CELL GENESYS REPORTS SUCCESSFUL PRECLINICAL
STUDIES OF LENTIVIRAL GENE THERAPY FOR HEMOPHILIA
A
FOSTER CITY, Calif., March 24, 2000-Cell Genesys (Nasdaq: CEGE) today
announced that Inder Verma, Ph.D., and colleagues at The Salk Institute have
reported the successful use of lentiviral vectors in preclinical studies of
hemophilia A, an inherited bleeding disorder. In addition, Flavia Borellini,
Ph.D. and colleagues at Cell Genesys reported the successful development of
the scaleable manufacturing technology for lentiviral vectors required for
clinical studies in hemophilia and other serious diseases. These presentations
were made in Washington D.C. at the Third Workshop on Gene Therapies for
Hemophilia sponsored by the National Hemophilia Foundation.
Dr. Verma reported that Cell Genesys' proprietary lentiviral gene delivery
system efficiently delivered the full-length factor VIII gene into target cells in
a biologically active form. In addition, biologically active factor VIII was
detected following administration to small laboratory animals. Importantly,
since other gene delivery systems currently being evaluated by Cell Genesys in
hemophilia A gene therapy (such as the AAV or adeno-associated viral system)
are unable to accommodate the full-length factor VIII gene, lentiviral vectors
may be particularly advantageous in gene therapy for this more common form
of hemophilia. Successful delivery of the factor VIII gene is expected to result
in production of the factor VIII protein, representing a potential new approach
to the treatment for hemophilia A patients who are deficient in factor VIII, a
blood clotting factor.
Dr. Borellini reported that Cell Genesys has developed technology for
scaleable manufacturing of the lentiviral vector system, which is critical for
advancing clinical trials and for potential product commercialization. Using
the scaleable manufacturing process, the company has produced lentiviral
vectors that maintain the quality, safety and gene delivery efficiency that had
been previously demonstrated using earlier production systems. This
accomplishment represents an important step towards the initiation of human
clinical trials.
"These data further enhance our competitive advantages in the hemophilia A
area, as we have overcome the hurdle of delivering the complete factor VIII
gene and have demonstrated the ability to manufacture the lentiviral gene
delivery system at increasing scale," stated Joseph J. Vallner, Ph.D., executive
vice president and chief operating officer at Cell Genesys. "As a result of our
progress in both hemophilia A and hemophilia B gene therapy preclinical
studies, we expect to initiate human clinical trials in 2001."
In Cell Genesys' preclinical hemophilia program, a 90 percent reduction in
bleeding episodes in a canine model of hemophilia B was achieved with a
single administration of factor IX gene therapy. Additionally, 20 months after
the single injection, the treated animals continued to produce the factor IX
protein which was deficient in these animals prior to treatment. These studies
utilized Cell Genesys' proprietary adeno-associated viral (AAV) vector system,
which like the lentiviral vector, inserts the therapeutic gene into the DNA of
the patient's cells, thereby allowing a potentially permanent genetic correction.
A single administration of gene therapy could therefore potentially eliminate
the need for repetitive treatment regimens.
Successful gene therapy depends to a great extent on the vector systems or gene
delivery vehicles used to transfer genes into cells. Cell Genesys has four
different viral vector systems and is using this technology "toolbox" to capture
multiple product opportunities. The company's proprietary vector technologies
include AAV, lentiviral, adenoviral and retroviral vectors engineered to
provide safe, efficient, long-term gene expression. Lentiviral vectors have
demonstrated efficient and long-lasting gene transfer into a variety of human
cells including both dividing and non-dividing cells such as nerve, liver,
muscle and bone marrow stem cells potentially providing the opportunity to
treat multiple genetic deficiency diseases such as hemophilia, cancer and
Parkinson's disease.
Cell Genesys currently has one of the largest patent portfolios in the gene
therapy field including more than 220 issued or granted patents and over 335
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. For example, the
portfolio currently contains over 90 filings alone pertaining to the two types of
gene delivery systems-lentiviral and AAV-with potential applicability to the
treatment of hemophilia and other genetic deficiency diseases.
Cell Genesys is focused on the development and commercialization of gene
therapies to treat cancer and other major, life-threatening diseases. The
company is conducting two multicenter Phase II human clinical trials for its
GVAX© cancer vaccine in prostate cancer and plans to initiate a multicenter
Phase I/II trial of GVAX© vaccine in lung cancer. 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. (Nasdaq: ABGX) and the
company's licensing program in gene activation technology. For additional
information, please visit the company's web site at www.cellgenesys.com. |
