SOUTH SAN FRANCISCO, Calif. and PRINCETON, N.J., June 3 /PRNewswire-FirstCall/ -- Cell Genesys, Inc. and Medarex, Inc. today announced encouraging data from a Phase 1 clinical trial of Cell Genesys' 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 GVAX plus either of 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 either 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. These data were presented today by Winald Gerritsen, M.D., Ph.D., director of the University Hospital Vrije Universiteit Cancer Center in Amsterdam, at the annual meeting of the American Society of Clinical Oncology (ASCO) being held in Atlanta, GA.
This dose-escalation combination trial was designed to enroll up to a total of approximately 25 patients with metastatic, hormone-refractory prostate cancer (HRPC). The treatment dose for GVAX(R) immunotherapy for prostate cancer used in this combination trial is the same dose currently being tested in Cell Genesys' VITAL-1 Phase 3 trial. The treatment dose for ipilimumab is being escalated in sequential groups of three patients and has now reached the same treatment dose or higher than that currently being tested in an ongoing Medarex Phase 3 clinical trial in melanoma. The primary endpoints of the study are safety and the determination of a maximum tolerated dose for the combination therapy. Efficacy endpoints include time to clinical disease progression, time to PSA progression and PSA response, immune response to GVAX, reduction in metabolic bone activity and survival. The study is being conducted under a research collaboration agreement between Cell Genesys, Inc. and Medarex, Inc. signed in 2003 which provides an equal sharing of expenses for the above clinical trial.
"We are very encouraged by the frequency of antitumor responses seen in this trial, which we believe is unprecedented for a combination of any two immunotherapies in advanced prostate cancer," stated Joseph J. Vallner, Ph.D., president and chief operating officer of Cell Genesys. "In addition, we believe these findings provide further support for our ongoing Phase 3 trials of GVAX immunotherapy for prostate cancer and additional validation for the GVAX immunotherapy platform in general."
"We are also encouraged by the data reported today and are looking forward to receiving additional results from this important combination clinical trial in prostate cancer," said Donald L. Drakeman, J.D., Ph.D., president and chief executive officer of Medarex. "Ipilimumab is a potent activator of the immune response and a product which we believe has great potential for treatment of multiple types of cancer, including melanoma which is our lead effort now in Phase 3 development."
GVAX immunotherapy for prostate cancer is currently being studied as a single agent and in combination with docetaxel chemotherapy in two Phase 3 clinical trials expected to enroll approximately 1200 patients with metastatic HRPC. Cell Genesys received Special Protocol Assessments (SPA) from the Food and Drug Administration (FDA) for each of the Phase 3 studies and recently also received Fast Track designation for the product. The company's ongoing Phase 3 program is supported by the median survival results from two, independent, multi-center Phase 2 clinical trials in approximately 115 patients that are not only consistent with each other, but also compare favorably to the previously published median survival of 18.9 months for metastatic HRPC patients treated with Taxotere(R) (docetaxel) chemotherapy plus prednisone, the current standard of care. GVAX immunotherapy for prostate cancer is comprised of two prostate cancer cell lines that have been modified to secrete GM-CSF (granulocyte-macrophage colony stimulating factor), an immune stimulatory hormone, and irradiated for safety. GVAX cancer immunotherapy for prostate cancer is being developed as a non patient- specific, "off-the-shelf" pharmaceutical product.
Clinical Trials Information for GVAX:
Patients seeking information about clinical trials of GVAX immunotherapy for prostate cancer can obtain information by calling 1.866.275.8580, and also by checking http://www.clinicaltrials.gov (keyword: GVAX) and by visiting the company's website at http://www.cellgenesys.com.
Ipilimumab (also known as MDX-010) is a fully human antibody against human CTLA-4, a molecule on T cells that is believed to be responsible for suppressing the immune response. Medarex and Bristol-Myers Squibb are investigating the potential of ipilimumab to enable the immune systems of cancer patients to help suppress tumor growth. Ipilimumab is currently being evaluated in two registrational studies as second-line therapy for metastatic melanoma under two separate Special Protocol Assessment (SPA) agreements with the FDA. One is a newly initiated monotherapy study, to be completed this year, and the other is a study in combination with MDX-1379 (a melanoma peptide vaccine). A front-line dacarbazine combination registrational study is expected to initiate this year. Ipilimumab is also being evaluated in multiple Phase II clinical trials to investigate the product's potential activity in other tumor types, as well as in combination studies with chemotherapy, immunotherapy and vaccines. Further information regarding the Medarex ipilimumab program can be found in Medarex's public disclosure filings with the U.S. Securities and Exchange Commission (SEC).
Clinical Trials Information for Ipilimumab:
For study enrollment information, in the United States and Canada contact 1-866-892-1BMS Ext. 342 or http://www.clinicaltrials.gov. Outside of the United States and Canada, call 1-941-906-4711 Ext. 342.
About Cell Genesys
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.
About Medarex
Medarex is a biopharmaceutical company focused on the discovery, development and potential commercialization of fully human antibody-based therapeutics to treat life-threatening and debilitating diseases, including cancer, inflammation, autoimmune disorders and infectious diseases. Medarex applies its UltiMAb(R) technology and product development and clinical manufacturing experience to generate, support and potentially commercialize a broad range of fully human antibody product candidates for itself and its partners. Thirty-two of these therapeutic product candidates derived from Medarex technology are in human clinical testing or have had INDs submitted for such trials, with four of the most advanced product candidates currently in Phase III clinical trials. Medarex is committed to building value by developing a diverse pipeline of antibody products to address the world's unmet healthcare needs. For more information about Medarex, visit its website at http://www.medarex.com.
For Cell Genesys: Statements made herein about the company, other than statements of historical fact, including statements about the company's progress, financial results, timing and results 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 funding. 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.
For Medarex: Except for the historical information presented herein, matters discussed herein may constitute forward-looking statements that are subject to certain risks and uncertainties that could cause actual results to differ materially from any future results, performance or achievements expressed or implied by such statements. Statements that are not historical facts, including statements preceded by, followed by, or that include the words "potential"; "believe"; "anticipate"; "intend"; "plan"; "expect"; "estimate"; "could"; "may"; or similar statements are forward-looking statements. Medarex disclaims, however, any intent or obligation to update these forward-looking statements. Risks and uncertainties include risks associated with product discovery and development, uncertainties related to the outcome of clinical trials, slower than expected rates of patient recruitment, unforeseen safety issues resulting from the administration of antibody products in patients, uncertainties related to product manufacturing as well as risks detailed from time to time in Medarex's public disclosure filings with the U.S. Securities and Exchange Commission (SEC), including its Annual Report on Form 10-K for the fiscal year ended December 31, 2005 and subsequent Quarterly Reports on Form 10-Q. There can be no assurance that such development efforts will succeed or that other developed products will receive required regulatory clearance or that, even if such regulatory clearance were received, such products would ultimately achieve commercial success. Copies of Medarex's public disclosure filings are available from its investor relations department.
Cell Genesys(R) and GVAX(R) are registered trademarks of Cell Genesys, Inc. All rights are reserved.
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Contacts: Ina Cu Laura Choi (Investor Relations) Cell Genesys, Inc. Medarex, Inc. 650-266-3200 609-430-2880, x2216 Jean Mantuano (Corporate Communications) Medarex, Inc. Phone: 609-430-2880, x2221
Cell Genesys, Inc.; Medarex, Inc.CONTACT: Ina Cu of Cell Genesys, Inc., +1-650-266-3200; Laura Choi(Investor Relations), +1-609-430-2880 ext. 2216, or Jean Mantuano(Corporate Communications), +1-609-430-2880 ext. 2221, both of Medarex,Inc.
