SOUTH SAN FRANCISCO, Calif., June 5 /PRNewswire-FirstCall/ -- Cell Genesys, Inc. today provides a recap of clinical data reports from two GVAX(R) cancer immunotherapy programs that were presented this past weekend at the 2006 American Society of Clinical Oncology (ASCO) Annual Meeting being held in Atlanta, GA.
In the first oral presentation entitled, “A dose-escalation trial of GM-CSF-gene transduced allogeneic prostate cancer cellular immunotherapy in combination with a fully human anti-CTLA-4 antibody (MDX-010, ipilimumab) in patients with metastatic hormone-refractory prostate cancer (HRPC),” (Abstract #2500), Cell Genesys and collaborator, Medarex, Inc., presented encouraging data from a Phase 1 clinical trial of the company’s’ GVAX(R) immunotherapy for prostate cancer, administered in combination with Medarex’s fully human anti-CTLA-4 antibody, ipilimumab (MDX-010), in patients with advanced prostate cancer. Twelve patients have been treated to date, including six patients who received the combination therapy at the therapeutic doses currently being evaluated in both GVAX and ipilimumab Phase 3 clinical trials. Antitumor activity has been observed in five of these six patients including reductions in prostate-specific antigen (PSA) levels that are ongoing at two months or longer and qualify in all five patients as partial responses (greater than 50% sustained reduction) by the National Cancer Institute (NCI) Working Group criteria with two patients having greater than 95% reductions. Moreover, clinical evidence of antitumor activity has been observed in three of these five PSA responders, including improvement of multiple lesions on bone scan, resolution of abdominal lymph node disease by CT scan, and improvement in pain due to bone metastases, respectively. In addition to these findings, four of the six remaining patients who received the two lower doses of ipilimumab were noted to have stable disease by PSA with at least two months of follow-up. There have been no dose-limiting toxicities seen to date with the combination therapy. All five patients with PSA partial responses have experienced grade 2 or 3 immune-mediated endocrine deficiencies similar in type to those previously reported with ipilimumab therapy which have been successfully treated with standard hormone replacement therapy.
In the second oral presentation entitled, “K562/GM-CSF vaccination reduces tumor burden, including achieving molecular remissions in chronic myelogenous leukemia (CML) patients with residual disease on imatinib,” (Abstract #6509), the company reported encouraging long-term follow-up data from a Phase 2 trial of GVAX(R) immunotherapy for chronic myelogenous leukemia (CML). A total of 19 CML patients with molecular evidence of persistent leukemia following at least one year of Gleevec(R) (imatinib mesylate) therapy were treated with GVAX immunotherapy while continuing to receive Gleevec. Updated results show that the addition of GVAX immunotherapy to Gleevec therapy reduced persistent leukemic disease in 10 of 19 patients as demonstrated by a complete disappearance (five patients) or a greater than one log (90%) reduction (five patients) in bcr-abl -- a validated genetic marker found on the leukemic cells. The new findings reported today also show that with a median follow up from treatment initiation of 14 months for all patients, the molecular responses are ongoing in the five patients showing a one log or greater reduction in bcr-abl. In addition, four of the 5 patients with a complete disappearance of bcr-abl continue to have undetectable values at the most recent follow up. Of the remaining 10 patients, only one patient has developed cytogenetic progression on therapy and this patient had the highest level of disease burden at study entry. To date all patients have tolerated treatment well and completed the planned follow-up period.
Clinical trials of GVAX(R) cancer immunotherapies are under way for multiple types of cancer including prostate cancer, pancreatic cancer, and leukemia. These products are whole-cell immunotherapies which are designed to stimulate an immune response against the patient’s tumor. The products 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 response to such 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, Cell Genesys, Inc., +1-650-266-3200
Web site: http://www.cellgenesys.com//
