Cell Genesys Reports Successful Preclinical Studies of Parkinson's Disease Gene Therapy
THURSDAY, JUNE 22, 2000 7:30:00 AM EST
FOSTER CITY, Calif., Jun 22, 2000 /PRNewswire via COMTEX/ -- Cell Genesys CEGE
today announced that a single gene therapy treatment in a rat model of Parkinson's disease
resulted in behavioral recovery and nerve cell regeneration as well as significant reinnervation
of the striatum, an area of the brain that typically deteriorates in Parkinson's disease. Cell
Genesys' proprietary adeno-associated viral (AAV) gene delivery system was used to deliver
the gene for glial cell line-derived neurotrophic factor (GDNF), a protein which stimulates
nerve growth. Following gene delivery to the targeted nerve cells with an AAV vector,
biologically active levels of the GDNF protein were detected for six months, which was the
duration of the study. These studies were conducted by Ronald J. Mandel, Ph.D. of the
University of Florida College of Medicine in collaboration with Cell Genesys and were
published in a June issue of the Journal of Neuroscience.
"These data provide additional proof of principle for our preclinical Parkinson's disease gene
therapy program and further demonstrate the therapeutic potential of our proprietary AAV gene
delivery system," stated Joseph J. Vallner, Ph.D., executive vice president and chief operating
officer of Cell Genesys. "Based on these successful preclinical studies, we are actively
evaluating collaborations for the further development of Parkinson's disease gene therapy."
Cell Genesys previously announced data from preclinical Parkinson's diseases studies which
demonstrated that following a single gene therapy treatment, a strain of mice with certain
symptoms of Parkinson's disease could survive without daily L-dopa treatments for at least one
year, which was the duration of the study. Without L-dopa treatment, these mice die of
starvation by three weeks of age. An AAV vector system was used to deliver the genes required
for the production of L-dopa to specific regions of the brain where L-dopa production was
detected throughout the observation period. L-dopa is a commonly prescribed drug for
Parkinson's disease, which is converted to dopamine, the neurotransmitter chemical missing in
patients with Parkinson's disease.
In addition to encouraging results in Parkinson's disease gene therapy, Cell Genesys has had
significant success using its AAV gene delivery system in preclinical studies for other diseases.
In the Cell Genesys hemophilia program, an 85 percent reduction in bleeding episodes in dog
models of hemophilia B was achieved with a single administration of AAV-factor IX gene
therapy. Moreover, more than two years after the single injection, the dogs continued to
produce the factor IX protein which was deficient in these animals prior to treatment.
Therefore, a single administration of AAV-mediated gene therapy could potentially eliminate the
need for repetitive treatment regimens. Additionally, the AAV vector has been shown to
effectively deliver genes to cells of the liver, skin and muscle as well as the central nervous
system, providing the basis for many other potential therapeutic applications.
Gene delivery systems, or vectors, are the vehicles by which therapeutic genes are introduced
into target cells or tissues to induce a therapeutic effect and are a critical component of any
successful gene therapy. Cell Genesys has four vector systems from which to choose including
AAV, lentiviral, adenoviral and retroviral vectors. The choice of vector depends upon such
considerations as the disease indication, production efficiencies and the size of the gene. For
example, in Cell Genesys' hemophilia A gene therapy program, the company has the option to
utilize either its proprietary AAV vector system if a shorter form of the defective factor VIII
gene can be successfully applied or its proprietary lentiviral vector system if the full length
factor VIII gene is required.
Cell Genesys currently has one of the largest patent portfolios in the gene therapy field
including more than 230 issued or granted patents and over 320 pending patent applications.
The portfolio includes issued or granted patents for multiple gene delivery systems, specific
therapeutic genes and gene therapy applications and multiple genetically modified cell types
used in gene therapy independent of the gene delivery system or therapeutic gene. The portfolio
currently contains over 80 filings alone pertaining to the company's AAV gene delivery system,
which has potential applicability to the treatment of hemophilia and other genetic deficiency
diseases as well as Parkinson's disease.
Cell Genesys is focused on the development and commercialization of cancer vaccines and gene
therapies to treat major, life-threatening diseases. The company is conducting two multicenter
Phase II human clinical trials for its GVAX(R) cancer vaccine in prostate cancer, a multicenter
Phase I/II trial of GVAX(R) vaccine in lung cancer and expects to initiate additional GVAX(R)
vaccine trials in pancreatic cancer, myeloma and leukemia during the coming year. Preclinical
stage programs include gene therapy for hemophilia, cancer, cardiovascular disorders and
Parkinson's disease. Cell Genesys' assets outside gene therapy include its approximately 12
percent ownership of Abgenix, Inc. and the company's licensing program in gene activation
technology. For additional information, please visit the company's web site at
www.cellgenesys.com.
Statements made herein, other than statements of historical fact, including statements about the
company's progress and results of Parkinson's disease and other preclinical studies, clinical
trials, marketability of potential products and nature of product pipelines, corporate
partnerships, licenses and intellectual property including that pertaining to AAV, lentiviral and
other gene delivery technologies and the company's patent portfolio are forward-looking
statements and are subject to a number of uncertainties that could cause actual results to differ
materially from the statements made, including risks associated with the success of research
and development programs, results achieved in future preclinical studies and clinical trials, the
regulatory approval process, competitive technologies and products, the scope and validity of
patents, corporate partnerships and additional financings. For information about these and other
risks which may affect Cell Genesys, please see the company's Annual Report on Form 10-K
dated March 30, 2000 as well as Cell Genesys' reports on Form 10-Q and 8-K and other
reports filed from time to time with the Securities and Exchange Commission.
Jennifer Cook Williams, Manager, Corporate Communications of Cell Genesys, Inc.,
650-425-4542.
SOURCE Cell Genesys, Inc.
CONTACT:Jennifer Cook Williams, Manager, Corporate Communications of
Cell Genesys, Inc., 650-425-4542
/Company News On-Call:http://www.prnewswire.com/comp/134113.html or fax,
800-758-5804, ext. 134113
URL:http://www.cellgenesys.com
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