Cell Genesys Earns $4.5 Million Payment from GVAX Cancer Vaccine Collaboration
Cell Genesys Inc. (Foster City, CA) announced on July 1 that it has earned a $4.5 million payment following the completion of an initial Phase I/II clinical trial of GVAX prostate cancer vaccine. Completion of this trial represents a milestone under Cell Genesys's worldwide collaboration for the development of GVAX cancer vaccine with the pharmaceutical division of Japan Tobacco Inc. (JT; Tokyo). Based on positive results from this trial, Cell Genesys has recently initiated two multicenter trials of the vaccine.
Cell Genesys is developing GVAX cancer vaccines for prostate cancer and lung cancer through a worldwide deal, signed in December 1998 with the pharmaceutical division of JT. Under this collaboration, the two companies will share equally in product development costs and future profits. Cell Genesys will have marketing rights in North America, while JT will have marketing rights in Japan, Taiwan, and Korea, and the companies will share rights in Europe and the rest of the world. Cell Genesys expects to receive approximately $45 million during the first two years of this collaboration.
The recently completed Phase I/II trial showed that the vaccine was safe, well tolerated, and had antitumor activity. When given to men whose only evidence of recurrent prostate cancer was a rising prostate specific antigen (PSA) level, the vaccine apparently caused the disease to stabilize, as evidenced by a decrease in the rate at which PSA rose. The effect was observed in 15 of 21 (71%) patients. Additionally, 14 of the 15 patients with stable disease produced cancer-specific antibodies in their blood, whereas none of the six patients with progressive disease produced these antibodies. Based on these findings, Cell Genesys recently initiated two multicenter GVAX clinical trials.
The first trial, begun in December 1998, will enroll approximately 40 early stage patients who have not yet received hormone therapy for prostate cancer. The second trial, initiated in April 1999, will enroll approximately 40 patients who have failed hormone therapy.
GVAX vaccine for prostate cancer consists of irradiated prostate cancer cells that have been genetically modified to continually produce granulocyte-macrophage colony stimulating factor (GM-CSF), a hormone which plays a key role in augmenting the body's immune response to vaccines. GVAX is a non patient-specific vaccine product that is designed to be used as an "off-the-shelf" pharmaceutical to stimulate an immune response.
Cell Genesys is also testing a patient-specific form of GVAX for lung cancer. Encouraging data from this clinical program, including both clinical and biopsy evidence of antitumor immunity, prompted the company to plan a multicenter clinical trial of for late 1999. GVAX has been shown to provide antitumor activity in all four types of cancer tested to date, including prostate cancer, lung cancer, melanoma, and kidney cancer, suggesting that the vaccine approach may be applicable to several types of cancer.
In related news, Cell Genesys announced that it was issued a second broad U.S. patent for its GVAX. The patent claims cover methods of stimulating an antitumor immune response and methods of suppressing tumor growth following the administration of the cancer vaccine.
Other Cell Genesys programs focus on cancer, AIDS, hemophilia, Parkinson's disease, and cardiovascular ailments.
Cell Genesys's Focus: Gene Therapy
With all its recent success in the cancer vaccine arena, it's easy to overlook Cell Genesys's substantial effort in gene therapy. The patent mentioned above adds to the company's already huge gene therapy patent estate, which includes more than 165 issued or granted patents and more than 310 patent applications pending.
Cell Genesys's gene therapy strategy seeks to harness the disease-fighting power of the immune system by genetically modifying CD4 T cells and CD8 T cells to specifically target and destroy virally infected or malignant cells. Cell Genesys has developed a method for arming T cells with receptors that recognize specific diseases such as cancer and AIDS. Proprietary genes are introduced into killer T cells, enabling the cells to express genetically engineered cellular receptors recognizing specific antigens (usually proteins) that appear on the surface of diseased or malignant cells. These modified killer T cells can then bind to the infected cells and destroy them.
For more information: Bruce A. Hironaka, VP of Corporate Development, Cell Genesys Inc. 342 Lakeside Drive, Foster City, CA, 94404. Tel: 650-425-4400. Fax: 650-425-4457.
By Angelo DePalma