Patient Recruitment Completed for First Phase III Clinical Trial of GVAX Immunotherapy for Prostate Cancer

Cell Genesys has announced that it has completed recruitment of more than 600 patients into VITAL-1, the first of two ongoing Phase III clinical trials of GVAX immunotherapy for prostate cancer.

Cell Genesys’ GVAX cancer immunotherapies are whole-cell products that are designed to present the immune system with a broad spectrum of tumor antigens and stimulate an immune response against the patient’s tumor. GVAX Immunotherapy for Prostate Cancer is made up of two prostate tumor-cell lines that have been modified to secrete granulocyte-macrophage colony-stimulating factor, an immune stimulatory hormone that plays a key role in stimulating the body’s immune response. It is being developed as an “off-the-shelf” pharmaceutical for use after hormonal therapy for advanced-stage prostate cancer. The GVAX Phase III trials have been designed to evaluate whether GVAX Immunotherapy for Prostate Cancer can benefit patients who have metastatic, hormone-refractory prostate cancer (HRPC).

VITAL-1 commenced in July 2004 and is designed to compare GVAX Immunotherapy for Prostate Cancer to docetaxel plus prednisone with regard to survival benefit in patients with metastatic HRPC who do not have cancer-related pain. VITAL-2 commenced in June 2005 and compares GVAX Immunotherapy for Prostate Cancer plus docetaxel to docetaxel plus prednisone with respect to survival benefit in patients with metastatic HRPC and cancer-related pain. Cell Genesys expects to enroll approximately 600 patients in the VITAL-2 trial. Both VITAL-1 and VITAL-2 are being conducted in the United States, Canada, and Europe.

Clinical Cancer Research

Cell Genesys’ ongoing Phase III GVAX Immunotherapy for Prostate Cancer program is supported by the median survival results from two independent, multicenter Phase II trials in approximately 115 patients. The subset of patients in these trials who received the doses comparable to the Phase III dose showed median survival of 34.9 months and 35.0 months, respectively. These results also exceeded the predicted survival of 22.5 months and 22.0 months, respectively, as determined by a 7-point patient disease characteristic nomogram. The results of the first trial were published recently in . Results from both studies compare favorably to the previously published median survival of 18.9 months for patients with metastatic HRPC who were treated with docetaxel plus prednisone, the current standard of care.

In addition, the safety profile observed in Phase II trials of GVAX Immunotherapy for Prostate Cancer compares favorably with that reported for chemotherapy. In addition to evaluating effectiveness, the Phase III program is also designed to confirm the safety profile for GVAX immunotherapy for prostate cancer.

In May 2006 the FDA granted Fast Track designation for GVAX Immunotherapy for Prostate Cancer. Prostate cancer is the second-leading cause of cancer death in men in the United States, with approximately 30,000 men dying each year from the disease.