SOUTH SAN FRANCISCO, Calif., May 22 /PRNewswire-FirstCall/ -- Cell Genesys, Inc. today announced preliminary results of a Phase 1 clinical trial of CG0070 in patients with recurrent bladder cancer who have failed previous therapy with bacillus Calmette-Guerin (BCG), the current standard therapy for recurrent bladder cancer. Nine patients have been treated to date who received escalating single-dose administrations of CG0070. Evidence of anti-tumor activity documented by a complete response at follow-up cystoscopy was obtained in three of the nine patients treated. Treatment was tolerable with no serious adverse events or dose limiting toxicities reported to date. These data were presented today by Donald L. Lamm, M.D., clinical professor at the University of Arizona, at the annual meeting of the American Urological Association (AUA) in Atlanta, GA.
CG0070, an oncolytic virus therapy, has been shown to destroy cancer cells of multiple types in numerous preclinical studies. CG0070 is the first "armed" oncolytic virus therapy developed by the company, so-named because it has been engineered to include the therapeutic gene for GM-CSF, an immune stimulating hormone which is also a key component in Cell Genesys' lead product platform, GVAX(R) cancer immunotherapies. As a result, CG0070 can potentially destroy cancer cells by two different mechanisms: direct cell killing by the virus and immune-mediated cell killing stimulated by GM-CSF.
The open-label, dose-escalation trial reported today is designed to evaluate intravesical (into the bladder) single-dose administration of CG0070 in patients with superficial bladder cancer who have failed previous therapy with BCG. Three patients are being evaluated at each escalating dose level determined by the number of viral particles of CG0070 administered. The primary endpoints of the study are safety and the determination of a maximum tolerated dose. Secondary endpoints include clinical response based on follow-up cystoscopy and recurrence free survival. Nine patients have been treated to date through the third dose level. Evidence of anti-tumor activity documented by a complete response at follow-up cystoscopy performed at approximately 3 months was obtained in three of the nine patients treated, including two at the first (lowest) dose level and one at the third dose level. The duration of the complete responses after just a single administration of CG0070 were 6, 9, and 3+ months respectively. Treatment was generally tolerable and the majority of treatment-related side effects were local bladder toxicities. No serious adverse events or dose limiting toxicities have been reported to date. Pharmacokinetic studies show detectable CG0070 in the urine in all patients for one to two weeks after treatment. In contrast, very low levels of CG0070 were transiently measurable in the blood of only one of the nine patients, suggesting minimal systemic exposure to the virus. Additionally, GM-CSF was detected in the urine of all patients for at least five days, suggesting that biologically active CG0070 persists in the bladder for at least this time period.
"We are pleased with the early results for CG0070, our lead oncolytic virus therapy product in clinical trials and believe that this study strongly supports advancement of CG0070 into a multiple-dose Phase 1 trial," stated Joseph J. Vallner, Ph.D., president and chief operating officer of Cell Genesys. "We are optimistic that the dual mechanism of action of CG0070 might result in enhanced local anti-tumor activity as well as potential systemic anti-tumor immunity following local administration."
Oncolytic (cancer cell killing) virus therapies represent a new approach in the treatment of patients with cancer and are comprised of adenoviruses, a cause of the common cold, that are engineered to selectively replicate in and destroy cancer cells through the use of tumor- or tissue-specific promoters. Cell Genesys is developing certain of its oncolytic virus therapy products through a global alliance with Novartis AG, which may provide for the further development and commercialization of these products. Additionally, the alliance provided Cell Genesys with preclinical stage product opportunities developed by Novartis, including CG0070. In addition to CG0070, Cell Genesys is also developing CG5757, which is engineered with a secondary telomerase promoter employing technology licensed from Geron Corporation, and may also have the potential to target multiple types of cancer.
The American Cancer Society estimates that approximately 61,500 new cases of bladder cancer will be diagnosed in 2006, and that the majority of these are superficial bladder cancer. Superficial bladder cancer has traditionally been treated by transurethral resection (TUR) upon initial diagnosis, but unfortunately is marked by recurrence in the majority of patients. The current standard therapy after TUR is intravesical BCG. Patients with superficial bladder cancer who fail BCG have limited options. Historically, cystectomy has been the standard of care in this setting. Intravesical chemotherapeutic agents have been tried but with limited efficacy. Additional therapies for recurrent bladder cancer are needed in order to decrease treatment morbidity, increase bladder preservation, and improve long term outcomes.
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 www.cellgenesys.com.
Clinical Trial Enrollment Information
Patients seeking information about how to participate in the clinical trial of CG0070 can obtain information by visiting the company's website at www.cellgenesys.com or by calling 800-648-6747, ext. 3210.
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, +1-650-266-3200.
Cell Genesys, Inc.CONTACT: Ina Cu, Investor Relations of Cell Genesys, Inc., +1-650-266-3200
Web site: http://www.cellgenesys.com//
