SOUTH SAN FRANCISCO, Calif., Feb. 27 /PRNewswire-FirstCall/ -- Cell Genesys, Inc. today reported updated results from its second multi-center Phase 2 trial of GVAX(R) immunotherapy for prostate cancer in patients with advanced metastatic hormone-refractory prostate cancer (HRPC). Additional follow-up of the patients who received the dose that is comparable to that being employed in the company's ongoing Phase 3 program indicates that the median survival has not yet been reached and that the estimated median survival will be no less than 29.1 months. The company also presented for the first time, an analysis of the survival data for the company's two Phase 2 trials of GVAX immunotherapy for prostate cancer, based on a published, validated nomogram that uses seven prognostic factors to calculate a patient's predicted survival. This analysis demonstrated a favorable comparison of observed to predicted median survival for both Phase 2 trials. These new findings were reported yesterday at the 2006 American Society of Clinical Oncology (ASCO) Prostate Cancer Symposium in San Francisco, CA, by Eric J. Small, M.D., professor of Medicine and Urology, University of California San Francisco Comprehensive Cancer Center.
The company's second Phase 2 trial enrolled a total of 80 patients who were sequentially assigned to escalating dose groups, including 22 patients who were treated with a dose comparable to that being used in the company's Phase 3 program. As noted above, the median survival has not yet been reached for these 22 patients, and the estimated Kaplan-Meier median survival is expected to meet or exceed 29.1 months based on the patients still in follow-up. Four patients have withdrawn consent to further follow-up and thus were censored in the analysis. The company previously reported final median survival results from its first multi-center Phase 2 trial of GVAX immunotherapy for prostate cancer in 34 patients with metastatic HRPC that showed an overall median survival of 26.2 months. The survival results from the two, independent multi-center Phase 2 clinical trials are not only consistent with each other, but also compare favorably to the previously published median survival of 18.9 months for metastatic hormone-refractory prostate cancer patients treated with Taxotere(R) (docetaxel) chemotherapy plus prednisone, the current standard of care for these patients. The company's ongoing Phase 3 program is designed to confirm this potential survival benefit for GVAX immunotherapy for prostate cancer.
"We are encouraged by the updated survival data from this second Phase 2 trial of GVAX immunotherapy for prostate cancer and also by the consistency of the survival data from this trial with that reported in our earlier Phase 2 trial in a similar patient population," stated Joseph J. Vallner, Ph.D., president and chief operating officer of Cell Genesys. "We continue to hope that GVAX immunotherapy for prostate cancer may some day offer an improved and less toxic treatment alternative to chemotherapy for patients with this disease."
In addition to the updated survival data for the second Phase 2 study, an analysis was also presented of the observed versus predicted median survival results for the two Phase 2 trials of GVAX immunotherapy for prostate cancer. A published, validated nomogram based on seven prognostic variables including PSA, ECOG performance status, Gleason score sum, alkaline phosphatase, hemoglobin, LDH and presence/absence of visceral metastatic disease was used to calculate each patient's predicted survival (Halabi, et al. Prognostic model for predicting survival in men with HRPC: Journal of Clinical Oncology, 2003; 21(7):1232-7). The median value of the predicted survivals were then calculated for each trial and compared to the observed median survival calculated by the Kaplan-Meier method. In the first Phase 2 trial, the observed median survival for the 34 patients was 26.2 months, compared with the predicted median survival based on the Halabi nomogram of 19.5 months. In the second Phase 2 trial, the median survival has not been reached and the estimated median is expected to meet or exceed 29.1 months based on the patients still in follow-up. The predicted median survival for these patients based on the Halabi nomogram was 22.0 months. Cell Genesys believes that the fact that the observed median survival exceeds the predicted median survival in both Phase 2 trials provides further support for the company's ongoing Phase 3 program with respect to the potential of GVAX immunotherapy for prostate cancer to demonstrate a survival benefit.
Cell Genesys is currently enrolling two Phase 3 clinical trials of GVAX immunotherapy for prostate cancer in approximately 1200 patients with metastatic HRPC, comprising one of the largest Phase 3 clinical programs ever conducted in men with advanced prostate cancer. The first trial (VITAL-1) is enrolling chemotherapy naive, asymptomatic patients without cancer-related pain and will compare GVAX cancer immunotherapy to Taxotere chemotherapy plus prednisone. The second trial (VITAL-2) is enrolling patients who are symptomatic with cancer-related pain and will compare GVAX cancer immunotherapy plus Taxotere chemotherapy to Taxotere plus prednisone. Each Phase 3 trial is expected to enroll 600 patients and is designed to demonstrate a survival benefit compared to Taxotere plus prednisone. Cell Genesys received Special Protocol Assessments (SPA) from the U.S. Food and Drug Administration (FDA) for each of the VITAL-1 and VITAL-2 Phase 3 studies.
Clinical trials of GVAX(R) cancer immunotherapies are under way for multiple types of cancer including prostate cancer, pancreatic cancer, and leukemia. Cell Genesys' GVAX cancer immunotherapies are whole-cell immunotherapies which are designed to stimulate an immune response against the patient's tumor. The immunotherapies are comprised of tumor cells that have been irradiated and genetically modified to secrete GM-CSF (granulocyte- macrophage colony stimulating factor), an immune stimulatory hormone which plays a key role in stimulating the body's immune response to immunotherapies. GVAX cancer immunotherapies are being developed as non patient-specific, "off-the-shelf" pharmaceutical products.
Cell Genesys is focused on the development and commercialization of novel biological therapies for patients with cancer. The company is currently pursuing two clinical stage product platforms - GVAX(R) cancer immunotherapies and oncolytic virus therapies. Ongoing clinical trials include Phase 3 trials of GVAX immunotherapy for prostate cancer, Phase 2 trials of GVAX immunotherapy for pancreatic cancer and leukemia, and a Phase 1 trial of CG0070 oncolytic virus therapy for bladder cancer. Cell Genesys continues to hold an equity interest in its former subsidiary, Ceregene, Inc., which is developing gene therapies for neurodegenerative disorders. Cell Genesys is headquartered in South San Francisco, CA and has its principal manufacturing operation in Hayward, CA. For additional information, please visit the company's website at http://www.cellgenesys.com.
Statements made herein about the company, other than statements of historical fact, including statements about the company's progress, results and timing of clinical trials and preclinical programs and the nature of product pipelines 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 clinical trials and research and development programs, the regulatory approval process for clinical trials, competitive technologies and products, patents, continuation of corporate partnerships and the need for 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 for the year ended December 31, 2004 filed on March 14, 2005 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. The company assumes no obligation to update the forward-looking information in this press release.
Contact: Ina Cu Investor Relations 650-266-3200
Cell Genesys, Inc.CONTACT: Ina Cu, Investor Relations for Cell Genesys, Inc.,+1-650-266-3200
Web site: http://www.cellgenesys.com/
