Dendreon Corporation Initiates Second of Two New Phase 2 Trials of PROVENGE for Prostate Cancer

SEATTLE, Aug. 14 /PRNewswire-FirstCall/ -- Dendreon Corporation today announced that the Company has initiated its second of two new Phase 2 trials of PROVENGE(R) (sipuleucel-T), Dendreon's investigational active cellular immunotherapy for the treatment of advanced prostate cancer. The multicenter trial, called ProACT (PROstate Active Cellular Therapy), has begun enrolling 120 patients with metastatic, androgen independent prostate cancer.

All patients will receive active treatment but will be randomized into one of three cohorts which will receive PROVENGE manufactured with different concentrations of the immunizing antigen. Patients will receive three infusions of PROVENGE, each two weeks apart. The trial is being conducted by Dendreon to explore the effect of antigen concentration on CD54 upregulation, a measure of product potency, as well as the immune response. Overall survival data will also be collected. The enrollment criteria are essentially the same as the criteria for the Phase 3 IMPACT (IMmunotherapy for Prostate AdenoCarcinoma Treatment, also known as D9902B) study, which completed enrollment in October 2007 and, upon receipt of positive data, will serve as the primary study for amending Dendreon's Biologics License Application (BLA) for PROVENGE.

"We are grateful for the continued support from patients, physicians and patient advocates and are pleased to be able to provide them with access to PROVENGE while we await results from the IMPACT trial," stated Mitchell H. Gold, president and chief executive officer of Dendreon.

ProACT is the second of two studies the Company is initiating. Dendreon recently announced it had begun enrolling patients in a 40-subject, single-center trial called NeoACT (NEOadjuvant Active Cellular immunoTherapy), or P07-1, which is being conducted at UCSF Helen Diller Family Comprehensive Cancer Center.

About Prostate Cancer

Prostate cancer is the most common 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 186,320 new cases expected to be diagnosed in 2008, and approximately 28,660 men expected to die this year from the disease. Currently there are limited treatment options for men with advanced, metastatic prostate cancer.

About Active Cellular Immunotherapy with PROVENGE

PROVENGE may represent the first product in a new class of active cellular immunotherapies (ACIs) that are uniquely designed to use live human cells to engage the patient's own immune system with the goal of eliciting a specific long-lasting response against cancer. Active cellular immunotherapy holds promise because it may provide patients with a meaningful clinical benefit, such as survival, combined with low toxicity.

About Dendreon

Dendreon Corporation is a biotechnology company whose mission is to target cancer and transform lives through the discovery, development and commercialization of novel therapeutics. The Company applies its expertise in antigen identification, engineering and cell processing to produce active cellular immunotherapy product candidates designed to stimulate an immune response. Dendreon is also developing an orally-available small molecule that targets Trp-p8 that could be applicable to multiple types of cancer as well as benign prostatic hyperplasia. The Company has its headquarters in Seattle, Washington and is traded on the Nasdaq Global Market under the symbol DNDN. 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 existing clinical trials or from additional clinical trials for PROVENGE will not support approval 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, 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, which are available at http://www.sec.gov.

CONTACT: Jennifer Williams, Investor Relations of Dendreon Corporation,
+1-206-829-1500; or Katherine Stueland of WeissComm Partners,
+1-312-208-0320, for Dendreon Corporation

Web site: http://www.dendreon.com/

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