods: The University of Colorado Skin Cancer Biorepository hosts an extensive collection of clinically annotated blood and tumor samples. We screened 175 metastatic melanoma tissue samples for 37 separate mutations in 10 different genes to identify somatic mutations suitable for monitoring in matched patient blood samples. Cell free DNA (cfDNA) was isolated from patient plasma samples, and somatic mutations were measured using digital PCR (dPCR). Results: In our tissue screen, approximately 65% of the samples contained at least one mutation, BRAF being the most commonly mutated oncogene, while RAS (KRAS and NRAS) and KIT mutations were second and third. In our cfDNA analysis, BRAFV600E levels in patient plasma correlated with disease burden. Conclusion: We demonstrate that somatic mutations are detectable in cfDNA isolated from patient blood samples. Our results show that 60 Wednesday 19 November 2014 Poster Session – Preclinical Models BRAFV600E mutation levels correlate with tumor burden and suggest a possible role as a prognostic indicator. Studies are currently underway to examine RAS mutations in patient blood as a possible marker for acquired resistance to BRAF inhibitors, and to monitor disease progression in patients with BRAF wildtype tumors. 181 POSTER (Board P175) Aberrant Wnt signaling activation in human cancers: In vitro and in vivo models to facilitate Wnt targeted drug development 1 1 1 1 1 1 1 G. Liu , C. Dong , R. Zhang , L. Zhang , S. Qian , J. Cai , J. Zhang , J. Ning1 . 1 Crown Bioscience Inc., Molecular and Cellular Biology, Taicang, China Activation of Wnt signaling has emerged as one of the major oncogenic aberrations in human cancers, which has been demonstrated to play critical roles in the maintenance of the undifferentiated cancer stem/progenitor cell phenotype, as well as to directly stimulate the malignant growth of tumors. Mutations in the downstream signaling components, including APC, AXIN, and b-catenin, have been well described in several cancer types, and recent studies have further extended the Wnt activation mechanisms beyond these downstream mutations to upstream signaling molecules in this pathway. By screening primary cancer cells established from the patient derived xenograft models, we identified multiple cancer types that secrete Wnt stimulating ligands. We also successfully established primary cancer cell line harboring recurrent R-spondin fusion mutations. Inhibition of the activated Wnt signaling in these cancer cells results in reduced cancer cell growth, indicating the critical dependence of cancer cells on the autocrine Wnt signaling. Thus, these in vitro and in vivo models provide a valuable resource for the high throughput screening of Wnt antagonists, efficacy assessment of candidate Wnt inhibitors, biomarker analysis, as well as the preclinical development of Wnt targeted therapeutics. 182 POSTER (Board P176) TRAP1 represents a key mediator of stemness and glycolytic metabolism in colorectal cancer cells G. Lettini1 , F. Maddalena1 , L. Sisinni1 , V. Condelli1 , L. Del Vecchio2 , M. Gemei2 , T. Notarangelo1 , M. Landriscina3 . 1 CROB − IRCCS, Laboratory of Pre-Clinical and Translational Research, Rionero in Vulture (PZ), Italy; 2 CEINGE, Biotecnologie Avanzate, Napoli, Italy; 3 University of Foggia, Clinical Oncology Unit Department of Medical and Surgical Sciences, Foggia, Italy Background: Tumor cells undergo a metabolic shift from mitochondrial oxidative phosphorylation to a preferential glycolytic metabolism, known as Warburg effect. Furthermore, cancer stem cells (CSCs), known for being responsible for tumor initiation and growth, are located in a hypoxic microenvironment, heavily relying on anaerobic glycolysis. Recently, tumor necrosis factor receptor-associated protein 1 (TRAP1), a HSP90 mitochondrial molecular chaperone up-regulated in colorectal, prostate, breast and lung carcinomas, has been identified as a key regulator of tumor cell metabolism, being responsible for suppression of mitochondrial oxidative phosphorylation and post-translational stabilization of HIF1a. This study was designed to address the hypothesis that TRAP1 is relevant in determining specific features of the CSC phenotype and, more specifically, the reprogramming of their metabolism. Methods: TRAP1 levels were investigated in CD166-positive CSC fractions of HCT116 and HT29 colorectal carcinoma cells (CRCs) and primary stem cells derived from dental pulp by flow cytometry, cell sorting and upon colony formation assay. Interfering strategies were used to evaluate TRAP1 role in regulating glucose uptake and glycolytic metabolism. Results: TRAP1-interfered CRC HCT116 cells showed lower clonogenic potential than scramble cells in soft agar assay. Furthermore, CD166positive CSCs derived from CRC cell lines exhibited higher TRAP1 levels compared to non-CSC subpopulations and, consistently, TRAP1 stable interference resulted in the down-regulation of CD166 expression in HCT116 cells. In parallel experiment, TRAP1 expression was downregulated upon differentiation of primary stem cells derived from dental pulp. Finally, TRAP1 interference resulted in increased O2 consumption and in reduced glucose uptake, and the parallel inhibition of the expression of glucose transporters 1 and 2 and lactate production in CRC cells. Conclusion: These preliminary data suggest a potential role of TRAP1 in the maintenance of the CSC phenotype, likely due to its capacity to enhance glucose uptake and glycolytic metabolism, thus favoring the adaptation to a hypoxic microenvironment. 183 POSTER (Board P177) Spatio-temporal characterization of tumor growth and invasion A.M. Jimenez1 , O. Yogurtcu2 , M. Horn-Lee1 , P. Rao1 , S.X. Sun2 , D. Wirtz1 . 1 Johns Hopkins University, Chemical and Biomolecular Eng, Baltimore MD, USA; 2 Johns Hopkins University, Mechanical Engineering, Baltimore MD, USA Background: Tumors are a complex arrangement of tissues made up of several components, including dense masses of cancer cells and extracellular matrix (ECM). Recent studies have revealed the crucial role extracellular matrix components have on single cancer cell behavior, but how the interaction of ECM components affect the growth dynamics of an entire tumor is not well understood. Materials and Methods: We designed a novel three-dimensional (3D) in vitro system and used human derived fibrosarcoma cell (HT1080) aggregates embedded in 3D collagen matrices in combination with live cell imaging, cryo-stat sectioning, and immunostaining to characterize tumor growth and invasion. Results: Multicellular aggregates grow linearly with a rate that decreases with increasing collagen concentration. The spatio-temporal cell density distribution of the aggregates differs with differing collagen concentrations. Both cell migration and proliferation are highly dependent on collagen concentration and local cell density. Conclusion: We identified cell migration as a key contributor to multicellular aggregate size and demonstrate that different cell phenotypes correlate with different invasion patterns of the cell aggregates at various collagen concentrations. 184 POSTER (Board P178) Molecular profiling of heterogeneous tumor cells A. Chenchik1 , D. Deng1 , K. Bonneau1 , M. Makhanov1 , M. Coram2 , G. Dolganov2 , S.S. Jeffrey2 . 1 Cellecta Inc., Mountain View CA, USA; 2 Stanford University, Palo Alto CA, USA Molecular profiling of heterogeneous circulating tumor cells (CTCs) and tumor biopsy samples at the single-cell level is critical for identifying different cancer cell subpopulations and understanding their value in predicting metastatic cancer progression and responses to treatment. Unfortunately, the isolation and comprehensive characterization of hundreds to thousands of individual cancer cells present formidable analytical and technical challenges. To this end, we developed a high-throughput (HT) HiCellex technology to obtain the genome-wide expression and mutation profiles of hundreds to thousands of epithelial cancer cells at the single cell level. Importantly, HiCellex allows selective molecular profiling of a complete set of viable cells at the single-cell level in the presence of contaminating leukocytes without physical separation of individual cells. The genetic profiling technology uses unique cell-specific molecular barcodes to label mRNAs in individual viable cancer cells by a spliceosome-mediated trans-splicing mechanism. Barcoded trans-splicing constructs, necessary for the labeling of the entire population of pre-mRNAs, are delivered and expressed in a pool of target cancer cells with lentiviral vectors. Digital expression data are generated by HT sequencing of barcoded amplified cDNAs and easily cluster to each cell in silico using cell-specific barcodes. This presentation will provide results of development and validation of genome-wide and multiplex RT-PCR profiling assay of the 500 most informative subtyping and metastatic signature genes (MGS) in model cancer cell lines, CTC and tumor samples. The developed HiCellex 500 MGS profiling assay is a cost-effective approach to effectively characterize, subtype and identify prognostic and diagnostic biomarkers in heterogeneous cancer cells at the single-cell level. 185 POSTER (Board P179) Treatment of patient-derived NSCLC xenograft preclinical models using image-guided small animal irradiation N. Papadopoulou1 , A. McKenzie1 , J. King1 , M. Page1 , R. Kumari1 . 1 Precos Ltd, Crown Bioscience, Loughborough Leicestershire, United Kingdom Background: Radiotherapy is a primary, adjuvant or neoadjuvant treatment for a number of different cancers such as glioblastoma, breast, lung and prostate. Image-guided micro-irradiation (IGMI) is widely used to treat cancer patients providing more accurate treatment plans and reduced side effects. However in the preclinical setting the use of IGMI is less common with traditional irradiation studies utilising whole body irradiation with lead shielding to focus the radiation to a specific area on the animal or simple single beam techniques. The development of the image-guided small animal radiation research platform (SARRP) allows the treatment of animal models of cancer more accurately and with planned protocols Poster Session – Preclinical Models similar to those utilised in the clinic. We have established a panel of Caucasian NSCLC patient-derived xenograft (PDX), which are sensitive or have acquired resistance to standard of care treatments. Methods: NSCLC samples obtained from untreated patients undergoing surgery were collected with ethical consent, disaggregated and implanted subcutaneously in MF-1 nude mice (Harlan, UK) admixed with a human stromal cell component to generate patient-derived xenograft (PDX) models. Resistant models were generated in vivo through repeated cycling of treatment for up to 10 weeks with standard of care or targeted agents. Patient-derived xenografts were maintained in vivo and monitored by calliper measurements three times weekly and mice recruited to the study when mean tumour volume was approximately 100–200 mm3 . Irradiation protocols and dose calculation were designed to deliver appropriate irradiation dose (2−3 Gy/day/mouse) to the tumours either alone or in combination with a targeted agent/chemotherapeutic, whilst sparing the surrounding normal tissue. Response to treatment was evaluated by tumour growth inhibition and clinical condition of mice monitored daily. Results: Mice treated with IGMI using the SARRP tolerated irradiation doses either alone or in combinations. Response and resistance to irradiation across a panel of Caucasian NSCLC PDX and resistant models will be reported along with any outcome of the combination treatments to re-sensitize resistant cancer to radiotherapy. Conclusions: The SARRP platform allows the evaluation of irradiation alone or in combination with anti-cancer agents in small animals with reduced side effects and improved safety outcome, allowing these novel preclinical models to be used effectively for drug discovery programmes and to derive irradiation schedules and regimens suitable for testing subsequently in clinical trials. 186 POSTER (Board P180) The use of Quantitative Textural Analysis imaging biomarkers to predict response to temsirolimus treatment in advanced HCC subjects R. Korn1 , R. Osarogiagbon2 , R. Newbold3 , D. Burkett4 , J. Sachdev5 . 1 Scottsdale Healthcare Research Institute TGEN, Imaging Endpoints, Scottsdale, USA; 2 Baptist Cancer Center, Oncology, Memphis, USA; 3 Scottsdale Medical Imaging, Radiology, Scottsdale, USA; 4 Imaging Endpoints Core Lab, Radiology, Scottsdale, USA; 5 Scottsdale Healthcare Research Institute-TGEN, Virginia G Piper Cancer Center, Scottsdale, USA Background: The treatment of advanced HCC can be challenging. Being able to predict who will respond to therapy would represent a major step forward in disease control. We have developed an exploratory CT imaging biomarker that may predict treatment response to temsirolimus (T) after sorafenib (S) failure using quantitative textural analysis (QTA) of hepatic tissue and tumors on CT scans. Material and Methods: Pre and Post venous phase contrast CT scans through the abdomen were obtained in 10 subjects enrolled in a IIT from a single institution prior to treatment with T after S failure. QTA was performed on the axial slice of the liver containing both uninvolved hepatic tissue and tumor in the same slice. QTA parameters were generated at a fine filter level (SSF 3) and displayed as histogram derived features of mean, SD, mean positive pixel (MPP), entropy, skewness and kurtosis. Statistical Correlation between QTA parameters and subsequent CT tumor responses by mRECIST criteria, Barcelona score, tumor markers, OS, PFS were performed using spearman correlations, regression analysis and ROC analysis. P values <0.05 were considered significant. Results: A single arm Simon two-stage phase II trial was conducted to test the activity of T in previously S treated HCC patients. Of the 26 subjects enrolled 10 subjects qualified for QTA analysis as having both pre and post contrast venous phase CT scans available for evaluation. Of the 10 subjects, 7 had PR and 3 had SD as best response by mRECIST. The mean change in tumor size was −26.7% (median −34.4%, range −52.5% to 11.3%) for the 10 subjects. Using QTA there was a significant correlation between baseline tissue-tumor texture and best mRECIST response as measured by MPP (rho = 0.7551, p = 0.0011). ROC analysis showed that a MPP cutoff value of 7.95 had the best separation of predicting PRs with a 85% sensitivity and 100% specificity. No significant correlation was noted between QTA and PFS, OS, serum tumor markers, Barcelona scores. Conclusion: This limited analysis of responding HCC patients indicates that textural analysis from CT scans may provide an imaging biomarker for predicting response to T therapy following S failure. Although preliminary, these findings merit further investigation. Wednesday 19 November 2014 61 187 POSTER (Board P181) Targeted genomic profiling of penile squamous cell carcinoma using the Oncomine cancer research panel A.S. McDaniel1 , D. Hovelson1 , A. Cani1 , C.J. Liu1 , Y. Zhang1 , S. Sadis2 , S. Bandla2 , P. Williams2 , D. Rhodes2 , S.A. Tomlins1 . 1 University of Michigan, Pathology, Ann Arbor MI, USA; 2 ThermoFisher Scientific, Ann Arbor MI, USA Background: Penile squamous cell carcinoma (PeSCC) is a rare cancer notable for significant morbidity and mortality as well as an incomplete understanding of the underlying molecular alterations and lack of effective non-surgical therapeutic approaches. Material and Methods: A retrospective cohort of 60 formalin fixed, paraffin embedded (FFPE) tumor samples from 44 PeSCC cases (including 14 matched primary/metastasis pairs) was subjected to targeted next generation sequencing (NGS) using the Oncomine Cancer Research Panel encompassing actionable recurrent somatic alterations in ~125 oncogenes and tumor suppressors identified by analysis across multiple cancer types. Sequencing of multiplexed templates was performed using the IonTorrent Proton system. Sequence analysis was performed in Torrent Suite 4.0, with sequence alignment by TMAP, and variant calling using the Torrent Variant Caller plugin. HPV infection status for each sample was assessed using additional genomic DNA for PCR with the GP5/6 and My09/11 consensus primer sets for viral detection and typing. Results: Highly multiplexed targeted NGS yielded an average of 1,136,032 mapped reads per sample with high coverage (mean >450×) over targeted bases using 20 ng of input genomic DNA. High risk HPV was detected in five cases (Four with HPV 16, one with HPV 33). All classes of genomic alterations were evaluated, including single nucleotide variants (SNVs), insertions, deletions, stopgains, and copy number variants (CNVs). Frequently altered genes included CDKN2A (20 of 44), TP53 (19 of 44), NOTCH1 (9 of 44), FBXW7 (8 of 44), PIK3CA (7 of 44), NFE2L2 (6 of 44), and HRAS (6 of 44). Notably, tumor specimens from four cases harbored amplifications of EGFR and one case demonstrated CDK4 amplification; genes for which approved and investigational targeted therapies are available. Importantly, cases with multiple tumor samples profiled showed significant differences in 4 of 14 paired samples, indicating heterogeneity for actionable mutations such as EGFR amplification between primary tumors and metastases. Conclusions: We evaluated a cohort of PeSCC FFPE specimens using an NGS panel of recurrently altered cancer-associated somatic variants, providing detailed molecular analysis of this disease for the first time. The scope of mutations identified was similar to squamous cell carcinomas from other locations such as the lung and head and neck region. We identified a subset of cases harboring mutations with immediate therapeutic potential, including EGFR amplifications. This research suggests that NGS profiling of PeSCC may have utility as part of a precision medicine approach to aid clinical decision making. 188 POSTER (Board P182) RANBP2 knock-down is synthetic lethal with BRAF V600E in colon cancer L. Vecchione1 , V. Gambino1 , G. d’Ario2 , S. Tian3 , A. Schlicker1 , S. Mainardi1 , B. Diosdado1 , I. Simon3 , M. Delorenzi2 , C. Lieftink1 , R. Beijersbergen1 , S. Tejpar4 , R. Bernards1 . 1 NKI/AVL, Division of Molecular Carcinogenesis, Amsterdam, Netherlands; 2 Swiss Institute for Bioinformatics, Bioinformatics Core Facility, Lausanne, Switzerland; 3 Agendia BV, Agendia BV, Amsterdam, Netherlands; 4 KULeuven, Laboratory of Digestive Oncology, Leuven, Belgium Background: Approximately 8−15% of colon (CC) patients carry an activating mutation in BRAF. This CC subtype is associated with poor outcome and with resistance to chemotherapeutic treatments. We recently showed that BRAF (V600E) colon cancers have a characteristic gene expression signature, which is found also in subsets of KRAS mutant and KRAS-BRAF wild type (WT2) tumors. Tumors having this gene signature, referred to as ‘BRAF-like’, have a similar poor prognosis irrespective of the presence of the BRAF (V600E) mutation. By using a shRNA-based genetic screen in BRAF mutant CC cell lines we aimed to identify genes necessary for survival and growth of BRAF mutant CC in order to reveal novel targets for therapy. Method: We selected 363 genes that are specifically overexpressed in 89 BRAF mutant tumors as compared to 608 WT2 type tumors, based on gene expression profiles generated in two independent datasets The 363 genes list was used to generate a shRNA library consisting of 1815 hairpins targeting these genes (BRAF library) selected from the TRC human genome-wide shRNA collection (TRC-Hs1.0). Vaco432 and WIDR (BRAFV600E) CC cell lines and Lim1215 (WT2) CC cell line were infected with the BRAF library and screened for shRNAs that are selectively synthetic lethal with BRAFV600E mutation. Cells stably expressing the shRNA 62 Wednesday 19 November 2014 library were cultured for 13 days, after which shRNAs were recovered by PCR. Deep sequencing was applied to determine the relative abundance of each shRNA in BRAF (V600E) cells as compared to WT2 CC cells. Results and Conclusions: Based on the results of the pooled shRNA screen, we were able to identify six candidate synthetic lethal genes in BRAF mutant CC cell lines. In particular, further validation showed RANBP2 gene knock-down to be synthetic lethal with BRAFV600E and BRAFlikeness in CC. Experiments addressing the identification and the biological characterization of RANBP2 will be presented. 189 POSTER (Board P183) Molecular and pharmacological characterization of primary mesothelioma tumor cell lines orthotopically xenografted in nude mice C. Pisano1 , A. Cole1 , A. Barbarino1 , E. Bianchino1 , M. Guglielmi1 , C. Melito1 , G. Mercadante1 , A. Porciello1 , A. Riccio1 , I. La Porta1 , S. Orecchia2 , R. Libener2 , L. Mazzucco2 , S. Licandro3 , M. Ceccarelli4 , F. D’Angelo4 , P. De Luca1 . 1 Biogem, Preclinical Research&Development Service, Ariano Irpino (AV), Italy; 2 Azienda Ospedaliera, Hematology, Alessandria (AL), Italy; 3 IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Oncology, Milano (MI), Italy; 4 Biogem, Bioinformatic, Ariano Irpino (AV), Italy Background: Mesothelioma is estimated at less than 1% of all cancers, however its incidence is increasing, with an expected peak in the next 10−20 years. In order to setup in vivo models of human mesothelioma, putatively relevant to studies of the human pathology in terms of histology, antigen expression, and pharmacological response to chemotherapy, we have established in vivo models of mesothelioma, using primary tumors, having different histotypes. Material and Methods: primary cells derived from nine mesothelioma patients were xenografted orthotopically in immunodeficient nude mice. Cells derived from three of nine xenografted mice (MM432: sarcomatoid, MM473: epithelioid and MM487: biphasic) were stably transfected with luciferase expression vector. These cells and the nine original cell lines were used for further molecular and biochemical characterization. Results: The selected MM473 and MM487 high luc-expressing clones were intrapleurally reinoculated in immunodeficient nude mice. They successfully invaded and proliferated within the murine host. In particular, the epithelioid histotype presented tumour growth in 100% of mice, after a short latency period. The biphasic histotype showed tumour growth in 30% of the cases, although it was far more aggressive than the epithelial histotype in engrafted mice. Immunohystochemistry evaluation of resultant tumour masses confirmed the histotype from the parental patient tumours (i.e. for CEA, EMA, Mesothelin, Podoplanin, calretinin). Interestingly, biochemical characterization (i.e. EGFR, VEGF, Top1, TKs pathways) of the three histotypes, revealed histotype-related differences. The exposure of the nine cell lines to a panel of pharmaceutical drugs (i.e. Doxorubicin, Topotecan, Cyclophosphamide, Dacarbazine, Gemcitabine, Temozolomide, Bortezomib, 5-Azacitidine, Paclitaxel, Etoposide, 5-FU, Cisplatin, and AZD-2281) revealed a different not histotypes-related sensitivity. Western blot and RT-PCR analysis revealed that mesothelioma cell lines express elevated levels of EGFR (RNA and protein) not correlate with downstream signaling pathways. Thus, the sensitivity to gefitinib of these cells was not correlated with the EGFR expression. Finally, gene expression analysis between the three histotypes (MM432, MM473 and MM487) revealed that more than 1000 genes are differentially expressed. Conclusions: Taken together, these results have led to expand our knowledge on the molecular and biochemical features of various type of mesotheliomas. In addition, our in vivo models, being established from primary cells from patients, enlarged the available models of mesothelioma that, with the limitations intrinsic to the experimental models, can be predictive about the efficacy of new drugs or new therapeutic approaches for this incurable disease. 190 POSTER (Board P184) Differential chemosensitivity between CETCs and tumour spheroids in cancer patients with solid tumors D. Zimon1 , M. Pizon2 , E.L. Stein2 , U. Pachmann2 , K. Pachmann2 . 1 Simfo GmbH, Bayreuth, Germany; 2 Simfo GmbH, Research, Bayreuth, Germany Background: In vitro chemosensitivity testing of circulating epithelial tumor cells (CETCs) provides real-time information about the sensitivity of the tumor cells present in the patient and correlates with treatment success. Nevertheless, a fraction of CETCs can survive after conventional chemotherapy and grow into distant metastasis. A subpopulation of CETCs with proliferation activity has the ability to form spheroids in suspension Poster Session – Preclinical Models culture. Spheroids exhibit stem cell-like properties and may be responsible for chemo therapeutic resistance. Therefore, the aim of our study was the comparison of the efficacy of chemotherapeutics on CETCs and on spheroids originated from the same individuals. Methods: The enumeration of CETCs collected from patients with solid tumors in clinical stage 1−4 were performed using the maintrac® method. Subsequently, viable CETCs were cultured in suspension culture system allowing for spheroid formation. To evaluate the cytotoxic effect CETCs and spheroids we exposed to anticancer drugs in short time culture in different concentrations and for different periods of time. Results: The response to chemotherapeutics was different between CETCs and spheroids. In contrast to CETCs, spheroids from the same patients were significantly more chemoresistant. Whereas active drugs led to membrane permeability in single CETCs with subsequent staining of the nuclei with propidium iodide, the same drugs led to disintegration of tumorspheres with destruction of part of the cells but often part of the cells in the spheres were able to survive. Epirubicin and, interestingly, and especially salinomycin, a polyether ionophore antibiotic isolated from Streptomyces albus, showed the best effects. Docetaxel, cyclophosphamide and 5-fluoruracil showed almost no cytotoxic effects onto the cells in the spheres. Conclusion: Our results show, for the first time, that stem cells circulating in peripheral blood, capable of forming spheroids are way more resistant to anticancer drugs than the remnant circulating tumor cells. We, furthermore, demonstrate that salinomycin efficiently destroy spheroids cultured from CETCs, strengthening its role as promising anti-cancer therapeutic. 191 POSTER (Board P185) Homotypic and heterotypic cell signaling transduction using a dielectrophoresis microfluidic device M. Tellez Gabriel1 , D. Heymann1 . 1 Université de Nantes, UMR 957, Nantes, France Studying cell signaling transduction in homotypic and heterotypic cell interactions can have a great impact in clinics as could be useful to determine which cells are able to establish communication (e.g. tumoral niche). In this study, taking the advantage of a dielectrophoresis based microfluidics device (the DEPArray), we show the possibility of observing homotypic (Human osteosarcoma cells) and heterotypic (Human osteosarcoma cells vs. Mesenchymal Stem Cells) cell signaling transduction either single cells or clusters. We prepared two different cell populations − acceptors and donors − stained with two different fluorescent markers, one with DiI − a red non transferable molecule − and the other one with Calcein-AM − a green fluorochrom, able to be transferred through GAP junctions- and mixed them. We predetermined spatial coordinates by software-guided routing for establishing cell interactions − at different ratios of populations − within the chip, and we programmed a time-lapse for taking images of the interacting cells. The analysis of the images showed a decreasing in time of the green fluorescence intensity in donor cells, concomitant with an increasing of green fluorescence in acceptor cells, indicating the existence of cell signaling transduction between cells in both homotypic and heterotypic interactions. These findings are promising to study which specific cell–cell communications are established between different populations present in a microenvironment. 192 POSTER (Board P186) Extensive characterization of patient derived colon cancer xenografts for preclinical biomarker identification V. Vuaroqueaux1 , F. Kiefer1 , P. Bronsert2 , A.L. Peille1 , B. Zeitouni1 , F. Foucault1 , T. Kees1 , J. Guo3 , J. Schüler3 , H.H. Fiebig4 . 1 Oncotest GmbH, Biomarker Development and Bioinformatics, Freiburg, Germany; 2 Institute of Pathology University Hospital, Freiburg, Germany; 3 Oncotest GmbH, In vivo, Freiburg, Germany; 4 Oncotest GmbH, Freiburg, Germany The use of large collections of preclinical models with extensive molecular characterization is essential for improving preclinical drug sensitivity testing and biomarker identification. We established a collection of 70 patient derived xenografts (PDX) of colorectal cancer and analyzed them for morphological features, genomic alterations (Whole Exome Sequencing & Affymetrix SNP6), transcriptomic profiles (affymetrix U133 2 plus) and sensitivity to various anticancer agents. Furthermore, we set up an ‘R’ based bioinformatics process for integrative analyses and automated biomarker identification. Here, we used an integrative OMICS approach to characterize our colon cancer PDX collection and we evaluated their relevance for biomarker identification. At the histological level, colon PDX tumor tissues closely resembled the patient tumors and retained similar differentiation grades. Furthermore, we observed heterogeneity in between the different colon PDX regarding Poster Session – Preclinical Models Wednesday 19 November 2014 63 stroma content and vascularization. At the transcriptomic level, we identified several PDX clusters similar to Goblet-like, Enterocyte, Transit-Amplifying, Inflammatory and Stem-like subtypes recently reported in CRC patients. In addition, well and moderately differentiated PDX showed a different gene expression profile than poorly and undifferentiated models. At the genomic level, the colon PDX models exhibited alteration profiles comparable to those reported for patient tumors regarding signatures of mutational processes (patient-age related or associated to mismatch repair gene deficiencies), chromosomal rearrangement and mutated genes (e.g. APC, TP53, KRAS and TP53). Moreover, we identified 6 PDX models with microsatellite instability (MSI), 5 of them being hyper-mutant with a loss of MLH1 expression. Interestingly, colon PDX displaying the MSI phenotype showed gene expression patterns of the Globlet-like or Inflammatory subtypes. To demonstrate the potential of our approach, we searched for molecular determinants of cetuximab sensitivity in colon PDX by combining in vivo drug sensitivity and molecular data. The study identified the Transit Amplifying subtype, AREG/EREG expression and KRAS mutation among the best predictors of response. Similarly, predictive biomarkers for oxaliplatin and irinotecan were found, and their associations with particular PDX subtypes are under investigation. The accuracy in predicting patient outcome following treatment with FOLFOX and FOLFIRI will be evaluated by assessing publicly available datasets. The comprehensive characterization of our colon PDX models confirmed their similarities with patient tumors and their inter-tumoral diversity. The combined use of PDX molecular and drug sensitivity data represents a promising approach for biomarker identification and tumor response prediction at a preclinical stage. with advanced PDA have improved their overall survival, but the disease still inexorably progresses. The most commonly used system for drug discovery/screening and development are PDA monolayer cell lines coupled to preclinical studies in mice. However, this approach has not been successful and new ones are needed. Material and Methods: In the last year our lab has developed an organotypic three-dimensional culture system to study PDA. Murine organoids derived from normal ductal, preneoplastic or neoplastic pancreatic cells are cultured in semisolid media. In the case of human, normal and tumor are also grown in this semisolid media. Following orthotopic transplantation, these cultures form the normal, premalignant or malignant ductal structures from which they were derived and they are termed ‘pancreatic ductal organoids’. Using different methods that assess cell viability (ATP based luminescence and fluorescence), we have measured the effect of single drugs and combinatorial strategies. Results: This platform allows us to compare the IC50 of different drugs and search for those with a higher therapeutic index by comparing normal vs tumor. We have evaluated several chemotherapeutic drugs (Gemcitabine, 5-Flurouracil, paclitaxel, irinotecan and oxaliplatin) as well as some targeted agents (eg. Selumetenib, Neratinib, and MK-2206). We have also included tumor microenvironment cell types in our cultures to evaluate their role in drug responsiveness. Furthermore, organoid cultures have been transplanted orthotopically into immune-competent mice allowing for the study of therapeutic responses in vivo. Conclusions: We present this versatile ex vivo system as a promising experimental platform for achieving further insight into biologically and clinically important questions regarding cancer therapeutics in PDA. 193 POSTER (Board P187) The identification of new therapies for ependymoma subgroups 195 POSTER (Board P189) A humanized mouse model for preclinical testing of molecules targeting immune checkpoints N. Boulos1 , J.D. Dapper1 , Y.T. Patel2 , M. DeCuypere1 , B. Bianski3 , K.M. Mohankumar1 , M.O. Jacus2 , B. Freeman III4 , K.D. Wright5 , A. Gajjar5 , A.A. Shelat6 , C.F. Stewart2 , R.K. Guy6 , R.J. Gilbertson1 . 1 St Jude Children’s Research Hospital, Developmental Neurobiology, Memphis TN, USA; 2 St Jude Children’s Research Hospital, Pharmaceutical Sciences, Memphis TN, USA; 3 St Jude Children’s Research Hospital, Radiologic Sciences, Memphis TN, USA; 4 St Jude Children’s Research Hospital, Preclinical Pharmacokinetics Shared Resources, Memphis TN, USA; 5 St Jude Children’s Research Hospital, Oncology, Memphis TN, USA; 6 St Jude Children’s Research Hospital, Chemical Biology and Therapeutics, Memphis TN, USA Current treatment for ependymoma is limited to surgery and radiation; existing chemotherapies are generally ineffective. We aimed to identify new therapies for ependymoma subgroups using accurate mouse models driven by ependymoma oncogenes, including the highly recurrent C11orf95RELA fusion (RELA+ ). First, we performed unbiased, high throughput drug screening against tumor cells generated from a RTBDN-driven ependymoma (mEPRTBDN ) mouse model. Initial screens performed at a single concentration and dose response screen of 6500 compounds, comprising FDA-approved drugs and developmental candidates, identified 377 compounds with 50% activity. Of these, 30 potent compounds (with EC50 1mM) were selected for rigorous preclinical pharmacokinetics (PK) and efficacy studies that included mouse tumor neurosurgery and cranial irradiation. Our lead compound gemcitabine proved highly active in vitro against RELA fusion-negative (RELA− ) ependymoma (mEPRTBDN and mEPEPHB2 ) and RELA+ ependymoma. Applying stringent preclinical PK with consideration of pediatric clinical dosing and toxicity, we identified the optimal route of administration, dose and schedule for gemcitabine (fixed dose rate infusion of 0.805 mg/kg/min over 3 hrs). Treatment of mice harboring murine RELA− and human RELA+ ependymoma with this PK guided regimen significantly prolonged survival. Moreover, combination of gemcitabine infusions with surgery further improved survival that we are now testing in a triple treatment regimen in mice that includes surgery, radiation and gemcitabine. We currently are developing gemcitabine as a new treatment for children with both RELA+ and RELA− ependymoma. 194 POSTER (Board P188) Pancreatic ductal organoids as a new platform for drug discovery M. Ponz-Sarvise1 , V. Corbo1 , D. Öhlund1 , T. Oni1 , A. Handly-Santana1 , D. Engle1 , H. Tiriac1 , C. Chio1 , M. Feigin1 , L. Baker1 , C. Ardito-Abraham1 , Y. Park1 , C. Hwang1 , E. Elyada1 , K. Yu1 , H. Clevers2 , D.A. Tuveson1 . 1 Cold Spring Harbor Laboratory, Cancer Center, Cold Spring Harbor, USA; 2 Hubrecht Institute for Developmental Biology and Stem Cell Research, Utrecht, Netherlands Background: Pancreatic ductal adenocarcinoma (PDA) is a lethal disease with a 5-year survival rate of 6%. Newer cytotoxic regimens for patients G. Baia1 , D. Vasquez1 , D. Ciznadija1 , D. Sidransky2 , A. Katz1 , K. Paz1 . 1 Champions Oncology, Baltimore MD, USA; 2 Johns Hopkins University, Baltimore MD, USA Background: The blockade of immune checkpoints is a promising therapeutic avenue for cancer therapy, with durable objective responses observed in patients with a variety of solid tumors. Despite these successes, current animal models do not reliably identify targets with the greatest clinical potential due in part to differences between human and murine immune systems. Hence, robust preclinical tools to test these drugs directly against human cancers in the context of a human immune system are required. To circumvent this limitation, Champions Oncology has developed the ImmunoGraft, whereby two innovative technologies, the Champions TumorGraft (patient-derived xenograft) and humanized mice (immunodeficient mice reconstituted with a human immune system), are combined in a single platform. Materials and Methods: Thirty-nine melanoma, colorectal, breast, and lung TumorGrafts were characterized with respect to HLA expression, mutation status, and expression of PD-L1, a pathway targeted by several therapeutics currently in clinical trial. Immune-compromised NOG (Prkdcscid Il2rgtm1Sug ) mice were reconstituted with human CD34+ cells and the animals monitored for cell engraftment and expansion. Humanized and non-humanized NOG animals were subcutaneously implanted with tumor fragments and growth rates were compared between the two groups. Results: As early as 6 weeks after humanization was initiated, mature human CD45+cells could be detected in the circulation of humanized animals. We found at least 70% of reconstituted animals had >15% hCD45+ cells in the peripheral blood 10 weeks post-hCD34+ reconstitution. Of the hCD45+ cells present in the peripheral circulation of humanized animals, 19% were hCD3+ (T cells), of which 67% were hCD4+ helper T cells, and 25% were hCD8+. Although still early in the growth phase, tumor volumes in humanized animals are comparable to those in nonhumanized animals. Assessing ImmunoGraft responses to checkpoint inhibitors is underway. Conclusion: Our study has demonstrated the potential of combining humanized mice with Champions TumorGrafts to generate a novel and unique preclinical model. The ImmunoGraft will allow direct assessment of immuno-modulatory agents on tumor growth and progression in a platform more reflective of the complete human microenvironment. It will also facilitate research examining the critical interplay between tumors and the immune system, potentially leading to identification of the most active drugs, and perhaps additional drug targets. 64 Wednesday 19 November 2014 196 POSTER (Board P190) Neuropilin 2 (NRP2) modifies CXCL12/CXCR4 signaling and promotes lymph node metastases in colon cancer H. Schneider1 , P. Hönscheid1 , S. Schölch2 , C. Jakob1 , M. Muders1 . 1 Universitätsklinikum Carl Gustav Carus, Institute of Pathology, Dresden, Germany; 2 Universitätsklinikum Carl Gustav Carus, Department of Surgery, Dresden, Germany Aims: Dissemination of cancer cells to regional lymph nodes is one of the most important prognostic factors for colorectal cancer. To be able to form lymph node metastases tumor cells need a supportive microenvironment. One important part of this niche are lymph vessels that are located inside the lymph node. This lymphovascular niche has been shown to be an independent prognostic factor in rectal cancer patients after neoadjuvant radiochemotherapy (Jakob et al., Plos One 2011). These intranodal lymph vessels produce chemoattractant factors like CXCL12, that can bind to CXCR4-positive tumor cells and mediate cell migration. We investigated if the receptor Neuropilin-2 (NRP2) mediates lymph node metastasis by modulating the CXCR4/CXCL12 signaling pathway. Methods: In a cohort of 113 node negative colon cancer patients the lymph vessel density in regional lymph nodes was quantified by standard immunohistochemistry staining against D2−40, which labels lymphatic endothelium. In vitro experiments were performed with standard cell lines. Protein and mRNA levels were assessed by Western Blot and quantitative real time PCR. After stimulation with human recombinant CXCL12, RNAi mediated depletion of NRP2 and CXCR4 as well as after addition of recombinant Semaphorin 3F (Sema3F) Boyden Chamber Migration Assays were performed. To confirm our in vitro results a cohort of 78 patients with locally advanced node positive colon cancer was analyzed for NRP2expression in primary tumors and lymph node metastases by standard immunohistochemistry. Parallely, a nude mouse model with orthotopically implanted colorectal cancer cells was assessed. Results: In node negative colon cancer patients, intranodal lymphangiogenesis scorrelated with disease-free survival (P < 0.05). siRNA mediated depletion of NRP2 decreased CXCR4-mRNA and protein expression, while CXCR4 had no influence on NRP2 expression. Blocking NRP2 abrogated CXCL12-induced AKT phosphorylation. Increase of CXCR4 mRNA after stimulation with CXCL12 (‘feed forward loop’) was inhibited after NRP2 depletion. Tumor cell migration towards a CXCL12-gradient was reduced when NRP2 function was blocked by siRNA or Sema3F (P < 0.001). Our in vitro results were confirmed by an up-regulation of NRP2 in lymph node metastases of advanced colon cancer patients’ tissue (P < 0.001) as well as an increased expression of NRP2 in metastasis after orthotopic implantation of colorectal cancer cells in nude mice. Conclusion: NRP2 modulates the CXCL4/CXCL12 signaling axis in colorectal cancer cells and influences cell migration. Therefore, NRP2 might have an impact on the metastatic potential of colorectal cancer cells. Additionally, the detection of intranodal lymh vessels in node negative colon cancer patients by standard immunohistochemistry against D2−40 might offer a new tool for oncologists to decide whether an adjuvant treatment is recommended. 197 POSTER (Board P191) Statistical aspects of kinetic analysis of gliomas with FDG-PET D. Hawe1 , F.R. Hernandez1 , S. Murphy1 , E. Wolsztynski1 , J. Huang1 , J. O’Sullivan1 , M. Muzi2 , J. Eary3 , K. Krohn2 , F. O’Sullivan1 . 1 University College Cork, Statistics, Cork, Ireland; 2 University of Washington, Radiology, Seattle, USA; 3 University of Alabama, Radiology, Birmingham, USA Background: Positron emission tomography (PET) is used to examine the distribution of radio-labelled molecules in vivo, which allows the status of healthy and pathological tissue to be examined by studying how it processes substances of interest. Material and Methods: The interpretation of dynamic PET time-course data is complicated because the measured signal is a combination of vascular delivery and tissue retention effects. The tissue time-course can be expressed as a convolution between the arterial time-course (directly measurable) and the tissue residue. In light of this, estimating the residue is essentially a survival analysis problem, which has been examined in great detail in the literature. Kinetic analysis of PET data is concerned with estimation of the residue function and parameters such as flow, flux and volume of distribution. This is generally done using compartmental models, however as these models assume that the area being studied is homogenous, and that there is instant mixing within compartments, its validity has been questioned. Accordingly, we examine both a nonparametric model, and a mixture model approach, which do not require the same assumptions of the compartmental model and compare Poster Session – Preclinical Models these alternatives with the classic compartment model approach to the estimation of the residue function. Results: We evaluate the improvement in the mixture and nonparametric models relative to compartment models using simulations and crossvalidation. Estimates of key functionals including flow, flux and volume of distribution for the three models are compared. This is illustrated with data from ongoing 18 F-fluorodeoxyglucose-PET studies in a series of 46 brain tumour subjects. Conclusions: Significant statistical evidence against the compartment model in favour of both the nonparametric and mixture models has been found. Supported by Science Foundation Ireland under SFI-PI 11/27 and by the National Institute of Health (NCI) under PO1-CA-42045. 198 POSTER (Board P192) Genetic and pharmacological inhibition of PIM-1 reduces tumor development in a K-Ras-driven mouse model of non-small cell lung cancer E. Aguirre1 , O. Renner1 , M.C. Rodriguez de Miguel1 , M.I. Albarran1 , A. Cebria1 , D. Cebrian1 , F. Ramos-Lima1 , J. Pastor1 , C. Blanco-Aparicio1 . 1 Spanish National Cancer Research Centre (Cnio), Experimental Therapeutics Program, Madrid, Spain Lung cancer is the leading cause of cancer deaths worldwide, and 40% of these cases are diagnosed as adenocarcinomas, a subtype of nonsmall cell lung cancer (NSCLC). Activating mutations in the K-Ras protooncogene have been found in 30% of human NSCLC, and these tumors are still an unmet medical need as in most of the cases the current treatments failed. K-Ras G12V is one of the commonest mutations observed in NSCLC. Several mouse models have been created to understand the role of K-Ras in tumor initiation and progression. In this study, we have evaluated the effect of inhibiting PIM proteins in tumor progression in a mouse model in which K-Ras (G12V) mutation is conditionally activated resembling human NSCLC. The PIM proteins are a family of highly homologous serine/threonine kinases that are implicated in the regulation of apoptosis, metabolism, the cell cycle, and homing and migration, which makes these proteins interesting targets for anti-cancer drug discovery. To evaluate Pim1 inhibition as a therapeutic target for NSCLC, a conditional knock-in mouse model had been used in which Pim1 kinase activity was ablated, controlling its expression using a Cre/loxP recombination system. This kinase-dead (KD) mutant was crossed with K-Ras (G12V) mice, and 7 months after intra-tracheal administration of Cre-recombinase adenovirus, tumor development was assessed by computer tomography. The images showed that K-Ras (G12V) Pim1-KD mice developed later and less lung tumors than K-Ras (G12V) mice, significantly increasing their survival rate. Besides, histological examination of these tumors revealed that only 14% of K-Ras (G12V) Pim1-KD mice developed adenocarcinomas, whereas 73% of K-Ras (G12V) mice presented this malignant type of lung cancer. Having genetically validated PIM1 kinase as a molecular target for NSCLC treatment, we reinforced these results by pharmacological inhibition of the PIM proteins activity. For this purpose, a selective and potent proprietary panPIM inhibitor was generated in our Programme. In the PK/PD assay, this compound revealed that 24 hours after oral single dose administration (100 mg/kg), a 60% specific inhibition of phospho-4E-BP1 (Thr37/46) was detected in K-Ras (G12V) lung tumors samples. After that, the compound efficacy was evaluated by orally administrating a daily dose of 50 mg/kg for three weeks to K-Ras (G12V) mice. Pre- and post-treatment computer tomography images revealed that tumor growth inhibition rate was 61% in treated mice when compared to control mice. Besides, when the administered dose was of 80 mg/kg, tumor growth inhibition reached the value of 70%. In summary, in this study we have confirmed that genetic or pharmacological inhibition of Pim-1 kinase is an effective strategy to be considered in the treatment of NSCLC using a transgenic mouse model. In the future, further studies will be needed to establish the role of Pim inhibitors in the treatment of human NSCLC. Poster Session – Radiation Interactive Agents 199 POSTER (Board P193) Inhibitor of differentiation 1 (Id1) expression in lung cancer cells and liver microenvironment is required for liver metastasis (LM) development from non-small cell lung cancer (NSCLC) by regulating EMT-related and proliferation-related proteins E. Castanon1 , A. Soltermann2 , I. López3 , M. Ecay4 , M. Collantes4 , J.M. Lopez Picazo1 , M. Ponz5 , C. Rolfo6 , A. Calvo7 , I. Gil-Bazo1 . 1 Clinica Universidad de Navarra, Department of Oncology, Pamplona, Spain; 2 University Hospital Zurich, Institute of Surgical Pathology, Zurich, Switzerland; 3 Centro de Investigación Médica Aplicada, Laboratorio de Nuevas Dianas Terapéuticas, Pamplona, Spain; 4 Clinica Universidad de Navarra, Nuclear Medicine, Pamplona, Spain; 5 Cold Spring Harbour, Cold Spring Harbour Laboratory, New York, USA; 6 University of Amberes, Phase I Clinical Trials Unit, Antwerp, Belgium; 7 Centro de Investigación Médica Aplicada, Department of Oncology, Pamplona, Spain Introduction: Id1 is involved in carcinogenesis. We previously showed Id1 as an independent prognostic factor in NSCLC. Id1 and Id3 are required for breast cancer metastasizing to the lungs. We studied the potential role of Id1 in LM in an in vivo model of NSCLC and its correlation with EMT-related proteins. Methods: We selected 40 Id1 wild-type mice (Id1+/+) and 40 Id1 knockout mice (Id1−/−). We intrasplenically injected 5×105 Id1-silenced (Id1s), Id1/Id3-silenced (Id1/Id3s) or wild-type (Id1Id3wt) Lewis Lung Carcinoma (LLC) cells. Mice were followed by weekly microPET for 4 weeks or until death. Microscopic LMs were studied in all necropsies. A gene expression study (Affymetrix) was performed to assess differences in LM from Id1+/+ and Id1−/− mice. Three tissue microarrays (TMA) containing 538 NSCLC human samples were stained with against Sox10, Betacatenin, E-cadherin, Vimentin, Slug, Podoplanin, S6, ERCC1, Id1 and Id3. An H-score was calculated. Multivariable analysis investigated potential predictive factors for LM colonization in mice. Spearman’s Rho test for measuring the possible correlation between Id1, Id3 and the proteins studied in the TMA was used. Results: Among Id1+/+ mice the LM rate was: 57.1% when Id1/Id3wt cells were injected, 33.3% for animals injected with Id1s cells and 0% in those in which Id1/Id3s cells were used (p < 0.001). Nonetheless, no significant differences in LM were found regarding the cell type injected among Id1−/− mice (p > 0.05). In the logistic regression model, Id1 silencing in tumor cells reduced the risk of LM in an 84.9% independently of the mice strain used (p = 0.03). We also found an 84.5% reduction in the probability of developing LM among Id1−/− mice compared to Id1+/+ animals regardless the expression of Id1 and Id3 in the tumor cells injected (p = 0.006). In the LM gene expression profile, the loss of Id1 expression in mice produced a significant downregulation of different genes involved in proliferation such as FGFGR1 (p < 0.001), Myc (p < 0.001), Akt (p = 0.03) and Hoxd10 (p = 0.02). EMT-related genes such as Versican (p = 0.003), Vimentin (p = 0.007), Snail (p = 0.04), Podoplanin (p = 0.02) and IntegrinBeta 1 (p = 0.04) were also downregulated by Id1 loss in the tumor microenvironment compared to Id1+/+ mice (p < 0.001). Coincidentally in the NSCLC samples studied, Vimentin, Podoplanin and Akt expression was positively correlated with Id1 levels. In human NSCLC samples a positive and significant correlation between Beta-catenin, E-cadherin, Slug, ERCC1 and S6 with Id1 expression was found too. Conclusions: Id1 expression in lung cancer cells and liver microenvironment may be required for LM. Id1 expression would favor the migration and colonization capacity of lung cancer cells by regulating EMT-related and proliferation-related proteins in mice and humans. If proven in further mechanistic experiments, Id1 and Id3 targeting might help prevent and treat liver metastasis from lung cancer. 200 POSTER (Board P194) The influence of different cMET and EGFR backgrounds on the cytotoxicity of cMET and EGFR small molecule inhibitors in vitro N. Van Der Steen1 , K. Zwaenepoel2 , C. Rolfo3 , E. Giovannetti4 , M. Castiglia2 , V. Deschoolmeester1 , A.P. Carreca2 , P. Germonpre5 , P. Pauwels2 . 1 University Antwerp, Center for Oncological Research, Antwerp, Belgium; 2 Antwerp University Hospital, Molecular Pathology Unit Department of Pathology, Antwerp, Belgium; 3 Antwerp University Hospital, Phase I − Early Clinical Trials Unit Oncology Department, Antwerp, Belgium; 4 VU Amsterdam, Pharmacology Lab Cancer Center, Amsterdam, Netherlands; 5 AZ Maria Middelares, Department of Respiratory Medicine, Ghent, Belgium Background: Despite recent advances lung cancer shows poor prognosis and high incidence of recurrence. Today, targeted therapies against the epidermal growth factor receptor (EGFR) are frequently used in the clinic. Besides EGFR, the cMET receptor and its ligand hepatocyte growth factor Wednesday 19 November 2014 65 (HGF) play a role in cancer growth, as cMET amplification is a known resistance mechanism against these EGFR-targeted therapies. In vitro, the combination of anti c-Met synergistically enhanced gefitinib-induced growth inhibition in all NSCLC cMET-expressing cell lines. The current study determines the influence of cMET amplification, expression and autocrine stimulation, and EGFR mutational status and expression on the cytotoxicity of small molecule inhibitors. Materials and Methods: Therefore 4 non small cell lung cancer (NSCLC) and 1 myeloma cell line were selected: HCC827 (EGFR exon 19 deletion), H1975 (EGFR L858R and T790M substitutions), EBC-1 (cMET amplification), LUDLU-1 (EGFR and cMET wild-type) and the JJN3 myeloma cell line (HGF secreting). Furthermore, 4 tyrosine kinase inhibitors (TKI) were selected: erlotinib (EGFR-TKI), PHA665752 (cMETTKI), crizotinib (dual ALK and cMET-TKI) and 17-AAG [Heat shock protein 90 (Hsp90) inhibitor]. To determine the cytotoxic effect of these inhibitors, a sulforhodamine B assay was performed. Each cell line was treated using monotherapy for 72 h under normoxic conditions. Results: The cMET amplified EBC-1 cell line seemed to be very sensitive to the Hsp90 inhibitor (IC50 = 90 nM), possibly because Hsp90 folds the cMET-protein. The JJN3 cell line showed moderate sensitivity to cMETTKIs (IC50 = 3000–4000 nM) and very low sensitivity to Hsp90 inhibition (IC50 = 941 nM) compared to the other cell lines. The EGFR mutant cell lines (sensitizing and resistance mutations) are relatively sensitive to the Hsp90 inhibitor (IC50 = 200–250 nM) in comparison with the wild-type LUDLU cell line (IC50 = 780 nM), which showed low sensitivity to the whole panel of inhibitors. Conclusions: These observations can possibly open the door for combination therapy that targets both EGFR and cMET. Further research will be needed to investigate the sensibility of this cMET amplified cell line to Hsp90 inhibition. 201 POSTER (Board P195) Transcriptome analysis of CD133-positive stem cells and prognostic value of survivin in colorectal cancer S. Kim1 , S.H. Park2 , J. Lee2 , Y.S. Park2 , H.C. Kim3 . 1 Korea University Hospital, Seoul, Korea; 2 Samsung Medical Center, Medical Oncology, Seoul, Korea; 3 Samsung Medical Center, Surgery, Seoul, Korea CD133 is an important, but not exclusive, biomarker of colorectal cancer (CRC) stem cells. In order to identify other CRC stem cell-specific genes, we performed a comparative expression profiling of CD133+ and CD133− cell populations in primary and metastatic tumors from four patients with CRC. CD133+ and CD133− CRC cells were isolated using MagSweeper and were used for whole transcriptome analysis with RNA-Seq. We found thatin CD133+ cells, 17 genes (RNASE2, PRB2, IL4, MGC27382, CLEC4C, SALL3, GIMAP1, ISG15, LOC728875, ZIK1, ICAM2, CCDC7, CDYL2, LRRC2, ZEB1, OSTF1, and CCDC144B) were significantly upregulated compared to CD133− CRC cells. Among them, IL4 has been known as an inducer of survivin implicated in the survival and proliferation of cancer cells. However, the prognostic value of survivin in CRC is controversial. We evaluated survivin expression in formalin-fixed paraffin-embedded tumor samples of 188 patients with CRC by immunohistochemistry. Survivin overexpression was detected in 85 patients (45.2%) and was significantly associated with primary tumor sites (P = 0.028), lymph node metastasis (P = 0.029), and advanced III/IV CRC stages (AJCC 7; P = 0.001). Furthermore, survivin upregulation correlated with reduced disease-free survival (DFS; P = 0.021) and overall survival (OS; P < 0.000) and was proved to be an independent prognostic factor for both DFS and OS in multivariate analysis. Collectively, our data suggest that CD133+ CRC stem cells have a distinct expression pattern and that survivin, upregulated by differentially expressed IL-4, is a candidate biomarker for the prediction of recurrence and survival in CRC. Radiation Interactive Agents 202 POSTER (Board P196) The novel microtubule-destabilizing drug BAL101553 (prodrug of BAL27862) sensitizes a treatment refractory tumor model to ionizing radiation A. Broggini-Tenzer1 , F. Bachmann2 , V. Vuong1 , A. Messikommer1 , K. Nytko-Karouzakis1 , T. O’Reilly2 , H.A. Lane2 , M.N. Pruschy1 . 1 University Hospital Zurich (USZ), Radiation Oncology, Zürich, Switzerland; 2 Basilea Pharmaceutica International Ltd, Basel, Switzerland Background: Microtubule-targeting agents (MTAs) are widely used for cancer treatment, both alone and in combination. BAL27862 is a novel 66 Wednesday 19 November 2014 microtubule-destabilizing drug with a dual action against human tumors; targeting tumor cells refractory to standard MTAs as well as tumor blood supply. The water soluble prodrug BAL101553 has completed Phase I clinical evaluation administered i.v. but is also orally bioavailable. We have investigated the effect of ionizing radiation (IR) in combination with BAL27862 in vitro in human cancer lines resistant to standard MTAs, and with BAL101553 in a genetically defined paclitaxel-, epothilone- and IRrefractory xenograft model. Different routes of BAL101553 administration were compared. Methods: Alamar blue/crystal violet proliferation, clonogenic survival and apoptotic death assays were performed in human lung carcinoma A459, b-tubulin-mutated A549EpoB40 and Pgp-overexpressing colon carcinoma SW480 cells. Antitumor response was determined in SW480- and A549EpoB40-derived tumor xenografts with BAL101553 administered i.v. (21.3 mg/kg/wk) or p.o. (15 mg/kg QD×5 or 38 mg/kg/wk) and IR fractionated over a week (3×5 Gy). Results: BAL27862 reduced the proliferation/survival of wild type A549 cells, paclitaxel/epothilone-resistant A549EpoB40 cells and paclitaxelresistant SW480 cells with similar potency (anti-proliferative IC50s: 28nM, 22nM & 9nM, resp). BAL27862 combined with IR resulted in additive cytotoxicity with no apoptosis induction. In SW480 xenografts, BAL101553 exhibited antitumor activity when administered i.v. or p.o., with daily and weekly oral administration eliciting equivalent antitumor responses (final D%T/C: 36 & 41, resp). Equipotent single i.v. bolus and daily p.o. BAL101553 regimens were identified which partially inhibited tumor growth (%T/C: 66 & 52, resp) in microtubule stabilizing agent-resistant A549EpoB40 tumor xenografts, as did IR (%T/C: 35). Interestingly, both BAL101553 regimens induced a profound antitumor effect when combined with IR, associated with almost complete tumor stabilization (%T/C: 4 & 7, resp) over 5 weeks. Based on the in vitro data, involvement of tumor microenvironment in antitumor response to this combination is likely. Conclusions: BAL101553 single bolus (i.v.) or daily (p.o.) treatment regimens positively interact with IR in a human cancer model refractory to clinically relevant MTAs and IR, demonstrating the potential of this combination therapy for the treatment of cancer patients. 203 POSTER (Board P197) Ionizing radiation induced phosphatidylserine externalization on endothelial cell surface − a potential target for vascular targeting Z. Zhao1 , M. Johnson2 , B. Chen1 , M. Grace3 , J. Ukath3 , V. Lee1 , M. Stoodley1 . 1 Macquarie University, Australian School of Advanced Medicine, Sydney NSW, Australia; 2 University of Technology Sydney, Faculty of Science, Sydney NSW, Australia; 3 Genesis Cancer Care, Macquarie University Hospital, Sydney NSW, Australia Background: Vascular targeting agents can deliver anti-cancer drugs specifically to tumor sites by binding to unique markers/targets on endothelial surface of tumors. The discriminating power of the markers/targets relative to normal tissues determines the specificity of the technique. Stereotactic RadioSurgery (SRS) can precisely deliver focused ionizing radiation to a target tumor site. Radiation-induced molecular changes should be restricted within the tumor tissue, and be good targets for vascular targeting. This study investigated radiation-induced externalization of phosphatidylserine (PS) in endothelial cells, a potential target for vascular targeting. Materials and Methods: An immortalized cell line generated from mouse brain endothelium, bEnd3 cells, were cultured and irradiated at different radiation doses using a linear accelerator (LINAC) Elekta Synergy. Then PS externalization in the cells was visualized using pSIVA-IANBD, a polarity sensitive probe for PS. Live cell imaging was used to monitor the PS externalization in real time. Results: Ionizing radiation has remarkable effects on the cells and the effects are found to be dose dependent. The cell proliferation rate decreased after exposure to 5 Gy radiation whereas higher radiation doses (15 Gy and 25 Gy) totally inhibited proliferation. In comparison with shamradiation treated cells, the irradiated cells showed distinct pseudopodial elongation with little or no spreading of the cell body. The percentages of pSIVA positive cells were significantly higher in the cells that received 25 Gy and 15 Gy radiation 24 hours after treatment. This effect sustained until the end of the experiment (3 days). Radiation at 5 Gy did not induce significant PS externalization compared with the sham-radiation control at any time points. Conclusions: Ionizing radiation can cause remarkable cellular changes in the endothelial cells. Significant PS externalization can be induced by the radiation at dose levels 15 Gy and above. Given the precise focusing of the radiation beams, the radiation-induced markers/targets may have high discriminating power to be harnessed in vascular targeting for cancer treatment. Poster Session – Radiation Interactive Agents 204 POSTER (Board P198) High-throughput functional screening identifies the flavoreductase POR as a principal determinant of sensitivity to the hypoxia-targeting prodrug SN30000 F.W. Hunter1 , Z. Shalev2 , J. Wang1 , J. Moffat3 , T. Katella4 , M. Koritzinsky3 , W.R. Wilson1 , B.G. Wouters3 . 1 University of Auckland, Auckland Cancer Society Research Centre, Auckland, New Zealand; 2 University Health Network, Princess Margaret Cancer Centre, Toronto, Canada; 3 University of Toronto, Department of Radiation Oncology, Toronto, Canada; 4 University of Toronto, Donnelly Centre and Banting and Best Department of Medical Research, Toronto, Canada Background: Hypoxia constitutes an attractive therapeutic target owing to its prevalence in tumours and its contribution to disease progression and treatment resistance. Several hypoxia-selective prodrugs have been developed to address this target, including the preclinical agent SN30000 which is an optimised analogue of the well-studied prodrug tirapazamine. These prodrugs are enzymatically activated under hypoxic conditions and thus selectively toxic to viable hypoxic cells. Biomarkers that are predictive of prodrug activation and tumour sensitivity are urgently needed to support their clinical development. Figure: SN30000. Materials and Methods: We deployed whole-genome lentiviral shRNA screens interrogating 82,017 unique hairpins targeted to 16,019 human genes, and a high-representation focused library enriched for oxidoreductases (1,821 hairpins targeting 359 genes), in tandem with massively parallel sequencing, to identify determinants of sensitivity to SN30000 in HCT116, HT-29 and PANC-1 cells under hypoxic conditions. Potential determinants were evaluated by RNAi-mediated knockdown and zinc finger nuclease-mediated genetic knockout in cell lines and xenografts. Results: Our functional screens identified the flavoprotein P450 (cytochrome) oxidoreductase (POR) as the predominant determinant of sensitivity to SN30000 in all cell lines evaluated, except a POR knockout clone derived from HCT116, with no other genes consistently selected. Specific hairpins against POR were validated by qPCR and immunoblotting, where POR suppression directly correlated with the degree of enrichment in the high-throughput screens. Knockdown or knockout of POR inhibited metabolic activation of SN30000 and enhanced clonogenic survival of cells exposed under hypoxic conditions. We are currently assessing effects of POR knockout on the activity of SN30000 against hypoxic cells in xenografts. Gene shRNA clone Z-score HT-29 PANC-1 HCT116 POR POR POR TRCN0000046524 TRCN0000046526 TRCN0000046527 3.3 3.2 2.6 3.5 3.1 2.2 5.0 3.3 2.3 Conclusions: POR acts as a critical determinant of tumour cell sensitivity to SN30000 by catalysing reductive activation of the prodrug. As a single gene apparently responsible for a major component of SN30000 activity, tumour expression of POR may be a clinically tractable predictive marker of response to SN30000. The methodology established in this study may be repurposed to study determinants of sensitivity to additional hypoxiaactivated prodrugs such as the clinical agents TH-302 and PR-104. Poster Session – Radiation Interactive Agents 205 POSTER (Board P199) Metformin to modulate AMP-kinase and enhance chemotherapy and radiotherapy in non-small cell lung cancer M.J. Troncone1 , S.M. Cargnelli1 , G. Pond2 , E. Tsiani3 , J. Wright2 , G. Steinberg4 , H. Skinner5 , L. Bo6 , J. Bradley7 . 1 McMaster University, Medicine, Hamilton Ontario, Canada; 2 McMaster University, Oncology, Hamilton Ontario, Canada; 3 Brock University, Community Health Science, Hamilton Ontario, Canada; 4 McMaster University, Biochemistry, Hamilton Ontario, Canada; 5 M.D. Anderson, Radiation Oncology, Houston Texas, USA; 6 Jefferson University, Radiation Oncology, Philadelphia, USA; 7 Washington University, Radiation Oncology, St. Louis, USA Background: In the past few years our group investigated the response of AMP-activated kinase (AMPK) to clinical doses of radiation therapy (RT). We found that AMPK is not only a metabolic but also a genomic stress sensor that is activated in epithelial tumour cells downstream of Ataxia Telengiectasia Mutated (ATM) and leads to induction of p53 and cyclin dependent kinase inhibitors such as p21cip1 and p27kip1 . We observed that AMPK is involved in mediation of the G2-M cycle arrest and the cytotoxicity of RT. Knock down of AMPK in cancer cells and knockout models of AMPK show dramatic activation of the Akt-mTOR pathway. In tumours RT induced growth inhibition and chronic suppression of angiogenesis that was associated with sustained activation of ATM and AMPK and inhibition of Akt and mTOR axis. We used the anti-diabetic drug metformin (MET) to activate AMPK in lung tumours. MET is a safe and well-tolerated agent that has no reported toxicity when combined with RT or chemotherapy. Materials and Methods: We performed pre-clinical evaluation of MET in combination with RT in in-vitro and in-vivo models of lung prostate cancer. Further, we performed a retrospective analysis of clinical outcomes in stage III NSCLC treated with chemotherapy and radiotherapy at the Juravinski Cancer Center over the past 14 years. Results: MET at low microM concentrations, that are safely achieved in the serum of diabetic patients, activated the AMPK pathway, inhibited growth and enhanced RT responses in cancer cells and tumours. The antiproliferative and radio-sensitizing activity of MET was depended on AMPK and led to effective inhibition of the Akt-mTOR pathway. MET increased the pro-apoptotic and anti-angiogenic action of RT. Retrospective analyses of clinical outcomes show that diabetic patients with locally advanced (LA) non-small cell lung cancer (NSCLC) treated with RT and chemotherapy have improved survival after chemotherapy or RT treatment if they receive metformin for the treatment of diabetes. Conclusions: Based on our pre-clinical and retrospective clinical data we propose prospective clinical trials in LA-NSCLC. Two phase II studies of MET in combination of chemo-RT will open to accrual soon. The Canadian Ontario Clinical Oncology Group (OCOG) ALMERA and US NRG LU001 studies will investigate MET in combination with concurrent chemo-RT in LA-NSCLC. LU001 will examine the pure chemo-radio-sensitizing action of MET using the drug only concurrently with chemo-RT while ALMERA will examine the benefits of MET when used both concurrently with chemoRT and adjuvant for 1 year. Tumour bio-specimens collected in NRGLU001 and OCOG-ALMERA will help show whether expression or mutation status of tumour (LKB1, K-Ras, p53, EGFR and Alk) and microenvironment (HIF1a and micro-vessel density) markers could serve as biomarkers of MET response in NSCLC. 206 POSTER (Board P200) Identification of novel targets for radiosensitisation of non-small cell lung cancer by secretome analysis A. Sharma1 , S. Bender1 , O. Riesterer1 , A. Broggini-Tenzer1 , M. Pruschy1 . 1 University Hospital Zurich, Department of Radiation Oncology, Zurich, Switzerland Background: The therapeutic response of ionizing radiation (IR) is imparted by genomic instability and DNA damage. However, IR also triggers multiple intracellular signaling processes as part of IR-induced stress responses that lead to the secretion of various para- and autocrine factors into the tumor microenvironment. Here we investigated treatmentdependent secretion of auto- or paracrine factors, which drive acquired rescue mechanisms and determine the overall radiation sensitivity of the tumor. Material and Methods: Exhaustive large scale secretome analysis was performed using antibody arrays for a wide range of secretory factors. Secretion kinetics of selected factors were determined using ELISA across different established tumor cells and in murine blood serum, derived from irradiated tumor xenograft-carrying mice. Clonogenic survival and xenograft tumor growth delay assays were performed in response to IR in siRNAtargeted tumor cell lines or in combination with small molecular agents. Results: We performed an exhaustive IR-dependent secretome analysis (>300 factors) in lung carcinoma cells and investigated IR-induced Wednesday 19 November 2014 67 expression and tumor cell secretion of the top hits, including amphiregulin, transforming growth factor-a and ALCAM. All these factors were secreted in a similar IR-induced time- and dose-dependent way from several nonsmall cell lung cancer (NSCLC) cell lines, indicative of a common upstream mechanism. No changes were observed at the transcriptional level implying potential modulation at the posttranslational level. Interestingly, irradiation induced a dose-dependent increase in cleavage of the proform of ADAM17 (A Disintegrin and metalloprotease domain 17), which resulted in enhanced ADAM17 activity and correlated with subsequent substrate shedding. IRinduced ADAM17 activation required both p38 mitogen-activated protein kinases (MAPKs) and Furins. siRNA mediated silencing of ADAM17 or targeting of ADAM17 with the small molecular inhibitor TMI-005 suppressed IR-induced shedding of these factors, down regulated ErbB-signaling in target cells and enhanced IR-induced cytotoxicity in vitro and in vivo. Ex vivo substrate analysis of murine blood serum derived from irradiated tumor xenograft-carrying mice correlate with our in vitro results. Conclusions: Our findings demonstrate that IR significantly activates ADAM17, which results in shedding of multiple survival factors, growth factor pathway activation and contributes to treatment resistance in NSCLC cells. We provide a sound rationale for positioning ADAM17 inhibitors as radiosensitizers to improve the treatment of NSCLC. 207 POSTER (Board P201) The enhancement of radiotherapy efficacy with docetaxel-titanate nanotubes as a new nanohybrid for localized high risk prostate cancer C. Mirjolet1 , J. Boudon2 , A. Loiseau2 , S. Chevrier1 , T. Gautier2 , R. Boidot3 , J. Paris2 , N. Millot2 , G. Crehange1 . 1 Georges-Francois Leclerc Cancer Centre, Radiotherapy, Dijon, France; 2 UMR 6303 CNRS U Bourgogne, NanoScience Department MaNaPI, Dijon, France; 3 Georges-Francois Leclerc Cancer Centre, Molecular Biology, Dijon, France Background: From 30% to 50% of high risk prostate cancer patients who undergo radiation therapy (RT) will have a biochemical failure. These failures are either due to a poor local control or to distant disease which may also be related to a local failure. Taxane-based chemotherapy has proved to be useful in prostate cancer. Combining chemotherapy, such as docetaxel (DXL), with RT can enhance its efficiency, however systemic injection of the classical formulation leads to 95% uptake by healthy tissues whereas 2−5% only reach tumors; adverse side effects are a crucial problem. Moreover, multidrug resistance mechanisms often limit drug efficacy by decreasing tumor cell intracellular concentration of drugs. There is interest to develop nanocarrier of DXL to maintain drug inside cancer cells by improving its efficacy. In a previous in vitro study, we have highlighted that titanate nanotubes (TiONTs) which have a needle shape can enter and stay inside cancer cells until 10 days without cytotoxic effects induction. We suggest in this study to develop TiONt-DXL nanocarrier and to evaluate its in vivo biodistribution as well as its efficacy in association with RT on a prostate cancer model. Materials and Methods: TiONts are obtained from hydrothermal synthesis. DXL molecules were grafted on TiONts using PEG-3000 molecules to generate the nanohybrid. In vitro cytotoxic activity of nanohybrid was evaluated on PC-3 cell line using MTS assay. BALB/c nude mice bearing subcutaneous PC-3 human prostate tumors were used to evaluate nanohybrid biodistribution and efficiency after intratumoral injection. Biodistribution analysis was performed by SPEC-CT imaging using 111Indium. To evaluate the benefit of TiONt-DXL and RT association, tumors were irradiated using three daily fractions of 4 Gy administrated the day after nanohybrids injection. Mice behavior, health status and tumor volume were monitored twice a week until tumor growth recovery. Result: TiONt-DXL in vitro cytotoxic activity was showed on PC-3 cells. Biodistribution kinetics showed that more than 70% of nanohybrids were localized into the tumor 96 hours after injection. Tumor growth was stopped for mice receiving RT combined or not to TiONt or TiONt-DXL. Moreover, mice receiving TiONT-DXL alone exhibited a decrease in tumor growth when compared to mice receiving free DXL. Conclusions: These results highlight that our nanocarrier improve DXL efficacy. Local control might be improved by injecting TiONT-DXL in the tumor during prostate brachytherapy as a boost in high risk localized prostate cancer. A longer follow-up period will be needed to determine if TiONt-DXL combined to RT will improve outcome. This work was supported by the ‘Ligue Contre le Cancer du Grand Est’ (Comités Doubs and Côte d’Or). 68 Wednesday 19 November 2014 208 POSTER (Board P202) Combined treatment of a DNA-PKcs inhibitor (NU7441) and ionizing radiation causes a differential mode of cell death in a panel of NSCLC cell lines and exhibits robust radiosensitisation D. Saha1 , Y. Lan1 , F. Hsu2 , V. Tumati1 , Z. Zhang1 , Y. Lin1 , B. Chen1 . 1 UT Southwestern Medical Center, Radiation Oncology, Dallas TX, USA; 2 National Taiwan University College of Medicine, Urology, Taipei, Taiwan Background: Lung cancer is still the leading cause of cancer death worldwide. The current standard of care for lung cancer consists of concurrent chemotherapy and radiation. Several studies have shown direct evidence that a novel DNA-PKcs inhibitor NU7441 is highly potent radiosensitizer in different tumor models. However, the mechanism of NU7441 induced radiosensitization has not been fully elucidated. In this study, the combined effect of NU7441 and ionizing radiation (IR) in a panel of non-small cell lung cancer cell lines (A549, H460 and H1299) has been thoroughly investigated. The purpose of the study is to enhance the effect of the radiation using a DNA-PKcs inhibitor in radio-resistant NSCLC lines representing different genetic background. Material and Methods: Clonogenic surviving fraction analysis, DNA double strand break repair kinetics, cell cycle analysis, immunofluorescence, immunoblot, apoptosis and autophagy assays were used in this study. Results: We found that NU7441 significantly enhances the effect of IR in all cell lines tested. The notable findings in response to this combined treatment are (i) prolonged delay in IR induced DNADSB repair, (ii) induced robust G2/M checkpoint in these cell lines, (iii) increase of aberrant mitosis followed by mitotic catastrophe specifically in H1299 cells, (iv) dramatically induced autophagy in A549 cells and (v) IR-induced senescence specifically in H460 cells. We observed that H1299 cells show greater G2 checkpoint adaptation after combined treatment which can be attributed to the higher expression level of Plk1 compared to A549 and H460. The enhanced autophagy after NU7441 treatment in A549 cells is possibly due to the higher endogenous expression of pS6K compared to H1299 and H460 cells. Conclusion: Differential mode of death was noticed and that leads to the extensive radio-sensitization in all NSCLC lines tested. The choice of cell death pathway, in response to the combined treatment with NU7441 and IR, can be attributed to mutation status of the cells treated. Poster Session – Radiation Interactive Agents th 26 EORTC–NCI–AACR Symposium on Molecular Targets and Cancer Therapeutics Thursday 20 November 2014 Plenary Session 5 Thursday 20 November 2014 Thursday 20 November 2014 08:00–10:00 PLENARY SESSION 4 Antibody-Based Therapies (ADC and others) 209 ORAL PRESENTATION Pre-clinical and translational pharmacology, pharmacokinetics and pharmacodynamics for a humanized anti-OX40 antibody MOXR0916, a T-cell agonist in the treatment of solid tumors S. Sukumaran1 , J.M. Kim1 , M. Huseni1 , J. Ruppel1 , H. Taylor1 , K. Totpal1 , J. Zhu1 , C. Zhang1 , H. Chiu1 , E.G. Stefanich1 . 1 Genentech, gRED, So San Francisco CA, USA Background: Targeting T cell surface proteins to restore and enhance the function of tumor-reactive T cells have been found to be an effective way to combat cancer. OX40 is a costimulatory receptor in the TNFreceptor family that is transiently expressed on antigen-experienced T-cells. OX40 signaling in the context of antigen recognition by the T-cell receptor enhances the proliferation and survival of CD4+ and CD8+ effector T cells and inhibits the suppressive function of regulatory T cells. MOXR0916 is a humanized effector-competent IgG1 agonistic antibody against human OX40 that is being developed as treatment for refractory solid tumors. Methods: In vitro characterization of the effects of MOXR0916 on T cell proliferation and interferon g (IFNg) production was performed in human primary CD4+ memory T cells stimulated with anti-CD3. In vivo studies in mouse syngeneic tumor models were performed with the surrogate antimouse OX40 antibody PRO307205, as MOXR0916 does not bind mouse OX40. Dose ranging efficacy studies were performed with the EMT6 model and relevant pharmacodynamic (PD) markers including CD4 and CD8 T cell proliferation, IFNg production, and FOXP3 and CD8B gene expression were measured in blood and/or tumor. Pharmacokinetics (PK) of MOXR0916 and PRO307205 were assessed in SCID mice and PK of MOXR0916 was assessed in cynomolgus monkeys. Results: Treatment of CD4+ memory T cells with varied concentrations of MOXR0916 and a fixed concentration of anti-CD3 produced a concentration-dependent increase in cell proliferation and IFNg production with EC50 values estimated as 10 ng/mL. Both single and multiple dosing of 0.1 to 10 mg/kg of PRO307205 treatment were found to be efficacious in the EMT6 model, with more animals responding to treatment with higher and more frequent dose administration. No efficacy was observed with a 0.01 mg/kg dose. Efficacious doses were associated with evidence of peripheral and intratumoral increase in IFNg, proliferation of effector T cells, and reduction in number of regulatory T cells. MOXR0916 showed linear PK with typical IgG1 clearance and distribution parameters in both mouse and cyno. Human PK was projected based on allometric scaling of cyno PK. Conclusion: Based on in vitro and in vivo studies of anti-OX40 pharmacology, MOXR0916 is predicted to counteract the immunosuppressive tumor microenvironment and promote T cell-dependent, anti-tumor immunity via two distinct mechanisms: (1) enhancing proliferation and cytokine production of antigen-experienced effector T cells and (2) reducing the number and activity of intra tumoral regulatory T cells. Quantitative data from pharmacology, PK and PD were used for predicting relevant activity and doses of MOXR0916 for testing in clinical trials. 210 ORAL PRESENTATION A phase 1 study of KTN3379, a human anti-ErbB3 monoclonal antibody in patients with advanced cancers P. LoRusso1 , T. LaVallee2 , L. Kimmel2 , C. Lubeski2 , R. Gedrich2 , C. Sidor2 . 1 Wayne State University, Detroit Michigan, USA; 2 Koltan Pharmaceuticals, New Haven CT, USA Purpose: ErbB3 is an important dimerization partner for other ErbB family members and is emerging as a key component in the development of resistance. KTN3379 is a human monoclonal antibody against human epidermal growth factor receptor-3 (ErbB3 or HER3) that blocks both ligand-dependent and independent activation of ErbB3 and is engineered to extend half-life. The Phase 1 trial (KTN3379-CL-001) is an open label, dose escalation and expansion study to assess the safety and pharmacokinetics of KTN3379 in patients with advanced cancers to determine a recommended dose for efficacy studies and to evaluate potential biomarkers related to KTN3379 activity. Methods: The study is being conducted in two Parts. In Part I, using a 3 + 3 design, patients received escalating doses of KTN3379 ranging from 5 to 20 mg/kg every 3 weeks until disease progression or intolerable 71 toxicity. In Part II, KTN3379 will be administered along with a Standard of Care (SOC) regimen in disease specific cohorts of 6 patients. Adverse events are assessed according to the National Cancer Institute Common Terminology Criteria for Adverse Events and dose limiting toxicities (DLTs) were evaluated during the initial cycle. RECIST tumor measurements were obtained every 3rd cycle and pharmacokinetics (PK) and pharmacodynamic (PD) assessments were evaluated during each cycle. Archival tumor tissue was obtained if available. Results: In Part I, 12 patients with advanced cancer (CRC, ovarian, pancreatic, endometrial, pancreatic, HCC and germ cell cancers), median age of 62 with ECOG performance status of 0 or 1 and multiple prior therapies (median of 4) received at least one dose of KTN3379. There were no DLTs or Grade 3 related events reported to date and the highest dose administered was 20 mg/kg. The most frequent treatment related AEs were Grade 1 and 2 diarrhea (one Grade 3), dry mouth and skin, and anemia. PK parameters were consistent with humanized monoclonal antibodies and could support q3 week dosing. Early PD assessments indicated elevation of sErbB3 levels in all patients following treatment. Additional assessments are ongoing. Conclusions: Results suggest that doses of 20 mg/kg are safe and well tolerated and PK supports 3-week dosing. Expansion is ongoing to assess the safety and tolerability of KTN3379 in combination with other targeted agents in specific cancers and to evaluate the potential for biomarkers to identify sensitive patients. Thursday 20 November 2014 10:30–12:30 PLENARY SESSION 5 Epigenetic Targets 211 ORAL PRESENTATION A novel synthetic lethal interaction between the histone mark H3K36me3 and checkpoint kinases S.X. Pfister1 , E. Markkanen1 , Y. Jiang1 , S. Sarkar1 , V. D’Angiolella1 , G. Dianov1 , A.J. Ryan1 , T.C. Humphrey1 . 1 CRUK MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, United Kingdom Background: Synthetic lethal interactions between cellular pathways can be exploited to selectively kill cancer cells that carry a mutation in a gene of one pathway by chemically inhibiting the function of a gene in a second pathway. SETD2, a histone H3K36me3 methyltransferase, has recently been recognised as a tumour suppressor in several cancer types, thereby identifying SETD2 loss of function mutation as potential target for cancer therapy. Here, we report a novel synthetic lethal interaction between SETD2 loss and inhibition of DNA replication checkpoint proteins, and provide insights on the underlying molecular mechanisms. Material and Methods: Growth of p53 wild type SETD2-deficient (A498, LB996) or -proficient (RCC4, U2OS) human cancer cell lines were measured after treatment using WEE1 (MK1775), CHK1 (LY2603618, AZD7762, Gö6976) or ATR (VE821) kinase inhibitors. DNA replication was analysed by DNA fibre assay and by iPOND (isolation of proteins on nascent DNA). dNTP pools were measured by polymerase-catalyzed incorporation of radioactive dNTP. We confirmed the in vitro efficacy of MK1775 in vivo in SETD2-deficient A498 xenografts. Results: Compared to wild type, SETD2-deficienct cells were more sensitive to growth inhibition by VE821 (IC50 = 8.5 vs 3.8mM), LY2603618 (IC50 = 750 vs 374nM) or MK1775 (IC50 = 327 vs 109nM) (p < 0.0001). Increased cell death in SETD2-deficient cells was due to DNA damage arising from replication stress, and not premature mitosis as has been previously reported in TP53 mutant tumour cell lines. SETD2independent methods to reduce H3K36me3 levels (overexpression KDM4A demethylase, or expression of the dominant-negative K36M histone H3.3 variant) also significantly inhibited cell growth and increased apoptosis on treatment with ATR, CHK1, or WEE1 inhibitors (p < 0.0001). SETD2 and WEE1 acted on two independent pathways regulating dNTP production during DNA replication. An in vivo experiment in established SETD2deficient A498 xenografts grown in nude mice showed that treatment with MK1775 (60 mg/kg, po, bid, d1−12) regressed tumours, producing a marked reduction in tumour size compared with vehicle-treated control animals (mean tumour size = 291.2±40.0 vs 50.2±4.7 mm3 , p < 0.0001). In addition, MK1777-treated tumours had significantly greater levels of DNA damage as measured by gH2AX foci (p < 0.0001). Conclusions: The findings suggest that targeted inhibition of ATR, CHK1 or WEE1 may be exploited to create novel treatments for cancers with reduced levels of H3K36me3. 72 Thursday 20 November 2014 Plenary Session 6 212 ORAL PRESENTATION Novel anti-tumor activity of targeted LSD1 inhibition by GSK2879552 H. Mohammad1 , K. Smitheman1 , G. Van Aller2 , M. Cusan3 , S. Kamat4 , Y. Liu2 , N. Johnson2 , C. Hann4 , S. Armstrong3 , R. Kruger2 . 1 GlaxoSmithKline, Cancer Epigenetics, Collegeville PA, USA; 2 GlaxoSmithKline, Cancer Epigenetics, Collegeville, USA; 3 MSKCC, Pediatrics, New York, USA; 4 Johns Hopkins University, Oncology, Baltimore, USA Lysine specific demethylase 1 (LSD1) is a histone H3K4me1/2 demethylase found in various transcriptional co-repressor complexes. LSD1 mediated H3K4 demethylation can result in repressive chromatin environment that silences gene expression and has been shown to play a role in development and hematopoietic differentiation. LSD1 is overexpressed in multiple tumor types, including acute myeloid leukemia (AML). Together, these studies suggest LSD1 is an important regulator of the epigenome that modulates gene expression through modification of histones and its presence in transcriptional complexes. The current study describes the anti-tumor effects of a novel, potent, irreversible, GSK LSD1 inhibitor (GSK2879552) in AML and small cell lung cancer (SCLC). Screening of over 150 cancer cell lines revealed that SCLC and AML cells have a unique requirement for LSD1. While LSD1 inhibition did not affect the global levels of H3K4me1 or H3K4me2, local changes in these histone marks were observed near transcriptional start sites of putative LSD1 target genes. This increase in the transcriptionally activating histone modification correlates with increased gene expression. Treatment of AML cells with GSK2879552 promotes the expression of cell surface markers associated with a differentiated immunophenotype, including CD11b and CD86. In an MV-4−11 engraftment model, increases in CD86 and CD11b were observed as early as 8 hours post dosing. GSK2879552 treatment resulted in a potent anti-proliferative growth effect in a subset of SCLC cell lines tested and all AML cell lines tested. Potent growth inhibition was also observed on AML blast colony forming ability of bone marrow samples derived from primary AML patient samples. The effects of LSD1 inhibition were further characterized in vivo using a mouse model of AML induced by transduction of mouse hematopoietic progenitor cells with a retrovirus encoding MLL-AF9 and GFP. Primary AML cells were transplanted into secondary recipient mice that were treated with an LSD1 tool molecule inhibitor for 17 days. Control mice succumbed to AML by 45 days post transplant, while treated mice showed prolonged survival. GSK2879552 treatment of mice engrafted with SCLC cell lines resulted in greater than 80% tumor growth inhibition. Studies using patient derived primary SCLC showed similar efficacy demonstrating the growth inhibition of SCLC with an LSD1 inhibitor extended beyond cell lines. Together, these data demonstrate that pharmacological inhibition of LSD1 may provide a promising treatment for AML and SCLC. A Phase I clinical trial using GSK2879552 was initiated in March, 2014. All studies were conducted in accordance with the GSK Policy on the Care, Welfare and Treatment of Laboratory Animals and were reviewed the Institutional Animal Care and Use Committee either at GSK or by the ethical review process at the institution where the work was performed. Thursday 20 November 2014 13:30–15:35 PLENARY SESSION 6 Proffered Paper Session 213 ORAL PRESENTATION A phase I dose-finding study of BI 853520, a potent and selective inhibitor of focal adhesion kinase (FAK), in Japanese and Taiwanese patients with advanced or metastatic solid tumors T. Doi1 , C.C. Lin2 , A. Ohtsu3 , J.C.H. Yang2 , K. Shitara3 , L.C. Pronk4 , A. Sarashina5 , A.L. Cheng2 . 1 National Cancer Center Hospital East, Gasrtointestinal Oncology, Chiba, Japan; 2 National Taiwan University Hospital, Department of Oncology, Taipei, Taiwan; 3 National Cancer Center Hospital East, Department of Experimental Therapeutics, Chiba, Japan; 4 Boehringer Ingelheim España S.A., Clinical Development Oncology, Barcelona, Spain; 5 Nippon Boehringer Ingelheim Co. Ltd, Clinical PK/PD department, Kobe, Japan Background: Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase that contributes to activation of multiple downstream-signaling pathways involved in tumor cell survival, proliferation, invasion, and metastasis. BI 853520 is a potent and highly selective inhibitor of FAK with an IC50 of 1nM. It has shown efficacy in multiple xenograft models of human cancer. Material and Methods: This is a phase I, dose-finding study of BI 853520 given as a continuous oral dosing regimen in 28-day cycles in a mixed population of Japanese and Taiwanese patients (pts) with progressive, advanced or metastatic solid tumors. Endpoints include safety, determination of maximum tolerated dose (MTD), pharmacokinetics (PK), pharmacodynamics, and efficacy, determined according to RECIST v1.1 criteria. Results: To date, 18 pts have received doses of 50, 100 and 200 mg qd of which 14 pts are evaluable for dose limiting toxicity (DLT). Male/female ratio was 12/6, median age 65 years (range, 35−77 years), ECOG PS 0/1:10/8. Primary tumor types: 4 gastric cancer, 2 colorectal cancer; 2 oesophageal cancer, and 10 others. Median number of prior systemic treatments: 3. Drug-related adverse events (AEs) in >10% of pts included proteinuria (44.4%), diarrhea (38.9%), nausea (22.2%), vomiting (22.2%), inflammatory fibrous thickening in the palm of the hand (11.1%), maculopapular rash (11.1%) and decreased appetite (11.1%), all of NCI Common Terminology Criteria for AEs (v4.03) grade 1−2 except for one patient who had proteinuria grade 3 that occurred during cycle 2 at the 200 mg dose and was considered DLT. So far, no DLTs have been observed during cycle 1 and no drug-related serious AEs have been reported. The MTD was determined as 200 mg qd and the 200 mg cohort is expanded to a total of 12 patients to confirm the MTD. PK:Preliminary data suggest that plasma exposure increased with increasing doses. Based on the observed accumulation and half-life, a once-daily dosing scheme is supported. Preliminary efficacy: Of 12 evaluable pts, 1 pt with gastric cancer achieved a partial response (100 mg qd), 2 pts presented stable disease: 1 pt with oesophageal cancer and 1 with urachal cancer lasting 7 and 8 cycles, respectively (both 50 mg qd), and 9 pts progressed. Conclusion: The safety profile of BI 853520 is favourable. PK analysis supports the once-daily dosing schedule. Recruitment at the 200 mg dose is ongoing to confirm the MTD. An update will be provided at the meeting. 214 ORAL PRESENTATION Homologous recombination deficiency (HRD) score and niraparib efficacy in high grade ovarian cancer P. Haluska1 , K.M. Timms2 , M. AlHilli1 , Y. Wang3 , A.M. Hartman2 , J. Jones2 , A. Gutin2 , Z. Sangale2 , C. Neff2 , J. Lynchbury2 , L. Rudolph-Owen3 , M.A. Becker1 , S. Agarwal3 , K.M. Wilcoxen3 . 1 Mayo Clinic, Rochester, USA; 2 Myriad Genetics, Salt Lake City, USA; 3 Tesaro Inc., Waltham, USA Purpose: The therapeutic potential of PARP inhibitors is predicted to extend beyond BRCA mutant (BRCAmut ) phenotypes to homologous recombination deficient (HRD) cancers. An HRD assay amenable for clinical testing was applied to treatment naı̈ve, high grade ovarian primary tumor samples. Niraparib treated patient-derived tumorgraft models selected from these primary ovarian tumors were utilized to evaluate the correlation between HRD score, BRCA deficiency, platinum sensitivity and niraparib anti-tumor response. Methods: Utilizing patient-derived ovarian xenografts we previously demonstrated response to niraparibin both BRCAmut and BRCA wild type (BRCAwt ) tumors. BRCAmut status alone was neither necessary nor sufficient to predict response to niraparib. To understand the selectivity observed, samples from a collection of >100 high grade ovarian tumors were subjected to HRD analysis. The HRD analysis is a DNA-based assay that is capable of detecting homologous recombination deficiency independent of its etiology. Genome-wide SNP data was generated from a custom Agilent SureSelect XT2 capture followed by sequencing on an Illumina HiSeq2500. SNP data was analyzed using all three algorithms; Loss of Heterozygosity (LOH), Telomeric Allelic Imbalance (TAI) and Large-scale State Transistions (LST). The final HRD score is the sum of the LOH+TAI+LST scores with numerical outputs ranging from 0– 100. RNAseq analysis was also conducted on a subset of the ovarian tumors. Niraparib was then evaluated as a monotherapy in a series of high grade ovarian cancer tumorgrafts with a diverse range of HRD scores. Intraperitoneal tumorgrafts were monitored for tumor growth with twiceweekly transabdominal ultrasound imaging. In-vivo response to niraparib was correlated to the HRD score, BRCA status, patient’s platinum response and RNAseq data. Results: One hundred and six high grade ovarian tumors were evaluated for HRD, BRCA mutation, and RNAseq analysis. Twenty one tumors (20%) had a deleterious somatic or germline BRCAmut . BRCA1 hypermethylation was evaluated in 98 tumors and found in 6, representing approximately 6% of this cohort. Collectively, there was 26% BRCA deficiency in this primary tumor collection. HRD scores ranged from 1−86 with a median score of 32 and an average score of 39. All BRCAmut tumors and 83% (5/6) of the BRCA1 hypermethylated tumors had an HRD score of 31 or greater. The BRCA1 hypermethylated tumor with a low HRD score does not have loss of heterozygosity (LOH) at BRCA1, and likely retains functional BRCA1. Invivo response to niraparib monotherapy was demonstrated in BRCAmut and Plenary Session 6 BRCAwt models with high HRD scores. In addition, niraparib resistance or lack of in vivo efficacy was demonstrated in tumors with low HRD scores. Conclusion: HRD testing of ovarian cancer was predictive of BRCA deficiency. Response to niraparibwas seen in both BRCAmut and BRCAwt tumors. Our data are supportive of the use of HRD testing to select high grade ovarian cancer patients for the clinical evaluation of niraparib treatment. 215 ORAL PRESENTATION Updated clinical and preliminary correlative results of ARIEL2, a Phase 2 study to identify ovarian cancer patients likely to respond to rucaparib E. Swisher1 , J. Brenton2 , S. Kaufmann3 , A. Oza4 , R.L. Coleman5 , D. O’Malley6 , G. Konecny7 , L. Ma8 , M. Harrell9 , D. Visscher3 , A.W. Hendrickson3 , K. Lin10 , M. Raponi10 , E. Mann10 , H. Giordano10 , L. Maloney11 , L. Rolfe12 , I. McNeish13 . 1 University of Washington School of Medicine, Seattle WA, USA; 2 Cancer Research UK Cambridge Institute, Oncology, Cambridge, United Kingdom; 3 Mayo Clinic, Oncology, Rochester, USA; 4 Princess Margaret Cancer Centre, Oncology, Toronto, Canada; 5 The University of Texas MD Anderson Cancer Center, Oncology, Houston, USA; 6 The Ohio State University James Cancer Center, Oncology, Columbus, USA; 7 University of California Los Angeles (UCLA), Oncology, Los Angeles, USA; 8 Rocky Mountain Cancer Center, Oncology, Lakewood, USA; 9 University of Washington School of Medicine, Oncology, Seattle WA, USA; 10 Clovis Oncology, San Francisco, USA; 11 Clovis Oncology, Boulder, USA; 12 Clovis Oncology, Cambridge, United Kingdom; 13 Institute of Cancer Sciences University of Glasgow, Glasgow, United Kingdom This abstract is part of the media programme and is embargoed until the day of presentation, when it will be published online at 08:00. Thursday 20 November 2014 73 Methods: Patients with recurrent gliomas (WHO grade II-IV) were eligible for this trial. FSRT was prescribed to 30−35 Gy delivered in 10 daily fractions. Panobinostat was administrated orally once daily every Monday, Wednesday, and Friday concurrently with radiation treatment. The panobinostat dose was escalated from 10 to 30 mg using a 3+3 trial design. Results: A total of 16 patients were enrolled on the trial. Four patients were excluded from the analysis due to 1 patient failing to receive study treatment due to rapid progression, and 3 patients having increased QTc exceeding the protocol limit and were unable to finish protocol treatment. Of the 12 evaluable patients, 8 had recurrent GBM, and 4 had recurrent anaplastic astrocytoma. There were 3 patients in the 10 mg panobinostat cohort, 3 patients in the 20 mg cohort, and 6 patients in the 30 mg final cohort. There were no treatment related grade 3 or higher toxicities in the 10 mg or 20 mg cohort. In the 30 mg panobinostat cohort, one patient developed grade 3 leukopenia and grade 4 neutropenia which was possibly related to the treatment. There are 5 living patients in the study. The minimum follow up of the living patients is 8.5 m. The 4-m progression survival (PFS) of all the evaluable patients is 87%, and 6-m PFS of 56%. The medial overall survival is 9.5 m. There is a suggestion of dose response to the panobinostat. The 4-m PFS is 100%, 100%, and 67% for 30 mg, 20 mg, and 10 mg cohort respectively. The 6-m PFS is 83%, 33%, and 67% for 30 mg, 20 mg, and 10 mg cohort respectively. The overall survival for the 30 mg cohort is not reached with a median follow up of 11.5 m. Conclusions: Panobinostat administrated with FSRT is well tolerated at a 30 mg dose, which is the recommended dose for phase II trial. There is a suggestion of a dose–response relationship with panobinostat dose. The median overall survival is not reached with a median follow up of 11.5 m for the 30 mg cohort. A phase II trial is warranted to confirm the efficacy of combining panobinostat with FSRT for recurrent gliomas. 217 ORAL PRESENTATION Results of a phase I, open-label, multicentre study to assess the safety, tolerability, pharmacokinetics and preliminary antitumour activity of AZD9150 in patients with advanced/metastatic hepatocellular carcinoma Y.K. Kang1 , B.Y. Ryoo1 , T.Y. Kim2 , K.H. Lee2 , H.Y. Lim3 , S.J. Lee3 , M. Ikeda4 , T. Okusaka5 , S. Nadano6 , C.C. Lin7 , T.P. Poon8 , C.J. Yen9 , P. McCoon10 , F. Neumann10 , K. Vishwantahan10 , R. DuPont10 , P. Lyne10 . 1 Asan Medical Center, Oncology, Seoul, Korea; 2 Seoul National University Hospital, Oncology, Seoul, Korea; 3 Samsung Medical Center, Oncology, Seoul, Korea; 4 National Cancer Center Hospital East, Chiba, Japan; 5 National Cancer Center Hospital, Tokyo, Japan; 6 National Hospital Organization, Ehime, Japan; 7 National Taiwan University Hospital, Oncology, Taipei, Taiwan; 8 Queen Mary Hospital, Surgery, Hong Kong, Hong Kong; 9 National Cheng Kung University Hospital, Tainan, Taiwan; 10 AstraZeneca Pharmaceuticals, Oncology IMED, Waltham, USA 216 ORAL PRESENTATION Phase I study of panobinostat and fractionated stereotactic re-irradiation therapy (FSRT) for recurrent high grade gliomas W. Shi1 , Y.R. Lawrence1 , M. Werner-Wasik1 , D.W. Andrews2 , J.J. Evans2 , J. Glass2 , L. Kim1 , V. Bar Ad1 , Y. Moshel1 , K. Judy1 , C. Farrell1 , N.L. Simon1 , A.P. Dicker1 . 1 Thomas Jefferson University Hospital, Radiation Oncology, Philadelphia PA, USA; 2 Thomas Jefferson University Hospital, Neurological Surgery, Philadelphia PA, USA Background: This is a phase I study to evaluate the safety, and tolerability of oral panobinostat, an HDAC inhibitor, when combined with fractionated stereotactic re-irradiation therapy (FSRT) for recurrent gliomas. Background: STAT3 plays a role in tumour biology by modulating critical functions of both tumour and stromal/immune cells. AZD9150 is a STAT3 antisense oligonucleotide (ASO) in Phase I dose expansion in two clinical trials. We present safety, preliminary response, pharmacokinetic (PK) and pharmacodynamic (PD) data for the dose escalation portion of a Phase I clinical, open-label, multi-center study in advanced hepatocellular carcinoma (HCC) patients. Methods: Patients with advanced sorafenib relapsed/refractory HCC and Child-Pugh A liver function were enrolled in a 3+3 dose escalation study to determine dose limiting toxicities (DLTs), maximum tolerated dose (MTD), safety, tolerability, PK, PD, and preliminary efficacy. AZD9150 was administered intravenously with 3 loading doses of AZD9150 on days 1, 3, and 5 and weekly thereafter in 28 day cycles. STAT3 RNA and protein expression in circulating leukocytes and serum CRP were evaluated on day 8 of treatment and the first day of subsequent cycles vs. pre-treatment. Results: Twenty-four patients were dosed in 1, 1.5, 2 and 3 mg/kg cohorts between May 2013 and May 2014. One partial response was observed in the 2 mg/kg cohort with 61% reduction in lung metastases and 87% decrease in AFP. Adverse events reported in 20% patients included AST elevation (G1/2/3 46, 8, 4%), ALT elevation (G1/2/3 35, 15, 4%), thromobocytopenia (G1/2/3 31, 19, 4%) neutropenia (G1/2/3 0, 23, 0%) hypertension (G1/2/3 0, 19, 4%). Transaminase elevations were mostly mild and were reversible after interruption of AZD9150. Thrombocytopenia was mostly mild/moderate, typically occurred after ~10 weeks of dosing, and did not require dose modification or intervention. One patient had G3 thrombocytopenia and transient dosing interruption. DLTs of G3 transaminase elevations occurred in 3 patients, one each in the 1.5, 2 and 3 mg cohort. 3 mg/kg was declared the MTD and the recommended dose for subsequent studies. Maximum AZD9150 plasma concentration (Cmax) was observed at the end of the 3 hr infusion and was dose proportional between 1 and 3 mg/kg dose levels. There was no accumulation in mean plasma Cmax or AUC0−24 hr after repeated 3-hr infusions. Knockdown of 74 Thursday 20 November 2014 Plenary Session 7 STAT3 RNA and protein (up to 80%) in all circulating leukocytes of patients by day 8 of treatment was detected in the majority of samples analyzed so far and confirms activity of the drug at the target level. Decreased serum CRP in the majority of patients treated in the 1 and 1.5 mg/kg cohorts and all patients in the 2 and 3 mg/kg cohorts is consistent with functional inhibition of STAT3. Updated data will be presented. Conclusion: Preliminary data suggest activity of AZD9150 in patients with advanced HCC. A tolerated dose with clinical and pharmacodynamic activity has been identified and is being explored further in dose expansion. 218 ORAL PRESENTATION Genomic analysis identifies novel drivers and targetable pathways in inflammatory breast cancer patient samples D.M. Moran1 , K. Rao1 , P. Bacon-Trusk1 , K. Pry1 , V. Weigman2 , V. Velculescu3 , M. Cristofanilli4 , S. Bacus1 . 1 Quintiles, Translational R&D Oncology, Westmont, USA; 2 Quintiles/Expression Analysis, Translational Genomics, Durham, USA; 3 Johns Hopkins University, Oncology, Baltimore, USA; 4 Thomas Jefferson University, Medical Oncology, Philadelphia, USA Background: Inflammatory breast cancer (IBC) is a rare aggressive breast cancer in which cancer cells block the lymph vessels in the skin of the breast. IBC tumors are typically hormone receptor negative but have shown a high rate of HER2 (human epidermal growth factor receptor 2) positivity and response to HER2 targeted therapies such as lapatinib. Genomic drivers associated with progression and drug response of IBC are not well established. This study interrogates the mutational background of IBC to understand drug responses in breast cancer. Materials and Methods: A targeted NGS panel that covers whole coding regions of 208 of the most common cancer related genes (copy numbers and somatic mutations) and rearrangements in 17 well characterized cancer genes was used to analyze 20 IBC patient tumor and matched normal samples. Pathway analysis was performed on genomic variants identified. Cell line studies were performed to understand the impact of genomic variants on drug treatment. Results: Intra- and inter-tumor heterogeneity was observed across the IBC samples studied, however, common pathway motifs were also identified among cases. Multiple variants in the HER signaling pathway were observed including HER2 amplification (54% of samples) and a high rate of ERBB3 mutations (26% of samples). ERBB3 point mutations were discovered in hotspot regions in both the extracellular and kinase domains and occurred at higher rates than previously observed in other cancers. Genomic alterations were also identified among many genes of the PI3K-mTOR pathway in the majority of IBC cases. Activity of the PI3K-mTOR pathway was further confirmed by immunohistochemistry for phosphorylated S6, a target of mTOR kinase activity. Cell studies demonstrated potent effects of lapatinib on proliferation of IBC cells harboring ERBB3 mutations in conjunction with HER2 amplification. Breast cancer cells harboring PI3K mutations and HER2 amplification were less sensitive to lapatinib but were synergistically responsive to a combination of PI3KCA inhibitors and lapatinib. Other frequent genomic alterations were also detected in pathways related to chromatin modification, DNA repair, APC, JAK-STAT, KIT and Notch signaling which may also be novel drug targets in IBC. Notably, hotspot and/or kinase domain mutations were discovered in JAK (1 & 2) and KIT genes in multiple IBC samples. Conclusions: Genomic and protein analysis of IBC identified multiple pathways that may be targetable using single and/or combination targeted therapies in all cases studied. This study also highlighted that drugs such as PI3K/mTOR and novel ERBB3 targeted therapies, used alone or in combination with HER2 inhibitors, may be important in the treatment of IBC. Co-occurrence of ERBB3 mutations and HER2 amplification/overexpression likely sensitize cancer cells to HER2 targeted therapies and should be further explored in other HER2 positive cancers. 219 ORAL PRESENTATION Phase I trial evaluating the antiviral agent Cidofovir in combination with chemoradiation in cervical cancer patients: A novel approach to treat HPV related malignancies? E. Deutsch1 , A. Levy2 , R. Mazeron2 , A. Gazzah2 , E.A. Angevin3 , V. Ribrag3 , R. Balheda3 , A. Varga3 , C. Lhomme4 , C. Haie-Meder2 , J.C. Soria3 . 1 Institut Gustave Roussy, Villejuif, France; 2 Institut Gustave Roussy, radiation oncology, Villejuif, France; 3 Institut Gustave Roussy, DITEP, Villejuif, France; 4 Institut Gustave Roussy, Medicine, Villejuif, France This abstract is part of the media programme and is embargoed until the day of presentation, when it will be published online at 08:00. Thursday 20 November 2014 16:00–17:50 PLENARY SESSION 7 Novel Mechanisms for Drug Resistance 220 ORAL PRESENTATION Overcoming drug-resistance in multiple myeloma by XPO1 inhibitor combination therapy J. Turner1 , J. Dawson1 , S. Grant2 , K. Shain3 , C. Cubitt4 , Y. Dai2 , L. Zhoui2 , M. Kauffman5 , S. Shacham5 , D. Sullivan1 . 1 Moffitt Cancer Center, Chemical Biology and Molecular Medicine Program, Tampa Florida, USA; 2 Massey Cancer Center, Virginia Commonwealth University, Richmond Virginia, USA; 3 Moffitt Cancer Center, Department of Malignant Hematology, Tampa Florida, USA; 4 Moffitt Cancer Center, Translational Research Laboratory, Tampa Florida, USA; 5 Karyopharm Theraeutics, Natick Massachusetts, USA Background: The purpose of this study was to investigate the use of XPO1 (exportin 1, CRM1) inhibitors (XPO1i) to sensitize de novo and acquired drug resistant multiple myeloma (MM) cells to the proteosome inhibitors (PI) bortezomib (BZ) and carfilzomib (CZ), the topoisomerase II (topo II) inhibitor doxorubicin (DX) and the alkylating agent melphalan (ML). Materials and Methods: Cells were treated in vitro with XPO1i (KPT-330 or KOS-2464) +/− BZ, CZ, DX or ML. Sensitivity was measured by cell viability assay (CellTiter-Blue). Proximity ligation assays (PLA) were performed to assess XPO1-topoIIa binding in the presence of an XPO1i. Western blot of proteins related to PI and XPO1i were used to determine the potential mechanism of XPO1i-PI synergy. Comet assay for DNA damage was performed in XPO1i/DX treated cells. Drug resistant U266 and 8226 MM cell lines were developed by incremental exposure to BZ. Resistant and parental MM cells were treated in vitro with XPO1i +/− MM drugs. Sensitivity was measured by apoptosis (caspase 3). U266 resistant MM cells were also used to challenge NOD/SCID-g mice treated with XPO1i +/− BZ or pegylated liposomal doxorubicin (PLD). MM cells isolated from patients with newly diagnosed, relapsed or refractory MM were treated with XPO1i +/− BZ, CZ, DX or ML and CD138+/light chain+ MM cells assayed for apoptosis. Results: MM cell viability was decreased synergistically by XPO1i when used in combination with BZ, CZ, DX or ML (CI values 0.502, 0.482, 0.092 and 0.687). XPO1i prevented binding of XPO1 to topoIIa as shown by PLA, and XPO1i increased DNA fragmentation when combined with DX (Comet assay). Western blot showed that the XPO1i/PI combination increased IkB and decreased NFkB in MM cells. BZ selected MM cells were found to be resistant (>10-fold) to BZ, CZ, DX and ML when compared to parental cell lines. Resistant MM cell lines were sensitized by the XPO1i to drugs as shown by apoptosis assay (3 to10-fold). Drug resistant MM challenged mice treated with XPO1i +/− BZ or PLD had increased survival when compared to BZ or PLD alone (p0.027). CD138+/light chain+ MM cells derived from Poster Session – Chemoprevention newly diagnosed, relapsed and refractory MM patients were sensitized by XPO1 inhibitors to BZ, CZ, DX and ML as shown by apoptosis. Conclusions: XPO1i greatly improved the response of de novo and acquired drug resistant MM to BZ, CZ, DX and ML in vitro, in vivo and ex vivo. Combination therapies using XPO1i may significantly improve the treatment of myeloma. Thursday 20 November 2014 Poster Sessions Chemoprevention 221 POSTER (Board P001) Docosahexaenoic acid along with modulation of actin binding proteins reduces cancer cell migration M. Ali1 , L.K. Rogers1 . 1 Nationwide Children’s Hospital The Ohio State University College of Medicine, The Research Institute at Nationwide Children’s Hospital and Department of Pediatrics, Columbus Ohio, USA Background: Cancer is the leading cause of death worldwide and all age groups, including children, are at risk for cancer associated death. Disease progression and metastasis are major contributors to cancer-associated morbidity and mortality. Increased cell migration rate is characteristic of tumor progression and metastasis. Actin binding proteins regulate cytoskeletal remodeling at the leading edges of cancer cells, facilitate invasive organelle (invadopodia) formation, and promote higher migration rates. Docosahexaenoic acid (DHA), a poly unsaturated fatty acid, has been shown to inhibit the cancer cell metastatic phenotype. Here, we test the hypothesis that changes in actin binding proteins regulate cancer cell migration and that supplementing cells with DHA will prevent these changes. Materials and Methods: Fatty acid profile of Non-cancer (MLE12) and cancer (A549) done with mass spectrophotometry. Further cells were treated with 8-Br-cAMP and/or DHA. F-actin content was measured using confocal microscopy. Cell migration was estimated by wound assay and transwell apparatus. Actin binding proteins, profilin, cofilin, vimentin and gelsolin, were identified and quantified using confocal microscopy and western blot to evaluate wound edges and actin co-immunoprecipitate, respectively. Results: F-actin content and cell migration were increased by cAMP in association with changes in profilin, cofilin, vimentin and gelsolin levels. DHA treatment suppressed the increase in actin content and cell migration in cancer cells but not in non-cancer cells in association with altered levels of actin binding proteins. Conclusion: We postulate that DHA specifically inhibits cancer cell migration via alterations in actin binding proteins indicating a therapeutic potential against cancer cell metastasis. The changes in actin binding proteins could serve as biomarkers for cancer progression and as innovative therapeutic targets. 222 POSTER (Board P002) Estimating predictive values of short-term morphologic assays of cancer chemoprevention for efficacy in animal tumor assays B. Dunn1 , V.E. Steele1 , R.M. Fagerstrom1 , C.F. Topp2 , D. Ransohoff3 , C. Cunningham4 , R. Lubet5 , L.G. Ford5 , B.S. Kramer5 . 1 National Cancer Institute NIH, Division of Cancer Prevention, Bethesda Maryland, USA; 2 CCS Associates, Preclinical Research and Development Resources, McLean Virginia, USA; 3 University of North Carolina at Chapel Hill, Department of Medicine, Chapel Hill NC, USA; 4 Information Management Services, Rockville MD, USA; 5 National Cancer Institute, Division of Cancer Prevention, Bethesda MD, USA Background: The predictive value of chemopreventive agent efficacy in morphologic (in vitro/in vivo) assays for efficacy in in vivo tumor assays is not well characterized. Over a 25-year period, the Chemopreventive Agent Development Research Group in the U.S. NCI’s Division of Cancer Prevention has tested approximately 800 agents for potential chemopreventive activity. The current project focuses on agents tested in both morphologic and tumor assays in order to gain a deeper understanding of the relevant predictive values. Materials and Methods: The early stages of the testing pathway involve two critical steps: (1) in vitro/in vivo morphologic assays and, for agents Thursday 20 November 2014 75 successful in these, (2) testing for tumor prevention (measured in terms of tumor incidence and multiplicity reduction) in animal tumor assays. The ultimate goal is to test agents that successfully decrease tumor incidence and multiplicity in animal tumor assays in humans. In the current project we evaluated the predictive values of our preclinical models by determining how well the earlier-stage (morphologic) assays predict efficacy in the laterstage (animal tumor) assays. The 210 agents that were tested in both morphologic and animal tumor assays in our program were included in our analysis. Statistical modeling to determine how well the six most commonly used morphologic assays predicted efficacy of the 210 tested agents in animal tumor assays was carried out by multimodel inference applied to ordinal logistic regression. Results: The ability of these six morphologic assays to predict tumor outcomes was evaluated in three statistical models, one for each animal tumor setting: (1) all tumor types (general model), (2) colon cancer only, and (3) mammary gland cancer only. Based on this statistical modeling, each morphologic assay was assigned a value describing how strongly it predicted outcomes in each of the three animal tumor assay settings. Conclusions: These predictive models can be used to guide our future decision-making with respect to agent selection as well as morphologic and animal tumor assay use. The overall goal is to improve the efficiency of the process of chemopreventive agent development. 223 POSTER (Board P003) Preclinical assessment of nintedanib for chemoprevention in hepatocellular carcinoma V. Tovar1 , A. Moeini1 , S. Torrecilla1 , M. Higuera1 , J. Peix1 , I.M. Quetglas1 , L. Rodriguez-Carunchio1 , H. Cornella1 , M. Sole1 , J.M. Llovet1 . 1 Institut d’Investigacions Biomediques August Pi i Sunyer (IDIBAPS), HCC Translational Research Laboratory, BCLC group, Hospital Clı́nic, Liver Unit − CIBEREHD, University of Barcelona, Barcelona, Spain Background: Hepatocellular carcinoma (HCC) is the 2nd cause of cancerrelated mortality. Cirrhosis is the most common risk factor in 80−90% of HCC patients. Angiogenesis has a pivotal role in both chronic liver disease and hepatocarcinogenesis. Thus, early interference with anti-angiogenic agents at cirrhotic stages may prevent HCC development. In this study, we evaluate the chemopreventive efficacy of the angiokinase inhibitor nintedanib (VEGFR1−3, FGFR1−3, PDGFR-a/b; Boehringer Ingelheim) in an animal model of HCC. Material and Methods: HCC was induced in male C57Bl/6 mice (n = 55) by a single intraperitoneal (i.p.) injection of DEN (25 mg/kg) at day 15 postpartum followed by weekly i.p. injections of CCl4 (0.5 ml/kg) starting at 4 weeks of age. At 12 weeks-old, mice were randomized to receive nintedanib (50 mg/kg) (n = 29) or vehicle (n = 26). To assess chemopreventive efficacy, mice were sacrificed at 15, 17 and 18 weeks of age. Liver samples were collected for immunohistochemical and molecular analysis (western blot and qRT-PCR). The primary study end-points included HCC incidence, number and size of macroscopic tumors. Drug tolerance was evaluated by body weight losses and plasma ALT/AST levels. Results: Nintedanib reduced HCC incidence in treated animals compared to placebo group at 15 weeks (13% vs 43%), 17 weeks (30% vs 89%, p = 0.02), and 18 weeks (90% vs 100%). The number of tumor/mouse significantly decreased at 17 weeks (0.9 vs 4.7, p = 0.003) and 18 weeks (3.5 vs 11.4, p = 0.003). Nintedanib also prevent the development of large number of tumors (>4 tumors) at 17 weeks (p = 0.01) and 18 weeks (p = 0.008). Moreover, tumor size was significantly reduced at 17 weeks (0.7 mm vs 6.4 mm, p = 0.01) and 18 weeks (4.8 mm vs 16.2 mm, p = 0.001). Nintedanib was well tolerated and no significant toxicity was reported. Histological analysis and up-regulation of collagen levels confirmed the development of HCC in a context of well-established fibrosis. Assessment of nintedanibmechanism of action showed a trend to reduce VEGFR-2 activation while significantly decreased downstream activation of AKT and ERK. Conclusion: Nintedanib decreases overall HCC incidence, number of tumors and tumor size in a liver fibrosis-based mouse model. Nintedanib acts by blocking the MAPK/PI3K pathway downstream of the proangiogenic receptors (VEGFR and PDGFR). Our data provides rationale for testing nintedanib as a potential chemopreventive agent for the development of HCC in cirrhotic patients. 76 Thursday 20 November 2014 Poster Session – Clinical Methodology 224 POSTER (Board P004) Synergic tumor growth suppression with carbohydrate-restriction diet and natural AMP-dependent protein kinase activators 226 POSTER (Board P006) Efficacy of cancer preventing drugs administered by intermittent dosing regimens M. Choi1 , J. Lee2 . 1 Yonsei Cancer Center Yonsei University College of Medicine, Department of Nuclear Medicine, Seoul, South Korea; 2 Yonsei Cancer Center Yonsei University College of Medicine, Department of Nuclear Medicine Brain Korea 21 Project for medical Sciences, Seoul, South Korea V.E. Steele1 , C. Grubbs2 , C.V. Rao3 , R.A. Lubet1 . 1 National Institutes of Health/National Cancer Institute, Division of Cancer Prevention, Bethesda MD, USA; 2 University of Alabama at Birmingham, Department of Surgery, Birmingham AL, USA; 3 Oklahoma University Health Sciences Center, Center for Cancer Prevention and Drug Development, Oklahoma City OK, USA Background: Calorie restriction (CR) or low-carbohydrate diet (LCD) can increase life-span in normal cells but inhibit carcinogenesis. Various AMPdependent protein kinase (AMPK) activating phytochemicals also have CR-mimetic anticancer properties. We investigated whether carbohydraterestriction diet and phytochemical supplementation induce synergic tumor suppression. Methods: We used a mixture of curcumin, quercetin, catechins and resveratrol extracts for natural AMPK-activating agent. Survival analysis was performed in B16F10 melanoma model after fed control diet, control diet with phytochemicals (MP formula), LCD, LCD with phytochemicals (LCDmp), moderate-carbohydrate diet (MCD), and MCD with phytochemicals (MCDmp). Tumor suppression mechanisms, especially alterations in energy-dependent signaling pathways, histone methylation, and global gene expression were investigated. We evaluated the role of SIRT1 under glucose-restriction condition with MTT assay. Diet-induced cancer prevention effects were analyzed in a transgenic liver cancer model. Results: In melanoma model, MP, LCD, or MCD intervention did not produce survival benefit but LCDmp and MCDmp interventions increased median survival time significantly (p < 0.05). Suppression of the IGF-1R/PI3K/Akt/mTOR signaling, activation of the AMPK/SIRT1/LKB1pathway and NF-kB suppression were the major tumor suppression mechanisms. MTT assay showed suppressed proliferation of the B16F10 and A375SM cells after treatment of SIRT1 activator under low-glucose condition. Alterations in histone methylation within Pten and FoxO3a were demonstrated in tumor tissues. In transgenic liver cancer model, the MCDmp and LCDmp groups showed fewer tumor nodules. Microarray analysis revealed increased PPARa with decreased IL-6 and NF-kB after MCDmp intervention, which could be the major cancer prevention mechanism. Conclusion: AMPK-activating phytochemicals exert synergic anti-cancer activities under low-carbohydrate condition, and SIRT1 induces tumor suppression. 225 POSTER (Board P005) Molecular targets of interest to the NCI PREVENT cancer preclinical drug development program R.H. Shoemaker1 , B.K. Dunn1 , C. Suen1 , R.A. Lubet1 , D.L. Boring1 , B.D. Klein1 , M.S. Miller1 , V.E. Steele1 . 1 National Cancer Institute Division of Cancer Prevention, Chemopreventive Agent Development Research Group, Bethesda MD, USA Chemoprevention research in the Division of Cancer Prevention was re-structured in 2011 creating the PREVENT Cancer Preclinical Drug Development Program. This Program provides for peer-review of proposals from the general research community for development of small molecules or biologicals, including vaccines, for cancer prevention or biomarkers to facilitate clinical evaluation of prevention strategies. The process for applying to the Prevent Program is described at: http://prevention.cancer.gov/ programs-resources/programs/prevent. Applications are submitted twice yearly and reviewed by a panel of experts and scored for scientific merit, feasibility, etc. Top scoring applications undergo secondary review and prioritization by a panel of NIH scientists. Applications with potential for near-term clinical translation are given highest priority. Approved projects are implemented as Task Orders via a system of contracts with academic and nonprofit, independent research institutions that provide the full range of preclinical studies, including GLP toxicology, needed to support Investigational New Drug Applications. Twenty-five Task Orders addressing a range of molecular targets have been awarded in the first two years of the Program. Small molecules targeting classic aspects of inflammation as well as newer molecular-targeted agents (n = 16) are under study. Pharmacodynamic assays are coupled to efficacy studies. Immunoprevention strategies targeting tumor-associated antigens as well as antigens from cancer-associated infectious agents (n = 6) are being pursued. Preliminary data from current projects will be presented. The PREVENT Cancer Program has engaged a broad cross-section of investigators, supporting preclinical development of agents addressing a wide variety of cancer prevention targets. Background: Many potential chemopreventive drugs have adverse effects on human subjects when given daily. One strategy to alleviate these adverse events is to give the drugs on an intermittent dosing schedule. Such intermittent dosing has proven effective in other scenarios to reduce toxicity with limited effect on efficacy. Two animal models were used: the rat methylnitrosourea (MNU)-induced mammary cancer model and the rat hydroxy-butyl(butyl)-nitrosamine (OH-BBN)-induced urinary bladder cancer model. Materials and Methods: For the mammary study female Sprague-Dawley rats were given 75 mg of MNU/kg body weight at 50 days of age and five days later the EGFR inhibitors, erlotinib, gefitinib or lapatinib were administered either daily or once a week at two dose levels. Multiplicity of ER-positive mammary cancers was followed weekly for four months. For the urinary bladder study female Fischer 344 rats were given 150 mg OHBBN/gavage twice weekly beginning at 56 days of age and continuing for 8 weeks. Two weeks after the last OH-BBN treatment the rats were given naproxen either daily, one week on/one week off, or 3 weeks on/3 weeks off. Bladders were excised after 8 months of naproxen treatment and bladders with tumors were excised and weighed. Results: EGFR inhibitors and the NSAID, naproxen, have similar efficacy when given intermittently compared to daily. Data will be presented with two organ specific chemoprevention animal models: ER-positive mammary and invasive urinary bladder cancer. The EGFR antagonists, erlotinib, gefitinib and lapatinib, decreased mammary cancer multiplicity by 90% given daily and 75% given weekly. The NSAID, naproxen, decreased large bladder cancers by about 65−80% given either daily, one week on/one week off or 3 weeks on/3 weeks off. Conclusions: Intermittent dosing can be used for agents in two different mechanistic classes in animal mammary and bladder cancer models to lower toxicity yet show little reduction in chemoprevention efficacy compared to daily dosing. Intermittent dosing schedules should reduce EGFR mediated rash and NSAID induced gastric toxicity clinically while retaining efficacy. Clinical Methodology 227 POSTER (Board P007) Multiplexed ICE COLD-PCR: A mutation detection methodology for achieving sensitivities of <0.01% using either Sanger or NGS G. Wu1 , B. Legendre2 , S. Cherubin1 , C. Cubrich1 , A. Dowers2 , S. Jensen1 , J. Gniffke3 , A. Kruempel2 , P. Krzycki2 , E. McCutchen2 , E. Montagne1 , S. Peterson4 , J. Pope2 , K. Scott1 , K. Richardson5 . 1 Transgenomic, R&D, Omaha, USA; 2 Transgenomic, Biomarker Identification, Omaha, USA; 3 Transgenomic, IT, Omaha, USA; 4 Transgenomic, CLIA, Omaha, USA; 5 Transgenomic, Omaha, USA Background: Blood-based mutation analysis from circulating free DNA (cfDNA) is becoming very important for molecular demographics and diagnostics where no tumor is available as well as in the pharmacodynamic monitoring of the patient during therapy. ICE COLD-PCR technology is capable of high sensitivity detection for both point mutations and insertion/deletions through unbiased enrichment of relevant gene regions. This method preferentially amplifies low levels of mutant DNA in a sample containing a vast excess of wild-type DNA. Materials and Methods: In order to increase throughput as well as address the limited amounts of DNA present from cfDNA sources, a multiplex approach for ICE COLD-PCR has been developed. Horizon Cell line DNA with digital PCR verified mutation percentages was first amplified using singleplex PCR for a single region of interest or multiplex PCR for several regions of interest. The advantage of the multiplex PCR is to allow simultaneous amplification of all targets with the same input DNA. The digitally-verified DNA was used for the LOD dilutions where the starting mutation percentage was below 1%. The amplified DNA can then be used in multiple singleplex or multiplex ICE COLD-PCR reactions. A constraint of all ICE COLD-PCR reactions is the optimal thermal cycling parameters needed for mutation enrichment and this critical temperature Poster Session – Clinical Methodology (Tc) is dependent on the sequence context. A Veriti thermal cycler was used for ICE COLD-PCR analysis of EGFR Exons 19, 20, and 21, KRAS Exons 2 and 3, and NRAS Exons 2 and 3 because it can simultaneously perform thermal cycling at 6 different Tc’s on a single 96-well plate. This was followed by hemi-nested PCR using a single thermal cycling program, if required, to provide sufficient sample for Sanger sequencing and NGS using an Ion Torrent. Results: Limits of detection experiments using the Horizon Cell Line DNA and serial dilution of this DNA indicated that samples containing 0.01% mutation in the starting material were easily confirmed using both Sanger and NGS sequencing platforms. This was true for the point mutations as well as the EGFR Exon 19 E746_A750delGGAATTAAGAGAAGC. Concordance of cfDNA and matched FFPE tumor DNA is also presented. Conclusion: ICE COLD-PCR can be used in a multiplex fashion for the sensitive detection of all mutations in a region. This is important when investigating regions with multiple mutations such as EGFR Exon 19 deletions. The sensitivities achieved indicate that ICE COLD-PCR is an ideal tool for detection of low level mutations found in cfDNA and potentially circulating tumor cells. The ability to confirm these mutations by either Sanger or NGS platforms allows flexibility in rapid confirmation when few or many gene regions need to be interrogated. 228 POSTER (Board P008) Her2−3 heterodimer is a new and better than HER2 IHC score for clinical outcome prognosis G. Weitsman1 , P.R. Barber2 , K. Lawler3 , C. Gillett4 , N. Woodman4 , B. Kholodenko5 , L.K. Nguyen5 , T. Santra5 , B. Vojnovic2 , T. Ng1 . 1 Richard Dimbleby Department of Cancer Research Randall Division & Division of Cancer Studies Kings College London, Guy’s Medical School Campus, London, United Kingdom; 2 CRUK & MRC Oxford Institute for Radiation Oncology Gray Laboratories, Department of Oncology, Oxford, United Kingdom; 3 Institute for Mathematical and Molecular Biomedicine Kings College London, Guy’s Medical School Campus, London, United Kingdom; 4 Research Oncology Division of Cancer Studies King’s College London, Guy’s Hospital, London, United Kingdom; 5 Systems Biology Ireland at UCD Conway Institute, University College Dublin, Dublin, Ireland The efficacy of anti-Her2 therapies in Her2-positive breast cancer patients is proven and well documented. However, some patients with Her2-negative tumours also benefit from the same therapies (NSABP B-31) and there is no solid hypothesis to explain those observations. Furthermore, the definition of positive vs. negative Her2 status actually reflects overexpression of Her2 above levels detected in normal and non-malignant tissues. Her2 can heterodimerize with other members of the EGFR family, regardless of expression levels, but the dimerization is dependent upon availability of ligand(s). Her2-Her3 dimer has been shown to drive proliferation of breast cancer cells. We have developed a new FRET/FLIM (Förster resonance energy transfer/fluorescence-lifetime imaging microscopy) based assay reporting protein–protein interaction at distance below 10 nm for detection of Her2-Her3 dimer in formalinfixed paraffin embedded (FFPE) patient samples. Fluorophore labelled antibodies against Her2 and Her3 allow us to measure a FRET signal, which is dependent upon the number of interacting molecules. Using FFPE samples from the METABRIC cohort, we found that the interaction between two proteins does not correlate with expression levels of interacting partners as judged using standard IHC scoring system. The FRET signal measurements were evenly distributed across all samples with 0, 1, 2 and 3-plus scores for Her2 expression. Mathematical modelling suggests that the absence of correlation between Her2 and Her3 protein and their dimer levels, although can be quite unintuitive, is in principle possible, particularly under scenarios when both Her2 and Her3 compete for binding with other receptor tyrosine kinases including the other ErbB family receptors. Interestingly, we also did not find any correlation with known genetic signatures associated with cancer progression. However, a low FRET signal significantly correlated with longer metastasis free survival, when patients with metastatic events up to 10 years are considered. Our findings may pave the way for better understanding of the biology of EGFR family receptor’s adaptation to drug treatment, helping to predict individual patient response to select the right patient for appropriate treatment. 229 POSTER (Board P009) DNA methyltransferase 1 expression in human solid tumors and lymphomas by immunohistochemistry S.X. Yang1 , D. Nguyen1 , L. Rubinstein1 , S. Kummar1 , J.E. Tomaszewski1 , J.H. Doroshow1 . 1 National Cancer Institute NIH, Division of Cancer Treatment and Diagnosis, Bethesda Maryland, USA Background: CpG island methylation in some tumor suppressor genes has been linked to the development or progression of certain human Thursday 20 November 2014 77 cancers. DNA methyltransferase 1 (DNMT1) is the most abundant enzyme among the three members of the DNMT family. Anti-tumor activity of DNMT inhibitors has been demonstrated largely in myelodysplastic syndrome and acute myeloid leukemia in unselected patient populations, and less frequently in solid tumors. Currently, there are no biomarkers capable of predicting efficacy of DNMT inhibitors and available for prospective patient selection. This study was undertaken to investigate the expression of DNMT1, the putative target of some DNMT inhibitors, in a spectrum of human malignancies in an effort to identify a biomarker for efficacy. Materials and Methods: NCI-H23 non-small cell lung cancer cells were treated with and without a novel DNMT inhibitor, 4 -thio-5-aza-2 deoxycytidine (5-aza-T-dCyd), and changes in DNMT1 expression were assessed by western blot and immunocytochemistry (ICC). Expression of DNMT1 was also examined by immunohistochemistry in formalin-fixed and paraffin-embedded primary lung and ovarian cancers as well as lymphomas. Results: Expression of DNMT1 in NCI-H23 cells was nearly depleted by treatment with 1 mM aza-T-dCyd for 96 h revealed by both western blot and ICC (mean staining index, 56.7 versus 4.3; P<0.0001; 2-sided t test). These suggest that 5-aza-T-dCyd is a potent novel DNMT inhibitor and the antibody used detects the difference, indicative of its specificity. DNMT1 was primarily localized in the nucleus, and constitutively expressed in tumor cells at intermediate and high levels in 12.5% (7/56) of lung cancers, 7.7% (3/39) of ovarian tumors, and 15% (12/78) of lymphomas across histologies including diffuse B-cell, Burkitt-like, T-cell, lymphocyte predominant Hodgkin’s, or mixed cellularity Hodgkin’s lymphoma. Conclusions: We have established a DNMT1 immunohistochemical assay that covers a dynamic range from undetectable to weak, intermediate or strong staining in paraffin-embedded tumor samples. The data demonstrate that intermediate to high levels of DNMT1 expression are found in 15% or fewer patients with either lung cancers, ovarian tumors or lymphomas. The application of this assay holds promise for evaluating DNMT1 expression levels as a potential pharmacodynamic and efficacy biomarker for DNMT inhibitors. 230 POSTER (Board P010) High correlation between clinical responses to first line AML patients treated with cytarabine and idarubicin and their pharmacological profiles in patient samples measured by ExviTech J. Ballesteros1 , P. Hernandez1 , D. Primo2 , A. Robles1 , A.B. Espinosa2 , E. Arroyo2 , V. Garcia-Navas1 , J. Sanchez-Fenoy1 , M. Jimenez1 , M. Gaspar1 , J.L. Rojas1 , J. Martinez-Lopez3 , J. Gorrochategui1 . 1 Vivia Biotech, Tres Cantos-Madrid, Spain; 2 Vivia Biotech, Salamanca, Spain; 3 Hospital 12 de Octubre, Hematology, Madrid, Spain Background: Complete remission (CR) after induction therapy is the first treatment goal in acute myeloid leukemia (AML) patients. The aim of this study is to determine the ability of the Vivia’s novel ex vivo drug sensitivity platform Exvitech to predict the CR rates after induction chemotherapy with cytarabine (Ara-C) and idarubicin (Ida) in 1st line AML. Material and Methods: Bone marrow samples from adult patients diagnosed with de novo AML in Spanish centers from the PETHEMA group were included. Whole marrow samples were incubated for 48 h in well plates containing Ara-C, Ida, or their combination. Pharmacological responses are calculated using pharmacokinetic population models. Induction response was assessed according to the Cheson criteria (2003). Patients attaining a CR/CRi were classified as responders and the remaining as resistant. Results: 180 patient samples were used to calculate the dose–response (DR) curves for Ara-C alone, Ida alone, and their synergism. For clinical correlation we used 77 patients with a median age of 55 years. Many samples had a significant number (>20%) of resistant cells to Ara-C. This is a strong clinical predictor of resistance because in the patient the drug will never be present at these high doses for 48 h. The second variable that is a good predictor of response is the synergism between these 2 drugs. The generalized additive model identified an algebraic combination of these 2 variables that yielded the best marker to separate both groups of patients. The probability density functions had minimal overlap. The area under the corresponding ROC curve was 0.935 (0.872, 0.997), and the classification probabilities for the optimal cut point, were 87% (68%to 95%) and 91% (80% to 96%) for sensitivity and specificity, respectively. 54 patients (70.1%) achieved CR after Ida+Ara-C, and the remaining 23 (29.9%) were resistant. 20 of the 23 (86.9%) patients who fail to achieve CR were predicted as resistance in the ex vivo test. 49 of the 54 patients (90.74%) who achieved CR showed good ex vivo sensitivity to Ida+Ara-C predicting for CR. When the ex vivo test predicted a patient as sensitive it was correct in 49/52 cases (94.23%), and when it predicted resistant it was correct 20/25 cases (80%). Overall, 69/77 patients (89.61%) had an accurate prediction of their response to treatment. 78 Thursday 20 November 2014 Conclusions: This novel ex vivo pharmacological profile test is able to predict the clinical response to Ida+Ara-C induction. We are increasing the number of patients in this ongoing study, and we are planning a personalized medicine test-adapted Clinical Trial. 231 POSTER (Board P011) Clinical pharmacodynamic assay development for the first in class investigational ubiquitin activating enzyme (UAE) inhibitor MLN7243 B. Bahamón1 , F. Gao2 , B. Stringer3 , Y. Yang3 , J. Shi4 , K. Burke5 , J. Huck4 , T. Traore4 , D. Bowman5 , H. Danaee1 , M. Millhollen5 , M. Hyer4 , N. Bence5 , Y. Ishii1 . 1 Takeda Pharmaceuticals International Co., Translational Medicine, Cambridge, USA; 2 Takeda Pharmaceuticals International Co., Biostatistics, Cambridge, USA; 3 Takeda Pharmaceuticals International Co., Molecular Pathology, Cambridge, USA; 4 Takeda Pharmaceuticals International Co., Cancer Pharmacology, Cambridge, USA; 5 Takeda Pharmaceuticals International Co., Molecular & Cellular Oncology, Cambridge, USA MLN7243 is a first in class investigational small molecular inhibitor of the ubiquitin-activating enzyme (UAE) that is currently in Phase I. UAE controls cellular ubiquitin conjugation and inhibition of UAE by MLN7243 induces cell cycle arrest, endoplasmic reticulum stress, defects in DNA repair pathways and ultimately apoptosis. In nonclinical studies, MLN7243 behaves as a strong apoptosis inducer in vitro and also exhibited antitumor activity against a broad range of human tumor xenograft models representing solid and hematologic tumor types. The first in human trial of MLN7243, a Phase I dose escalation study in patients with advanced solid tumors is underway. Here we describe development of pharamacodynamic (PD) biomarker assays for clinical studies of MLN7243. PD immunohistochemistry (IHC) biomarkers were selected to examine MLN7243 target engagement (MLN7243ubiquitin adduct) as well as pathway inhibition (cellular polyubiquitin and monoubiquitin histone 2B (Ub-H2B)). Each IHC assay was optimized and tested for dynamic range using a panel of xenograft samples treated with MLN7243 for varying time points. Reproducibility and specificity were calculated using xenograft tumor tissues of known varying expression (5 low, 5 medium and 5 high expressers for polyubiquitin or Ub-H2B). Baseline expression of the pathway inhibition biomarkers using resected human tumor samples from four cancer types (non-small cell lung cancer, ovarian, colon and breast; each n = 30) was evaluated. The stained slides were scanned using the automated Aperio System, relevant tumor area was selected by a pathologist and analyzed by Definiens Software for positive index (% positive) and histological score. All three PD biomarker assays displayed a large dynamic range, small day-to-day and operator-to-operator variation (largest CV = approx. 13%) in both positive index (% positive) or histological scores in a xenograft model. Power to detect 20% change in both positive index (% positive) and histological score was calculated for each marker to determine the number of slides needed in the clinical study (MLN7243-ubiquitin adduct = 2, polyubiquitin = 5, Ub-H2B = 4) based on assay variability. Polyubiquitin and Ub-H2B image analysis revealed a wide variation within each cancer type while between cancer types variation was relatively small (similar mean/median) with the exception of ovarian cancer. It is possible that the baseline variation stems from differences in sample fixation, storage and age or a biological variation in basal ubiquitin pathway flux between patient samples. Supported by these studies, these PD biomarker IHC assays have been implemented in the MLN7243 first in human study. 232 POSTER (Board P012) Development of a targeted NGS assay system for patient enrollment to the NCI-MATCH study M. Williams1 , D. Sims1 , J. Lih1 , A. Datta1 , S. Hamilton2 , A.J. Iafrate3 , J. Sklar4 , S. Sadis5 , N. Takabe6 , J. Tricoli7 , J. Doroshow8 , B. Conley7 . 1 National Cancer Institute-Frederick, Molecular Charterization and Clinical Assay Development Laboratory, Frederick, USA; 2 MD Anderson Cancer Center, Molecular Pathology, Houston, USA; 3 Massachusetts General Hospital, Molecular Pathology, Boston, USA; 4 Yale University Medical Center, Molecular Pathology, New Haven, USA; 5 Life Technologies, Compendia, Foster City, USA; 6 NCI, CTEP, Bethesda, USA; 7 NCI, CDP, Shady Grove, USA; 8 NCI, DCTD, Bethesda, USA Background: NGS provides a tool for multi-analyte testing and is well suited for identifying predictive biomarkers. The NCI and ECOG-ACRIN are leading an effort to launch a U.S. national cancer trial for the treatment of cancer patients who have progressed after standard treatments. NCIMATCH will encompass multiple (20+) treatment arms and rely on an NGS screening assay to identify biomarkers with sufficient levels of evidence associated with treatment selection. This study will be open to all of the Poster Session – Clinical Methodology U.S. Oncology Cooperative groups. Patient treatment will be open at all NCTN Cancer Centers (>2,400 sites) including community cancer centers. Four clinical laboratories have been selected and have established a clinical laboratory network. Material and Methods: The screening NGS assay uses the Oncomine Cancer Panel NGS Assay which is a targeted NGS assay. Patient biopsies will serve as the source of RNA and DNA for the assay. A single tissue preanalytics center will process all specimens prior to shipment to the clinical laboratories. NGS data will be uploaded to a central data analysis pipeline, where data will be mapped and variants called. Treatment actionable variants will be identified. Upon laboratory verification of the variant calls, the data will uploaded to a rules engine, ‘MATCHBOX’, where treatment will be selected and the results sent to the treating physician. Details of this process will be discussed. Results: The NGS assay will assess 137 genes (including gain of function and loss of function/tumor suppressors). The assay will report out approximately 10,822 different cancer variants (SNV, small indel, large indel, CNV and gene fusions). Details of the levels of evidence required for selection of treatment actionable variants will be provided. Feasibility studies will be completed and data will be presented demonstrating the performance of the NGS assay from the four clinical laboratories. The analytical validation plan will be discussed. 233 POSTER (Board P013) Analytical validation and application of the MPACT assay, a next generation sequencing based targeted mutation detection assay for treatment selection C. Lih1 , D.J. Sims1 , R.D. Harrington1 , E.C. Polley2 , Y. Zhao2 , R.M. Simon2 , M.G. Mehaffey1 , T.D. Forbes1 , W.D. Walsh1 , V. Datta1 , B.A. Conley3 , A.P. Chen4 , S. Kummar4 , J.H. Doroshow4 , P.M. Williams1 . 1 Leidos Biomedical Inc. Frederick National Laboratory for Cancer Research, Molecular Characterization Lab, Maryland, USA; 2 National Cancer Institute, Biometric Research Branch, Maryland, USA; 3 National Cancer Institute, Cancer Diagnosis Program, Maryland, USA; 4 National Cancer Institute, Division of Cancer Treatment and Diagnosis, Maryland, USA Background: Robust and analytically validated assays are essential for development of molecular targeted cancer therapies. Here we described the development, analytical performance and application of a clinical diagnostic assay for MPACT (Molecular Profiling based Assignment of Cancer Therapeutics) trial. MPACT is a pilot and randomized trial that applies a next generation sequencing assay to select therapy. Materials and Methods: Using Life Technologies’ Ampliseq technology and PGM sequencer, we developed a custom NGS assay, called the MPACT assay and assessed the performance metrics (sensitivity, specificity, accuracy, reproducibility) for each type of actionable mutations of interest. The assay utilizes core needle biopsies shipped and processed as formalin fixed paraffin embedded specimens. Results: The MPACT assay interrogates a total of 59,150 bp that represents 391 treatment actionable variants. The rules for treatment selection will be discussed. The analytical sensitivity study showed the MPACT assay achieved 100% sensitivity for SNVs, SNVs at homopolymeric region (HP), and large Insertions and deletions (large indels, >3 bp) and 83.3% for indels and 93.3% in Indels at HP. Confirmation of 39 known variants by Sanger sequencing demonstrated 95% accuracy. The MPACT assay achieved 100% specificity for all 5 variant types. Inter and intraoperator concordance was 100% and 97.15% respectively with greater than 0.99 R square values in allele frequency correlation for detected variants. Analysis of 10 clinical specimens that contained 11 known mutations identified previously by another validated sequencing assay demonstrated the MAPCT assay identified all known mutations. By testing 10 core needle biopsies biopsied 4 independent times by two operators, we demonstrated the MPACT assay showed 100% reproducibility in the detected mutations and treatment selection between all replicates. These data were submitted to the FDA as part of the study IND. Recent upgrades of the data analysis pipeline to TS4.0 have increased sensitivity and specificity of the assay to 100%. The MPACT Study is ongoing and data will be presented discussing the frequency of detection of treatment actionable variants and overall assay success rates. Conclusions: This validation study demonstrated the MPACT assay was well-suited for the intended investigational trial use. The MPACT Study is open and aMOI incidence will be presented. Poster Session – Clinical Methodology 234 POSTER (Board P014) Kinetic analysis of dynamic 11 C-verapamil PET study: Compartmental v adaptive mixture models comparison F. Hernandez1 , D. Hawe1 , S. Murphy1 , J. O’Sullivan1 , E. Wolsztynski1 , J. Huang1 , M. Muzi2 , J. Eary3 , K. Krohn2 , F. O’Sullivan1 . 1 University College Cork, Statistics, Cork, Ireland; 2 University of Washington, Radiology, Seattle, USA; 3 University of Alabama, Radiology, Birmingham, USA Background: Temporal aspects of dynamic positron emission tomography (PET) generally rely on compartmental models (CM), with questionable assumptions to summarise functional kinetics of injected radio-tracers in living tissues. Material and Methods: The tracer signal time-course is a combination of vascular delivery and tissue retention effects which do not always satisfy the assumptions of tissue homogeneity and instant mixing within compartments required by the CM. This tissue activity time-course can typically be expressed as a convolution between the signal of the tracer in the arterial supply and the tissue residue function. The residue represents the amount of tracer remaining in the tissue and provides a description of the tracer kinetics measurable by the PET scan. Thus, in statistical terms, the residue can be thought of as a survival function for the residence of the tracer in the tissue which does not require the physiological constraints intrinsic in the exponential-like residue needed for CM. Accordingly more flexible novel approaches − nonparametric and later adaptive mixture models − to estimate the residue based on a piecewise linear form have been developed. The new approaches have been successfully probed on two of the most well-established PET radiotracers, 15 O-H2 O and 18 F-fluorodeoxyglucose, used for perfusion and glucose metabolism respectively. This study shows the extension of the new approaches to the multiple-drug resistance transporter P-glycoprotein (P-gp) highly present at the blood–brain barrier (BBB) using 11 C-Verapamil (Vp) in healthy humans before and after inhibition of the P-gp by Cyclosporine (CsA) infusion. Previous PET studies on measuring BBB activity by CsA infusion using Vp have revealed difficulties for the CM to recover metabolic information as they require a full understanding of the tracers metabolisation in the tissue, which is still not certain for Vp. This problem is especially latent when the inhibition of the P-gp allows the tracer through the BBB where it is retained once at the brain tissue level. Results: This work examines and evaluate adaptive mixture model as an alternative to conventional compartment techniques in recovering metabolic information from dynamic PET studies with less biological restrictions. Key bioparameters such as flux, flow, blood volume and volume of distribution from the two different approaches are compared. Cross-validation is used to make regional comparisons and evaluate the fit of the two different estimated residue functions to the tissue activity curves. Conclusions: The accuracy of the standard models for Vp PET studies can be questionable, likely because behaviour of Vp metabolites in tissue is still unclear. Significant statistical evidence in favour of the new adaptivemixture models has been found. Supported by Science Foundation Ireland under SFI-PI 11/27 and by the National Institute of Health (NCI) under PO1-CA-42045. 235 POSTER (Board P015) Kinetic analysis of dynamic 11 C thymidine PET imaging studies: Compartmental and nonparametric approaches S. Murphy1 , D. Hawe1 , F. Hernandez1 , E. Wolsztynski1 , J. Huang1 , J. O’Sullivan1 , M. Muzi2 , J. Eary3 , K. Krohn2 , F. O’Sullivan1 . 1 University College Cork, Statistics, Cork, Ireland; 2 University of Washington, Radiology, Seattle, USA; 3 University of Alabama, Radiology, Birmingham, USA Background: Positron emission tomography (PET) with 11 C thymidine (TdR) as a radiotracer has been used to quantify cell proliferation and DNA synthesis in a variety of cancer types such as malignant brain tumours. Materials and Methods: Given time-dependent records of the tracer activity in blood and tissue, compartment models are used to describe the mechanisms for transfer and metabolism of the radiotracer. These models are based on assumptions such as homogeneity of the tissue and instant mixing within compartments, which can be difficult to justify. This may lead to the model being a poor fit to the data and hence give misleading results. A nonparametric approach was developed to alleviate these restricting assumptions. This technique has been validated in the case of the 15 OH2 O and the 18 F-fluorodeoxyglucose (FDG) PET radiotracers. For TdR, this estimation problem is more complex as the tracer is metabolised in the body, which leads to the presence of both TdR and metabolites in blood and tissue, with the activities of each being jointly observed by the scanner. Therefore a multiple-input function compartment model is required to capture and summarise metabolic activity. Calibration of the Thursday 20 November 2014 79 multiple-input compartment model is achieved using an arterial time-course measured by arterial sampling, which allows the activity in the arterial blood to be separated into TdR and metabolites. An adapted version of the nonparametric approach that is used for 15 O-H2 O and FDG is applied to the TdR data. Results: Simulations were undertaken to examine the efficacy of the multiple input compartment model and also to gain an understanding of the rates of convergence of the parameters of interest. Similar simulations are carried out on the nonparametric model. Comparisons between the models are generated by cross-validation. In TdR-PET studies the key parameter of interest is the thymidine flux constant. Further numerical analysis was carried out to examine the bias and variance of the models for this parameter as well as others estimated in this modelling. Conclusions: Residual analysis shows non constant variance for the compartment model, which leads one to conclude the validity of the model is questionable. Performance analysis of the nonparametric method suggests it is a relevant candidate alternative for the estimation of flux as imaged by thymidine. Supported by Science Foundation Ireland under SFI-PI 11/27 and by the National Institute of Health (NCI) under PO1-CA-42045. 236 POSTER (Board P016) Whole genomic assay on endoscopic ultrasound-guided fine needle aspiration samples of unresectable pancreatic cancer J.M. Ha1 , K.H. Lee1 , J.K. Lee1 , K.T. Lee1 , W.Y. Park2 , J.S. Bae2 , J.K. Jung2 , D.H. Park2 , Y.K. Seong3 , E. Kim1 . 1 Samsung Medical Center, Gastroenterology, Seoul, South Korea; 2 Samsung Medical Center, Genomic Medicine, Seoul, South Korea; 3 Sung Kyun Kwan University Medical School, Internal Medicine, Seoul, South Korea Background: Targeted therapy according to an individual’s genetic profile can improve the oncological outcomes. Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) has been widely used to obtain tumor tissue to diagnose unresectable pancreatic cancer. We tested the feasibility of whole genomic assay on EUS-FNA samples for personalized therapy of unresectable pancreatic cancer. Material and Methods: Whole exome and whole transcriptome sequencing were performed with ten EUS-FNA samples from retrospectively collected pancreatic cancer (9 ductal adenocarcinomas, 1 undifferentiated carcinoma). We compared these results with the reported genomic and transcriptomic profiles of 57 pancreatic cancer tissues in The Cancer Genome Atlas (TCGA) to find novel mutations, differentially expressed genes and gene fusions. Results: Genomic profiles were successfully generated from 7 of 10 (70%) pancreatic EUS-FNA samples by whole genomic sequencing. The frequency of observed genomic mutations was concordantly distributed with that of TCGA; KRAS, TP53, RNF43, SMAD4, MEN1, MLL3, APC and ARID1A, sequentially, and the cluster dendrogram of combining 7 EUSFNA samples’ profiles with TCGA data showed intergroup similarity after TMM (trimmed mean of M-values) normalization. We also identified several new fusion genes from analysis of our whole transcriptome dataset. Conclusions: We were able to perform whole genomic and transcriptomic assay on most EUS-FNA samples from pancreatic cancers and identify that genomic alterations were well correlated with those listed in TCGA of pancreatic cancer. 237 POSTER (Board P017) Impact of phase 1 expansion cohorts on probability of success in phase 2 and time-to-drug-approval: analysis of 385 new drugs in oncology D. Bugano1 , K. Hess2 , L.L. Siu3 , F. Meric-Bernstam4 , A.R.A. Razak3 , D.S. Hong4 . 1 MD Anderson Cancer Center, Hematology/Oncology Fellowship, Houston, USA; 2 MD Anderson Cancer Center, Department of Biostatistics Division of Quantitative Sciences, Houston, USA; 3 Princess Margaret Cancer Centre, Drug Development Program, Toronto, Canada; 4 MD Anderson Cancer Center, Department of Investigational Cancer Therapeutics, Houston, USA Background: Expansion cohorts (EC) are becoming more common in the design of oncology phase 1(P1) trials. Our objective was to determine their impact on phase 2 (P2) trials and on time-to-drug-approval (TDA). Material and Methods: Systematic review of MEDLINE and EMBASE for P1 trials and their corresponding P2 trials. We included single-agent dosefinding adult oncology P1 trials published in 2006–2011. ECs were defined as the enrollment of additional patients (pts) after identification of the P2 dose. Drug approval status and date were based on the FDA website by 04.31.2014. TDA was measured since the first publication of a P1 trial. Positive P2 trials were those that met their primary endpoints. ‘Probability 80 Thursday 20 November 2014 Poster Session – DNA Repair Modulation (including PARP, CHK, ATR, ATM) Table (abstract 237): Characteristics of phase 1 trials, ‘probability of positive phase 2’ and ‘time-to-drug-approval’ Targeted agent Industry-sponsored Multicenter Pub >2008 Pts in dose escalation part Tumor type Pts in EC Y vs N Y vs N Y vs N Y vs N 21−37 vs <21 >37 vs <21 Hematologic vs solid Hematologic + solid vs solid Specific histology vs any solid 2−20 vs 0 21–271 vs 0 Prob Positive P2 OR (95% CI) p Time-to-approval HR (95% CI) p 0.9 1.7 0.9 1.0 0.9 1.4 4.1 0.6 1.2 2.4 3.3 0.78 0.12 0.73 0.84 0.62 0.31 0.03 0.36 0.49 0.0054 0.0008 1.0 2.1 2.4 1.0 0.9 1.4 2.4 0.6 2.1 2.1 6.6 0.95 0.33 0.17 0.94 0.88 0.46 0.17 0.62 0.066 0.14 <0.0001 (0.5; 1.6) (0.9; 3.2) (0.5; 1.6) (0.7; 1.7) (0.5; 1.5) (1.3; 4.4) (1.1; 14) (0.2; 1.7) (0.7; 2.0) (1.3; 4.4) (1.6; 6.6) (0.4; 2.4) (0.5; 9.5) (0.7; 8.5) (0.5; 2.2) (0.3; 2.6) (0.6; 3.4) (0.7; 8.8) (0.1; 4.6) (1.0; 4.4) (0.8; 5.4) (2.9; 15) All values are after multivariate analysis. of positive P2’ was evaluated with logistic regression and TDA with Cox proportional hazards regression. Results: We identified 515 P1 and 608 P2 trials. There were 385 drugs and 115 (30%) had at least one P1 with EC. A higher proportion of drugs with EC moved into P2 (62% v 37%, p < 0.0001) and had at least one randomized P2 trial (34% v 15%, p = 0.0001). We classified drugs according to the combined number of pts enrolled in all EC for different trials of that drug: No EC (267 drugs), EC2 − 20pts (60), EC21 − 271pts (44), missing (14). Enrolling more than 20 pts in EC was associated with higher probability of a positive P2 and shorter TDA (table). The probabilities of approval at 5 years were: No EC 5%(2−8%), EC2−20 16%(4−26%), EC21– 271 31%(15−44%). Conclusions: Expansion cohorts were associated with a higher probability of positive phase 2 trials and shorter time-to-drug-approval. Factors involved in the decision to open an expansion cohort might influence this association. DNA Repair Modulation (including PARP, CHK, ATR, ATM) 238 POSTER (Board P018) Reversal of primary and acquired PARP-inhibitor resistance in BRCA-mutated triple-negative breast cancers by inhibition of transcriptional cyclin-dependent kinases (CDKs) S. Johnson1 , N. Johnson2 , D. Chi3 , B. Primack4 , C. Cruz5 , D. Stover1 , A.K. Greifenberg6 , S. Cao7 , K. O’Connor1 , J. Baselga8 , J. Balmaña5 , V. Serra5 , M. Geyer6 , A. D’Andrea9 , E. Lim10 , G.I. Shapiro1 . 1 Dana-Farber Cancer Institute, Department of Medical Oncology, Boston, USA; 2 Fox Chase Cancer Center, Clinical Therapeutics, Philadelphia Pennsylvania, USA; 3 Dana-Farber Cancer Institute, Department of Medical Oncology, Boston MA, USA; 4 Dana-Farber Cancer Institute, Department of Radiation Oncology, Boston MA, USA; 5 Vall d’Hebron Institute of Oncology, Experimental Therapeutics Group, Barcelona, Spain; 6 Max Planck Institute of Molecular Physiology, Department of Physical Biochemistry, Bonn, Germany; 7 Dana-Farber Cancer Institute, Medical Oncology, Boston, USA; 8 Memorial Sloan-Kettering Cancer Center, Human Oncology & Pathogenesis Program, New York City, USA; 9 Dana-Farber Cancer Institute, Radiation Oncology, Boston, USA; 10 Ludwig Institute of Cancer Research, Olivia Newton John Cancer & Wellness Center, Melbourne, Australia Background: PARP-1 is synthetically lethal with homologous recombination (HR) defects. Tumors harboring mutations in BRCA1 and BRCA2 show sensitivity to PARP inhibition to varying degrees. Additionally, acquired resistance to PARP inhibition occurs via emergence of reversion mutations, re-expression of mutated BRCA proteins or alterations in expression of negative HR regulators. CDKs regulate cell cycle progression and transcription, and recent evidence has shown that cyclin K-CDK12 controls transcription of HR genes. We show that CDK12 is a target of the CDK inhibitor dinaciclib, which causes transcriptional repression of multiple DNA damage response and repair pathways. CDK inhibition is known to confer HR deficiency to HR-competent tumors, rendering them PARP inhibitor sensitive. Here, we tested whether dinaciclib-mediated transcriptional inhibition could (1) augment the response of BRCA-mutated triple-negative breast cancer (TNBC) cell lines and patient-derived xenograft (PDX) models that demonstrate modest sensitivity to PARP inhibitor monotherapy; or (2) restore PARP-inhibitor sensitivity in BRCA-mutated TNBC models that have acquired PARP inhibitor resistance. Results: In MDA-MB-231 cells, dinaciclib reduced phosphorylation of the C-terminal domain of RNA polymerase II in a concentration-dependent manner. RNA was collected from vehicle and dinaciclib-treated cells and levels of global transcription expression change were analyzed using Affymetrix U133A 2.0 arrays. Ingenuity Pathway Analysis (IPA) was used to assess networks of gene transcripts significantly repressed after dinaciclib. The top canonical pathways downregulated were comprised of DNA damage response networks. CDK12 kinase assays using pSer7 CTD as substrate were performed in the presence of vehicle or dinaciclib, demonstrating potent inhibition with IC50 61.8 nM. Dinaciclib was used in combination with veliparib or olaparib in BRCAmutated cell lines and PDX models. These combinations were synergistic in HCC1937 and SUM149 TNBC cells (modestly sensitive to PARP inhibitor monotherapy), as well as in a PARP inhibitor-resistant derivative of highly sensitive MDA-MB-436 cells. Additionally, these combinations demonstrated substantial efficacy in two PDX models with somatic BRCA1 and BRCA2 mutations, and limited de novo PARP inhibitor sensitivity, as well as in a model derived from a BRCA1 germline carrier whose tumor was slowly progressive on PARP inhibitor treatment. Conclusions: PARP inhibitor monotherapy in BRCA-mutated TNBCs is complicated by both de novo and acquired resistance. Transcriptional CDK inhibition represents a promising strategy for augmenting responses and reversing resistance. These results have justified clinical exploration of the combination of dinaciclib and veliparib in both BRCA-proficient and BRCAmutated tumors (NCT NCT01434316). 239 POSTER (Board P019) Niraparib, a selective PARP 1/2 inhibitor, is efficacious in pre-clinical models of small-cell lung cancer Y. Wang1 , J. Ricono2 , K. Admunson2 , S. Agarwal1 , R.J. Fram1 , T. Broudy2 , K.M. Wilcoxen1 . 1 Tesaro Inc., Waltham, USA; 2 Molecular Response, San Diego, USA Purpose: Small cell lung cancer (SCLC) is an aggressive form of cancer that accounts for approximately 15% of all lung cancers. Treatment options have not benefited from the development of currently approved targeted agents, and platinum based chemotherapeutic regimens still dominate treatment in both limited and extensive-stage disease. The PARP inhibitor niraparib, currently in phase 3 studies in ovarian and breast cancer, was investigated for its ability to inhibit the proliferation of SCLC in vitro and in vivo. Methods: Niraparib was evaluated for its ability to inhibit proliferation and colony formation of SCLC cell lines with known deficiencies in p53, Rb1, and PTEN as well as amplifications in FGFR and MYC genes. Low passage SCLC patient-derived xenograft (PDX) models in mice were utilized to evaluate the in vivo efficacy of niraparib as a monotherapy and in combination with common first and second line therapies cisplatin/ etoposide and irinotecan. Molecular characteristics of individual tumors were determined through RNAseq analysis and correlated with niraparib response. Results: Niraparib exhibited in vitro anti-proliferative effects on selected SCLC lines with mutations in p53, Rb1, PTEN, PIK3CA and STK11. However, niraparib activity in these cells was not definitively correlated with a known mutationsor platinum sensitivity. In a SCLC PDX model derived from a metastatic tumor, daily 50 mg/kg niraparib demonstrated antitumor activity in combination with both irinotecan and cisplatin/ etoposide. A cohort treated with a single cycle of etoposide (8 mg/kg, days 1−3) and cisplatin (4 mg/kg, day 1) and 4 weeks of niraparib (50 mg/kg, QD) showed significant tumor growth inhibition. Upon rechallenge with niraparib (75 mg/kg) after a dosing holiday and observable Poster Session – DNA Repair Modulation (including PARP, CHK, ATR, ATM) tumor regrowth, tumor growth inhibition was again observed despite the presence of large tumors (>500 mm3 ). Additional SCLC PDX models were selected for evaluation of niraparib efficacy based on in vitro sensitivity to platinum agents. Tumor growth inhibition and/or regression during treatment of PDX mice with niraparib (100 mg/kg, QD) was observed in 75% of evaluable models. The determination of niraparib efficacy in SCLC platinum responsive maintenance treatment and molecular characterization of niraparib sensitive models is ongoing. Results will be discussed in the context of developing translational tumor marker classifier candidates for niraparib sensitivity in clinical studies of SCLC. Conclusion: Niraparib exhibited anti-cancer activity against SCLC as an in vitro and in vivo as a monotherapy and in combination with standard of care agents. These results support the clinical investigation of niraparib in SCLC. 240 POSTER (Board P020) The combination of Chk-1 and ATR inhibitor synergistically kills cancer cells K. Sanjiv1 , A. Hagenkort1 , P.M. Reaper2 , T. Koolmeister1 , O. Mortusewicz1 , N. Schultz1 , M. Scobie1 , U.W. Berglund1 , P.A. Charlton2 , J.R. Pollard2 , T. Helleday1 . 1 Science for Life Laboratory Karolinska Institutet, Division of Translational medicine and Chemical Biology MBB, Stockholm, Sweden; 2 Vertex Pharmaceuticals, (Europe), Abingdon Oxfordshire, United Kingdom Inhibition of Chk1 has been reported to lead to phosphorylation of a series of ATR substrates. We therefore hypothesized that a combination of ATR and Chk1 inhibition may provide benefit. Herein we show that treatment of cancer cells with the Chk-1 inhibitor, AZD7762, led to replication stress, which was converted to replication catastrophe and apoptosis when cells were co-treated with the ATR inhibitor VE-821. Synergism was observed in a variety of cancer cell lines but not in normal fibroblast cells. In contrast to previous studies that have shown ATR or Chk-1 inhibitors are most effective in cells defective for p53 function, we observed that the combination of ATR and Chk1 inhibition was equally effective in cancer cells with or without a functional p53 response. Co-treatment with AZD7762 and VE-821 in U2OS cancer cells induced massive loading of RPA onto chromatin and pan nuclear gH2AX, indicative of high levels of ssDNA formation and severe DNA damage. This was associated with stalled replication fork progression, S-phase arrest and cell death. In contrast, non-cancer fibroblast VH-10 cells tolerated the combination well with no DNA damage or cell death observed. Under conditions of induced replication stress, by treatment with hydroxy urea, AZD7762 plus VE-821 caused marked nuclear fragmentation and early onset of apoptosis in the U2OS cancer cells but not in normal fibroblast cells. In mouse xenograft models of lung and breast cancer, treatment with VE-822 (an analog of VE-821) in combination with AZD7762 significantly delayed tumor growth and increased overall survival when compared with mice treated with vehicle or either agent alone. These data support the clinical development of ATR and Chk-1 inhibitor combinations to complement existing DNA damage based chemotherapy. 241 POSTER (Board P021) Epigenetic loss-of-function BRCA1 mediates tumor cure by single dose radiotherapy C. Campagne1 , T.H. Thin1 , J.D. Fuller2 , K. Manova-Todorova3 , A. Haimovitz-Friedman1 , S.N. Powell1 , R.N. Kolesnick2 , Z. Fuks1 . 1 Memorial Sloan-Kettering Cancer Center, Radiation Oncology, New York, USA; 2 Memorial Sloan-Kettering Cancer Center, Molecular Pharmacology and Chemistry, New York, USA; 3 Memorial Sloan-Kettering Cancer Center, Molecular Cytology, New York, USA Background: The mechanism of tumor cure by ionizing radiation is regarded tumor cell autonomous, effected by misrepair of radiation-induced DNA double strand breaks (DSBs) via the function of error prone nonhomologous end joining (NHEJ). This model prevails at the low dose range (8 Gy), with cure depending on tumor propensity for NHEJ misrepair, requiring repeated exposures for tumor ablation. Here we report high (>10 Gy) single dose radiotherapy (SDRT) engages an alternative dual target model. Material and Methods: DSB repair was analyzed in situ by quantitative assessment of the time-dependent buildup and resolution of ionizing radiation-induced foci (IRIF) of specific NHEJ or homology-driven repair (HDR) mediators. Effect of SDRT on the tumor microvasculature was assessed by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Engagement of microvascular dysfunction in DSB repair was assessed using acid sphingomyelinase (ASMase)-deficient mice, refractory to vascular endothelial injury. Western blot analysis of Small Ubiquitin-like Modifiers (SUMO) in tumor extracts and studies of SUMO conjugating enzymes IRIF in situ were used to evaluate effects of SDRT on SUMOylation. Thursday 20 November 2014 81 Results: SDRT concomitantly induces DSBs in tumor cells and an early wave of ASMase-mediated microcirculatory ischemia/reperfusion (I/R). Reactive oxygen species (ROS) generated therein in parenchymal tumor cells oxidize and dysfunction SUMO conjugating enzymes, leading to catastrophic reprograming of DSB repair. Ku- and Tumor Suppressor p53Binding Protein 1 (53BP1)-mediated NHEJ are not affected, although 53BP1 resolution is delayed. In contrast, HDR is aborted, as SUMO dysfunction impairs recruitment of Receptor-Associated Protein 80 (RAP80), Breast Cancer 1 protein (BRCA1), Replication Protein A (RPA) and RAD51 recombinase into DSB repair foci, reversible by genetic I/R inhibition or pharmacological post-I/R ROS scavenging. The epigenetic loss-offunction BRCA1, coupled with abnormally persistent 53BP1 function, diverts DSB repair to an aberrant 53BP1-dependent lethal pathway, mediating tumor cure. Conclusions: We present a new mechanism of tumor cure by ionizing radiation, in which high SDRT engages a co-dependent dual target model, involving both DNA DSBs and a transient tumor microvasculature injury. It represents an alternative to the classical single target mechanism operating at the low dose range, and provides new targets for modulation of the radiation response, with a potential for yielding new cures in cancer. 242 POSTER (Board P022) BMN 673 as single agent and in combination with temozolomide or PI3K pathway inhibitors in small cell lung cancer and gastric cancer models Y. Feng1 , L.E. Post1 , R. Cardnell2 , L.A. Byers2 , B. Wang1 , Y. Shen1 . 1 BioMarin Pharmaceutical Inc., Research and Drug Discovery, Novato CA, USA; 2 MD Anderson Cancer Center, Thoracic/Head & Neck Medical Oncology, Houston TX, USA BMN 673 is a potent, specific PARP1/2 inhibitor with an antitumor cytotoxic mechanism that includes efficient trapping of PARP-DNA complexes. BMN 673 shows significant clinical activity in patients with germline BRCA mutation ovarian and breast cancer; partial responses were also reported in non-BRCA small cell lung cancer (SCLC) patients treated with BMN 673 (ASCO 2014). To explore BMN 673 anti-tumor activity beyond BRCA, we further investigated the combination potential of BMN 673 with temozolomide (TMZ) or PI3K pathway inhibitors in SCLC and gastric cancer (GC) models. TMZ potentiates the activity of PARP inhibitors including BMN 673 in various tumor models and has shown single-agent activity in SCLC patients. Here we evaluated the combination of BMN 673 with TMZ using human SCLC cell-derived xenograft models. In NCI-H209 xenografts, BMN 673 (0.25 mg/kg, qd×4) plus TMZ at much reduced dosage (3 mg/kg, qd×4) resulted in tumor shrinkage, while each drug alone had no inhibitory effect on tumor growth under the same dosage and schedule. Recent studies show that PARP inhibitor treatment activates the PI3K/mTOR pathway in SCLC cell lines and animal models (CSHL, 2014). We therefore assessed anti-tumor activity of BMN 673 in combination with several PI3K pathway inhibitors including Pan-PI3K, isoform-specific PI3K, and Akt inhibitors in SCLC cells. Additive or weak synergistic effect was observed in different lines based on combination index (CI) value at ED50. In vivo studies are currently being conducted to confirm the in vitro observation. Beyond BRCA1/2 mutations, defects in other components of homologous recombination DNA repair pathway could induce sensitivity to PARP inhibition. Report has suggested that low ATM expression in some GC cell lines may contribute to Olaparib sensitivity in vitro. We examined 14 GC cell lines with various mutational backgrounds and found many of them are highly sensitive to BMN 673 with IC50 values similar to those of BRCA mutant cell lines. Western analysis of protein markers in these cell lines suggests a correlation of BMN 673 sensitivity with reduced ATM protein level and activity (p-ATM). Consistent with the SCLC findings, in vitro assays also demonstrated a synergistic activity of BMN 673 and PI3K pathway inhibitors in some of the GC lines. Together, these findings suggest that combination of BMN 673 with TMZ or PI3K inhibitor(s) have better anti-tumor activity than either single agent alone in SCLC and GC models. 243 POSTER (Board P023) Modulation of PI3K/mTOR pathway following PARP inhibition in small cell lung cancer R.J. Cardnell1 , Y. Feng2 , L. Diao3 , Y. Fan1 , F. Masrorpour1 , S. Mukherjee1 , J. Shen2 , J. Wang3 , L.A. Byers1 . 1 MD Anderson Cancer Center, Thoracic/Head & Neck Medical Oncology, Houston TX, USA; 2 BioMarin Pharmaceutical Inc., Novato CA, USA; 3 MD Anderson Cancer Center, Bioinformatics & Computational Biology, Houston TX, USA Background: Small cell lung cancer (SCLC) is the most aggressive form of lung cancer, accounting for 13% of new lung cancers in the US. We have 82 Thursday 20 November 2014 Poster Session – DNA Repair Modulation (including PARP, CHK, ATR, ATM) previously shown that PARP1 is expressed at high levels in SCLC and that preclinical models of SCLC are sensitive to PARP inhibition. Based on this work, clinical trials of single agent BMN 673 are ongoing and have shown partial responses in a subset of SCLC patients (Wainberg, Z., et al., ASCO 2014). Recently, we also identified an association between higher baseline activation of the PI3K pathway and PARP inhibitor resistance. Here, we investigate changes in PI3K/mTOR pathway signaling in SCLC following PARP inhibition and the impact of combined PARP−PI3K targeting. Material and Methods: >140 total and phospho-proteins were measured by reverse phase protein array (RPPA) pre- and post-treatment with three PARP inhibitors (olaparib, rucaparib, BMN 673) in cell lines and xenograft tumors. Results: In cell lines, treatment with PARP inhibitors caused a significant increase in several phosphorylated proteins in the PI3K/mTOR pathway, including p-mTOR, pAKT and pS6 (p 0.02). This observation was recapitulated in H1048 xenografts treated with BMN 673, with increases in p-mTOR and p-AKT (p 0.02). In contrast, the LKB1 pathway was down-regulated after treatment with decreased levels of LKB1, p-AMPK, and p-TSC (p 0.04). Because LKB1 negatively regulates PI3K/mTOR, reduced levels of LKB1 may play a role in PI3K/mTOR activation. On the basis of these results, we then tested the combination of BMN 673 with the PI3K inhibitor BKM120. Preliminary in vitro analyses show an additive effect of BKM120, with a greater decrease in SCLC proliferation from combination treatment vs either drug alone. Conclusions: In conclusion, we have demonstrated activation of the PI3K/mTOR pathway in response to treatment with multiple PARP inhibitors in SCLC. These results, along with our published work showing greater PARP inhibitor resistance in SCLC with baseline PI3K/mTOR activity, suggest a potential role of this pathway in both primary and acquired PARP inhibitor resistance. We propose that PI3K inhibition may increase clinical activity of PARP inhibitors in SCLC. Based on these results, in vivo testing of PI3K−PARP targeting is ongoing. 244 POSTER (Board P024) Development of xenoimplants from germline BRCA1/2 mutant breast cancer (BC) for the identification of predictive biomarkers, mechanisms of resistance against poly(ADP-ribose) polymerase (PARP) inhibitors and evaluation of novel therapies C. Cruz1 , Y. Ibrahim2 , B. Morancho3 , P. Anton2 , J. Grueso2 , P. Cozar2 , M. GuzmÁn2 , P.M. Avilés4 , M.J. Guillén4 , C. Galmarini4 , J. Arribas3 , J. Baselga5 , J. Balmaña1 , V. Serra2 . 1 Vall d’Hebron Institute of Oncology, High Risk Cancer Prevention Group, Barcelona, Spain; 2 Vall d’Hebron Institute of Oncology, Experimental Therapeutics Group, Barcelona, Spain; 3 Vall d’Hebron Institute of Oncology, Growth Factors Group, Barcelona, Spain; 4 PharmaMar S.A., Non Clinical Pharmacology and Toxicology Department, Colmenar Viejo Madrid, Spain; 5 Memorial Sloan Kettering Cancer Center, NY, New York, USA BRCA1/2-mutant BC is characterized by deficient homologous recombination (HR) DNA repair, resulting in synthetic lethality upon treatment with inhibitors of the single-strand DNA repair enzyme PARP and remarkable clinical responses. Nevertheless, PARP inhibitors (PARPi) have failed to show primary efficacy and/or durable responses in a subset of patients. Several mechanisms of resistance to PARPi have been described both in vitro and in vivo, but their significance in the clinic and their impact on subsequent treatments is unknown. In order to improve current treatment strategies for individual BRCA1/2-mutation carriers, clinically relevant preclinical models are required, which allow the study of PARPiresistance mechanisms, the identification of predictive biomarkers and the assessment of novel therapies. PM01183 is a novel transcription inhibitor with promising activity in BRCA1/2-mutated BC that is currently in phase II clinical trials, and a potential therapeutic strategy for PARPiresistant tumors. Material and Methods: BRCA1/2 mutation carriers with BC or ovarian cancer (OvCa) treated at our institution for primary surgery or metastatic disease were selected for the study and signed the corresponding IRBapproved informed consent. Primary or metastatic tumor samples from these patients were implanted in immunosupressed mice to establish patient-derived xenograft models (PDXs). To characterize PDX sensitivity to the PARPi olaparib, tumor-bearing mice were treated with olaparib 50 mg/kg po 6 days per week or vehicle; bi-weekly tumor growth measurements were performed. Olaparib treatment was maintained in olaparib-sensitive models to generate PDX models with acquired resistance to the PARPi. PM01183 antitumor activity was tested in an olaparibresistant model (PDX196) derived from a BRCA1-mutated OvCa (PM01183 0.18 mg/kg iv per week). Results: Ten PDX models were obtained from BRCA1/2-related cancer patients. Six PDX models were tested for PARPi response with good correlation with the corresponding patient response. PM01183 showed antitumor activity in an olaparib-resistant PDX. Conclusions: PM01183 might show efficacy in patients with BRCA1/2mutant metastatic disease resistant to PARPi. 245 POSTER (Board P025) Chk1 is a potential novel therapeutic target that regulates cell survival and potentiates chemotherapy in osteosarcoma (OS) models S.J. Strauss1 , P. Mistry1 , A. Mendoza1 , M. Robson1 , H. Holme1 , P. Nandabhiwat1 , B. Kwok2 , M. Qadir2 , R.B. Pedley1 , J.S. Whelan3 , P.H.B. Sorensen2 . 1 UCL Cancer Institute, Dept of Oncology, London, United Kingdom; 2 BC Cancer Research Centre, Dept of Molecular Oncology, Vancouver, Canada; 3 University College Hospital, Dept of Medical Oncology, London, United Kingdom Background: Outcome for patients with osteosarcoma (OS) is improved when chemotherapy is given to treat micrometastatic disease. However, micrometastatic cells differ from those of the primary tumour and appear more resistant to chemotherapy. The aim of this study was to identify potential novel therapeutic targets through the use of genetic loss of function screens in primary and ‘micrometastatic’ in vitro OS tumour models. Methods: An siRNA kinome screen was performed in an OS cell line, MNNG grown as monolayers (M) and ‘micrometastatic’ anchorageindependent cultures (S). Genes that significantly reduced cell survival in both conditions were validated using a panel of OS cell lines and specific inhibitors. Results: Silencing of the cell cycle checkpoint kinase 1 (Chk1) had the most significant effects in M and S cultures inhibiting growth by 60% in 5 of 6 OS cell lines tested. Chk1 is a serine/threonine-protein kinase that regulates S and G2/M phases of the cell cycle. It plays a role in regulation of the DNA damage response and is highly expressed in OS tumours with a poor response to neo-adjuvant chemotherapy (Man et al., Cancer Res, 2005). Here, Chk1 protein was expressed in all OS cell lines. OS cell lines were sensitive to the Chk inhibitor LY2606368 mesylate monohydrate (hereafter LY2606368) with IC50 concentrations in the low nanomolar range (3.4−9.3nM). Chk1 siRNA and LY2606368 caused cell cycle arrest in G1/S by 24 hours, and caspase 3 cleavage indicative of apoptosis. Sub-toxic concentrations of LY2606368 (0.31−5nM) potentiated the effect of methotrexate and doxorubicin in M and S cells. Synergistic effects were most marked when the Chk1 inhibitor was administered 24 hours after the cytotoxic agent and with antimetabolite methotrexate (CI 0.0001–0.03). Combining LY2606368 and doxorubicin or methotrexate resulted in significantly greater gH2AX formation than either drug alone demonstrating increased DNA damage (p < 0.0001). Single agent in vivo activity of LY2606368 was demonstrated in a subcutaneous MNNG OS mouse model with administration of 4 mg/kg twice daily for 4 of 7 days for 3 weeks, significantly delaying tumour growth (p < 0.01) with no significant weight loss. Conclusions: Inhibition of Chk1 is a potentially valuable therapeutic strategy in OS and warrants further validation. 246 POSTER (Board P026) PARP inhibitors trap PARP1 onto damaged DNA via catalytic inhibition and not by an allosteric mechanism T. Hopkins1 , L. Solomon1 , Y. Shi1 , L. Rodriguez1 , C. Donawho1 , E. DiGiammarino1 , S. Panchal1 , A. Olson1 , D. Stolarik1 , D. Osterling1 , W. Gao1 , E. Johnson1 , D. Maag1 . 1 AbbVie, Oncology Discovery, North Chicago IL, USA Background: PARP inhibitors potentiate the cytotoxicity of DNA alkylating agents in vitro and in vivo. Trapping of PARP1 onto single-strand breaks in the presence of PARP inhibitors appears to be related to this increased cytotoxicity of PARP inhibitor-alkylator combinations. Two models have been proposed to explain this effect. In the first, catalytic inhibition of PARP1 prevents auto-PARylation, which is known to promote dissociation of PARP1 from DNA. In the second, PARP inhibitors allosterically enhance the affinity of PARP1 for damaged DNA. Direct evidence of allostery has yet to be reported. The aim of this study was to probe the relative contributions of allostery and catalytic inhibition to the trapping phenomenon. Methods: In vivo efficacy and pharmacokinetics were evaluated in HeyA8 xenograft tumor-bearing SCID mice. PARP1 trapping was evaluated by cellular fractionation, TR-FRET and BLI. Results: Veliparib markedly potentiates the activity of TMZ in vivo in a HeyA8 xenograft model. PARP inhibitors (veliparib, olaparib and BMN-673) all potentiate the activity of MMS and TMZ and trap PARP1 in HeyA8 cells in vitro. PARP inhibitors do not directly stabilize the PARP1-DNA complex. Complex stabilization is achieved by inhibition of auto-PARylation in the presence of NAD+ . In HeyA8 cells, NAD+ depletion via NAMPT inhibition traps PARP1 as effectively as PARP inhibitors. PARP inhibitors do not enhance PARP1 trapping after NAD+ depletion. Poster Session – DNA Repair Modulation (including PARP, CHK, ATR, ATM) Conclusions: These studies reveal no evidence for an allosteric trapping mechanism and indicate that all PARP inhibitors examined trap PARP1 via catalytic inhibition. The potency of PARP inhibitors with respect to trapping and catalytic inhibition is linearly correlated in biochemical systems. In cells, trapping potency is related to concentrations required for potentiation in animal models. Detection of PARP trapping in cells requires supraphysiologic conditions that exhaust cellular NAD+ and PAR, exceed concentrations required to elicit synergism and are not tolerated in vivo. In addition trapping potency appears to be inversely correlated with tolerability. Quantitation of the degree of trapping that is tolerable and is required for therapeutic benefit is under active investigation. Disclosures: All authors are employees of AbbVie. The design, study conduct, and financial support for this research were provided by AbbVie. AbbVie participated in the interpretation of data, review, and approval of the publication. 247 POSTER (Board P027) Selective inhibitors of nuclear export (SINE) block the expression of DNA damage repair proteins and sensitize cancer cells to DNA damage therapeutic agents T. Kashyap1 , M. Crochiere1 , S. Friedlander1 , B. Klebanov1 , W. Senapedis1 , E. Baloglu1 , D. del Alamo1 , S. Tamir1 , T. Rashal1 , D. McCauley1 , R. Carlson1 , M. Kauffman1 , S. Shacham1 , Y. Landesman1 . 1 Karyopharm Therapeutics, Natick MA, USA Background: SINE is a family of small-molecule drugs that inhibit Exportin 1 (XPO1/CRM1) mediated nuclear export, resulting in retention of major tumor suppressor proteins (TSPs) such as p53, FOXO, pRB and IkB and subsequently in specific cancer cell death. Selinexor is the clinical SINE compound currently in human phase I/II clinical trials in patients with solid and hematological malignancies. The goal of this study was to evaluate the effects of selinexor on DNA repair mechanisms and to test the cytotoxic effects of combining selinexor with DNA damaging agent on hematological and solid tumor. Methods: Whole protein cell lysates from solid and hematological cancer cell lines treated with selinexor with or without agents that induce DNA damage were analyzed in Reverse Phase Protein Arrays (RPPA), immunoblots and quantitative PCR. Selinexor treated cells from solid and hematological cancer lines were analyzed by immunofluorescence to evaluate DNA damage. Non-small cell lung cancer A549 Xenografts were treated with the selinexor (5 mg/kg) and radiation (3 Gy) alone or in combination and tumor growth was evaluated for 28 days. Results: Treatment of solid and hematological cancer cell lines with selinexor did not induce DNA damage in cancer cells but reduced the expression of DNA damage repair proteins: MSH2, MSH6, PMS2, MLH1, Rad51, CHK1 and FOXM1. Selienxor regulates the expression of CHK1, RAD51, MSH2, MSH6 and MLH1 on the transcriptional levels and PMS2 expression on the posttranslational level. There was a trend between the degree of DNA-damage-repair-protein reduction to selinexor sensitivity. Knock down of Chk1 alone, induced cytotoxicity whereas silencing of the other DNA repair proteins did not affect cell viability. Selinexor treatment following exposure to DNA damaging agents like doxorubicin and idarubicin inhibited the repair mechanism of DNA damage caused by these agents and resulted in synergistic cell killing as measured by induction of PARP and Caspase 3 cleavage. In vivo, selinexor (5 mg/kg) and radiation (3 Gy) decreased xenograft tumor size of the non-small cell lung cancer A549 by 15% and 43% respectively, relative to vehicle whereas combination of selinexor and radiation resulted in a 96% tumor decrease. Conclusion: Selinexor reduce the DNA repair mechanism in solid and hematological cancer cell lines and combination of selinexor with agents that cause DNA damage induces cancer cell death that is superior to each therapy alone. These data suggest that such a combination treatment is predicted to result with synergistic therapeutic outcome in cancer patients. 248 POSTER (Board P028) Use of ATR inhibitor in combination with topoisomerase I inhibitor kills cancer cells by disabling DNA replication initiation and fork elongation R. Jossé1 , S.E. Martin2 , R. Guha2 , P. Ormanoglu2 , T. Pfister3 , J. Morris4 , J. Doroshow4 , Y. Pommier1 . 1 NCI, Developmental Therapeutic Branch, Bethesda MD, USA; 2 NCATS, Division of Preclinical Innovation, Rockville MD, USA; 3 Leidos Biomedical Research Inc, Laboratory of Human Toxicology and Pharmacology, Frederick MD, USA; 4 DTP-DCTD, Drug synthesis and Chemistry Branch, Bethesda MD, USA Camptothecin and its derivatives, topotecan and irinotecan are specific topoisomerase I inhibitors and potent anticancer drugs. These agents produce well-characterized double-strand breaks upon collision of replication forks with topoisomerase I cleavage complexes. In an attempt to Thursday 20 November 2014 83 develop novel drugs combinations, we conducted a synthetic lethal siRNA screening using a library that targets nearly 7000 human genes. Depletion of ATR, the main transducer of replication stress-induced DNA damage response came at the top candidate gene with synthetic lethality with camptothecin. Validation studies showed that ATR siRNA exacerbated cytotoxic response to both camptothecin and the indenoisoquinoline LMP400 (indotecan), a novel topoisomerase inhibitor in clinical trial. Inhibition of ATR by the recently developed specific inhibitor VE-821 induced synergistic antiproliferative activity when combined with either topoisomerase inhibitor. Cytotoxicity induced by the combination with LMP-400 was greater than with camptothecin. Using single cell analysis and DNA fiber spread, we show that VE-821 abrogates the S-phase checkpoint, and restores origin firing and replication fork progression in cells treated with camptothecin or LMP-400. Moreover, the combination of topoisomerase inhibitors with VE-821 inhibited the phosphorylation of ATR and ATR-mediated Chk1 phosphorylation, while strongly inducing gH2AX. Single cell analysis revealed that the gH2AX pattern changed over time from well-defined focus to a pan-nuclear staining. The change in gH2AX pattern can be useful as a predictive biomarker to evaluate the efficacy of therapy. The key implication of our work is the mechanistic rationale it provides to evaluate the combination of topoisomerase I inhibitors with ATR inhibitors. 249 POSTER (Board P029) Preclinical efficacy of the PARP inhibitor rucaparib (CO338/AG014699/PF-01367338) in pancreatic cancer models with homologous recombination deficiencies (HRD) L. Robillard1 , K. Lin1 , P.P. Lopez-Casas2 , M. Hidalgo2 , T.C. Harding1 . 1 Clovis Oncology, San Francisco CA, USA; 2 CNIO, Madrid, Spain Rucaparib is an oral, potent, small molecule inhibitor of poly (ADP-ribose) polymerase (PARP) being developed for the maintenance treatment of platinum-sensitive ovarian cancer in patients with homologous recombination deficient (HRD) tumors, including those with BRCA1 and BRCA2 mutations. Mutations in BRCA and other homologous recombination HR pathway genes are frequently observed in other tumor types including breast and pancreatic (Alexandrov et al., 2013; Nature). Here, we investigated the efficacy of rucaparib as single agent in pancreatic cancer (PC) cell lines and xenograft models with HRD. Sensitivity to rucaparib was determined in a panel of PC lines (SU86.86, Panc-1, MIA PaCa-2, Panc 10.05) following siRNA knock-down of HR genes (ATM, ATR, BRCA1, BRCA2, PALB2 and RAD51C) to model gene mutations frequently observed in PC. BRCA1, BRCA2, PALB2 and RAD51C siRNA knockdownshowed synthetic lethality (30% of control GI50 ) in the majority of PC cell lines examined and correlated with the induction of HRD as assessed by gH2AX and RAD51 foci formation. As a complement to the cell line data we examined the efficacy of rucaparib in 3 BRCA2 mutant patient-derived xenograft (PDX) PC models (Oncotest, GmbH): PAXF_1876 (BRAF, PTEN, HRAS), PAXF_2005 (KRAS, TP53) and PAXF_2094 (KRAS). Models were selected on BRCA2 frameshift or nonsense mutations that should be functionally deleterious. Rucaparib administration to animals bearing preestablished tumors at 150 mg/kg/day BID (modeled Phase 2/3 dose in mice) resulted in significant monotherapy activity in all models examined with a 44, 96 and 67% reduction in tumor growth at 28 days post-dosing for PAXF_1876, 2005 and 2094, respectively. Expansion of rucaparib preclinical efficacy data beyond BRCA2 mutated PDX models is currently on-going in a PALB2 mutated PDX PC model (JH033; Villarroel et al., 2010; Mol. Ca. Ther.). In addition, the activity of rucaparib was examined in a BRCA2 mutant pancreatic ductal adenocarcinoma patient following FOLFIRINOX progression in a Phase I study (NCT01482715) was shown to be consistent with preclinical observations; a 56% reduction in the patient’s target lesions and a PFS of 6.4 months was observed with no significant toxicity. A Phase 2 study of rucaparib in patients with pancreatic cancer and a known deleterious BRCA mutation is currently on-going (NCT02042378). These findings support the hypothesis that pancreatic cancers exhibiting HRD are sensitive to rucaparib inhibition. 84 Thursday 20 November 2014 Poster Session – DNA Repair Modulation (including PARP, CHK, ATR, ATM) 250 POSTER (Board P030) Comprehensive genomic profiling of pancreatic acinar cell carcinomas identifies recurrent RAF fusions and frequent inactivation of DNA repair genes J. Chmielecki1 , K.E. Hutchinson2 , G.M. Frampton3 , Z.R. Chalmers3 , A. Johnson3 , C. Shi4 , J. Elvin5 , S.M. Ali5 , J.S. Ross5 , O. Basturk6 , S. Balsubramanian7 , D. Lipson3 , R. Yelensky3 , W. Pao2 , V.A. Miller8 , D.S. Klimstra6 , P.J. Stephens9 . 1 Foundation Medicine, Cambridge, USA; 2 Vanderbilt University, Cancer Biology, Nashville, USA; 3 Foundation Medicine, Computational Biology, Cambridge, USA; 4 Vanderbilt University, Pathology, Nashville, USA; 5 Foundation Medicine, Pathology, Cambridge, USA; 6 Memorial Sloan Kettering Cancer Center, Pathology, New York, USA; 7 Foundation Medicine, Strategic Alliances, Cambridge, USA; 8 Foundation Medicine, Medical Affairs, Cambridge, USA; 9 Foundation Medicine, Cancer Genomics, Cambridge, USA Background: Pancreatic acinar cell carcinomas (PACCs) account for ~1% (~500 cases) of pancreatic cancer diagnoses annually in the United States. Oncogenic therapuetic targets have proven elusive in this disease, and chemotherapy and radiation have demonstrated limited efficacy against these tumors. Materials and Methods: We performed comprehensive genomic profiling of a large series of PACCs (n = 44), including closely related mixed acinar carcinomas (16 pure PACC, 14 mixed acinar/neuroendocrine, 6 mixed acinar/ductal, 2 mixed acinar/neuroendocrine/ductal, and 6 samples with incomplete histological analysis), using FoundationOne® , a nextgeneration sequencing (NGS)-based platform. DNA was analyzed for base substitutions, insertions/deletions, copy number alterations, and select rearrangements; eleven samples had sufficient material for broad fusion detection using targeted RNA-sequencing. Results: Recurrent rearrangements involving BRAF and RAF1 (CRAF) were observed in 10 samples (23%) of mixed and pure histology, and were mutually exclusive with other known driver events. Biochemical characterization of the most prevalent fusion, SND1-BRAF (n = 5), resulted in activation of the mitogen activated protein kinase (MAPK) pathway which could be abrogated with MEK inhibition. SND1-BRAF was transforming, and cells dependent on this fusion were sensitive to treatment with the MEK inhibitor, trametinib. Broad analysis of recurrent cancer-related genomic alterations in PACC revealed a unique genomic landscape compared to other subtypes of pancreatic cancer. Notably, we observed lower frequencies of KRAS and NF1 alterations compared to pancreatic ductal adenocarcinoma and neuroendocrine tumors, respectively. Inactivating alterations in DNA repair genes were observed in 45% of PACCs, including mixed and pure histologies, and were mutually exclusive with RAF genomic alterations. Conclusions: These findings have immediate clinical impact for PACC patients. RAF fusions in other diseases have demonstrated clinical sensitivity to targeted inhibitors; these agents may represent potential treatment options for the 23% of PACCs driven by these fusions. To our knowledge, this is the first report of RAF fusions in any form of pancreatic cancer. DNA repair deficiencies (45% of PACCs) are associated with sensitivity to platinum-based therapies and may also predict susceptibility to PARP inhibitors currently in late-stage clinical development. Although these alterations have been implicated in other forms of pancreatic cancer, they have been described only rarely in PACC. Collectively, these data suggest multiple potential therapeutic options for over two-thirds of PACC patients, and provide a rationale for using personalized therapies in this disease. 251 POSTER (Board P031) A combined in vitro and mathematical modelling approach for understanding the impact of an inhibitor of ATR on DNA damage and repair after ionising radiation J. Yates1 , S. Checkley2 , L. MacCallum2 , R. Odedra1 , J. Barnes3 , A. Lau1 . 1 AstraZeneca, iMED Oncology, Macclesfield, United Kingdom; 2 AstraZeneca, Discovery Sciences, Macclesfield, United Kingdom; 3 AstraZeneca, Drug Safety and Metabolism, Macclesfield, United Kingdom Background: AZD6738 is a potent specific inhibitor of ATR. As part of clinical development it is planned to investigate the combination of AZD6738 with ionising radiation (IR) in head and neck cancer patients. We have developed a novel cell cycle model to predict cellular responses to combination AZD6738/IR treatment. Materials and Methods: A simple mathematical model of the cell cycle, incorporating DNA damage and repair, was proposed. The model was formulated so that AZD6738 was assumed to inhibit the repair of replication stress induced damage during S-phase of the cell cycle. The model was calibrated using in vitro dose–response data generated using a colon carcinoma cell line. gH2AX biomarker data was used to measure DNA damage, with cell count as the indicator of tumour proliferation. The in vitro calibrated model was incorporated into a solid tumour growth model and AZD6738 time-varying concentration informed by observed plasma pharmacokinetics in the mouse. Validation of model predictions was against gH2AX changes over time in the same tumour cell line xenografted in mice in vivo and the resulting efficacy after repeated doses of AZD6738 and IR Results: The model was successfully parameterised using in vitro data generated at a range of concentrations of AZD6738 as well as after replenishing with AZD6738 free media to simulate drug washout. The resulting in vivo tumour growth model was capable of accurately predicting in vivo mouse xenograft data, without requiring any additional modification of model parameters. Conclusions: Our prediction of AZD6738/IR combination efficacy has informed on the minimum dosing levels required in the clinic to be pharmacologically active. Minimum efficacious dose will minimize the risk of overdosing and so toxicological effects such as mucositis. The model also predicts drug efficacy and tumour proliferation rates in response to intermittent dose schedules, thus optimizing drug exposure for tumour regression. The model provides a framework that can be extended across other targetted therapy classes, supplementing mathematical models of low throughput in vivo data with high throughput in vitro assays. 252 POSTER (Board P032) The DNA damage response gene Schlafen 11 (SLFN11) is a transcriptional target of ETS transcription factors in Ewing’s sarcoma and other cancers Y. Pommier1 , S.W. Bilke2 , F. Sousa3 , M. Yamade3 , J. Murai3 , V. Rajapakse3 , L. Helman4 , P. Meltzer2 . 1 National Cancer Institute, Laboratory of Molecular Pharmacology, Bethesda, USA; 2 National Cancer Institute, Genetics Branch, Bethesda, USA; 3 National Cancer Institute, Developmental Therapeutics Branch, Bethesda, USA; 4 National Cancer Institute, Pediatric Oncology Branch, Bethesda, USA SLFN11 is a critical determinant of response to DNA targeted therapies including topoisomerase I and II inhibitors (camptothecins, etoposide, doxorubicin) and cisplatin. Ewing’s sarcoma (EWS), which is characterized by expression of the chimeric transcription factor EWS-FLI1, has notably high SLFN11 expression. This led us to investigate whether EWSFLI1 is causative for elevated SLFN11 expression. ChIP-Seq analysis of EWS-FLI1 in A673 EWS cells showed that EWS-FLI1 binds near the transcription start site of SLFN11. We further demonstrate that EWSFLI1 is a positive transcriptional regulator for SLFN11 and that EWS-FLI1mediated SLFN11 overexpression is responsible for high sensitivity of EWS to the topoisomerase I inhibitor camptothecin. The correlated expression between SLFN11 and FLI1 extends to leukemia, pediatric, breast and prostate cancers. These analyses suggest that, in addition to FLI1, several ETS members, including ETS1 regulate SLFN11 expression. Together, our results suggest the emerging relevance of SLFN11 for therapeutic response to DNA damaging agents in ETS-activated cancers. 253 POSTER (Board P033) Phase 1 correlative study of ARQ761, a b-lapachone analogue that promotes NQ01-mediated programmed cancer cell necrosis D. Gerber1 , Y. Arriaga1 , M.S. Beg1 , J.E. Dowell1 , J.H. Schiller1 , A.E. Frankel1 , R. Leff2 , C. Meek2 , J. Bolluyt3 , O. Fatunde3 , R.T. Martinez3 , P. Vo4 , F. Fattah4 , V. Sarode5 , Y. Zhou6 , Y. Xie6 , M. McLeod7 , B. Schwartz7 , D.A. Boothman4 . 1 University of Texas Southwestern Medical Center, Hematology-Oncology, Dallas Texas, USA; 2 Texas Tech University, School of Pharmacy, Dallas Texas, USA; 3 University of Texas Southwestern Medical Center, Hematology-Oncology, Dallas Texas, USA; 4 University of Texas Southwestern Medical Center, Harold C. Simmons Cancer Center, Dallas Texas, USA; 5 University of Texas Southwestern Medical Center, Pathology, Dallas Texas, USA; 6 University of Texas Southwestern Medical Center, Clinical Sciences, Dallas Texas, USA; 7 ArQule Inc., Woburn Massachusetts, USA Background: NAD(P)H:quinone oxidoreductase 1 (NQO1) is a twoelectron oxidoreductase expressed in multiple tumor types at levels 5- to 200-fold above normal tissue. ARQ761 (ArQule, Woburn, MA, USA) is a highly soluble intermediate b-lapachone hydroquinone analogue, complexed in hydroxypropyl-b-cyclodextrin, that exploits the unique elevation of NQO1 found in solid tumors to cause tumor-specific cell death by eliciting a futile redox cycle generating high levels of reactive oxygen species and ultimately PARP1 hyperactivation-dependent cell death. Materials and Methods: We initiated a 3+3 dose escalation study of 3 schedules (weekly, every other week, 2/3 weeks) of ARQ761 monotherapy as a 1-hr or 2-hr infusion. Eligible patients had refractory advanced solid Poster Session – Drug Delivery tumors, ECOG 0−1, adequate organ function, and central venous access. Patient blood samples were analyzed for ARQ761 levels and NQO1 polymorphisms. Archival tumor tissue was analyzed for NQO1 staining intensity and prevalence. Results: As of May 2014, a total of 31 patients were enrolled and had received at least one regimen of ARQ761. For weekly administration, the maximum tolerated dose was 195 mg/m2 . For every other week and 2/3 week administration, dosing at 540 mg/m2 is ongoing. Mean ARQ761 halflife was approximately 50 minutes. Among 23 patients with response data available, best response was stable disease in 5 patients. Two patients had minor responses, including one heavily pretreated patient with bladder cancer with >50% shrinkage of lung metastases at the 195 mg/m2 dose level. Tissue biomarker analysis was performed for 20 cases. Clinical benefit was correlated with tissue NQO1 expression: disease control rate was 65% in NQO1-positive tumors and 18% in NQO1-negative tumors (P = 0.06). No patients were homozygous for *3 and/or *2 NQO1 polymorphisms. Hemolytic anemia and apparent methemoglobinemia (transient hypoxemia observed by peripheral saturation monitor but not confirmed by arterial blood gas) were the principal toxicities Conclusions: ARQ761 has clinical activity in NQO1-positive tumors. Principal toxicities include hemolytic anemia and methemoglobinemia. Monotherapy and combination studies in NQO1-positive tumors are underway. 254 POSTER (Board P034) Molecular analysis in breast cancer: correlation with immunohistochemical classification and pathologic complete response (pCR) to neoadjuvant chemotherapy (NAC) S. Baulies1 , M. Gonzalez-Cao2 , N. Karachaliou2 , A. Rodriguez Capitan2 , M.A. Molina-Vila2 , M.T. Cusido3 , C. Teixido2 , S. Viteri2 , R. Fabregas3 , X. Gonzalez2 , R. Rosell2 . 1 Institut Universitari Dexeus Quiron, Barcelona, Spain; 2 Institut Universitari Dexeus Quiron, Oncology, Barcelona, Spain; 3 Institut Universitari Dexeus Quiron, Gynecology, Barcelona, Spain Background: Breast cancer is a heterogeneous disease. Dysregulated genes, via expression alterations, affect cellular signalling pathways, leading to chemoresistance. In the present study, we analysed expression levels of a panel of genes implicated in molecular pathways that could have a role in chemoresistance. High expression levels of RTKs as AXL (and its ligand GAS6), and FGFR1 have been described as a poor prognostic factors, although they are mainly expressed in HR+ breast cancer. PTPN12 tumor supresor gene inhibits expression of erb2 or EGFR, and it has been described as frequently downregulated in Triple Negative (TN) tumors. BRCA1 and RAP80 genes are implicated in DNA repair pathway and they are downregulated in TN breast cancer conferring enhanced chemosensitivity. Lower expression levels of BIM (a proapoptotic protein) can be found after response to chemotherapy. As described in TN, EZH2 marks poor prognosis. BTRCP leds to EZH2 degradation through ubiquitination. ZNF217 is a transcription factor that confers poor prognosis in all breast cancer subtypes. YAP/TAZ is implicated in Hippo pathway and it has a role in breast cancer proliferation. Patients and Methods: Gene expression analysis was performed in pretreatment samples of 92 breast cancer patients treated with NAC. Expression levels of AXL/GAS6, FGFR1, PTPN12, BRCA1, RAP80, Bim, EZH2, BTRCP, YAP and ZNF217 genes were analysed by RT-PCR. We explored the correlation of molecular markers with immunohistochemical classification and with pCR. Results: 53 patients were classified as hormone receptor positive (HR+) (57%), 28 HER2+ (31%) and 11 patients as TN (12%). HR+ tumors had higher levels of AXL (p = 0.006), GAS6 (p = 0.05), FGFR1 (p = 0.006), RAP80 (p = 0.007), BTRCP (p = 0.003), PTPN12 (p = 0.023) and ZNF217 (p = 0.005). TN tumors had lower levels of BRCA1 (p = 0.18) and Bim (p = 0.05). Predictor of response: High levels of Bim (p = 0.014), or low levels of AXL (p = 0.003), low FGFR1 (p = 0.014), low YAP (p = 0.010), low BRCA1 (p = 0.008) and PI3K mutations (p = 0.031) were predictive of pCR. Interestingly, patients with high levels of FGFR1 had an OS at 10 years of 0% vs 78% (p = 0.051). Conclusions: Gene expression profile varies by breast cancer subtype. Chemosensitivity is higher in tumors with high levels of Bim or low levels of FGFR1, BRCA1, AXL and YAP. Thursday 20 November 2014 85 Drug Delivery 255 POSTER (Board P035) Pre-clinical in vivo characterization of MLN7243, an investigational ubiquitin activating enzyme inhibitor, in solid tumor models T. Traore1 , J.H. Huck1 , J.S. Shi1 , D.S. Sappal1 , J.D. Duffey1 , Y.Y. Yang1 , E.K. Kadakia1 , A.C. Chakravarty1 , B.S. Stringer1 , Y.I. Ishii1 , R.G. Griffin1 , C.X. Xia1 , M.M. Milhollen1 , J.C. Ciavarri1 , P.F. Fleming1 , N.B. Bence1 , M.H. Hyer1 . 1 Takeda Pharmaceuticals International Company, Oncology, Cambridge, USA Clinical results of VELCADE (bortezomib) For Injection have prompted evaluation of other enzymes within the ubiquitin proteasome system (UPS) as druggable targets for human cancer. We have identified a first in class investigational drug (MLN7243) which targets the ubiquitin activating enzyme, UAE (aka UBA1), an essential cellular enzyme responsible for activating >99% of all cellular ubiquitin. Ubiquitin is involved in multiple cellular processes including, but not limited to: ubiquitin-dependent protein turnover, cell cycle progression, regulation of apoptosis, protein localization and response to DNA damage. In vitro, MLN7243 has single digit nanomolar potency against the UAE enzyme and double digit nanomolar potency in cell-based viability assays. In vivo, MLN7243 administration leads to anti-tumor activity in a wide variety of cell-line-derived and primary human xenograft tumor models grown in mice. Pharmacokinetic analysis in mice indicates MLN7243 is quickly cleared from plasma but maintains a long half-life in xenograft tumor tissues. MLN7243, once in cells, binds to UAE and forms a MLN7243-ubiquitin adduct; this adduct species inhibits the UAE enzyme and remains detectable in tumors for days after the compound has cleared from plasma. A series of tumor biomarkers have been utilized to directly track MLN7243 target engagement (MLN7243ubiquitin adduct), measure global cellular polyubiquitin levels, measure mono-ubiquitinated Histone 2B and measure tumor cell apoptosis (cleaved caspase-3). Pre-clinical PK/PD/EF relationships have been established to help guide clinical decisions. MLN7243 is currently being evaluated in a phase I clinical trial that will evaluate safety, tolerability, pharmacokinetics, pharmacodynamics, and anti-tumor activity in patients with advanced solid tumors. ClinicalTrials.gov identifier: NCT02045095. 256 POSTER (Board P036) Minicell packaged targeted delivery of shRNA to cancer cells M. Jivrajani1 , N. Shrivastava2 , M. Nivsarkar1 . 1 B.V. Patel Pharmaceutical Education and Research Development (PERD) Centre, Pharmacology and Toxicology, Ahmedabad, India; 2 B.V. Patel Pharmaceutical Education and Research Development (PERD) Centre, Pharmacognosy and Phytochemistry, Ahmedabad, India Background: The genetic nature of cancer provides solid support for the rationale of si/shRNA-mediated gene therapy. However, a major hurdle to develop RNAi as cancer therapeutics is successful in vivo delivery. The aim of this study was to explore the efficacy of folate-conjugated bacterial minicells as a novel targeted delivery system for shRNA. Materials and Methods: In this work, plasmid based shRNA against VEGF A (psNIPERDU6A2) was packaged in minicells. These minicells were linked with folic acid for active targeting of tumor cells via folate receptor in vitro and in vivo. Cancer cell lines, LNCaP, HeLa and KB have been selected as positive control whereas A549 was selected as negative control in terms of folate receptor overexpression. In vitro delivery was studied by delivering 109 minicells from each the group, (1) FA minicellspSUPERneo , (2) minicellspsNIPERDU6A2 , (3) FA minicellspsNIPERDU6A2 in selected cell lines and expression of VEGF A was analysed by RT-PCR. Tumor xenograft of A549, LNCaP and KB cells were developed in immunosuppressed C57BL/6 mice, where the animals of each xenograft group were treated with (1) saline, and 109 of respective minicells, i.e. (2) FA minicellspSUPERneo , (3) minicellspsNIPERDU6A2 , (4) FA minicellsPSNIPERDU6A2 intravenously to study in vivo delivery. Tumor volume (mm3 ) was measured in each group every week during the study. At the end of study, tumor was excised to observed relative angiogenesis. Subsequently, expression of VEGF A was analyzed from tumor by RT-PCR. Eventually, In vivo biodistribution of FA minicellspsNIPERDU6A2 was studied. Results: Expression of VEGF A did not change in any of the groups in A549 cell line. In contrast, expression of VEGF A reduced significantly in FA minicellspsNIPERDU6A2 treated group when compared with other two groups in positive control cell lines. There was a gradual increase in the tumor volume till the end of treatment in all four treatment groups of A549 xenograft. Whereas in case of LNCaP and KB xenograft, there was 86 Thursday 20 November 2014 a significant decrease in tumor volume inFA minicellspsNIPERDU6A2 treated group as compared to other groups. Relative angiogenesis was decreased significantly in FA minicellspsNIPERDU6A2 treated LNCaP and KB xenograft as compared to A549 xenograft. Similarly, expression of VEGF A was found to be same in all the groups when compared with the saline treated group in A549 xenograft. On the contrary, significant downregulation of VEGF A was found in FA minicellsPSNIPERDU6A2 treated LNCaP and KB xenograft. In vivo biodistribution study revealed that majority of FA minicellspsNIPERDU6A2 localized in the tumor followed by liver and heart. Conclusions: FA minicellspsNIPERDU6A2 have delivered psNIPERDU6A2 effectively in vitro and in vivo in folate receptor overexpressing cancer cells through receptor mediated endocytosis which was confirmed by reduced gene expression of VEGF A and tumor regression. 257 POSTER (Board P037) Development of peptide-mediated drug delivery systems for colon cancer targeted imaging and therapy H.C. Wu1 , C.H. Wu1 , Y.H. Kuo1 . 1 Academia Sinica, Institute of Cellular and Organismic Biology, Taipei, Taiwan Colorectal cancer is one of the most common diagnosed cancers and a leading cause of cancer mortality worldwide. Lack of tumor specificity remains a major problem for chemotherapies in which side effects prevent the delivery of the drug dosages needed to eliminate the majority of cancer cells. Thus, targeted drug delivery system is necessary to effectively deliver the anticancer drugs to the tumor. In this study, we have successfully identified specific peptides binding to the human colorectal carcinoma (hCRC) cells through in vitro biopanning using phage-displayed peptide library. Three high affinity phage clones to colorectal carcinoma were identified, and their binding activities were confirmed by cellular ELISA and flow cytometry. The hCRC-targeted phages recognized five colorectal carcinoma cell lines and surgical specimens from colorectal cancer patients. The tumor homing ability of hCRC-targeted phages was confirmed by xenograft model in vivo. To investigate whether hCRCtargeted peptides could be used to enhance the therapeutic efficacy of anticancer drugs, we synthesized the peptide-mediated liposome encapsulated anti-cancer drugs. Notably, hCRC-targeted peptides conjugated liposomal drugs markedly inhibited hCRC tumor growth in mouse xenograft models. Combination treatment of peptide-mediated targeting liposomes was able to completely eradicate tumors in three-sixth of the total number of tumor-bearing mice without any signs of recurrence. Targeting liposomes improved the therapeutic index by enhancing therapeutic efficacy, reducing side effects, and increasing the survival rate of tumor-bearing mice in orthotopic animal model. Biodistribution studies in tumor-bearing mice indicated that chemotherapeutic drugs were localized in tumor tissue following administration of hCRC targeting peptides conjugated liposomal doxorubicin. Our findings indicate that hCRC-targeted peptides have great potential to be developed into targeted drug delivery systems and imaging for colorectal carcinoma. 258 POSTER (Board P038) Pancreatic cancer cells expressing the OATP1B3 transporter show promising sensitivity to the highly cytotoxic microcystin-LR molecule V. Kounnis1 , G. Chondrogiannis2 , M.D. Mantzaris3 , D. Fokas4 , N.A. Papanikolaou3 , I. Sainis1 , E. Briasoulis1 . 1 University of Ioannina, Cancer Biobank Center, Ioannina, Greece; 2 University of Ioannina, Department of Anatomy-Histology-Embryology Medical School, Ioannina, Greece; 3 University of Ioannina, Laboratory of Biological Chemistry Medical School, Ioannina, Greece; 4 University of Ioannina, Department of Materials Science and Engineering, Ioannina, Greece Background: Microcystins are natural cyclopeptides synthesized mainly by cyanobacteria and are considered health hazardous due to their toxic effects after acute consumption or chronic exposure. From a pharmacologic point of view, microcystins are extremely stable, hydrophilic cyclic heptapeptides with the ability to cause extensive cell damage once uptaken by the specific Organic Anion Transporting Polypeptides (OATP). Their main toxicity mechanisms are the inhibition of the protein phosphatases PP1 and 2A, the reduction of glutathione levels and the increase of Reactive Oxygen Species (ROS), ultimately leading to global hyperphosphorylation and increased cellular oxidative stress. The present study focused on the investigation of microcystin-LR as a potential anticancer compound to target pancreatic cancer cell lines proved to express the OATP1B3. Materials and Methods: For the purposes of this study, we used the characterized cell lines Bx-PC3, MIA PaCa-2 and CHO. The expression of OATP1B3 on the protein level was assessed by Western Blotting and Poster Session – Drug Delivery the monoclonal antibody mMDQ, whereas its endogenous expression was assessed by real time PCR and specifically designed primers. xCELLigence and flow cytometry (Annexin/PI) methods were used to study the cell toxicity of microcystin-LR, Gemcitabine and their combination. Results: Data resulted from the experimental procedures confirmed the expression of OATP1B3 in both cancer cell lines Bx-PC3 and MIA PaCa-2 with the first showing more prone expression by 38% on the protein and 2.4 fold on the mRNA level. In addition the two pancreatic cancer cell lines, showed a relative proportional − to the transporter expression − sensitivity to microcystin-LR with IC50 of 83.5nM and 2.1mM respectively. Of interest, microcystin LR surpassed the toxic effect of the approved chemotherapeutic agent gemcitabine for the Bx-PC3 cell line, which IC50 was 226nM. Furthermore the combination of microcystin-LR at low micromolar concentrations and gemcitabine at upper nanomolar concentrations showed an increased cytotoxic effect for both cell lines when compared to that of each agent alone with relevant IC50 of 2.9nM and 4.4nM for Bx-PC3 and MIA PaCa-2. Annexin/PI flow cytometry confirmed the proportional − to the transporter expression − dose response for microcystin-LR. Conclusions: The expression of OATP1B3 in cancer cells, could be considered as a candidate therapeutic target. We propose that structural modification of the highly cytotoxic MC-LR molecule − especially its conjugation with N-acetylcysteine, could result in the development of novel compounds with activity against pancreatic cancers that express OATP1B3. 259 POSTER (Board P039) Factors that limit delivery of Cdk4/6 inhibitor palbociclib to GBM K. Parrish1 , J. Pokorny2 , R. Mittapalli1 , K. Bakken2 , J. Sarkaria2 , W. Elmquist1 . 1 University of Minnesota Medical School, Minneapolis, USA; 2 University of Minnesota, Pharmaceutics, Minneapolis, USA Background: Developing effective therapies for glioblastoma multiforme (GBM) is significantly hampered by the blood–brain barrier (BBB), which limits delivery of many potentially effective anti-cancer agents to infiltrative tumor cells. The cyclin-dependent kinase 4 (Cdk4) pathway is hyperactivated in approximately 75% of GBM tumors in association with homozygous deletion of p16 (52%) and amplification of Cdk4 (18%) and Cdk6 (1%). Palbociclib (PD0332991) is a potent Cdk4/6 inhibitor that has shown efficacy in treating some non-brain tumors. The purpose of this study is to determine the mechanisms limiting delivery and efficacy of palbociclib therapy in an orthotopic xenograft model of patient-derived GBM. Methods: Palbociclib distribution to the brain was examined in FVB wildtype (WT), and triple-knockout (TKO; Mdr1a/b(−/−) Bcrp1(−/−) ) mice following escalating oral doses (10, 50, 100 or 150 mg/kg). Concentrations of palbociclib in plasma and brain were determined by LC-MS/MS. Survival studies were conducted in patient-derived primary GBM22 xenograft model in athymic nu/nu mice, and additional drug distribution studies were conducted in these tumor-bearing mice to correlate delivery with efficacy. Results: The brain exposure of palbociclib in TKO mice following a 10 mg/kg oral dose (AUCbrain-to-AUCplasma ratio) was 150-fold higher than in WT mice [WT: 0.044; TKO: 6.24]. Two hours post-dose, the brainto-plasma ratio was constant in WT and TKO mice over a dose range of 10 to 150 mg/kg [brain-to-plasma ratio (10 mg/kg: WT: 0.15±0.06; TKO: 10.3±1.7), (50 mg/kg: WT: 0.19±0.06; TKO: 8.5±3.6), (100 mg/kg: WT: 0.17±0.02; TKO: 4.5±1.7), (150 mg/kg: WT: 0.17±0.03; TKO: 7.8±0.52)]. For efficacy studies, palbociclib was dosed at 150 mg/kg/day continuously. Consistent with sub-therapeutic delivery across the BBB, palbociclib did not prolong the median survival of an orthotopic GBM22 xenograft model. Conversely, treatment of GBM22 xenografts grown as flank tumors resulted in a significant (45 day) survival benefit. Additionally, the brain concentrations following a 150 mg/kg dose were intentionally comparable to the flank tumor concentrations following a 10 mg/kg dose [770±230 ng/mL and 730±510 ng/mL, respectively], and neither provided a therapeutic response. Conclusion: These data suggest that efflux transport at the BBB limit the brain delivery of palbociclib and hence, efficacy, of this Cdk4/6 inhibitor in the treatment of GBM. This has important translational implications in the use of palbociclib in either mono or combination therapies for either primary or secondary brain tumors. Poster Session – Drug Delivery 260 POSTER (Board P040) Hsp90 Inhibitor Drug Conjugates (HDC): Payloads and possibilities D. Chimmanamada1 , W. Ying2 , J. Zhang2 , D. Proia3 , T. Przewloka1 , J. Jiang1 , D. Vutukuri1 , G. Lu1 , S. Osman1 , S. Chen1 , J. Chu3 , P. Rao3 , D. Zhou3 , T. Inoue4 , L. Shin Ogawa4 , R. Singh4 , N. Tatsuta4 , A. Sonderfan4 , C. Cortis5 . 1 Synta Pharmaceuticals, Chemistry, Lexington MA, USA; 2 Synta Pharmaceuticals, Chemistry, Lexington MA, USA; 3 Synta Pharmaceuticals, Biology, Lexington MA, USA; 4 Synta Pharmaceuticals, DMPK, Lexington MA, USA; 5 Synta Pharmaceuticals, Business Development, Lexington MA, USA Background: Despite the emergence of various therapies, chemotherapy still plays a significant role in the treatment of cancer. Though toxic, the potency and broad applicability of chemotherapeutic drugs make compelling rationale for using them as payloads in drug delivery systems. Several recent technologies, especially antibody drug conjugates (ADC) have been very successful, however for narrow sets of indications. We have recently disclosed the HSP90 inhibitor Drug Conjugate (HDC) platform, which utilizes the unique pharmacokinetic property of HSP90 inhibitors, where the drug is selectively retained in tumor in high concentrations while clearing from plasma and normal tissues relatively quickly. By combining the overexpression of HSP90 and longer residency of its inhibitors in tumor, we conceived an idea to conjugate small molecule anticancer drugs (payload) to HSP90 inhibitor in such a way that the payload is released selectively and gradually in tumor having a prolonged exposure. Results: In this presentation, the rationale for payload selection, their applicability and preliminary assessments will be discussed. Though virtually any small molecule anticancer agent qualifies as payload for HDC technology, the expensive drug development paradigm calls for a strong rationale every time. It has been shown by multiple groups including us that a combination therapy of an HSP90 inhibitor with a suitable drug, such as docetaxel is superior compared to the single agent. Hence, the HDC of taxanes make sense. Other categories include but not limited to, are the drugs that have poor solid tumor penetration such as proteasome inhibitors, drugs that have poor pharmacokinetics (highly metabolized) such as gemcitabine and other antimetabolites, drugs that develop resistance due to efflux (e.g., pgp) from cancer cells such as camptothecins all make good payloads. Several cell cycle inhibitors, such as pan-CDK inhibitors and pan-PI3K inhibitors (such as staurorporine) are also considered. A lead SN-38 conjugate for which detailed evaluations has been done showed that the payload is released in tumor for a prolonged period of time (0.22uM and 0.38uM at 24 h and72 h respectively in tumor against 30nM at 24 h and no drug quantified at 72 h for Irinotecan, at their maximum tolerated doses (MTDs). In vivo efficacy in multiple tumor models also exhibited remarkable activity for the HDC compared to Irinotecan. Toxicological evaluations also revealed that the HDC is safer than Irinotecan at their efficacious doses. Conclusion: The HDC platform has the potential to utilize a number of commonly used small molecule anticancer agents as payloads; expanding applicability through improved efficacy and toxicity profiles. It also has the potential to resuscitate the development of drugs that were abandoned due to toxicity. 261 POSTER (Board P041) Lesion characterization with ferumoxytol MRI in patients with advanced solid tumors and correlation with treatment response to MM-398, nanoliposomal irinotecan (nal-IRI) R.K. Ramanathan1 , R.L. Korn2 , J.C. Sachdev1 , G.J. Fetterly3 , G. Jameson1 , K. Marceau1 , V. Marsh1 , N. Raghunand4 , J. Prey3 , S.G. Klinz5 , J. Kim5 , E. Bayever5 , J.B. Fitzgerald5 . 1 Scottsdale Healthcare/TGen, Virginia Piper Cancer Center, Scottsdale AZ, USA; 2 Imaging Endpoints, Scottsdale AZ, USA; 3 Roswell Park Cancer Institute, Buffalo NY, USA; 4 Arizona Cancer Center, Translational Cancer Imaging, Tucson AZ, USA; 5 Merrimack Pharmaceuticals, Inc., Cambridge MA, USA Introduction: MM-398, a nanoliposomal irinotecan (nal-IRI), is designed to exploit leaky vasculature for enhanced drug delivery to tumors. Deposition of nal-IRI and subsequent conversion to SN-38 in both neoplastic cells and tumor associated macrophages (TAM) may positively correlate with activity. Predictive biomarkers to measure tumor deposition could identify patients likely to benefit from nal-IRI. Ferumoxytol (FMX), a 30 nm ironoxide nanoparticle with MRI contrast properties, is taken up by TAMs and has similar biodistribution patterns to nal-IRI in preclinical models. We have shown the feasibility of quantitative FMX MRI of tumor lesions and report here the correlation of FMX levels with nal-IRI activity in the study population. Patients and Methods: Eligible patients (n = 15; 4M, 11F; median age 58 [28−80] years) with refractory solid tumors had FMX MRI scans prior Thursday 20 November 2014 87 to and following (1, 24, 72 h) FMX infusion. T2* signal was used to calculate FMX levels in plasma and lesions by comparison to a standard curve. A mechanistic PK model built on these values indicated that tissue permeability to FMX contributed to early FMX MRI signals at 1 h and 24 h, while FMX binding contributed at 72 h. Patients continued on nal-IRI at 80 mg/m2 q2w until progression. Core biopsies were obtained 72 h after both FMX and nal-IRI infusions. RECIST v1.1 evaluation was done by CT every 8 weeks. Results: 13/15 (87%) patients received nal-IRI, and 11/13 (85%) were evaluated for response with 1 (7%) partial response (PR), 5 (38%) stable disease and 5 (38%) progressive disease. FMX levels were measured in 31 lesions from 9 patients and compared to lesion size changes after nal-IRI treatment. Median FMX levels in tumor lesions at 1 h and 24 h were 34.1 and 33.6 mcg/mL, respectively. FMX levels above the median were significantly associated with better lesion responses as measured by change in lesion size (p < 0.001 at 1 h; p < 0.003 at 24 h); no relationship was observed at 72 h. Receiver operating characteristics for lesion classification according to PR or lesion size reduction had an AUC 0.8 for early FMX measurements. Levels of irinotecan and SN-38 averaged 3.73 mcg/g [0.13–12.75 mcg/g] and 14.67 ng/g [1.2–64.0 ng/g], respectively, at 72 h. SN-38 levels in biopsies were 5-fold higher than in plasma at 72 h (p = 0.013). Prussian Blue staining of ferumoxytol in biopsies was predominately observed at the stroma-tumor interface where it colocalized with TAMs. Conclusions: Clinical activity of nal-IRI was observed in refractory solid tumors. Our findings are consistent with local activation of MM-398 in the tumor. The relationship between FMX levels in tumor lesions and nal-IRI activity suggests that lesion permeability to FMX may be a useful biomarker for tumor response to nal-IRI in patients with solid tumors. 262 POSTER (Board P042) Improved cytotoxic activity of Nor-b-lapachone-loaded PLGA microcapsules in PC3M prostate cancer cell line C. Pessoa1 , A.C.S. Feitosa1 , M.P. Costa1 , F.C. Evangelista1 , F.A.M. Sales1 , I.S. Bomfim1 , E.N. Silva Júnior2 , G.G. Dias2 , V.N. Freire3 , W.S. Caetano4 . 1 Ceara Federal University, Pharmacology and Physiology, Fortaleza, Brazil; 2 Minas Gerais Federal University, Chemistry, Fortaleza, Brazil; 3 Ceara Federal University, Physics, Fortaleza, Brazil; 4 Instituto Federal do Ceará, Physics, Fortaleza, Brazil Background: b-lapachone is one of the most widely studied naphthoquinones. However, several efforts have been made to find new lapachone analogues, more potent and less toxic. Nor-b-lapachone (NbL), a semisynthetic naphthoquinone derivative from b-Lapachone, is a cytotoxic agent against several cancer cell lines. Material and Methods: To overcome its liposolubility and non-specific toxicity, this drug was formulated in Poly(d,l)-lactide-co-glycolide (PLGA) microparticles by the emulsion-solvent evaporation technique. Surface morphology, particle size distribution, zeta potential, Raman spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, drug encapsulation efficiency, drug release kinetics and in vitro cytotoxicity of the drug-loaded microcapsules were determined. Results: Spherical microcapsules with a size range of 1.03±0.46 mm were obtained. The drug encapsulation efficiency was approximately 19%. The NbL-loaded PLGA microcapsules exhibited a pronounced initial burst release. After the in vitro treatment with the NbL-loaded PLGA microcapsules, a clearly phagocytosis of the spheres was observed in a few minutes. The cytotoxic activity of NbL against PC3M cells was greater when delivered by PLGA microcapsules compared to the free drug. After incubation for 72 h, the IC50 values of the free and encapsulated forms of NbL were 2.045 (1.97–2.12) and 1.046 (0.82–1.34) mg·mL−1 , respectively. We suggest that PLGA microcapsules containing NbL could be a promising drug delivery system to be studied using in vivo models of prostate cancer. Conclusions: The results suggest that NbL-loaded PLGA microcapsules could be used as a promising delivery system for NbL administration in in vivo tests of prostate cancer. 263 POSTER (Board P043) Controlled release of cisplatin using hyaluronic oligosaccharidescoated gold nanoparticles as an efficient delivery system applied to the treatment of pancreatic tumors H. Parkkola1 , L. Sobrevals Amieva1 , L. Vivero2 , R. Miñana2 , J. Sendra3 . 1 Endor Nanotechnologies, Preclinical, Barcelona, Spain; 2 Endor Nanotechnologies, Nanomaterials, Barcelona, Spain; 3 Endor Nanotechnologies, R&d Director, Barcelona, Spain Many chemotherapeutic agents currently used in oncology can produce toxicity inducing many side effects, even at the optimal therapeutic doses. 88 Thursday 20 November 2014 This problem could be addressed by targeting cellular differences between cancer and normal cells and controlling the delivery of cancer drugs. One such difference is the selective overexpression of cell surface receptors in tumor cells that can act as specific targets for the delivery of a drug. It is well known that CD44, the main receptor for hyaluronic acid (HA), is overexpressed in a wide range of malignancies and in cancer tumor initiating cells, playing an important role in promoting cancer cell proliferation, migration, invasion, and angiogenesis. The aim of our therapeutic approach is based on the need to develop new therapies that can efficiently target tumors, reducing the associated side effects and increasing the antitumor efficacy. In this line, the use of engineered HAcoated gold nanosystem for the delivery of chemotherapeutics is eligible to achieve those objectives. Advanced gold nanosystem uptake by tumoral cells was shown to be CD44-dependent, this was proven by studies with cell lines that exhibit differing CD44 expression levels as well as downregulating the expression of the HA receptor in a cell line that expresses high levels of CD44. Moreover, in vitro studies showed no signs of genotoxicity or oxidative damage and even though very high concentrations showed a slow decrease in cell viability. Advanced gold nanosystem carrying cisplatin was stable in solution and indicated a gradual drug release. Conjugation of cisplatin did not prevent the drug from performing its action in vitro, the drug showed slightly higher toxicity when encapsulated compared to the free drug. In vivo studies conducted in pancreatic cancer xenografts showed that the antitumoral effect was increased compared to free cisplatin, however we detected also increased toxicity when higher doses were administered, suggesting a fine tight therapeutic dosage schedule. Highest gold accumulation was in liver, followed by skin and tumor in pancreatic cancer xenografts. Therefore our data provide evidences of the relevance of using advanced drug delivery nanosystem for the treatment of pancreatic cancer. 264 POSTER (Board P044) Vasculogenic mimicry in small cell lung cancer F. Trapani1 , R.L. Metcalf1 , R. Polanski1 , A. Fusi2 , C. Hodgkinson1 , D. Nonaka3 , M.J. Hendrix4 , C. Morrrow1 , F. Blackhall3 , K.L. Simpson1 , C. Dive1 . 1 Paterson Institute for Cancer Research, Clinical and Experimental Pharmacology, Manchester, United Kingdom; 2 Christie NHS Foundation Trust, Manchester, United Kingdom; 3 Institute of Cancer Studies University of Manchester, Manchester, United Kingdom; 4 Cancer Biology and Epigenomics Program Ann and Robert H. Lurie Children’s Hospital of Chicago Research Center Robert H. Lurie Comprehensive Cancer Center Northwestern University Feinberg School of Medicine, Chicago, USA Introduction: Small cell lung cancer (SCLC) causes 25% of lung cancerrelated deaths worldwide. Despite initial responses to chemotherapy, most patients relapse with drug resistant disease. A minority of SCLC patients are inherently chemorefractory. Improved treatments are urgently required. Targeting tumour vasculature in SCLC with anti-angiogenic drugs produced disappointing results. Angiogenesis-independent tumour vascularisation pathways, including vasculogenic mimicry (VM), warrant further investigation. Aggressive cancer cells displaying VM mimic characteristics of host endothelial cells forming fluid conducting vascular channel-like structures. We sought to determine the prevalence of VM in SCLC and explore any associations of VM with chemotherapy sensitivity and patient survival. Methods: VM was evaluated using CD31/periodic acid-Schiff (PAS) staining in a tissue micro-array (TMA) from 41 limited stage SCLC chemonaive patients and in tumours from 2 chemosensitive and 2 chemorefractory Circulating Tumour Cell (CTC) Derived Explant (CDX) models that mimic donor patient responses to platinum/etoposide chemotherapy (Hodgkinson et al Nature Medicine, 2014). The relative abundance of VM channels (CD31-ve/PAS+ve) compared to host derived blood vessels (CD31+ve/PAS+ve), (VM/total vessels) in the TMA was compared to patient overall survival (OS) and in CDX models, to chemotherapy sensitivity. Results: In the TMA, a VM/Total Vessels score >16% was a poor prognostic factor for OS by univariate (p = 0.011) and multivariate (p = 0.014) analyses. In CDX models, chemo-sensitive tumours had a more VM structures than chemo-refractory tumours. Conclusion: We present the first evidence of VM in SCLC patient biopsies and of the VM phenotype in our unique CDX models. The correlation between high VM in patient biopsies and poorer OS corresponds with findings in other cancers notably melanoma, and may reflect a ‘cancer stem cell’ phenotype linked to VM. We are pursuing the testable hypothesis that high versus low VM levels in chemo-sensitive versus chemo-refractory CDX respectively could affect tumour drug delivery. Poster Session – Drug Delivery 265 POSTER (Board P045) Pretargeted nanoparticles to deliver both chemotherapeutics and radiation for the treatment of lymphoma C. Fang1 , J.C. Jones1 , S.M. Frayo1 , M.H. Hylarides1 , M. Zhang2 , O.W. Press1 . 1 Fred Hutchinson Cancer Research Center, Clinical Research Division, Seattle WA, USA; 2 University of Washington, Materials Science & Engineering, Seattle WA, USA Background: We developed a new generation of therapeutic nanoparticles (NPs) that can deliver both chemotherapeutics and radionuclides specifically to non-Hodgkin lymphoma (NHL) cells. Only one third of NHL patients are presently cured with chemotherapy and antibody (Abs) treatments. Radioimmunotherapy (RIT) delivers radiation specifically to tumor cells using Abs conjugated to a radioisotope that can be therapeutically effective against resistance to chemotherapy. However, the therapeutic window of RIT is limited by slow clearance of unbound radiolabeled Abs from the circulation, resulting in substantial radioactivity in normal tissues. Codelivery of both chemotherapeutics and radiation will result in therapeutic synergism that will maximize tumor cell killing while reducing resistance to single-agent therapy. Targeting NPs to the CD20 or CD19 antigen that is widely expressed on the NHL cell surface will result in effective delivery of the therapeutic payloads and thus maximize cell killing. Material and Methods: We use lymphoma xenograft athymic mouse model to demonstrate the efficacy of NPs. The NPs are based on multifunctional biodegradable chitosan polymer with well-characterized molecular weight and composition. Chemotherapeutic drug monomethyl auristatin (MMAE) is incorporated to polymer via disulfide linkages while therapeutic radionuclide yttrium-90 (90 Y) is attached via chelating agents. The size and zeta potential of NPs were characterized by dynamic light scattering. We administrate the NPs utilizing ‘pre-targeted’ delivery strategy by inject antibody-streptavidin conjugates (Ab-SA) first, then clearing agents to remove Ab-SA from circulation, and then inject NPs 24 h after. The pharmacokinetics (PK), biodistribution (BD), toxicity and therapeutic effects of NPs are examined. Results: The NPs were monodisperse and with neutral surface charge with sufficient drug loading. BD and PK studies showed rapid clearance of NPs in circulation and preferential accumulation of NPs in tumor (5% I.D./g) of xenograft mice. Pretargeted approach improves the tumor-to-normal organ ratio to over 1 for all clearance organs. The NPs show no sign of toxicity in terms of circulating blood cell analysis and blood chemistry panel. To date, the NPs with both chemo and radiation eliminated tumor at lower dose than the effective dose of single agents. Conclusions: The pretargeted NPs co-delivering MMAE and Y-90 to the antigens that are widely expressed on the NHL cell surface results in effective internalization of the therapeutic payloads and maximize tumor cell killing with minimum side effects. Data table Name Unit Data Hydrodynamic size Polydispersity Index Zeta Potential MMAE Loading nm 27.9 0.150 1.56 8.2 Figure: Structure. mV (w/w)% Poster Session – Drug Design 266 POSTER (Board P046) Auxiliar treatment by targeting the extracellular matrix to improve drug delivery and therapeutic response E. Henke1 , F. Roehrig1 , H. Hoffmann1 , F. Escorcia2 , M. Wartenberg3 , S. Volova4 , S. Gaetzner5 , A. Rosenwald3 , S. Erguen6 , D.A. Scheinberg2 , Z.V.I. Granot7 . 1 Institute for Anatomy and Cell Biology, Universität Würzburg, Würzburg, Germany; 2 Molecular Pharmacology, Memorial Sloan-Kettering Cancer Center, New York, USA; 3 Institute for Pathology, Universität Würzburg, Würzburg, Germany; 4 Institut for Clinical Biochemistry, Universitätsklinikum Würzburg, Würzburg, Germany; 5 Institute for Tissue Engineering, Universität Würzburg, Würzburg, Germany; 6 Institute for Anatomy and Cell Biology II, Universität Würzburg, Würzburg, Germany; 7 Developmental Biology and Cancer Research, Hebrew University, Jerusalem, Israel During the formation of a new tumor, tumor cells do not only proliferate, but also form their own microenvironment. The newly established microenvironment not only supports the further growth and proliferation of the tumor cells, but it also protects the tumor from the effects of therapeutic agents. An important part of the tumor microenvironment is the extracellular matrix (ECM). Besides providing structural support, the ECM is also directly involved in regulating cell behavior like motility and invasiveness. Lysyl oxidases are a family of enzymes that catalyze the cross linking of proximal fibrous protein strands. As a result, the ECM becomes more rigid. Lysyl oxidases are up-regulated in tumors and it has been shown that the resulting increased rigidity of the tumor tissuedirectly contributes to invasiveness and metastatic behavior. We found recently that crosslinking catalyzed by lysyl oxidases also increases the physical barrier function of ECM proteins. Lysyl oxidase activity reduces interstitial diffusion, thereby protecting tumor cells from exposure to drugs. Inhibition of lysyl oxidases can improve drug transport within the tumor and dramatically enhance treatment efficacy. We treated early lung metastasis in mouse models with the pan lysyl oxidase inhibitor 3-aminopropionitrile (BAPN). Lysyl oxidase inhibition reduced build-up of fibrous matrix and left the lesions in a more immature state. Drug diffusion and oxygenation was significantly improved. Adding lysyl oxidase inhibition to chemotherapeutic treatment strongly improved efficacy of the cytotoxic drugs both in primary tumors and in established metastatic disease. Impotantly, BAPN-treatment reversed the negative impact of antiangiogenic therapy on drug delivery in an anti-VEGF refractory tumor model, synergistically improving drug transport and treatment efficacy in a study that combined lysyl oxidase inhibition with VEGF-ablation and cytotoxic treatment. Our results indicate that interfering with the formation of the supportive tumor microenvironment might be an effective way to slow improve drug delivery and response. Especially, in combination with anti-angiogenic treatment it has the potential to significantly improve the effficacy of the therapeutics already at our disposal to combat cancer. 267 POSTER (Board P047) Novel adjuvant therapy with leptin peptide receptor antagonist-2 conjugated to nanoparticles (IONP-LPrA2) to minimize chemoresistance in triple negative breast cancer T. Harmon1 , A. Harbuzariu2 , L. Yang3 , R.R. Gonzalez-Perez1 . 1 Morehouse School of Medicine, Atlanta GA, USA; 2 Morehouse School of Medicine, MBI, Atlanta GA, USA; 3 Emory University, Atlanta GA, USA Background: Triple negative breast cancer (TNBC) is a life-threatening disease with no targeted therapy, which is linked to obesity incidence. Leptin, a cytokine produced by adipose tissue and overexpressed in breast cancer, induces TNBC growth and survival. Leptin binds to its receptor, OB-R, inducing expression of Notch and breast cancer stem cell (BCSC) genes. Notch is a pro-angiogenic factor, which interacts with leptin and IL-1 signaling crosstalk (NILCO). NILCO induces the expression of several pathways involved in cell proliferation, metastasis, and angiogenesis; notably vascular endothelial growth factor (VEGF/VEGFR2). We have created leptin peptide receptor antagonists linked to iron oxide nanoparticles which will inhibit leptin signaling, thus decreasing the expression of Notch and BCSC genes and proteins. Methods: Several human TNBC cell lines were treated with the chemotherapeutics (IC50 doses: taxanes, doxorubicin, cyclophosphamide and anti-angiogenic/chemotherapeutic, sunitinib) combined with IONPLPrA2 for 24−72 h. Cell viability, apoptosis rate and the expression levels of NILCO molecules were analyzed using the Cellometer Vision Image Cytometer® . Results: IONP-LPrA2 improved the effects of chemotherapeutics on cell viability and apoptosis, which could allow the reduction of effective dosage. Thursday 20 November 2014 89 The expression of several NILCO components was significantly reduced by IONP-LPrA2 alone and in combination with chemotherapeutics. Conclusion: These findings suggest that IONP-LPrA2 may be useful as an adjuvant therapy in the treatment of TNBC. Results also indicate that IONP-LPrA2 may work in concert with chemotherapeutics and antiangiogenic drugs in vivo. Present findings suggest that IONP-LPrA2 adjuvant therapy could be a novel way to specifically target TNBC, and to reduce chemoresistance as well as the undesired side effects of chemotherapeutics. This may be particularly important for obese patients that show a higher incidence and poorest prognosis of TNBC. Acknowledgements: This work was partially supported by the National Institutes of Health and National Cancer Institute Grant 1SC1CA138658−05 and U54 CA118638, and DOD Idea Award BC 123427 to RRGP; and facilities, and support services at Morehouse School of Medicine (NIH RR03034 and 1C06 RR18386) and NIH/NCRR grant 1G12RR026250−03. Drug Design 268 POSTER (Board P048) A potent and highly efficacious bivalent Smac Mimetic APG-1387 in Phase I clinical development J. Lu1 , S. Rong1 , H. Sun1 , L. Liu1 , D. McEachern1 , G. Wang2 , J. Wen2 , Y. Zhai2 , M. Guo2 , D. Yang2 , S. Wang1 . 1 University of Michigan, Comprehensive Cancer Center, Ann Arbor MI, USA; 2 Ascentage Pharma Group, Preclinical development, Taizhou Jiangsu, China Background and Aim: Inhibitors of apoptosis proteins (cIAP1/2 and XIAP) are key regulators of apoptosis and are attractive cancer therapeutic targets. Targeting IAPs with small molecules represents a promising new strategy for cancer treatment. APG-1387 was designed a potent smallmolecule inhibitors that mimic the natural dimeric Smac protein. We report the design and preclinical characterization of APG-1387 for its anticancer activity and mechanism of action. Methods and Results: Using a structure-based computational drug design method, we designed and synthesized SM-1387 (renamed as APG-1387 by Ascentage Pharma) as a bivalent Smac mimetic and a potent inhibitor of cIAP1, cIAP2 and XIAP. Biochemical assays showed that APG-1387 binds to XIAP, cIAP1, cIAP2 proteins with Ki values of 1, 30 and 20 nM, respectively. APG-1387 potently antagonizes XIAP proteins containing both the BIR2 and BIR3 domains and induces cIAP-1 degradation at 1−10 nM in human cancer cell lines. Cell growth assays showed that APG-1387 inhibits cell growth in a subset of human cancer cell lines and achieves IC50 values of 10 and 23 nM, respectively, in MDA-MB-231 human breast cancer and SK-OV-3 ovarian cancer cell lines. Flow cytometry and western blotting assays showed that APG-1387 at 10–100 nM induces profound apoptosis in the MDA-MB-231 and SK-OV-3 cell lines. In vivo study showed that APG1387 is capable of inducing tumor regression even at weekly dosing in the MDA-MB-231 xenograft model. APG-1387 shows a strong combination synergy with docetaxel and achieves tumor regression in the HCC1954 triple negative breast cancer model with no signs of toxicity. Conclusion: Our preclinical data suggest that APG-1387 is a promising anticancer agent. A phase I clinical trial of APG-1387 is ongoing to evaluate its safety, pharmacokinetics, PD biomarkers and preliminary efficacy in patients with advanced cancers. 269 POSTER (Board P049) The NCI-60 as an effective tool for scaffold hopping: A phenotypic systems-based approach to the design of novel chemotherapeutics D.G. Wishka1 , V. Kumar2 , B. Teicher3 , G. Kaur4 , B. Fang5 , P. Risbood6 , M. Hollingshead7 , J. Zais7 , J. Morris6 . 1 National Cancer Institute, Drug Synthesis and Chemistry Branch, Frederick MD, USA; 2 Leidos Biomedical Research, Drug Synthesis and Chemistry Branch, Frederick MD, USA; 3 National Cancer Institute, Molecular Pharmacology Branch, Rockville MD, USA; 4 National Cancer Institute, Molecular Pharmacology Branch, Frederick MD, USA; 5 M.D. Anderson Cancer Center, Houston TX, USA; 6 National Cancer Institute, Drug Synthesis and Chemistry Branch, Rockville MD, USA; 7 National Cancer Institute, Biological Testing Branch, Frederick MD, USA The indole-3-carbinol NSC-743380 [(1-(3-chlorobenzyl)-1H-indol-3-yl)methanol] causes regression in the mouse A498 renal xenograft model. Although its mechanism of action is not well understood, NSC-743380 produces a distinct growth inhibition pattern in the NCI-60 cell line screen. NSC-743380 acts very rapidly in cell culture, with changes observed in multiple signaling pathways within 5 minutes of exposure. 90 Thursday 20 November 2014 Using cell lines derived from the NCI-60 panel, a search for a second xenograft model sensitive to NSC-743380 was unsuccessful. In addition, a significant medicinal chemistry effort examining modifications to the indole-3-carbinol structure of NSC-743380 failed to produce a suitable alternative. The COMPARE algorithm is a powerful tool for identifying compounds that share common mechanisms of action by matching their respective growth inhibition patterns in the NCI-60 cell panel. Running a COMPARE analysis on the existing NCI-60 data for the NCI compound collection with NSC-743380 as the exemplar identified a number of alternative chemotypes, including one represented by the mustard, NSC101490 [(E)-N -(4-(bis(2-chloroethyl)amino)-2-chlorobenzylidene)nicotinohydrazide]. Using the NCI-60 growth inhibition patterns as a guide to overlay of the SAR features from indole-3-carbinol series of NSC-743380 with that of the mustard series of NSC-101490 provided the basis for the scaffold hop to the new Benzyl-Amino-Benzyl-Alcohol (BABA) class of chemotherapeutics. Herein, we report the identification of a potent subtype of the BABA chemotype that shares with NSC-743380 the ability to cause regression in the A498 xenograft model as well as its distinctive NCI60 growth inhibition pattern. In addition, evidence will be presented to show that sulfotransferase activation may be a component involved in the antiproliferative activity of the BABA series against sensitive cell lines. 270 POSTER (Board P050) Discovery, development and optimization of low molecular weight EPH−ephrin protein–protein inhibitors M. Tognolini1 , C. Giorgio1 , I. Hassan-Mohamed1 , E. Barocelli1 , M. Mor1 , D. Pala1 , S. Russo1 , M. Incerti1 , A. Lodola1 . 1 University of Parma, Pharmacy, Parma, Italy Background: The EPH−ephrin system plays a key role in tumorigenesis and its de-regulation correlates with a poor clinical prognosis in many solid tumors. Agents targeting the EPH−ephrin system could be potentially useful for the inhibition of different facets of cancer progression. However, even though some classes of small molecules targeting EPH−ephrin interactions have been reported, their use is hampered by poor chemical stability and low potency. Stable and potent ligands are essential to obtain strong pharmacological data. Materials and Methods: We recently identified lithocholic acid (LCA) as a competitive and reversible compound able to disrupt EPH−ephrin interaction showing a Ki value of 49 mM. Using LCA scaffold as a reference structure and starting from a docking model of the EPHA2−LCA complex we designed and synthetized a series of amino acid conjugates of lithocholic acid and the new compounds were characterized for their ability to disrupt the EPHA2–ephrin-A1 interaction by means of an ELISA binding assay. The most promising compounds were further characterized for their cellular functional properties including: aspecific cytotoxicity, antiproliferative effect, cell cycle, inhibition of Eph kinase phosphorylation, induction of morphological changes, angiogenesis and migration. In order to check for the overall selectivity of the new compounds selected molecules were tested for their ability to interact with physiological-targets of bile acids (FXR, TGR5) as well as some other kinases (EGFR, VEGFR). Results: The L-homo-Trp-conjugated of LCA (UniPR129) emerged as a potent and selective antagonist of EPH receptors, inactive on the FXR, TGR5, EGF and VEGF receptors. UniPR129 reversibly and competitively disrupted EPHA2–ephrin-A1 interaction with Ki = 370 nM in an ELISA binding assay and it showed low micromolar potency in cellular functional assays, including inhibition of EPHA2 activation, cell migration and cell rounding and disruption of in vitro angiogenesis without cytotoxic effects. Structure of UniPR129 was modified, with the aim to improve its pharmacokinetic properties, leading to the identification of a new orally bioavailable compound. Conclusions: The discovery of UniPR129 represents not only a major advance in potency compared to the existing EPH−ephrin antagonists but also an improvement in terms of cytotoxicity, making this molecule a useful pharmacological tool and a promising lead compound. Moreover, steroid scaffold can be modified in order to obtain potent, selective, and soluble bioavailable compounds. Poster Session – Drug Design 271 POSTER (Board P051) Data integration and graph analysis for cancer genomics and drug discovery B. Bernard1 , M. Miller1 , H. Rovira1 , I. Shmulevich1 . 1 Institute for Systems Biology, Seattle, USA Overview: Each tumor type being studied by TCGA consists of tens of thousands of molecular data points derived from thousands of primary human tumor samples, from which we identify millions of statistically significant molecular associations. From these data, we know that each tumor harbors numerous somatic mutations and copy number aberrations that contribute to loss and gain of function in the cancer cells. While certain genes are more frequently aberrated than others, each tumor sample has a unique mutation and copy number profile that should inform patient stratification, treatment planning, novel target identification, and drug repurposing for personalized therapeutic strategies and drug discovery. The search space across millions of associations for tens of thousands of genes and thousands of potential drugs is tremendously underexplored. Consequently, promising targets and therapies are not identified or evaluated. Approaches to integrate and query molecular associations from heterogeneous sources of data pose a significant research and computational challenge in drug discovery. To this end, we have integrated statistical analysis of molecular data from thousands of primary tumor samples in TCGA with a large and heterogeneous cancer knowledge base, including cell line screening, protein–inhibitor interactions, semantic-based information in the literature, and protein interaction databases. We model these heterogeneous relationships in a graph database, and query this large graph to generate novel and testable predictions for target identification, drug repurposing, and tumor type prioritization for therapeutic intervention. Example 1. Identification of novel targets in primary human tumors: We have combined the Cancer Cell Line Encyclopedia (CCLE) and Achilles shRNA screening projects to infer synthetic lethal (SL) relationships in cell lines with characterized mutation profiles. Integration of these SL relationships with molecular associations in TCGA enables the identification of graph patterns and subsequent prioritization of potential cross-cancer therapeutic targets with direct evidence for SL relationships in both cell line and primary human tumor samples. Example 2. Patient stratification and prioritization of tumor types for clinical trials: Analysis of targeted drug screening in cell lines reveals that the sensitizing genes (i.e., those genes harboring mutations and copy number aberrations in drug-sensitive cell lines) are invariably not limited to the drug target itself. For example, AKT1 inhibition is most effective in cell lines with PTEN mutations. By analyzing the integration of cell line screening hits with accompanying relationships derived from primary tumor sample data in TCGA, we can stratify patients based on their aberration profiles and prioritize clinical trials for tumor types with evidence for relationships between the drug target and sensitizing aberrations. 272 POSTER (Board P052) 8-(1-Anilino)ethyl)-2-morpholino-4-oxo-4H-chromene-6-carboxamides as PI3Kbeta/delta inhibitors: structure–activity relationships and identification of AZD8186, a clinical candidate for the treatment of PTEN deficient tumours B. Barlaam1 , S. Cosulich1 , S. Degorce1 , M. Fitzek1 , S. Green1 , U. Hancox1 , C. Lambert-van der Brempt1 , J.J. Lohmann1 , M. Maudet1 , R. Morgentin1 , M.J. Pasquest1 , A. Peru1 , P. Ple1 , T. Saleh1 , M. Vautier1 , M. Walker1 , L. Ward1 , N. Warin1 . 1 AstraZeneca, Oncology, Macclesfield, United Kingdom Several studies have highlighted the dependency of PTEN deficient tumours to PI3Kb activity and specific inhibition of PI3Kd has been shown clinical efficacy against human B-cell cancers. We previously reported the identification of a new series of pyrido[1,2-a]pyrimidin-4-ones and our efforts1−2 to optimize this series as orally active PI3Kb/d inhibitors, leading to compounds 1 and 2. Combining high potency, high solubility and high metabolic stability was a significant challenge in the pyrido[1,2-a]pyrimidin4-one series, possibly because of the intrinsic lipophilicity of the pyrido[1,2-a]pyrimidin-4-one core. In this poster, we describe the discovery and optimization of a new series of 8-(1-anilino)ethyl)-2-morpholino-4oxo-4H-chromene-6-carboxamides as PI3Kb/d inhibitors, leading to the identification of the clinical candidate AZD8186, a potent inhibitor of p-Akt in cells sensitive to PI3Kb inhibition (IC50 0.003 uM (+/− SEM: 0.001) in PTEN null breast adenocarcinoma MDA-MB-468 cells) and in cells sensitive to PI3Kd inhibition (IC50 0.017 uM (+/− SEM: 0.004) in Jeko B cell line), but not to cells sensitive to PI3Ka inhibition (IC50 0.752 uM (+/− SEM: 0.293) in PIK3CA mutant human breast ductal carcinoma BT474). On the basis of the lower lipophilicity of the chromen-4-one core compared to the previously utilised pyrido[1,2-a]pyrimid-4-one core, this series of compounds (and AZD8186 in particular) displayed high metabolic stability and suitable Poster Session – Drug Design physical properties for oral administration. AZD8186 showed profound pharmacodynamic modulation of p-Akt in PTEN-null PC3 prostate tumour bearing mice after oral administration and showed complete inhibition of tumour growth in the mouse PTEN-deficient PC3 prostate tumour xenograft model. AZD8186 was selected as a clinical candidate for treatment of PTEN-dependent cancers and has recently entered phase I clinical trials. Thursday 20 November 2014 91 cell growth of HCT116 cells and also significantly suppressed tumor growth in the HCT116 xenograft model. Those results suggest that the STLC derivatives with two linked phenyl rings could be a novel lead compound to design further clinical candidates of the next generation of KSP inhibitors for antitumor chemotherapies. 273 POSTER (Board P053) Significance of serine-167 and cysteine-129 residues in the active site of the immune-suppressive enzyme indoleamine 2,3-dioxygenase 1 (IDO1) for the binding of novel inhibitors P. Tomek1 , B.D. Palmer1 , J.U. Flanagan1 , L. Ching1 . 1 Auckland Cancer Society Research Centre, The University of Auckland, Auckland, New Zealand Background: IDO1 is an enzyme expressed by a broad range of cancers to suppress the host’s immune system. It is a validated target for cancer therapy, with two IDO1 inhibitors already in human clinical trials. The IDO1 active site amino acids Ser-167 and Cys-129 are predicted to form hydrogen bond interactions with inhibitors. We have screened for inhibitors to probe the importance of these residues in the IDO1 active site for ligandbinding and functional activity of the enzyme. Material and Methods: The National Cancer Institute Diversity Set III library (1597 compounds) was screened for inhibition of IDO1 enzymatic activity using our recently developed fluorescence assay automated with a JANUS robotic workstation. Mutant IDO1 proteins were prepared using Stratagene QuikChange® Site-Directed Mutagenesis Kit. Results: The NCI library was screened against wild-type IDO1 and alanine replacement mutants of serine-167 (S167A) and cysteine-129 (C129A). This identified three new classes of IDO1 inhibitors (pyrimidinones, phenanthroimidazoles and benzoxadiazoles). Compounds from the phenanthroimidazoles and benzoxadiazoles classes exhibited a tightbinding, reversible mode of inhibition that was strikingly different to that of a well-characterised IDO1 inhibitor, 4-phenyl-1H-imidazole. When screened against the S167A mutant, 18 of the 69 compounds that inhibited wildtype IDO1 (>25% at 20 mM) exhibited decreased activity against the S167A mutant. Structure–activity studies around two of these compounds, 2-(1H-phenanthro[9,10-d]imidazol-2-yl)phenol and 6-carboxy-5-((4-iodo-2methylphenyl)amino)benzo[c][1,2,5]oxadiazole 1-oxide, were performed, and showed that the hydroxy and N-oxide substituents on these two molecules respectively, were related to the decreased activity. When screened against C129A mutant, no compounds in the library showed decreased activity compared to wild-type IDO1, however three compounds showed increased inhibition. Conclusions: Three IDO1 inhibitors identified in this study displayed tight-binding reversible mode of inhibition, one of the more desirable mechanisms of action for therapeutic agents. The hydroxyl group of serine167, but not the thiol of cysteine-129 in the IDO1 active site appears to be important for interactions with a range of different inhibitors. 274 POSTER (Board P054) Novel cysteine derivatives for the next generation anticancer agents acting on KSP N. Ogo1 , J. Sawada1 , Y. Ishikawa1 , K. Matsuno1 , A. Hashimoto2 , A. Asai1 . 1 University of Shizuoka, Graduate School of Pharmaceutical Sciences, Shizuoka, Japan; 2 Taiho Pharmaceutical Co. Ltd., Tsukuba Research Center, Ibaraki, Japan Kinesin spindle protein (KSP), known as human Eg5, plays an important role in the early stages of mitosis. It is responsible for the formation and maintenance of the bipolar spindle. Inhibition of KSP leads to cell cycle arrest during mitosis and causes cells with a monopolar spindle followed by cell death. A large number of KSP inhibitors have been reported and some of them entered into clinical trials. Although clinical efficacy of these inhibitors has been limited to date, recently better results have been obtained in the treatment of hematological malignancies with thiadiazole based KSP inhibitors such as ARRY-520. We previously identified S-tritylL -cysteine (STLC) as a selective KSP inhibitor from our HTS campaign and reported that several STLC derivatives induced M-phase accumulation and subsequent apoptosis in leukemic cells (BMCL 2007, 17, 3921–3924, BMCL 2010, 20, 1578–1580, Cancer Lett. 2010, 298, 99–106). The objective of this study is to improve the potency of these leads and to confirm the antitumor efficacy in vivo. As a result of further structure–activity relationship studies, we identified novel derivatives with two fused phenyl rings which showed remarkably potent KSP inhibitory activity with IC50 values in nanomolar ranges. Docking simulation of these novel derivatives using AMBER12 indicated that cross-linking of the phenyl rings in the trityl group allowed for better binding by occupying a hydrophobic pocket in the L5 allosteric binding site. The representative derivatives potently inhibited Figure: Novel cysteine derivatives. 275 POSTER (Board P055) Modulation of PIP2 levels through small molecule inhibition of PIP5K D. Andrews1 , S. Cosulich2 , N. Divecha3 , D. Fitzgerald3 , V. Flemington2 , C. Jones1 , D. Jones3 , O. Kern4 , E. MacDonald4 , S. Maman4 , J. McKelvie5 , K. Pike1 , M. Riddick6 , G. Robb1 , K. Roberts2 , J. Smith4 , M. Swarbrick4 , I. Treinies7 , M. Waring1 , R. Wood6 . 1 AstraZeneca, Chemistry, Macclesfield, United Kingdom; 2 AstraZeneca, Bioscience, Macclesfield, United Kingdom; 3 Cancer Research UK, Inositide Laboratory, Manchester, United Kingdom; 4 Cancer Research Technology, Chemistry, Cambridge, United Kingdom; 5 Cancer Research Technology, Chemistry, London, United Kingdom; 6 Cancer Research Technology, Bioscience, Cambridge, United Kingdom; 7 Cancer Research Technology, Bioscience, London, United Kingdom Background: Phosphatidyl inositol (4,5)-bisphosphate (PIP2 ) is a key phospholipid signalling molecule, involved in cellular processes such as cell proliferation and survival. Cellular PI(4,5)P2 is synthesised by phosphorylation of PI(4)P on the D-5 position of the inositol head group by phosphatidylinositol-4-phosphate 5-kinases (PIP5Ks). The family of PIP5K is comprised of 3 isoforms a, b and g regulated by membrane receptors, phosphorylation and small GTPases of the Rho and ARF family. Activation of this pathway is known to promote growth and invasion of cancer cells, rendering PIP5K an attractive therapeutic target for antitumour therapies Material and Methods: Two separate focussed screening campaigns identified a number of hit series. Structure Activity Relationships (SAR) was built around three chemotypes, (A, B & C) with biochemical assays routinely run against all three isoforms of PIP5K, two isoforms of PI4K and PI3Ka. Compounds were also routinely assayed cellular assays, measuring surrogate markers of cellular PIP2 levels. Results: Potent, selective inhibitors (pIC50 >8), of PIP5K kinases have been developed in three chemical series. The SAR of series B will be described in detail. Live cell imaging results will be presented. Conclusions: Cell data demonstrate that PIP5K inhibition slows the rate of PIP2 synthesis. PIP5Ka (pIC50 ) PIP5Kb (pIC50 ) PIP5Kg (pIC50 ) PI3Ka (pIC50 ) PI4Ka (pIC50 ) PI4Kb (pIC50 ) PIP2 inhib @ 3mM Series A Series B Series C 5.8 7.2 7.2 5.3 5.1 5.1 3.7% 7.8 8.6 8.9 4.5 4.8 5.4 21% 9.3 8.8 8.9 <4.0 4.0 4.0 17% 276 POSTER (Board P056) An X-ray crystal structure-based understanding of the inhibition of the MDM2−p53 protein–protein interaction by isoindolinones B. Anil1 , E. Blackburn1 , T. Blackburn2 , S. Cully2 , J. Liu3 , C.J. Drummond2 , J.A. Endicott1 , B.T. Golding4 , R.J. Griffin2 , K. Haggerty2 , J. Lunec2 , D.R. Newell2 , C.H. Revill2 , C. Riedinger1 , A.F. Watson2 , Q. Xu2 , Y. Zhao2 , I.R. Hardcastle2 , M.E.M. Noble1 . 1 University of Oxford, Department of Biochemistry, Oxford, United Kingdom; 2 Newcastle University, Northern Institute for Cancer Research, Newcastle upon Tyne, United Kingdom; 3 Newcastle University, Northern Istitute for Cancer Research, Newcastle upon Tyne, United Kingdom; 4 Newcastle University, School of Chemistry, Newcastle upon Tyne, United Kingdom The p53 tumor suppressor plays a pivotal role in responding to cellular stress. Activation of p53 protein results in the transcription of a number of 92 Thursday 20 November 2014 genes that govern progression through the cell cycle, the initiation of DNA repair, and apoptosis. The activity of p53 is tightly regulated by the MDM2 protein, in an auto-regulatory feedback loop. Inhibition of the MDM2−p53 protein–protein complex by small molecule inhibitors has been shown to reactivate normal p53 pathways in cells overexpressing MDM2, and so exert an anti-cancer effect. A number of series of potent small-molecule inhibitors have been developed as far as clinical trials. Understanding of the structural basis for inhibition from ligand-bond protein X-ray structures has been important in the optimisation of most of these series. We have developed a class of inhibitors of the MDM2−p53 interaction, based on an isoindolinone scaffold [J. Med. Chem. 2006, 49, 6209–6221, Bioorg. Med. Chem. Letters 2011, 21, 5916– 5919]. NU8406A, (R)-4-chloro-3-(4-chlorophenyl)-3-((1-(hydroxymethyl)cyclopropyl)methoxy)-2-(4-nitrobenzyl)isoindolin-1-one (IC50 = 43.8±6.2 nM) shows comparable in vitro activity to Nutlin-3a. Recently, we reported the MDM2 co-crystal structure of Nutlin-3a using a surface-entropy reduction mutant [Acta Cryst 2013, D69, 1358–1366]. We have applied these MDM2 mutants to solve the co-crystal structure of NU8406A. The structure shows that the binding mode of the isoindolinone is comparable to that for Nutlin-3a, and confirms the (R)-stereochemistry of the ligand. Preliminary structure–activity studies have revealed significant differences between the two series in the way that the Phe19 pocket is occupied. 277 POSTER (Board P057) The discovery and pre-clinical development of the first clinical stage EZH2-inhibitor, EPZ-6438 (E7438) K. Kuntz1 , H. Keilhack2 , R. Pollock2 , S. Knutson2 , N. Warholic2 , V. Richon2 , R. Chesworth1 , R. Copeland1 , M. Porter-Scott1 , C. Sneeringer1 , T. Wigle1 . 1 Epizyme Inc, Molecular Discovery, Cambridge Massachusetts, USA; 2 Epizyme Inc, Biology, Cambridge Massachusetts, USA Mutations within the catalytic domain of the histone methyltransferase EZH2 have been identified in subsets of patients with non-Hodgkin lymphoma (NHL). Cancers harboring these genetic alterations are dependent on EZH2 enzymatic activity for cellular survival. Here, we disclose the discovery of EPZ-6438 (E7438), as a potent, selective and oral bioavailable small molecule inhibitor of EZH2 in preclinical models of NHL. Previously we have disclosed the properties of EPZ005687, a tool compound useful for exploring the in vitro biology of EZH2 inhibition. Multiparametric optimization of the potency, pharmokinetics, oral biovailability and safety properties of this series led to the discovery of the clinical compound, EPZ-6438. Modulation of the log P was required to reach the optimal balance between clearance and bioavailability while maintaining the requisite potency. EPZ-6438 selectively inhibits intracellular lysine 27 of histone H3 (H3K27) methylation in a concentration- and time-dependent manner in both EZH2 wild-type and mutant lymphoma cells. Inhibition of H3K27 trimethylation (H3K27Me3) leads to selective cell killing of human lymphoma cell lines bearing EZH2 catalytic domain point mutations. Treatment of EZH2-mutant NHL xenograft-bearing mice with EPZ-6438 causes dose-dependent tumor growth inhibition, including complete and sustained tumor regressions with correlative diminution of H3K27Me3 levels in tumors and selected normal tissues. EPZ-6438 recently entered clinical testing as E7438 in a dose escalation phase 1 trial in relapsed or refractory malignancies. Poster Session – Drug Design 278 POSTER (Board P058) Sentinel lymph nodes mapping of macrophage targeted mannosyl human serum albumin-indocyanine detected by combined color and near infrared fluorescence imaging system in esophagus Y. Quan1 , Y. Oh2 , J.I.H.O. Park3 , J. Park4 , J. Jeong4 , B. Kim5 , H. Kim1 . 1 Korea University Guro Hospital, Department of Thoracic Cardiovascular Surgery, Seoul, Korea; 2 Korea University, Department of Bio-Convergence Engineering, Seoul, Korea; 3 Korea Advanced Institute of Science and Technology, Department of Bio and Brain Engineering, Seoul, Korea; 4 Seoul National University, Department of Transdisciplinary Studies Program in Biomedical Radiation Science, Seoul, Korea; 5 Korea University, Department of Biomedical Engineering, Seoul, Korea Objective: Esophageal cancer is one of the most poor prognosis diseases. Therefore, 3-field lymph node dissection is performed for surgically curable esophageal cancer. However these extended lymphadenectomy is leads to high morbidity. Thus, sentinel lymph node (SLN) concept is essential point for esophageal cancer surgery to avoid unnecessary lymph node dissection. There are some pre-clinical trials use fluorescence indocyanine green (ICG) or radioisotope to selective removing SLN. In this study, we used mannosyl human serum albumin (MSA)-ICG as a new SLN targeting tracer to investigate esophageal SLN mapping using intraoperative color and fluorescence merged imaging system (ICFIS). Methods: We activated macrophage U937 cells and treated ICG or MSAICG respectively. The distributions of ICG and MSA-ICG in cells were investigated by Infrared Imaging System. In-vivo study, the ICG or MSAICG was injected into footpad of nude mice and then the lymphatic flow was investigated by Infrared Imaging System. Additionally, 5 Yorkshire pigs underwent thoracotomy and received submucosal injection of MSA-ICG with endoscopic needle through an esophagoscope. The distribution of MSA-ICG in SLN of pig esophagus was investigated by ICFIS. Results: Our study found that the MSA-ICG were specific bound to macrophage than free ICG, and also the detected lymph node imaging more distinguishable than free ICG in mice. The pig esophageal SLN which received MSA-ICG submucosal injection were detectable from 15 min. In 3 of 5, two SLN were identified, however in 2 of 5, one SLN was detected. Discussion: In fluorescence guided esophageal surgery, the MSA-ICG provided precise real-time imaging of SLN. Therefore the MSA-ICG may be a reliable tracer for SLN identification in esophagus cancer. 279 POSTER (Board P059) Discovery of multiple kinases inhibitors, DBPR114, as the novel anti-cancer agent H.P. Hsieh1 , C.C. Kuo2 , J.J. Chiu2 , T.A. Hsu1 , T.K. Yeh1 , C.T. Chen1 . 1 National Health Research Institutes, Institute of Biotechnology and Pharmaceutical Research, Zhunan Miaoli County, Taiwan; 2 National Health Research Institutes, Institute of Cellular and Systems Medicine, Zhunan Miaoli County, Taiwan Purpose: The goal of targeted therapy is to identify the suitable target molecules to be inhibited, in order to achieve the best antitumor effect. The classical viewpoint is that inhibitor acting on single target allows selectivity and less adverse effect. However, clinical experience revealed that almost relapsed cancer patients developed drug resistance, often due to the activation or development of alternative signaling pathways or mutations that single target drugs are unable to effectively inhibit them. A current trend in the development of kinase inhibitors is the assumption that multi targeted therapy, which targets at several signaling pathways simultaneously, is more effective than single targeted therapy. Thus, paradigm in designing new anticancer drug is shifted: The drugs that act on multiple targets might have a better chance of inhibiting cancer cell proliferation than drugs that act on a single target. The objective of this research is aimed at identifying a multi-targeted kinase inhibitor as a development candidate for cancer therapy. Material and Method: We established Structure–Activity Relationship (S.A.R.) study based on 800 compounds that were synthesized by High Throughput Parallel Synthesis. Scaffold hopping approach by changing pharmacophore moiety had led us to discover DBPR114 as a multipletargeted kinase inhibitor. Results: We discovered a novel multiple-targeted kinase inhibitor, DBPR114, that effectively inhibited 15 kinases in a panel of 57 oncogenic related kinases profiling, particularly against to Aurora kinase A and B, FLT-1, FLT-3 and c-Met in nanomolar range. In pharmacological study, DBPR114 significantly shrank tumor in 8 different xenograft models including Mia-Paca2, AsPC-1 (pancreatic carcinoma), Hep3B (hepatocellular carcinoma), MKN-45 (gastric carcinoma), MOLM-13 and MV4;11 (acute myeloid leukemia), NTUB-1 (bladder cancer), and Colo205 (colorectal carcinoma) at a dose of 3 to 20 mg/kg by intravenous Poster Session – Drug Design administration without significant adverse effect in most group of in vivo evaluations. Conclusion: This multiple targeting inhibitory properties plays a major role to shrinks tumor growth of various cancer cells in vivo and in vivo such as MOLM-13, MV4;11, MKN45, Colo-205, Mia-Paca2 and NTUB-1. The broad spectrum of anti-tumor activity of BPR1K0871 provides a great potential to become a promising multi-targeted kinase inhibitors as next generation of anti-cancer drug. 280 POSTER (Board P060) A hybrid drug design approach to overcome imatinib resistance for treating leukemia Y.M. Wei1 , K.K.W. To2 , S.C.F. Au-Yeung1 . 1 The Chinese University of Hong Kong, Department of Chemistry, New Territories, Hong Kong; 2 The Chinese University of Hong Kong, School of Pharmacy, New Territories, Hong Kong Background: Imatinib, a multi-targeted tyrosine kinase inhibitor, exhibits potent anticancer activity against leukemia harboring the bcr-abl oncogene and some solid tumors overexpressing c-kit and PDGFR. However, its clinical efficacy is severely hindered by the emergence of resistance primarily due to acquired mutations in the bcr-abl kinase domain. Material and Methods: By applying our established ‘Platinum (Pt) drug − Bioactive ligand’ drug design platform, novel Pt-imatinib hybrid compounds were synthesized and fully characterized by 1 H-NMR and ESI+ MS. In silico docking analysis was performed to investigate the interaction of the new compounds with wild-type bcr-abl and its various resistance-causing mutants. Anticancer activity was evaluated by the colorimetric MTT assay. Kinase inhibition profiling was performed to assess the specificity of the new compounds on various receptor tyrosine kinases. Cell cycle regulation and apoptosis were studied by propidium iodide and Annexin V-7AAD staining, respectively. Reaction between the new compounds and DNA was studied by NMR using 5 -GMP as a model nucleotide. Results: The new Pt-imatinib hybrid compounds were found to be highly effective against the leukemia cell line K562 harboring bcr-abl, but not in another non-bcr-abl expressing leukemia RPMI8226 and some other solid tumors. Importantly, the new compounds maintained their anticancer activity in an imatinib-selected resistant K562 subline. Moreover, the new compounds did not appreciably affect cell growth of normal HEK293 and LLC-PK1 cell lines. Kinase profiling revealed that the new compounds maintain selectivity towards bcr-abl, c-kit and PDGFR, similar to imatinib. By docking simulation, the new compounds were predicted to interact with both wild-type bcr-abl and some of its resistance-mediating mutants. This was verified by biochemical kinase inhibition assay on selected bcr-abl mutants. In K562 cells, the new compounds produced G1 phase arrest, in contrast to G2/M arrest mediated by classical Pt drugs. Unlike classical Pt compounds, the Pt-imatinib hybrids only form monofunctional Pt-DNA adducts, presumably contributing to the minimal toxicity in normal cells. Conclusions: New lead Pt-imatinib hybrid compounds were found to be specific towards bcr-abl-expressing leukemia cells and capable of circumventing resistance mediated by clinically identified mutations. Their good safety profile and unique mechanisms advocate further clinical development. Figure: General formula of the designed compounds. 281 POSTER (Board P061) Novel hybrid drug design strategy to circumvent erlotinib resistance and to optimize its pharmacokinetic properties for treating lung cancer D.C.S. Poon1 , S.C.F. Au-Yeung2 , K.K.W. To1 . 1 The Chinese University of Hong Kong, School of Pharmacy, New Territories, Hong Kong; 2 The Chinese University of Hong Kong, Department of Chemistry, New Territories, Hong Kong Background: Erlotinib is an EGFR tyrosine kinase inhibitor (TKI) highly potent towards lung cancer carrying the sensitizing EGFR mutations. However, its usefulness is severely compromized by resistance mediated primarily by the secondary EGFR T790M mutation. Most EGFR TKIs are substrates of the efflux transporters Pgp and ABCG2. Induction of these Thursday 20 November 2014 93 transporters can remarkably decrease cellular accumulation of erlotinib, thereby conferring drug resistance. Moreover, EGFR TKIs are not effective for brain metastasis from primary lung cancer because of poor drug penetration restricted by Pgp and ABCG2 at the blood–brain barrier. Material and Methods: Novel platinum (Pt)–erlotinib hybrid compounds were synthesized by our established ‘Pt-bioactive ligand’ drug design approach. They were fully characterized by 1 H-NMR and ESI+ MS. Anticancer activity in a panel of non-small cell lung cancer cell lines was evaluated by sulforhodamine B assay. Docking simulation was performed to investigate the interaction of the new compounds with EGFR harboring different mutations. Inhibition of different EGFR mutant kinases was evaluated by biochemical kinase assay. Drug uptake and transport across cell monolayer specifically overexpressing P-gp/ABCG2 were studied to examine whether the new compounds are substrate of the transporters. Results: Similar to erlotinib, new Pt-erlotinib hybrid compounds were found to be highly effective against HCC827 harboring the sensitizing EGFR L858R mutation (IC50 : 0.006–0.16 mM) but become inactive in H520 with minimal EGFR expression (IC50 ~15 mM). Importantly, they were much less affected than erlotinib by acquired resistance mediated by the secondary EGFR T790M mutation in H1975 cells (fold resistance: ~200 versus ~12,000 for erlotinib). By docking simulation, the new compounds were predicted to maintain their binding with the EGFR T790M mutant. Results from biochemical kinase assay reveal that the new compounds inhibited EGFR in an ATP-competitive manner and that the inhibition was only minimally reduced by the EGFR T790M mutation. Unlike erlotinib, cellular uptake and transport of the hybrid compounds were not affected by Pgp and ABCG2 overexpression. Conclusions: Novel Pt-erlotinib hybrids were found to circumvent resistance mediated by the acquired EGFR T790M mutation. By escaping P-gp/ABCG2-mediated efflux, the new compounds may be effective for treating metastatic brain cancer. Further development of the hybrid compounds is warranted. 282 POSTER (Board P062) Membrane anchorage of Stat3 via artificial protein lipidation M. Avadisian1 , S. Fletcher1 , B. Liu1 , W. Zhao2 , J. Turkson2 , C. Gradinaru1 , P. Gunning1 . 1 University of Toronto, Chemistry and Physical Sciences, Mississauga, Canada; 2 University of Central Florida, College of Medicine, Orlando, USA Lipidation localizes cytosolic proteins within cellular membranes through a covalent attachment of sterol or lipid groups. This post-translational modification restricts the motility of otherwise soluble proteins to the cell membrane. Using artificial lipidation, we propose to mimic Nature by artificially inducing protein–membrane anchorage through the use of a rationally designed Protein–Membrane Anchor (PMA) to inhibit a protein’s motility and function within the cell. We hypothesized that induced membrane anchorage of proteins can hold significant therapeutic value when applied to cancer-promoting cell-signaling proteins. To demonstrate the protein–membrane anchorage strategy, we choose to target Stat3 because of its constitutive activity in a number of cancers. Thus, our goal was to develop an inhibitor that could sequester Stat3, a 93 kDa protein, at the plasma membrane and suppress its motility through PMA-induced protein–membrane association. Our proto-type PMA 1 was composed of two binding modules: a recognition motif to bind the protein and an anchor to sequester the protein complex to the membrane. PMA 1 was composed of a potent Stat3 inhibitor covalently attached to a cholesterol membrane anchor. PMA 1 was able to anchor Stat3 to the cell membrane in MDA-MB-231 breast cancer cells that are known to have constitutively-active Stat3. Most excitingly, in the presence of 25mM concentration PMA 1, we observed complete sequestration of Stat3 to the cell membrane through PMA−Stat3 association. To improve metabolic stability, we synthesized a new library of PMAs with varying Stat3 binding and membrane anchoring moieties. Currently, we are conducting biophysical and immunofluorescent studies on the new PMAs. 94 Thursday 20 November 2014 283 POSTER (Board P063) The development of the first selective inhibitors of the UBA5 enzyme to probe for E1 activity in diseased cells S.R. da Silva1 , S.L. Paiva1 , M. Bancerz2 , M. Geletu2 , A.M. Lewis2 , J. Chen3 , Y. Cai3 , H. Li3 , P.T. Gunning1 . 1 University of Toronto, Chemistry, Toronto, Canada; 2 University of Toronto Mississauga, Chemical and Physical Sciences, Mississauga, Canada; 3 Georgia Regents University, Biochemistry and Molecular Biology, Augusta, USA Cancer cells produce and degrade proteins more rapidly than most normal cells, and are in turn more sensitive to changes in protein regulation. Similarly to secretory cells, cancer cells have the propensity to undergo endoplasmic reticulum (ER) stress due to higher protein turnover that, if left uncorrected, can result in apoptosis. To avoid these fates, cells have developed support systems such as the conjugation of the ubiquitin-fold modifier 1 (UFM1) ubiquitin-like protein to other protein targets, which has been implicated in counteracting apoptotic ER stress in pancreatic secretory cells. Our research has recently focused on the development of the first inhibitor of the UFM1 pathway by targeting its E1 enzyme, UBA5, in order to counteract the anti-apoptotic effects of this system and to further study the role of UFM1 conjugation in cancer cells. We have successfully identified a lead inhibitor, 5C-Z, which incorporates an adenosine moiety coupled to a zinc(II) polyazamacrocylic coordination complex. Through enzymatic assays that evaluate the transthiolation ability of UBA5 in the first step of UFM1 activation, our inhibitor exhibits low micromolar activity against UBA5 while demonstrating potent selectivity over other E1 enzymes (>20fold). Kinetic assays reveal that 5C-Z acts non-competitively on UBA5, indicating that the compound could possibly be binding to and inhibiting the “inactive” subunit of the UBA5 homodimer. Furthermore, treatment of lung and leukemia cells that exhibit high levels of UBA5 protein expression leads to a decrease in cell proliferation yet does not induce cell death in diseased or healthy cells, up to 200 mM. This novel strategy of inhibiting UBA5 and UFMylation would make cancer cells that are highly dependent on this system more susceptible to treatment regimens of principle drugs, which could lead to the use of milder drug dosing strategies. Our novel inhibitors produced from this research can be used as a probe to further investigate the role of E1 activating enzymes in cancer progression. Figure: General formula of the compounds. 284 POSTER (Board P064) Poly(ADP-ribose) glycohydrolase (PARG) inhibitors increase nuclear poly(ADP-ribose) after methylating DNA damage A. Jordan1 , B. Acton1 , E. Fairweather1 , N. Hamilton1 , S. Holt1 , J. Hitchin1 , C. Hutton1 , D. James1 , S. Jones1 , A. McGonagle1 , H. Small1 , K. Smith1 , A. Stowell1 , I. Waddell1 , B. Waszkowycz1 , D. Ogilvie1 . 1 Cancer Research UK Manchester Institute, Drug Discovery, Manchester, United Kingdom Background: DNA single strand breaks (SSBs) are the most common type of damage occurring in cells. Poly(ADP ribose) polymerase (PARP) binds to SSBs and auto-ribosylates itself using NAD+ as a substrate. This creates chains of poly ADP ribose (PAR) which provide a signal for other proteins to repair the lesion. Sequential removal of the PAR chains is accomplished by Poly(ADP-ribose) glycohydrolase (PARG). Failure to complete the DNA repair process, either by inhibition of PARP (e.g. with olaparib) or inhibition of PARG (with shRNA), can lead to cell death. PARG is the only enzyme known to efficiently catalyse the hydrolysis of O-glycosidic linkages of ADP-ribose polymers and exists (unlike PARP) as a single gene. We therefore sought to exploit this vulnerability and as part of a fostering agreement with AstraZeneca have developed novel small molecule inhibitors of PARG activity. Methods: A screening cascade for small molecule inhibition of PARG was developed. Biochemical inhibition of PARG was measured using a bespoke HTRF assay. In addition, selected PARG inhibitors were tested against other enzyme substrates (ARH3, PARP1) to assay for selectivity. Active compounds were then taken forward and tested in cells for PAR chain persistence and for cytotoxicity using a 3-day HeLa assay. Suitable compounds were then evaluated for their physico-chemical properties and their in vivo PK profiles determined. Poster Session – Drug Design Results: Early PARG inhibitors increased nuclear PAR chain levels in cells after 1 h treatment with the methylating agent methyl methanesulfonate (MMS) but also displayed off-target cytotoxicity in the absence of MMS. Applying computational chemistry enabled us to discover novel series of compounds with sub-micromolar potency with a wide differential to acute cytotoxicity. Compounds were also highly selective against PARP1 and ARH3 in vitro. PAR chain persistence in cells was also maintained after using the more clinically-relevant methylating agent temozolomide (TMZ). PARG inhibitors displayed satisfactory in vitro and in vivo PK profiles. Conclusions: We have developed PARG inhibitors that block the breakdown of PAR chains in cells after exogenous DNA damage by methylating agents. These tool compounds are potent and selective and enable us to both explore in more detail the cellular mode of action and investigate pre-clinical in vivo models for PARG inhibition. 285 POSTER (Board P065) A nanomolar-potency small molecule inhibitor of the STAT5 protein A.A. Cumaraswamy1 , A. Lewis2 , M. Geletu2 , A. Todic2 , D.B. Diaz2 , X.R. Cheng3 , C.E. Brown2 , R. Laister4 , D. Muench5 , K. Kerman3 , H.L. Grimes5 , M.D. Minden4 , P.T. Gunning1 . 1 University of Toronto, Department of Chemistry, Mississauga ON, Canada; 2 University of Toronto, Chemistry, Mississauga ON, Canada; 3 University of Toronto, Department of Physical & Environmental Sciences, Scarborough ON, Canada; 4 Princess Margaret Cancer Institute, Ontario Cancer Institute, Toronto ON, Canada; 5 Cincinnati Children’s Hospital Medical Centre, Division of Experimental Hematology, Cincinnati OH, USA Signal Transducer and Activator of Transcription 5 (STAT5) protein has gained notoriety for its aberrant role in many human cancers. In contrast to normal cells where STAT5 activity is rapid and transient, in cancer cells, including leukemias, STAT5 activity is routinely hyper-activated, conferring resistance to cell death and driving excessive expression of proto-oncogenes. Despite significant evidence showing STAT5’s role in human cancers, there has been little progress in developing direct inhibitors of STAT5 function. Potent and selective small molecule inhibitors of STAT5 will be effective therapeutics for treatment of hematological cancers and overcoming the side effects of current treatments. STAT5 is activated extracellularly by ligand-receptor binding, which results in STAT5 recruitment to intracellular receptor sites via their Src Homology 2 (SH2) domain. STAT5 is then phosphorylated, facilitating STAT5-STAT5 dimerization via reciprocal phosphotyrosine-SH2 interactions. The dimer shuttles to the nucleus and induces target gene transcription. In cancer cells, STAT5 is persistently activated, leading to the aberrant expression of STAT5 target genes that promote cancer cell survival and prevent cell death. To achieve this goal, we have employed a structure-based drug design strategy using computational analysis, medicinal chemistry and synthetic methods amenable to generating a diverse library. Herein, we report the first nanomolar, STAT5-selective inhibitor, AC-3-019, possessing a phosphotyrosyl-mimicking salicylic acid group, which potently and selectively binds to STAT5 over STAT3, inhibits STAT5-SH2 domain complexation events in vitro, silences activated STAT5 in leukemic cells, as well as STAT5’s downstream transcriptional targets, including MYC and MCL1, and as a result, leads to apoptosis. We believe AC-3-019 represents a useful probe for interrogating STAT5 function in cells as well as being a potential candidate for advanced preclinical trials. Poster Session – Drug Design 286 POSTER (Board P066) Potent and selective non-sulfamate-containing small molecule inhibitors of the ubiquitin activating enzyme S. Paiva1 , S.R. da Silva1 , M. Bancerz1 , H. Quereshi1 , G.W. Xu2 , A.D. Schimmer2 , P.T. Gunning1 . 1 University of Toronto, Chemical and Physical Sciences, Mississauga, Canada; 2 University Health Network, Princess Margaret Cancer Centre, Toronto, Canada Within the cell, many essential regulatory functions including protein recycling, translocation and cell signaling are mediated by the conjugation of ubiquitin (Ub) and ubiquitin-like (Ubl) proteins to target substrates. Ub/Ubl protein conjugation occurs through a cascade of events involving three enzymes: the ubiquitin activating enzyme (E1), the ubiquitin conjugating enzyme (E2) and the ubiquitin ligase (E3). In cancer cells, many of these systems are hyperactive making them attractive targets for the design of novel cancer therapeutics. More specifically, in recent years there has been a plethora of interest in the development of strategies that focus on designing inhibitors specific for different E1 isoforms. To this end, there has been some success, namely the mechanistic inhibitor MLN4924 and PYZD4409 that target the NEDD8 and Ub activating enzymes, respectively (NAE and UAE). MLN4924 is a sub-micromolar NAE inhibitor currently in Phase I clinical trials for the treatment of leukemia, lymphoma, multiple myeloma and solid tumours, while PYZD-4409 is a micromolar UAE inhibitor that promotes disease regression in leukemia and myeloma models. Given the great success of MLN4924 and the promising results of PYZD-4409, targeting E1s is an excellent strategy for controlling cancer cell growth and disease progression. However, the design of an inhibitor with potent and selective UAE activity still remains an elusive goal in this field of research. Our research has primarily focused on the rational design of selective and potent non-mechanistic UAE inhibitors by targeting a novel druggable site on the UAE protein using a two-prong approach. We have successfully developed inhibitors that display low nanomolar inhibition of UAE in purified enzymatic based assays (IC50 ~120–500 nM), as well as exhibiting >10fold selectivity for UAE over other E1 enzymes. To date, these are the most potent small molecule non-sulfamate-based inhibitors of UAE reported. 287 POSTER (Board P067) The discovery and optimization of small molecule antagonists of the WDR5−MLL interaction R. Al-Awar1 , R.S. Al-Awar1 , M. Getlik1 , D. Smil2 , Y. Bolshan2 , G. Poda1 , G. Senisterra2 , H. Wu2 , A. Allali-Hassani2 , G.A. Wasney2 , D. Barsyte-Lovejoy2 , L. Dombrovski2 , A. Dong2 , H. He2 , A. Seitova2 , I. Chau2 , F. Li2 , J.F. Couture2 , E. Kuznetsova2 , R. Marcellus1 . 1 Ontario Institute for Cancer Research, Drug Discovery, Toronto, Canada; 2 Structural Genomics Consortium, University of Toronto, Toronto, Canada ABSTRACT. Among other cellular processes, gene expression is regulated by epigenetic histone modifications. Histone methyltransferases catalyze the transfer of the methyl group from S-adenosylmethionine to specific lysine residues on histones. Mixed lineage leukemia 1 (MLL1) is a methyltransferase that methylates lysine 4 on histone H3 (H3K4me3) and is an important regulator of the haemopoietic system. Deregulation of MLL1 is often associated with acute myeloid and lymphoid leukemias and was proposed as a novel therapeutic target. WD40 repeat protein 5 (WDR5) is a component of the multiprotein MLL1 complex that is essential for its methyltransferase activity. Thus, therapeutic intervention of the WDR5/MLL1 interaction may lead to possible novel therapeutic agents for MLL-dependent leukemias. Using a structure-based design approach our structure activity relationship studies identified selective and cell-permeable compounds that bind to WDR5 with low nanomolar affinities. In future chemical biology studies these molecules will serve as valuable molecular probes to dissect the biological role of WDR5. 288 POSTER (Board P068) Synthetic isomalyngamide A analogs that inhibit breast cancer migration W. Li1 , T. Chang1 , C. Hung1 , C. Chen1 , S. Jao2 . 1 Academia Sinica, Institute of Chemistry, Taipei City, Taiwan; 2 Academia Sinica, Institute of Biological Chemistry, Taipei City, Taiwan Background: Because of frequent relapses in patients due to drug resistance and characteristically aggressive in very young women, breast Thursday 20 November 2014 95 cancers trigger enormous burden in health system, especially in the family of patient. Considerable progress has been made in the development of synthetic glycosylated isomalyngamide A analogs-related antitumor agents for medicinal interest. Based on the previous observations, we hypothesized that the isomalyngamide A analog might be a perfect substance with which to examine the role played by glycosylation and various linkers on antimigratory properties. Material and Methods: A series of synthetic glycosylated isomalyngamide A analogs with different linkers were prepared using the method of solution-phase synthesis and evaluated for their biological activities in human breast cancer cells. The effects of synthetic isomalyngamide A analogs on cell viabilities were determined by using the MTT assay. The inhibition of in vitro migration and invasion activities of synthetic isomalyngamide A analogs were examined by using a transwell assay. The potency in inhibition of cancer cell adhesion were studied by using the adhesion assay. Furthermore, the complete molecular mechanism for synthetic isomalyngamide A analog-mediated antimigratory property was explored using western blot analysis. Results: The findings show that the flexible rather than the rigid linkers to isomalyngamide A backbone more critically affect cell migration and invasive ability. Two synthetic isomalyngamide A analogs were observed to suppress migration, invasion and adhesion events in human breast adenocarcinoma MDA-MB-231 cells. Evidence has been achieved for a mechanism for inhibition of metastatic activities in MDA-MB-231 cells by synthetic isomalyngamide A analogs through the integrin-mediated antimetastatic pathway, suppression of the expression of p-FAK and paxillin. Conclusions: The observations made in this study demonstrate how the impact of the flexible and the rigid linker upon backbone of molecule affects the ability of synthetic isomalyngamide A analogs to modulate motility, migration, invasive capacity and adhesive property. In addition, the results of a complete western blot analysis of the in vitro antimigratory activities of synthetic isomalyngamide A analogs, show that these substances are potential antimetastatic agents for the treatment of breast cancer. 289 POSTER (Board P069) Progress in drugging CYP1A1, 1B1 and CYP2W1 overexpressed in cancer K. Pors1 , V. Le Morvan2 , S. Travica3 , S.D. Shnyder1 , M. Sutherland1 , H.M. Sheldrake1 , M. Searcey4 , I. Johansson3 , S. Mkrtchian3 , P.M. Loadman1 , J. Robert5 , M. Ingelman-Sundberg3 , L.H. Patterson1 . 1 University of Bradford, Institute of Cancer Therapeutics, Bradford, United Kingdom; 2 University of Bordeaux, Institut Bergonié, Bradford, France; 3 Karolinska Institute, Stockholm, Sweden; 4 University of East Anglia, School of Chemical Sciences and Pharmacy, Norwich, United Kingdom; 5 University of Bordeaux, Institut Bergonié, Bordeaux, France Background: The cytochrome P450 (CYP) enzymes are responsible for the oxidation of a diverse range of xenobiotic and endogenous compounds. Although CYPs operate mainly to detoxify xenobiotics and endogenous molecules, members of the CYP1 family are also known to catalyse one of the first steps in the metabolism of carcinogens originating from exposure to xenobiotics with the risk of developing cancer. Another member of the CYP family, CYP2W1, has been found to be expressed in adrenal gland, gastric, lung, rhabdomyosarcoma and colon cancer while the expression in adult non-transformed tissues remains absent. The high expression of CYP1A1, 1B1 and 2W1 in tumour tissue and surrounding stroma compared to nearby normal tissue provides an opportunity for development of selective cancer therapeutics. Materials and Methods: Briefly, these include synthetic chemistry necessary for synthesis of duocarmycin bioprecursors, use of recombinant CYP bactosomes for metabolite identification using LC/MS, transfected CYP1A1, 1B1 and 2W1 cancer cell lines and analysis of primary tissues. Results: At this meeting we will present both published and unpublished work, which is focussed on re-engineering the duocarmycin family of natural products for tumour-selective therapy. Novel data include progress on using ICT2726 as a biomarker to detect CYP2W1 functional activity and a range of agents that are activated in CYP1B1-transfed cell lines (Cal27 and Cal33). We are also disclosing information on our ongoing research of R and S-enantiomers of several duocarmycin bioprecursor compounds in both in vitro and in vivo models. Conclusions: Our findings reveal opportunities in targeting CYP1A1, 1B1 and 2W1 with personalized molecular cancer therapeutics based on the duocarmycin pharmacophore. 96 Thursday 20 November 2014 Poster Session – Molecular Targeted Agents I 290 POSTER (Board P070) Exosome analysis in cancer patients: From the preclinical towards the clinical application: Trial design I. Mertens1 , M. Castiglia2 , A.P. Carreca2 , G. Baggertman1 , M. Peeters3 , P. Pauwels2 , C. Rolfo4 . 1 University Antwerp − VITO, Center for Proteomics − CFP-CeProma, Antwerp, Belgium; 2 Antwerp University Hospital, Molecular Pathology Unit Department of Pathology, Antwerp, Belgium; 3 Antwerp University Hospital, Oncology Department, Antwerp, Belgium; 4 Antwerp University Hospital, Phase I − Early Clinical Trials Unit Oncology Department, Antwerp, Belgium Background: Cancer cells produce a heterogeneous mixture of vesicular, organelle-like structures (extracellular vesicles, EVs) into their surroundings including blood and other body fluids. Exosomes are small (40 to 100 nm) membrane derived vesicles that develop from exophytic budding of the cellular membrane after the fusion of multivesicular bodies or mature endosomes with the cellular membrane. It has been shown that tumour cells exposed to hypoxia secrete exosomes with enhanced angiogenic and metastatic potential. Thus exosomes might be involved in tumor progression and they can potentially be used for prognosis and therapy selection, as they contain a variety of molecules such as signal proteins and/or peptides, microRNAs, mRNAs and lipids, which could be potential biomarkers. Materials and Methods: To evaluate the biomarker potential of the exosome derived RNA and protein content, we first optimized an extraction protocol for exosomes in plasma based on the Optiprep density gradient protocol. After purification, the exosomes are characterized and quantified using Western Blot and Nanosight analysis. Later, the RNA and protein fraction of the extracted exosomes from 60 NSCLC, 60 pancreatic cancer and 60 colorectal cancer patients is compared to 60 healthy controls. The proteome content is evaluated using mass spectrometry based quantitative shotgun proteomics. The RNA profiles are generated using next generation sequencing. After profound bioinformatics analysis, the potential of the RNA and protein profiles will be evaluated for diagnostic, prognostic and therapy purposes. Results: We are able to purify and characterize exosome material from plasma samples derived from patients. The data from nanosight analysis and Western blot indicate that we are able to work with very pure exosome samples for RNA and protein axtraction. Currently, RNA and protein profiles from different cancer types are being compared to healthy controls. Conclusion: The first step in bringing exosome analysis to the clinic is optimized: exosome purification and characterization. In a next step, RNA and protein profiles are being evaluated as potential biomarkers. Molecular Targeted Agents I 291 POSTER (Board P071) Aflibercept has anti-tumor activity in bevacizumab-escaping tumors of colorectal cancer: Molecular profiles and mechanisms 1 2 2 2 3 4 C. Dib , R.G. Bagley , P. Mankoo , J. Pollard , J. Watters , M. Chiron . 1 Sanofi R&D, Oncology, Vitry-Sur-Seine, France; 2 Sanofi R&D, Oncology, Cambridge, Usa; 3 Sanofi R&D, Oncology, Vitry-Sur-Seine, France; 4 Oncotest Gmbh, Oncology, Freiburg, Germany Background: Aflibercept (Afl, ziv-aflibercept in the US) is a potent multiple angiogenic factor trap that prevents VEGF-A, VEGF-B, and placental growth factor (PlGF) from activating the native receptors. Based on an OS benefit in the phase 3 VELOUR trial, Afl + FOLFIRI was approved to treat metastatic colorectal cancer (mCRC) following a prior oxaliplatincontaining regimen. In prior preclinical studies, Afl demonstrated superior anti-tumor activity relative to bevacizumab (Bev) in 39/48 CRC patientderived xenografts (PDX). The PDX were profiled for KRAS status and genomic analysis to elucidate mechanisms and potential biomarkers behind the differential activity. Methods: Primary or metastatic CRC tumors were engrafted and passaged subcutaneously into NMRI nude mice (Chiron et al., Mol Cancer Ther, 2014). In 3 PDX models showing some response to Bev, mice were subsequently randomized to either continue treatment with Bev or switched to Afl treatment. Tumors collected 1 day after last treatment were profiled by RNA sequencing. An informatics workflow was devised to associate RNA expression changes to either the human tumors or the mouse stroma, and differentially expressed genes were identified in each of the two treatments (fold change magnitude of 2 by Wilcoxon test and BH corrected P-value <0.05). Profiling for KRAS status and genomic analysis was done by whole exome sequencing and/or Sanger technique. Results: In 48 CRC PDX models tested, the differential activity of Afl and Bev showed no association with KRAS mutation status (Fisher-exact test p-value >0.05): 24 were KRAS mutant and 24 were wild type. In 3 PDX models where treatment was either switched to Afl or maintained with Bev, Afl demonstrated greater anti-tumor activity than Bev (t-test: P < 0.0001, 2 being KRAS mutant and 1 KRAS WT). RNA sequence analysis revealed differential effects between Afl and Bev in both the murine host (643 genes, 374 up-regulated Afl vs. Bev) and human tumors (82 genes, 19 upregulated Afl vs. Bev). A number of angiogenesis-promoting genes were down-regulated by Afl vs. Bev including: VEGF receptor genes (FLT1, FLT4, KDR), Notch pathway genes involved in vessel formation control (Dll4, Notch 3 & 4), the Ephrin family that regulate cell migration (Epha2, Ephb1), and the matrix metalloproteinases (MMP10, 13, 15, 17, 28). Conclusions: The superior anti-tumor activity of Afl vs. Bev in CRC PDX was independent of KRAS status. Gene expression profiling of stroma and tumor genes of CRC PDX tumors showed clearly different modulation patterns of both stroma and tumor between Afl and Bev. The results suggest that increased control of expression of angiogenesis-promoting genes by Afl may be associated with its superior anti-tumor activity relative to Bev in CRC PDX. 292 POSTER (Board P072) Salmonella typhimurium A1-R decoys quiescent cancer cells to cycle rendering them chemosensitive S. Yano1 , Y. Zhang1 , M. Zhao1 , Y. Hiroshima1 , S. Miwa1 , F. Uehara1 , H. Kishimoto2 , H. Tazawa3 , T. Fujiwara2 , R.M. Hoffman4 . 1 AntiCancer Inc., San Diego California, USA; 2 Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences, Department of Gastroenterological Surgery, Okayama, Japan; 3 Okayama University Hospital, Center for Innovative Clinical Medicine, Okayama, Japan; 4 University of California San Diego, Department of Surgery, San Diego California, USA Background: A major problem with solid tumors is that most cancer cells within them are not cycling and therefore resistant to currently-used chemotherapy. Material and Methods: Tumor sphere models as well as tumors in vivo were infected with tumor-targeting Salmonella typhimurium A1-R (A1-R) and the cell cycle phase and drug sensitivity of the cancer cells within the spheres or tumors were determined. Results: Fluorescent ubiquitination-based cell cycle indicator (FUCCI)expressing cancer cells in tumor spheres in serum-free medium were quiescent. After A1-R infection, the cancer cells in the spheres entered S-phase and became sensitive to cisplatinum (CDDP) to which they were resistant before A1-R infection. A1-R infection of FUCCI-expressing subcutaneous tumors also induced them to cycle. The combination of A1-R followed by CDDP reduced tumor size compared with A1-R monotherapy or CDDP alone. Conclusions: This study demonstrates that A1-R decoys quiescent cancer cells to cycle and thereby become sensitive to conventional chemotherapy. 293 POSTER (Board P073) Inhibition of the cell cycle regulated Cdc7 kinase pathway is an efficacious therapeutic approach for hematologic malignancies and solid tumors R. Santos1 , D. Shum2 , D. Carrillo1 , R. Zhang1 , M. Churchill1 , S. Mukherjee1 , R. Brentjens3 , C. Radu2 , T.J. Kelly4 , H. Djaballah2 , M.G. Frattini1 . 1 Columbia University Medical Center, Medicine, New York NY, USA; 2 Memorial Sloan Kettering Cancer Center, Molecular Pharmacology and Chemistry, New York NY, USA; 3 Memorial Sloan Kettering Cancer Center, Medicine, New York NY, USA; 4 Memorial Sloan Kettering Cancer Center, Molecular Biology, New York NY, USA Background: Despite extensive drug discovery efforts, drug-candidate failure and patients relapsing in the clinic remain as persistent problems likely secondary to escape mechanisms focused on the control of both DNA replication and DNA repair pathways. Cdc7 is a cell cycle regulated serine/threonine kinase whose activity is required for the initiation of DNA replication and has also been implicated in the control of the DNA damage response, and therefore linked to the maintenance of genomic integrity. Both Cdc7 and its known substrate, the mini-chromosome maintenance (MCM) complex that functions as the replicative DNA helicase, are overexpressed in the majority of solid tumors, leukemias, and lymphomas making Cdc7 kinase activity a potential therapeutic target in both hematologic malignancies and solid tumors. Materials and Methods: In order to identify a small molecule inhibitor of the Cdc7 kinase, we performed a high throughput screen for inhibitors of Cdc7 kinase activity. Chemo-informatic analysis of the hits revealed enrichment in one chemical cluster made up of several naturally occurring allosteric inhibitory compounds, that we termed MSK-747 and MSK-777. Poster Session – Molecular Targeted Agents I Results: MSK-747 and 777 cytotoxic activities were assessed against panels of cancer cell lines and primary patient samples representing the majority of solid and liquid tumors and demonstrated efficacy, with potencies (EC50) in the low nanomolar range. We have shown that both 747 and 777 are effective against cell lines harboring over-expression of the multidrug resistance (MDR) efflux pump, demonstrating that Cdc7 inhibition can overcome a major mechanism of chemotherapy resistance in human tumor cells. In addition, cell lines and patient samples harboring high-risk structural and molecular mutations and samples from relapsed and/or chemotherapy refractory patients were also found to be susceptible to Cdc7 kinase inhibition. Cell cycle analysis in both cancer cell lines and primary patient samples exposed to the compounds revealed an S phase arrest, cell cycle dependent caspase-3 activation, and apoptotic cell death. In vivo dose-dependent anti-tumor activity of 747 and 777 was shown in mouse models of leukemias (ALL and AML), NSCLC, melanoma, and ovarian carcinoma. In addition, biomarker identification and the mechansim of cancer cell selectivity over normal cells with these compounds will be discussed. In all studies, MSK-777 was found to be more efficacious and therefore was chosen as the lead candidate to continue preclinical and clinical development. Conclusions: Cdc7 kinase inhibition is a novel and efficacious mode of therapy for both hematologic malignancies and solid tumors. MSK-777, a naturally occurring allosteric inhibitor of this kinase, is scheduled to enter Phase I clinical trials in early 2015. 294 POSTER (Board P074) Synthetic lethal screen identifies Aurora A as a selective target in HPV driven cervical cancer B. Gabrielli1 , F. Bokhari2 , M. Ranall2 , A. Stevenson2 , M. Murell3 , M. Kelly3 , S. McKee2 , G. Leggatt2 , T. Gonda4 , N. McMillan3 . 1 University of Queensland, Diamantina Institute for Cancer Immunology and Metabolic Medicine, Brisbane Qld, Australia; 2 University of Queensland, Diamantina Institute, Brisbane Qld, Australia; 3 Griffith University, Griffith Health Institute, Gold Coast Qld, Australia; 4 University of Queensland, School of Pharmacy, Brisbane Qld, Australia HPV has been identified as the definitive agent in cancers of the cervix, penis, vulva, vagina, anus, skin, eye, and head and neck, and is responsible for 5% of the total cancer burden worldwide. HPV oncogenes disable a number of tumour suppressor pathways, including p53 and Rb, contributing to the transformed phenotype. We have performed an siRNA screen using the kinome (779 genes) library to identify genes that when depleted are synthetically lethal with HPV transformation. The primary and validations screens have confirmed Aurora A kinase (AURKA) as a potential synthetic lethal target selective for HPV transformed cells. In vitro research using the investigational selective small molecule AURKA inhibitor alisertib found alisertib to be significantly more potent towards the HPV transformed cells, and selectively promoted apoptosis in the HPV cancers. The drug was shown to target the HPVE7 oncogene, the level of expression of this oncogene possibly influencing sensitivity. Apoptosis was sensitive to Mcl-1 but not Bcl-2 over expression, indicating that the mechanism is associated with the proteolytic destruction of Mcl-1 in the extended mitosis in the alisertib treated HPV cancer lines. Xenograft experiments with cervical cancer cell lines showed alisertib inhibited growth of HPV and non-HPV xenografts during treatment. The non-HPV cancer growth was delayed, but in two separate HPV cancers models, regression and no resumption of growth was detected at even 50 days post-treatment. A second transgenic model of premalignant disease driven solely by HPVE7 similarly demonstrated sensitivity to drug treatment. These findings provide preclinical evidnce that alisertib warrants evaluation as a potential targeted compound with activity in HPV-transformed cervical cancer and premalignant disease that may have application to other HPV driven cancers. 295 POSTER (Board P075) Combining forces: Study of the cytotoxic effect of the MDM2 inhibitor Nutlin-3 in combination with CDDP in non-small cell lung cancer cell lines C. Deben1 , C. Rolfo2 , V. Deschoolmeester1 , A. Wouters1 , M. Peeters3 , I. Gil-Bazo4 , F. Lardon1 , P. Pauwels5 . 1 University Antwerp, Center for Oncological Research, Antwerp, Belgium; 2 Antwerp University Hospital, Phase I − Early Clinical Trials Unit Oncology Department, Antwerp, Belgium; 3 Antwerp University Hospital, Oncology Department, Antwerp, Belgium; 4 Clı́nica Universidad de Navarra, Oncology Department, Pamplona, Spain; 5 Antwerp University Hospital, Molecular Pathology Unit Department of Pathology, Antwerp, Belgium Background: The p53/MDM2 interaction has been a well-studied target for new drug design leading to the development of, among others, the small Thursday 20 November 2014 97 molecule inhibitor Nutlin-3. Clinical phase 1 and 2 studies show promising results for drugs of the Nutlin-3 family administrated as monotherapy in several tumor types. Furthermore, combining targeted therapies with conventional treatments has received much attention in the past few years. Materials and Methods: Therefore, we combined Nutlin-3 with the chemotherapeutic drug CDDP, a known activator of the p53 pathway, in a series of non-small cell lung cancer cell lines with different p53 background. We focused on the importance of the dosing regime and the role of wild type p53. Thus we used the commonly used NSCLC cell line A549 as wild type p53 cell line and used a p53 shRNA lentiviral vector to obtain a p53 deficient sub cell line. In addition we used CRL-5908, harboring a p53 mutant genotype (R273H). Cells were treated with both CDDP and Nutlin-3 or CDDP followed by Nutlin-3 for 24 hours. The SRB-assay was used to determine the cytotoxic effect of both mono- and combination therapies after which possible synergism was calculated using the Chou– Talalay method, both under normoxic and hypoxic conditions. In addition we determined the p53 protein levels as well as the mRNA and protein levels of its main transcription targets MDM2, p21, PUMA and BAX. The induction of apoptosis and cell cycle arrest were determined by flowcytometric analysis. Results: The strongest synergistic effect was observed in the p53 wild type cell lines when treatment with CDDP (IC20 : 2mM) was followed by Nutlin-3 treatment under normoxic (CI: 0.486±0.138, 5mM Nutlin-3), and hypoxic conditions (CI: 0.625±0.082, 5mM Nutlin-3). However, when administrated simultaneously, this effect was only present at very low concentration of CDDP and induced an average additive effect under normoxic (CI: 0.990±0.082, 5mM Nutlin-3) and hypoxic conditions (CI: 1.068±0.361, 5mM Nutlin-3). After sequential treatment, the mRNA and protein levels of p53’s transcription targets MDM2, p21, PUMA, and BAX were markedly increased compared to CDDP monotherapy, as for the number of apoptotic cells (27.37±7.97% Ann V positive cells vs. 9.36±2.93%) and cells in G2/M phase arrest (66.67±0.64% vs. 18.15±7.89%). These findings were not observed in the p53 mutant and deficient cell lines, confirming the role of p53 in this synergistic effect. Conclusions: Our results point towards a promising combination therapy, being the induction of DNA damage by CDDP, followed by an increase in p53 levels by Nutlin-3, leading to a synergistic cytotoxic effect in a wild type p53 NSCLC cell line. Translationally, a lower dose of CDDP could be used in combination with Nutlin-3, potentially reducing side effects for NSCLC patients. 296 POSTER (Board P076) A first-in-Asian phase I dose escalation study to evaluate the safety and pharmacokinetics of VS-6063 (defactinib), a focal adhesion kinase inhibitor in subjects with non-hematologic malignancies T. Shimizu1 , H. Aida2 , J. Horobin3 , M. Keegan3 , M. Padval3 , A. Poli3 , C. Hashii2 , K. Nakagawa1 . 1 Kinki University Faculty of Medicine, Phase I Unit at Department of Medical Oncology, Osaka, Japan; 2 Japan Clinical Research Operations (JCRO), Tokyo, Japan; 3 Verastem Inc., Cambridge MA, USA Background: Defactinib (VS-6063) has been shown to be a potent, reversible inhibitor of focal adhesion kinase (FAK) and proline-rich tyrosinekinase-2. Blockade of FAK reduces tumor growth and metastasis through inhibition of tumor cell survival, proliferation and invasion as well as tumor angiogenesis. Treatment with FAK inhibitors has been demonstrated to reduce the proportion of cancer stem cells (CSCs) in a dose dependent manner while chemotherapy standard of care agents (SOC) enrich for CSCs. The ability of CSCs to survive exposure to chemotherapy but remain susceptible to novel drugs suggests a unique therapeutic approach whereby SOC may be combined or sequenced with targeted drugs to kill surviving CSCs, prevent tumor recurrence and metastasis. This is a single-center, phase 1, open-label, dose-escalation study to investigate the safety and pharmacokinetics (PK) of defactinib in first-in-Asian (Japanese) subjects. Methods: Subjects with no further standard of care options and a life expectancy of 3 months with advanced non-hematologic malignancies were enrolled. Defactinib was administered continuously at a starting dose of 200 mg BID, escalated to 400 mg BID and then to 600 mg BID. Patients continued treatment with defactinib until disease progression. Pharmacokinetics were collected on Day 1 and 15 during cycle 1. Results: Nine subjects were enrolled (n = 3 each; 200, 400 and 600 mg cohorts): median age was 60 years (38−75); ECOG PS was 0 or 1. Defactinib was well tolerated and no dose limiting toxicities were observed at any of the 200 mg, 400 mg or 600 mg dose levels. Common toxicities included: Fatigue, headache, increased bilirubin and diarrhea. PK analyses confirmed the exposure at the recommended phase 2 dose (RP2D) of 400 mg BID was comparable to that previously reported in non-Japanese subjects. Durable stable disease (SD) 24 weeks was confirmed in two patients (malignant mesothelioma and colon cancer) with improvement of clinical symptoms. 98 Thursday 20 November 2014 Conclusions: Overall PK and AE profiles of Japanese subjects are consistent with those previously reported in non-Japanese subjects. Data from this study supports the entry of Japanese subjects at the RP2D to the ongoing multinational trial (COMMAND) of defactinib in malignant mesothelioma patients. Clinical Trial Information: NCT01943292 297 POSTER (Board P077) Genetic and pharmacologic inhibition of EPHA2 promotes apoptosis in NSCLC J. Chen1 , K. Amato2 , S. Wang1 , V. Youngblood2 , D. Brantley-Sieders1 , R. Cook2 , L. Tan3 , N. Gray3 . 1 Vanderbilt University Medical Center, Medicine, Nashville TN, USA; 2 Vanderbilt University Medical Center, Cancer Biology, Nashville TN, USA; 3 Dana Farber Cancer Institute, Biochemistry & Molecular Pharmacology, Boston MA, USA Background: Genome-wide analyses determined previously that the receptor tyrosine kinase (RTK) EPHA2 is commonly overexpressed in nonsmall cell lung cancers (NSCLCs). EPHA2 overexpression is associated with poor clinical outcomes; therefore, EPHA2 may represent a promising therapeutic target for patients with NSCLC. Material and Methods: The EphA2 knockout mouse model was used to determine lung cancer progression in Kras-mutant knockin mice. RNAimediated depletion or pharmacologic inhibition of EPHA2 was employed to determine cell viability and signaling in human lung cancer cell lines in vitro and tumor growth in vivo. Tumor cell proliferation was measured by BrdU incorporation ELISA or PCNA immunohistochemistry and apoptosis by TUNEL assay or Cell Death ELISA. We assessed tumor growth in vivo using H358 human lung cancer cells xenografts in mice. Results: Targeted disruption of EphA2 in a murine model of aggressive Kras-mutant NSCLC impairs tumor growth. Knockdown of EPHA2 in human NSCLC cell lines reduced cell growth and viability, confirming the epithelial cell autonomous requirements for EPHA2 in NSCLCs. Targeting EPHA2 in NSCLCs decreased S6K1-mediated phosphorylation of cell death agonist BAD and induced apoptosis. Furthermore, an ATP-competitive EPHA2 RTK inhibitor, ALW-II-41−27, reduced the number of viable NSCLC cells in a time-dependent and dose-dependent manner in vitro and induced tumor regression in human NSCLC xenografts in vivo. Conclusion: Collectively, these data demonstrate a role for EPHA2 in the maintenance and progression of NSCLCs and provide evidence that ALWII-41−27 effectively inhibits EPHA2-mediated tumor growth in preclinical models of NSCLC. 298 POSTER (Board P078) Met degradation by SAIT301, a Met monoclonal antibody, reduces the invasion and migration of nasopharyngeal cancer cells via inhibition of EGR-1 expression C. Kim1 , B.S. Lee1 , K.A. Kim2 , Y.J. Song2 , K.H. Cheong2 . 1 Ajou Univ. Hospital, Otolaryngology, Suwon, South Korea; 2 Samsung Advanced Institute of Technology (SAIT)/Samsung Electronics Co., Bio Therapeutics Lab, Suwon, South Korea Nasopharyngeal carcinoma (NPC) is a common malignant tumor with high invasive and metastatic potential. The hepatocyte growth factor (HGF)-Met signaling pathway has a critical role in mediating the invasive growth of many different types of cancer, including head and neck squamous cell carcinoma. HGF also stimulates NPC cell growth and invasion in the cell line model. In this study, we determined the inhibitory effect of Met, using a Mettargeting monoclonal antibody (SAIT301), on the invasive and growth potential of NPC cell lines. Met inhibition by SAIT301 resulted in highly significant inhibition of cell migration and invasion in both the HONE1 and HNE1 cell lines. In addition, we also found that co-treatment of SAIT301 and HGF decreased the anchorage-independent growth induced by HGF in HNE1 cell lines. After SAIT301 treatment, Met, together with its downstream signaling proteins, showed downregulation of p-Met and p-ERK, but not p-AKT, in both HONE1 and HNE1 cell lines. Interestingly, we found that HGF treatment of NPC cell lines induced early growth response protein (EGR-1) expression, which is involved in cell migration and invasion. In addition, co-treatment with SAIT301 and HGF inhibited the HGF-induced expression of EGR-1. Next, knockdown of EGR-1 using small-interfering RNA inhibited HGF-induced cell invasion in NPC cell lines, suggesting that the expression level of EGR-1 is important in HGF-induced cell invasion of NPC cells. Therefore, the results support that SAIT301 inhibited Met activation as well as the downstream EGR-1 expression and could have therapeutic potential in NPC. Taken together, we suggest that Met is an anticancer therapeutic target for NPC that warrants further investigation and clinical trials and SAIT301 may be a promising tool for NPC therapy. Poster Session – Molecular Targeted Agents I 299 Tyk2-src dependence of kidney cancer POSTER (Board P079) B. Krishnan1 , S.C. Hanna2 , H.L. Wilson1 , S.T. Bailey1 , J.S. Damrauer1 , T. Simamura3 , R.L. Levine4 , K.K. Wong5 , G.L. Johnson2 , W.Y. Kim1 . 1 University of North Carolina Chapel Hill NC USA, Lineberger Comprehensive Cancer Center, Chapel Hill NC, USA; 2 University of North Carolina Chapel Hill NC USA, Department of Pharmacology, Chapel Hill NC, USA; 3 Loyola University Chicago, Oncology Institute Department of Molecular Pharmacology and Therapeutics, Maywood IL, USA; 4 Memorial Sloan-Kettering Cancer Center, Human Oncology and Pathogenesis Program Leukemia Service Department of Medicine, New York NY, USA; 5 Dana-Farber/Harvard Cancer Center, Department of Medicine Harvard Medical School Department of Medical Oncology and Lowe Center for Thoracic Oncology, Boston MA, USA Renal cell carcinoma (RCC) accounts for 209,000 new cases and 102,000 deaths worldwide each year. Cytotoxic chemotherapy and radiotherapy are largely ineffective, especially for metastatic disease, where the 5-year survival is only 10%. This represents an important need to develop better therapies against advanced RCC. Inhibitors of the vascular endothelial growth factor receptor (VEGFR) tyrosine kinase and the mammalian target of rapamycin (mTOR) delay the progression of advanced renal tumors. Given these therapeutic successes and that targeting kinase signaling cascades in cancer remains a promising avenue for drug development, we performed a high-throughput siRNA screen of the kinome to identify novel kinase targets for therapy. RNAi of the Janus kinase (JAK) family member tyrosine kinase 2 (TYK2) was highly lethal to RCC cells. Both shRNA as well as pharmacologic TYK2 inhibition were effective in decreasing in vitro and in vivo RCC tumor growth. Additionally RCC tumors were significantly enriched for the GNF2_TYK2 genes compared to adjacent normal kidney in 2 independent datasets (TCGA & GSE33093), also TYK2 is activated in a subset of RCC tumors; this increased activation correlates with poor overall survival of patients (TCGA). Moreover, we noted that mTORC1 inhibition resulted in IL6 mediated induction of pTYK2 and that dual inhibition of mTORC1 and TYK2 significantly reduced RCC cell growth over either alone, suggesting that TYK2 can mediate mTOR inhibitor resistance. We looked to further elucidate the effects of TYK2 knockdown on the reprogramming of RCC kinome. To this end, the phosphorylation status of 43 phospho-kinases was simultaneously assessed by phosphokinase arrays in RCC cells stably expressing shRNA’s to NS or TYK2. Of the probed phospho kinases, 4 of the 8 SRC family kinases (SFK) were significantly decreased relative to shNS. Furthermore treatment with rapamycin induced SFK activation as did knock-down of raptor. Given the lack of a clinically available selective TYK2 inhibitor, we explored the effect of combined mTOR and SRC inhibition in vivo; SRC + mTOR inhibition significantly decreased tumor growth over single agent treatment. In summary, our studies provide evidence that TYK2 is activated in RCC, demonstrate that TYK2 signals to regulate pSFK, and show that the TYK2−SRC axis is upregulated in the face of mTOR inhibition. In aggregate, we have uncovered a TYK2 and SRC dependence of RCC with important implications for therapy. 300 POSTER (Board P080) Preclinical pharmacologic characterization of GSK2849330, a ® monoclonal AccretaMab antibody with optimized ADCC and CDC activity directed against HER3 N. Clarke1 , C. Hopson2 , A. Hahn2 , K. Sully3 , F. Germaschewski3 , J. Yates1 , C. Akinseye1 , B. Mangatt2 , Z. Jonak4 , C. Matheny4 . 1 GlaxoSmithKline, Biopharm Discovery, Stevenage Herts, United Kingdom; 2 GlaxoSmithKline, Oncology R&D, Collegeville, USA; 3 GlaxoSmithKline, Biomarker Discovery, Stevenage Herts, United Kingdom; 4 GlaxoSmithKline, Biopharm R&D, Upper Merion PA, USA Background: HER3 is expressed in a broad range of solid tumors where its signaling is important in tumorigenesis and drug resistance. GSK2849330 is an IgG1/Ig3 chimeric, glycoengineered humanized monoclonal antibody directed against HER3 with enhanced potency to mediate antibodydependent cell cytotoxicity (ADCC) and complement dependent cytoxicity (CDC), resulting in three potential modes of anti-tumor activity. Methods: Various in vitro and in vivo studies were conducted in tumor cell lines and tumor xenograft models to characterize GSK2849330 pharmacology. Results: GSK2849330 selectively bound HER3 at extracellular Domain III with ~2 nM binding affinity, blocked ligand (heregulin) binding, receptor dimerization and activation. In tumor cell lines, GSK2849330 antagonized heregulin-induced phosphorylation of the HER3 receptor and its downstream effector, AKT, and inhibited heregulin-induced proliferation. Poster Session – Molecular Targeted Agents I GSK2849330 dose-dependently inhibited tumor growth in a variety of mouse xenograft models. Compared with the non-ADCC/CDC enhanced antibody, GSK2849330 had a ~17-fold greater binding affinity to human FcgRIIIA (initiation of ADCC) and to human complement protein C1q (initiation of CDC). In ADCC assays using human leukocytes as effector cells and various tumor target cells, GSK2849330 was up to two orders of magnitude more potent than the WT antibody. GSK2849330 caused complement-mediated lysis of HEK293 cells expressing HER3, which was proportional to HER3 protein expression on the cell surface. Conclusions: GSK2849330 inhibits HER3 signal transduction in vi