Provenge with Avastin Impacts PSA Doubling Time in Patients with Biochemically-Relapsed Prostate Cancer

Main Category: Cancer / Oncology
Article Date: 22 Feb 2005 - 2:00 PDT


Dendreon Corporation announced that results from its NCI-sponsored Phase 2 study of Provenge(R), in combination with Avastin(TM) (bevacizumab), increased PSA doubling time (PSADT) in patients with prostate cancer that had relapsed after prior surgical and radiation therapy. Provenge is the Company's investigational immunotherapy for the treatment of prostate cancer.

The data were presented today by Brian Rini, M.D., assistant professor of medicine, University of California, San Francisco, at the 2005 Multidisciplinary Prostate Cancer Symposium.

Study Details & Results

Twenty-two patients with androgen-dependent prostate cancer who had undergone prior definitive surgical or radiation therapy were enrolled and treated in this Phase 2 trial, known as the P-16 study.

Provenge was given intravenously (IV) on weeks one, two and four. Patients were given 10 mg/kg of IV Avastin immediately following Provenge and continued every two weeks thereafter until disease progression or toxicity was observed. Disease progression was defined as a doubling of the baseline or nadir PSA value or the development of metastases. PSA measurements were recorded and PSADT was calculated.

The median pre-treatment PSADT for the 21 evaluable patients was 6.7 months and the median on-treatment PSADT was 12.7 months, an approximate 90 percent increase in PSADT (p = 0.004). Eight patients displayed at least a 200 percent increase (range, 212 percent - 758 percent) in PSADT while on study compared with their pretreatment rate of change. In addition, 41 percent of patients exhibited a decrease in their absolute PSA value from baseline (range, 6 to 72 percent). No patient on study had objective disease progression (defined as the onset of measurable bone or soft tissue metastatic disease). Four patients were removed from study due to toxicity (congestive heart failure, hypertension, cerebrovascular ischemia and proteinuria).

"These results provide encouraging proof-of-concept that Provenge can be safely combined and work synergistically with other immune-modulating therapies such as Avastin for the treatment of men with prostate cancer," said Dr. Rini. "PSA doubling time has become increasingly used as a measure of prostate cancer disease biology. The alteration in PSADT seen in this trial may reflect the biologic effect of this combination therapy. If proven effective, the combination of Provenge with Avastin, or other immune modulating therapies, could prove to be an appealing treatment alternative for prostate cancer patients."

Provenge is an active immunotherapy designed to stimulate the immune system to attack cells that express prostatic acid phosphatase (PAP), a protein expressed on approximately 95 percent of prostate cancer cells. Avastin is a VEGF inhibitor. VEGF is a pro-angiogenic protein with inhibitory effects on dendritic (DC) cells. VEGF inhibition with Avastin has been shown to result in enhanced tumor rejection after DC-based vaccination in pre-clinical models.

About Prostate Cancer

Prostate cancer is the number one non-skin cancer in the United States and the third most common cancer worldwide. More than one million men in the United States have prostate cancer, with an estimated 232,000 new cases of prostate cancer diagnosed each year. More than 30,000 men die each year of the disease.

About Provenge

Provenge is designed to stimulate a patient's immune system against prostate cancer. It is developed through Dendreon's proprietary Antigen Delivery Cassette(TM) technology, which utilizes a recombinant form of an antigen found in 95 percent of prostate cancers, prostatic acid phosphatase (PAP). Provenge is being further evaluated in the ongoing, pivotal Phase 3 trial (D9902B) under a Special Protocol Assessment agreement with the U.S. Food and Drug Administration. Provenge also has Fast Track designation. The double-blind, placebo-controlled trial is enrolling patients at leading cancer centers around the country. To learn more about the trial, go to http://www.dendreon.com.

About Dendreon

Dendreon Corporation is a biotechnology company whose mission is to target cancer and transform lives through the development of innovative cancer treatments. In addition to its immunotherapies in clinical and preclinical development for a variety of cancers, Dendreon's product pipeline also includes monoclonal antibody and small molecule product candidates. Dendreon has research and development alliances with Genentech, Inc., Abgenix, Inc. and Dyax Corp. For more information about the company and its programs, visit http://www.dendreon.com.

Except for historical information contained herein, this news release contains forward-looking statements that are subject to risks and uncertainties surrounding the efficacy of Provenge to treat men suffering from prostate cancer, risks and uncertainties surrounding the presentation of data to the FDA and approval of product applications by the FDA and risks and uncertainties inherent in the process of discovering, developing and commercializing drugs that are safe and effective for use as human therapeutics. Factors that may cause such differences include risks related to our limited operating history, risks associated with completing our clinical trials, the risk that the safety and/or efficacy results of a clinical trial for Provenge will not support an application for a biologics license, the risk that the FDA may interpret data differently than we do or require more data or a more rigorous analysis of data than expected, the risk that the FDA will not approve a product for which a biologics license has been applied, the risk that the results of a clinical trial for Provenge or other product may not be indicative of results obtained in a later clinical trial, risks that we may lack the financial resources and access to capital to fund required clinical trials or commercialization of Provenge, our dependence on the efforts of third parties, including collaborators, and our dependence on intellectual property. Further information on the factors and risks that could affect Dendreon's business, financial condition and results of operations, are contained in Dendreon's public disclosure filings with the U.S. Securities and Exchange Commission.

Dendreon Corporation
http://www.dendreon.com

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