The Delaware Valley
DRUG METABOLISM DISCUSSION GROUP
On
Tuesday, March 10, 2015
At the
Sheraton Bucks County Hotel, Langhorne, PA
Presents
A Symposium on:
Humanized Animal Models for DMPK
AGENDA
8:00 – 8:45 am
Registration and Continental Breakfast
8:45 – 8:50
Introduction
8:50 – 9:30 am
A Comparison Between Genetically and Chimeric Liver
Humanized Mouse Models for Studies in Drug Metabolism
and Toxicity
Nico Scheer, PhD
9:30 – 10:10 am
Evaluation of OATP Knockout and Humanized Animal
Models to Study OATP-mediated Drug Disposition
Xiaoyan Chu, PhD
Pharmacokinetics, Pharmacodynamics & Drug Metabolism
Merck & Co. Inc.
10:10 – 10:30 am
Coffee break
10:30 – 11:10 am
In Vivo Models to Bridge the Translational Gaps in
Transporter-Mediated PK and DDIs
Maciej J. Zamek-Gliszczynski, PhD
Drug Metabolism and Pharmacokinetics
GlaxoSmithKline plc
11:10 – 11:50 am
Genetically Engineered Mouse Models in Preclinical Studies of
Drug Metabolism and Toxicity
Xiaochao Ma, PhD
Associate Professor, Department of Pharmaceutical Sciences
University of Pittsburgh School of Pharmacy
11:50 - 1:10 pm
Lunch
1:10 – 1:50 pm
Genetically Engineered Rat Models in Preclinical Research of
Drug Metabolism and Toxicity
Edward Weinstein, PhD
SAGE Research Labs
1:50 – 2:30 pm
Humanized Mice (FcRn-tg, FcγR-hu) for Investigating
Antibody PK and Fc Functions
Susan Tam, MSc
Principal Scientist, Fc Engineering-Structural Biology Group
Biologics Research, Janssen Research & Development
2:30 – 2:50 pm
Break
2:50 – 3:30 pm
Liver Humanized Mice – Models for Metabolism and
Toxicology
Lisa Wilson, BS
Senior Scientist
Yecuris Corporation
3:30 – 4:00 pm
Round Table Discussion
Nico Scheer, PhD, received his PhD in Developmental Biology from University of
Cologne, Germany. Until recently he was Head of the tADMET™ portfolio and Director
of Business Development at Taconic Biosciences, where he established and managed a
toolbox of translational mouse models and in vitro tools to better predict clinical
outcomes in pharmacokinetics, drug-drug interaction and drug-induced toxicity. Nico
now works as an independent consultant and he has published several papers in peerreviewed scientific journals in the field.
Abstract: A Comparison Between Genetically and Chimeric Liver Humanized
Mouse Models for Studies in Drug Metabolism and Toxicity
Genetically humanized mice for proteins involved in drug metabolism and toxicity and
mice engrafted with human hepatocytes are emerging and promising in vivo models for
an improved prediction of the pharmacokinetic, drug-drug interaction and safety
characteristics of compounds in humans. Their specific advantages and disadvantages
should be carefully considered when using these models for studies in drug discovery and
development. This talk gives an overview on the corresponding genetically and chimeric
liver humanized mouse models described to date and it provides examples for their utility
in drug metabolism and toxicity studies. It compares the strengths and weaknesses of the
two different approaches, provides guidance for the selection of the appropriate model for
various applications and discusses future trends and perspectives.
Xiaoyan Chu, PhD, is a Senior Principal Scientist in the Department of
Pharmacokinetics, Pharmacodynamics & Drug Metabolism (PPDM), Merck & Co. Inc.,
Rahway, NJ. She received her PhD from the Department of Molecular Pharmacokinetics,
Graduate School of Pharmaceutical Sciences, University of Tokyo, Japan. After
completing her post-doctoral research at the Department of Pharmaceutical Sciences,
College of Pharmacy, University of Michigan, she joined the Department of PPDM at
Merck & Co. Currently, her main responsibilities are to develop and lead transporter
strategies to support Merck discovery and development programs, and to evaluate and
establish new technologies to study the role of drug transporters in drug disposition and
drug-drug interactions. She has over 40 original publications in the area of membrane
transporters and pharmacokinetics, and is the invited speaker, organizer and steering
committee member of scientific meetings/organizations.
Abstract: Evaluation of OATP Knockout and Humanized Animal Models to Study
OATP-mediated Drug Disposition
OATP1B are major human hepatic uptake transporters that play important roles in the
disposition and elimination of many clinically used drugs. Currently, predicting the
impact of OATP1B on pharmacokinetics and DDI based on in vitro data alone is often
limited by lack of confidence in in vitro to in vivo extrapolation and the multiplicity of
transporters involved in the elimination of OATP1B substrates. Preclinical animal models
therefore could be useful to bridge such translational gaps. However, overlapping
substrate specificity between OATP/Oatp isoforms makes it difficult to understand the
role of Oatps in single gene knockout models. Furthermore, there are no direct orthologs
between rodent and human OATPs/Oatps. To overcome these limitations, Oatp1a/1b
knockout and OATP1B1 and -1B3 humanized animal models have been established. In
this presentation, the characterization of Oatp1a/1b knockout and humanized OATP1B
animal models will be presented and the rational application and limitations of animal
models to study OATP-mediated pharmacokinetics and DDIs will be discussed.
Maciej Zamek-Gliszczynski, PhD, has a decade of industry (Eli Lilly and GSK)
experience in supporting DMPK and PK/PD aspects of oncology, endocrine, and
infectious disease programs at all stages between discovery and late-stage clinical
development. He is currently leading the transporter strategy for support of the GSK
portfolio. His research is focused on clinical PK/PD and DDI implications of drug and
metabolite transport. Dr. Zamek-Gliszczynski is the author of over 40 manuscripts
(>2,300 cites, h-index = 22) and over 60 presentations on this subject. He serves on the
editorial board of Pharmaceutical Research, International Transport Consortium (ITC)
steering committee, American Association of Pharmaceutical Scientists (AAPS)
PK/PD/Drug Metabolism (PPDM) section executive council (vice-chair, 2015; chair,
2017), and he was the past chair of AAPS Drug Transport Focus Group. He was a coorganizer of the past five AAPS Workshops on Drug Transporters in ADME and two ITC
Workshops. Dr. Zamek-Gliszczynski is also an adjunct professor at the University of
North Carolina, Eshelman School of Pharmacy, where he lectures in the graduate-level
PK/PD course and serves as external advisor on dissertation committees.
Abstract: In Vivo Models to Bridge the Translational Gaps in TransporterMediated PK and DDIs
In vivo transporter models have proven utility in bridging the in vitro-to-clinical
translational gap by contextualizing in vitro transporter substrate interactions in terms of
in vivo pharmacokinetics. This presentation will focus on the fraction excreted (Fe) data
analysis approach. Four specific aspects of Fe-based analysis in transporterknockout/humanized models will be covered:
1) Metabolite transport as experimental support for Fe approach
2) Fe description of hepatic OATP uptake and Fe-based estimation of OATP1B1
contribution to hepatic uptake
3) Fe description of efflux-limited CNS distribution and explanation why is
clinical modulation of BBB efflux unlikely?
4) Fe sheds additional insight into metformin PK/PD and DDIs
Xiaochao Ma, PhD, is an Associate Professor in the Department of Pharmaceutical
Sciences, University of Pittsburgh School of Pharmacy. He obtained his PhD in
Pharmacology and Toxicology from Shanghai Institute of Materia Medica, Chinese
Academy of Sciences in 2003. From there, he went to NIH and completed his
postdoctoral training in Dr. Frank J. Gonzalez’ laboratory in 2008. Afterward, he worked
as an Assistant Professor at University of Kansas Medical Center, until he joined the
faculty at the University of Pittsburgh in 2013. Dr. Ma’s research focuses on the role of
nuclear receptors in drug-drug interactions and adverse drug reactions. Dr. Ma uses
genetically engineered mouse models and metabolomics in his research. He has published
over 40 peer-reviewed articles. Research in Dr. Ma’s laboratory is supported by NIH.
Abstract: Genetically Engineered Mouse Models in Preclinical Studies of Drug
Metabolism and Toxicity
Genetically-engineered mouse models, including gene knockout and transgene models,
have been widely used for preclinical studies on ADMET. A gene knockout mouse model
can serve as an ideal tool to investigate the role of a specific gene in ADMET of a drug
candidate. In addition, humanized mouse models can be generated on the background of
gene knockout mice, which can be used to overcome the species differences in ADMET.
The current presentation will highlight mouse models of the pregnane X receptor and
cytochromes P450 3A. The limitations of mouse models for preclinical studies will also
be discussed.
Edward Weinstein, PhD, is the Senior Vice President of Horizon Discovery where he
oversees all in vitro and in vivo service offerings. He was a cofounder and President of
SAGE Labs, where he managed a state-of-the-art facility dedicated to creation of
genetically engineered mouse, rat and rabbit models designed for research use. Prior to
this position, Edward served as Manager of Operations for Functional Genomics in the
Research Biotechnology business unit of Sigma-Aldrich. Before joining Sigma, he
performed basic research within the pharmaceutical industry. Edward had responsibility
for the Molecular Profiling portfolio within Merck’s oncology franchise. His work there
centered on discovery of new therapeutic targets as well as biomarkers for drug safety
and efficacy. At Pfizer, Edward worked on development of several therapeutic targets,
developing mouse models for breast and colon carcinoma. Edward received his Masters
of Medical Science from Harvard Medical School and his PhD in Genetics from Harvard
University where his research focused on mouse models of mammary gland carcinoma.
Throughout his career Edward has focused on the application of animal models for the
elucidation of mechanisms of complex disease processes.
Abstract: Genetically Engineered Rat Models in Preclinical Research of Drug
Metabolism and Toxicity
The rat, rabbit, zebrafish, and pig have long been important experimental models in
multiple fields of study. Unlike the mouse, efficient gene targeting in these species has
remained a near impossibility with researchers forced to rely on random methods of
mutagenesis. Using the zinc finger nuclease and the CRISPR/Cas9 technologies we have
circumvented the need for embryonic stem cells and directly targeted genes in the
fertilized embryo. Data will be presented on the creation and characterization of
genetically engineered rats where key genes have been removed from the genome. Data
will be shown for a panel of drug transporter knockout rats, with deletions in Mdr1a,
BCRP and Mrp2. Characterization will also be provided for “knock-in” rat models where
the endogenous gene for PXR, CAR and AHR have been deleted and replaced with the
human orthologs. These humanized models hold promise for more predictive drug
metabolism and toxicity research.
Susan Tam, MSc, is a Principal Scientist in the Fc Engineering-Structural Biology
Group within Biologics Research at Janssen R&D at Spring House, PA. She received her
BSc at UC Berkeley and MSc at UC Riverside & UCLA in Cell & Molecular Biology.
She worked for academics in plant genetics, and then for Centocor in antibody research.
Centocor was eventually acquired by Johnson & Johnson, so currently, Susan has about
30 years experience at her company. Her main role is doing exploratory research with
novel Fc molecules for therapeutics. She utilizes a number of rodent models for her
studies.
Abstract: Humanized Mice (FcRn-tg, FcγR-hu) for Investigating Antibody PK and
Fc Functions
Humanized mice are important for characterization of antibodies for therapeutic drugs.
Three humanized mouse models will be described along with examples. The role of the
neonatal receptor (FcRn) in prolonging the half-lives of IgG antibodies in vivo is well
known. Human FcRn-transgenic mice (licensed from Jackson Labs) were used to
evaluate antibody PK, and based on many studies, hemizygous Tg32 mice appeared to
offer potential as a predictive rodent model for human PK. FcγR-hu mice that lack mouse
FcγRs and are transgenic for five human FcγRs: CD16a, CD16b, CD32a, CD32b and
CD64 (licensed from Rockefeller Univ.) were used to evaluate T cell activation and B
cell depletion by a panel of Fc variants. The FcγR-hu mice could be used also to evaluate
antibody efficacy in a syngeneic tumor model involving mouse (B16F10) melanomas.
NSGS mice (immunodeficient NSG mice transgenic for 3 human cytokines that support
myeloid cell development from Jackson Labs) are being used in pilot studies for
evaluation of neutrophil-mediated cytotoxicity. While in various stages of validation,
these models appear to be highly relevant tools for evaluating Fc-containing molecules.
Lisa Wilson, BS, received her BS in Microbiology from Oregon State University and has
over thirty years of research experience in molecular and cell biology. She has a broad
range of expertise including recombinant virus technology, cell and molecular biology,
primary and stem cell technologies, protein production and purification, antibody
development, and chimeric animal technologies. Ms. Wilson is well published in the
areas of Insulin-like growth factors, Akt, and the use of siRNA in maturation processes.
She has presented as an academic researcher at numerous international meetings
spanning broad subject matter, and presents globally on the novel use of chimeric
technologies in primary cell molecular biology applications. Ms. Wilson has held
industry appointments in Research and Development and currently holds the position of
Senior Scientist at Yecuris Corporation where she serves as Study Director and oversees
management of Research & Development programs.
Abstract: Liver Humanized Mice – Models for Metabolism and Toxicology
The liver is the site of many metabolic processes, including the metabolism of
xenobiotics. Drug metabolism is phenotypically specific and can vary significantly
between individuals of the same species. To date no reliable in vivo system capable of
predicting the human-specific metabolic conversion of candidate small molecules exists.
Rodents and other animal models often fail to provide information relevant to the human
clinical outcome. Therefore, many promising pharmaceutical compounds fail only when
they are tested in human subjects in phase I clinical trials. Yecuris Corporation has
developed an in vivo genetic selection system, the FRG® KO mouse that permits
extensive humanization of murine liver by transplanted human hepatocytes. The ability to
routinely achieve >90% human hepatocyte replacement in the murine liver yields a model
where human specific metabolism may be observed from a systems biology perspective.
In addition, Yecuris has generated the FRG® KO/NOD strain to allow for the production
of a dual humanized mouse model by transplantation with human hematopoietic stem
cells along with the humanized liver. Many pathophysiologic processes involve both the
liver and the hematolymphoid system. Examples include hepatitis C/HIV co-infection,
immune mediated liver diseases, liver injuries with inflammation such as steatohepatitis
and alcoholic liver disease, idiosyncratic drug responses, development of biologics,
among many other applications. The dual humanized FRG® KO/NOD mouse will
provide an essential tool for the study and treatment of these diseases.
Regulatory agencies in the US, Europe and Japan demand extensive in vitro testing of all
potential pharmaceuticals on cultured human hepatocytes in preclinical drug
development. Hepatocytes are used for multiple important endpoints of clinical
relevance. The availability of high quality human hepatocytes for these mandated studies
is severely limited and is likely to become further restricted in the future. The FRG® KO
technologies provide a potential solution to the current supply constraint by generating
large amounts of high quality human hepatocytes in vivo. This technology promises to
permanently overcome the supply constraint in high quality, tissue culture grade human
hepatocytes.
In summary, the humanized FRG® KO model will provide an in vivo platform for the
determination of human specific metabolism, exploration of safety assessment,
examination of drug-drug interactions and other parameters needed in validating new
pharmaceutical compounds. In addition, the model provides a biological system for the
expansion of high quality human hepatocytes that can be serially propagated, thereby
alleviating the use of limited and often inferior hepatocytes for in vitro testing.