History
Milestones in the Discovery of HER2 Proto-Oncogene
and Trastuzumab (Herceptin™)
George L. Kumar *, PhD and
Sunil S. Badve °, MD, FRCPath
George L. Kumar, PhD
Sunil S. Badve, MD, FRCPath
Scientific Communications Manager
Global Marketing Communications
Dako North America, Inc.
Carpinteria, CA 93013 U.S.A.
An expert in the field of breast pathology, Dr. Badve is an Associate
Professor at the Department of Pathology and Laboratory Medicine
with additional appointment to the Department of Internal Medicine. He
serves as the Director of Translational Genomics Core at the Indiana
University Cancer Center.
Education
Doctorate in Natural Sciences: Max Planck Institute for Behavioral
Physiology- 82305 Starnberg-Seewiesen, Germany
He received his MBBS degree from the Bombay University in 1984 and
completed a residency in Pathology at the Grant Medical College & Sir
J.J. Group of Hospitals with a year of specialized training at the Tata
Memorial Hospital for Cancer. He served as a Lecturer at the Grant
Medical College for three years and was in the UK for five years where
he received further training at the St. George’s Medical School and
Royal Marsden Hospital. Following arrival in the USA, he completed
a residency in Anatomic and Clinical Pathology at the Albert Einstein
School of Medicine, New York. After a year of fellowship in Oncological
Pathology at Yale under Professor Darryl Carter, he was recruited to the
faculty of the Northwestern University in 1999. He has been part of the
faculty at Indiana University since 2002.
Ludwig-Maximilians-University of Munich, Germany
Post-Doctoral Work
The European Molecular Biology Laboratory
Cell Biology Programme, Heidelberg, Germany
University of Wisconsin Medical School- Department of Anatomy/
Laboratory of Molecular Biology. Madison, WI, U.S.A.
College of Engineering. Electrical and Computer Engineering.
University of Wisconsin. Madison, WI, U.S.A.
Area of Expertise
Neurobiology, Live-Cell Imaging, Confocal Fluorescence
Microscopy and High Content Screening
Experience
Sales Manager: India. Applied Precision, Inc. Issaquah, WA, U.S.A.
Senior Scientist: Applied Precision, Inc. Issaquah, WA, U.S.A.
Applications Scientist: Perkin Elmer Life and
Analytical Sciences, Waltham, MA, U.S.A.
Dr. Badve’s main research and clinical expertise is within the field
of breast cancer. He is the main Breast Pathologist for the Eastern
Co-operative Oncology Group, where he serves as the Pathology Chair
for several breast cancer clinical trials, including the TAILORx clinical
trial based on the oncotypeDx assay. He also serves on the NIHsponsored FFPE Working Group and Datamart Program. He has been a
Co-Investigator on several NIH, DOD and foundation grants which have
resulted in the publication of over 90 peer-reviewed scientific articles in
addition to invited reviews and book chapters.
Dr. Badve is a regular speaker at national and international pathology
meetings and has conducted short courses on breast pathology for
CAP and USCAP.
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Connection 2008 | 9
B
reast cancer is the most common malignancy in women, accounting
for 32% of all female cancers. The exact causes of breast cancer
are largely unknown, but both environmental and genetic factors are
involved. Specific mutations in genes called HER2, BRCA1, BRCA2,
and p53 have been linked to breast cancer, and surgery, radiation,
chemotherapy and biological therapy are common procedures for
treating this disease. Because HER2 protein is overproduced in 15-20%
of all breast cancer cases, it has become a therapeutic target for drug
developers. The monoclonal antibody HerceptinTM (or trastuzumab),
which can bind to and inactivate the HER2 receptor, has become one
of the common therapeutic agents used in breast cancer treatment.
Other types of anti-HER2-targeted therapies include lapatinib (or Tykerb
– a dual EGFR/HER2 small molecular tyrosine kinase inhibitor) - and
pertuzumab (also called 2C4 - an antibody that binds to the HER2
receptor at a different location than trastuzumab) (1).
Breast cancer became the first type of solid-tumor cancer to be
successfully treated with molecular-targeting therapy. Since its approval
in 1998, Herceptin™ in breast cancer has become the poster child for
targeted therapeutics. Here, we present a brief history of the discovery
of the HER2 gene and the drug to illustrate the long and often circuitous
route it takes from the discovery of a target to the development of a
successful therapeutic drug.
* Managing Editor, Connection
Dako North America, Inc.
6392 Via Real
Carpinteria, CA 93013
E-mail: george.kumar@dako.com
° Associate Professor
Indiana University School of Medicine
Clarian Pathology Laboratory
350 West 11th Street, Room 4050
Indianapolis, IN 46202-4108
E-mail: sbadve@iupui.edu
Acknowledgements
We wish to thank Prof. Mark I. Greene, MD, PhD, FRCPath;
John Eckman, Professor of Pathology and Laboratory
Medicine, University of Pennsylvania School of Medicine,
Philadelphia, PA, for providing us the historical guidance
and key references; and Dr. Jan Trøst Jørgensen, Senior
Principal Scientist, Clinical Research, Dako Denmark A/S,
for recommending to us the book “Her-2: The Making of
HerceptinTM - A Revolutionary Treatment for Breast Cancer by
Robert Bazell, Random House, New York.
The following table summarizes the milestones in these discoveries
starting from 1974 to the present day.
1978
Epidermal growth factor receptor (EGFR, ErbB*-1, HER1) - the first receptor tyrosine kinase is discovered by Stanley Cohen
and co-workers at Vanderbilt University, USA (2).
*ErbB stands for its origin in the Erb-b gene responsible for avian erythroblastosis virus.
1982-84
The neu oncogene is discovered by a group of scientists at Massachusetts Institute of Technology (M.I.T) (R.A. Weinberg
Group), Rockefeller and Harvard University (3-4). This gene is also known as Her2, ErbB2 or p185 (for encoding a
phosphoprotein of 185,000 dalton).
1984-86
ErbB-2 or HER2 (for human epidermal growth factor 2) is cloned by a group of scientists, notably Ullrich and Coussens
(Genentech, USA) and Yamamoto, et al. in Japan (5-9).
The name ErbB-2 is given to neu because the gene is a mammalian version of one previously identified in viruses called
ERBB2. The protein encoded by the human version of the gene ERBB2 is closely related to human EGFR, hence the name
HER2 (1).
The neu and Her-2 gene is now commonly called Her-2/neu in deference to the work of R. Weinberg and colleagues and
A. Ullrich and colleagues (10).
10 | Connection 2008
1984-86
Greene and colleagues at Harvard Medical School and scientists at M.I.T. raise monoclonal antibodies to identify a cell-surface
antigen associated with an activated cellular oncogene. They discover that these antibodies bind to and immunoprecipitate
p185 from a DNA donor rat neuroblastoma and 13 independent rat neuroblastoma DNA transfectants (11-12).
1985-86
Greene and colleagues discover that monoclonal anti-p185 antibody treatment causes neu-transformed NIH 3T3 cells to
revert to a nontransformed phenotype, as determined by anchorage-independent growth. They also show that anti-p185
monoclonal antibodies inhibit tumor growth and prolong survival in BALB/c nude (nu/nu) mice (13).
1985
Robert Seeger and his colleagues at the UCLA School of Medicine discover that the oncogene N-myc is present in multiple
copies in some human neuroblastomas, and this N-myc amplification correlates with the stage of the disease (14).
John Minna and Bruce Johnson of the National Cancer Institute look at c-myc oncogene amplification in lung cancer. They
find that those with oncogene amplification survive only one half to one third compared to patients whose tumors do not
have this amplification (15).
Stuart Aaronson, et al. of the National Cancer Institute find that the v-erB-related gene is amplified in one out of ten breast
cancer cell lines (16).
1985-86
The neu oncogene is cloned, sequenced and mapped to human chromosome 17 (17-20).
1987
Greene and colleagues study stage and tissue-specific expression of the neu oncogene in rat development, setting the stage
for the Slamon and Maguire Paper in Science in 1987 (21-22).
1987
Based on the independent studies of Seeger (1985), Minna (1985) and Greene (1985-87) (see above), Slamon and his
colleagues show that oncogenes might be amplified in breast cancer (22).
Dennis Slamon of the University of California, Los Angeles School of Medicine, and his colleagues Oncologist William
McGuire and Statistician Gary Clark, both of the University of Texas Health Science Center in San Antonio, and Axel Ullrich
of Genentech report that the amplification of HER-2/neu oncogene correlates with a shorter time to relapse and lower survival
rate in women with breast cancer (22).
1988
Philip Leder, William Muller and their colleagues at Harvard Medical School and the Howard Hughes Medical Institute
introduce the active neu oncogene into mice. Expression of the transferred gene in the mouse mammary tissue is sufficient
by itself to produce malignant mammary tumors in the animals (23).
1989
Slamon and colleagues report the results of an expanded study of breast cancer patients that confirms their 1987 original
conclusion. They also extend their findings to ovarian cancer, thereby providing a possible biological link between the two
types of cancer (24).
Other independent studies by Wright and co-workers at the Imperial Cancer Research Fund’s Clinical Oncology Unit in
Oxford, England, and by breast cancer specialist Marc Lippman of Georgetown University School of Medicine in Washington,
D.C., suggest that gene amplification is a major prognostic indicator (25-26).
Axel Ullrich and colleagues at Genentech show that a monoclonal antibody directed against the extracellular domain
of p185/HER2 specifically inhibits the growth of breast tumor-derived cell lines overexpressing the HER2/c-erbB-2 gene
product. They also show that the monoclonal antibody directed against the extracellular domain of p185/HER2 enhance the
sensitivity of tumor cells to tumor necrosis factor alpha (TNF-a) (27).
Greene and colleagues at the University of Pennsylvania, Philadelphia, show intermolecular association between the
p185/neu protein and EGF receptor and establish the formation of “neu” homodimers (28-30).
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Connection 2008 | 11
1990
Genentech scientists characterize murine monoclonal antibodies to be reactive to either the human epidermal growth factor
receptor or HER2/neu gene product (31).
1991
HerceptinTM, produced from CHO cells, is maintained in cell culture systems at Genentech for human clinical trials (FDA
Biologics Licence Application-98-0639).
First anti-HER2 antibody tested in humans.
1992
Genentech scientists humanize an antibody against HER2. Using a “gene conversion mutagenesis” strategy, Paul Carter, et
al. report the rapid and simultaneous humanization of heavy-chain (VH) and light-chain (VL) V region genes of the monoclonal
antibody mumAb4D5 (now called HerceptinTM) directed against the extracellular domain of p185/HER2 (32).
1992
1993
Phase I clinical trails commence: Dose studies conducted to characterize the pharmacokinetic profile of HerceptinTM.
1994
1995
Phase II HerceptinTM trial completed (Source: Genentech).
Phase II clinical trails commence: Open label, single-arm study of HerceptinTM conducted at 54 centers in North America,
Europe and Australia/New Zealand. Enrollment conducted from April 24, 1995 to June 4, 1997.
Phase III clinical trails: Chemotherapy and Antibody Response Evaluation (CARE): Multinational, randomized study
of HerceptinTM combined with chemotherapy in patients with HER2 overexpression who have not received cytotoxic
chemotherapy for metastatic breast cancer. Enrollment conducted from June 12, 1995 to March 7, 1997.
Kuo-Fen Lee and colleagues at the Salk Institute, MD Anderson Cancer Center and Whitehead Institute demonstrate that the
expression of HER/neu is crucial for cardiac and central nervous system development (33).
1996
Genentech contacts Dako regarding HerceptestTM.
Response Evaluation Committee (REC) established for patient review.
Scientists at the Weizmann Institute of Science, Rehovot, Israel, (Karunagaran, D. and Yarden, Y.) study the role of HER2 in
signal transduction (e.g. ErbB-2 can form heterodimers with both EGF receptor (ErbB-1) and NDF receptors (ErbB-3 and
ErbB-4) (34).
1997
Phase III clinical trails closed.
Genentech Dako FDA meeting.
1998
Premarket approval (9-25-98) for DAKO HerceptestTM (Source: FDA).
HerceptinTM receives fast-track designation from the FDA for the treatment of metastatic breast cancer (Source:
Genentech).
FDA approves HerceptinTM in combination with paclitaxel for the first-line treatment of HER2-positive metastatic breast
cancer, and as a single agent for second and third-line therapy (Source: Genentech).
HerceptinTM was the first therapeutic antibody targeted at a cancer-related molecular marker to receive FDA approval
(Source: Genentech).
Collaboration with Dako is initiated to develop HER2 diagnostic test for breast cancer.
American Society of Clinical Oncology (ASCO) guidelines recommend HER2 testing for all breast cancers (35).
12 | Connection 2008
2002
FDA approves inclusion of FISH (fluorescence in situ hybridization) gene amplification test for HER2 gene in HerceptinTM
product labeling (Source: Genentech).
Garrett and co-workers from the Walter and Eliza Hall Institute of Medical Research, Australia, solve the crystal structure of
a truncated epidermal growth factor receptor extracellular domain bound to transforming growth factor a determined at 2.5
A° resolution (36).
Yokoyama and co-workers at RIKEN Genomic Sciences Center, Japan, solve the crystal structure of a 2:2 complex of human
epidermal growth factor and the epidermal growth factor receptor extracellular region determined at 3.3 A° resolution (37).
2003
2005
2006
Dako receives CE (Conformité Européenne) European conformity marking.
2007
New American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guideline recommendations for
human epidermal growth factor receptor HER2 testing in breast cancer (38).
2008
FDA approves HerceptinTM as a single agent for the adjuvant treatment of HER2-overexpressing node-negative (ER/
PR-negative or with one high risk feature) or node-positive breast cancer following multi-modality anthracycline-based
therapy (Source: Genentech).
FDA approval of HER2 FISH pharmDx™ Kit for HerceptinTM selection.
FDA approves HerceptinTM as part of a treatment regimen containing doxorubicin, cyclophosphamide and paclitaxel for the
adjuvant treatment of patients with HER2-positive, node-positive breast cancer (Source: Genentech).
Lapatinib shown to have synergy with HerceptinTM in patients with metastatic HER2+ breast cancer progressing on Hereptinbased chemotherapy (39).
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