SOUTH SAN FRANCISCO, Calif., June 3 /PRNewswire-FirstCall/ -- Cell Genesys, Inc. today 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. The data were presented today by Dr. Douglas Smith, assistant professor of Hematologic Malignancies at Johns Hopkins Sidney Kimmel Comprehensive Cancer Center at the annual meeting of the American Society of Clinical Oncology (ASCO) in Atlanta, GA.
"We continue to be encouraged by the results of this Phase 2 trial in CML, in particular by the achievement of sustained molecular responses when GVAX is added to ongoing imatinib therapy," stated Joseph J. Vallner, Ph.D., president and chief operating officer of Cell Genesys. "GVAX immunotherapy in our view may represent an important new treatment strategy for CML."
The Phase 2 trial enrolled 19 patients with chronic phase CML. All patients had detectable bcr-abl levels at study entry as measured by a PCR (polymerase chain reaction) assay despite having received at least one year of Gleevec therapy. The median duration of Gleevec therapy prior to study entry was three years. Patients were treated with four injections of GVAX(R) vaccine for leukemia at three-week intervals over a total treatment period of nine weeks and then followed for nine months or longer from treatment initiation. To date, all patients have tolerated treatment well and completed the planned nine months follow-up. Today's presentation also included a new statistical analysis of the levels of bcr-abl observed. An analysis of trends was performed to compare changes in bcr-abl over time in patients pre- and post-treatment. Importantly, the average bcr-abl levels were significantly lower during and following treatment with GVAX immunotherapy for leukemia than in the 3 month period pre treatment (p=0.02 by Chi-squared).
The therapy of CML has improved substantially in recent years as a result of the introduction of Gleevec therapy which is now approved for the first- line treatment of CML in chronic phase. Hematologic responses are seen routinely in the majority of treated patients but complete molecular responses, as measured by quantitative PCR for bcr-abl, occur in less than 10 percent of patients even after 12 months of therapy. Given that the reduction in bcr-abl in patients is positively associated with clinical outcome, new therapeutic strategies to eliminate persistent leukemic disease as evidenced by bcr-abl positive cells are urgently needed.
Clinical trials of GVAX cancer immunotherapies are under way for multiple types of cancer including, in addition to leukemia, prostate cancer and pancreatic cancer. The products are comprised of tumor cells that have been modified to secrete GM-CSF, an immune stimulatory hormone, and then irradiated for safety. GVAX cancer immunotherapies are being developed as non patient- specific "off-the-shelf" pharmaceutical products and have demonstrated a favorable side effect profile in over 600 patients treated in clinical trials to date.
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, 2005 filed on March 13, 2006 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
Cell Genesys, Inc.
650-266-3200
