Dendreon Presents Updated IMPACT Results Confirming PROVENGE Improves Overall Survival in Patients with Metastatic Castrate-Resistant Prostate Cancer

-- Data to be Presented at ASCO-GU Annual Symposium --

SEATTLE, March 3, 2010—Dendreon Corporation (Nasdaq: DNDN) today announced updated results from its pivotal Phase 3 IMPACT (IMmunotherapy for Prostate AdenoCarcinoma Treatment) study demonstrating that PROVENGE® (sipuleucel-T) extends overall survival in men with metastatic, castrate-resistant (hormone-refractory) prostate cancer (CRPC). The data will be presented at the American Society of Clinical Oncology 2010 Genitourinary Cancers Symposium (ASCO-GU) in San Francisco on Friday, March 5 at 1:45 pm PT.

A sensitivity analysis performed with longer-term follow-up (36.5 months) and additional events (349 deaths) collected at the time of study closure demonstrated that PROVENGE increased three-year survival by 40 percent compared to placebo (32.1 percent vs 23.0 percent), the median survival difference of PROVENGE compared to placebo was maintained at 4.1 months, with a 24.1 percent reduction in the risk of death [HR=0.759] and a p-value of 0.017.

As previously reported in a primary analysis (34.1 months median follow-up; 331 deaths), the IMPACT study met its pre-specified primary endpoint of significantly improving overall survival compared to placebo, demonstrating that PROVENGE increased three-year survival by 38 percent compared to placebo (31.7 percent vs 23.0 percent), extending median survival by 4.1 months compared to placebo (25.8 months vs. 21.7 months), with a 22.5 percent reduction in the risk of death [HR=0.775] and a p-value of 0.032.

In addition, new analyses demonstrated that the median predicted survival of the two treatment arms using the Halabi model were well balanced (20.3 months for PROVENGE vs 21.2 months for placebo). Furthermore, in an analysis in which patients were censored at the time of docetaxel use, the PROVENGE treatment effect remained strong [HR=0.649].

As previously reported, the most common adverse reactions were chills, fever, headache, aches, influenza-like illness and sweating.
"The results from the IMPACT study corroborate earlier studies with sipuleucel-T in demonstrating an improvement in overall survival for men with metastatic castration resistant prostate cancer. This is the first therapeutic vaccine to demonstrate a survival benefit in cancer," said Philip Kantoff, M.D., Director of the Lank Center for Genitourinary Oncology, Chief of the Division of Solid Tumor Oncology, and Chief Clinical Research Officer at Dana-Farber Cancer Institute, Professor of Medicine at Harvard Medical School, and principal investigator of the IMPACT study. "Furthermore, the results of this study validate cancer immunotherapy as an entirely new treatment paradigm that can provide patients with a clinically meaningful survival benefit coupled with a well-tolerated safety profile."

Dendreon is seeking licensure for PROVENGE for men with metastatic CRPC and submitted an amended Biologics License Application for PROVENGE, for which the U.S. Food and Drug Administration assigned a Prescription Drug User Fee Act date of May 1, 2010.


IMPACT Study Detail

IMPACT (IMmunotherapy for Prostate AdenoCarcinoma Treatment) was a 512-patient, multi-center, randomized, double-blind, placebo-controlled study evaluating men with asymptomatic or minimally symptomatic, metastatic, castrate-resistant prostate cancer, and the primary endpoint was overall survival.

About PROVENGE

PROVENGE is Dendreon's investigational product candidate for men with advanced prostate cancer and may represent the first in a new class of active cellular immunotherapies (ACIs) specifically designed to engage the patient's own immune system against cancer. PROVENGE and other ACIs 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.

About Dendreon
Dendreon Corporation is a biotechnology company focused on the discovery, development and commercialization of novel therapeutics that may significantly improve cancer treatment options for patients. The Company applies its expertise in processing antigen-presenting cells and identifying and engineering antigens to produce active cellular immunotherapy (ACI) products, which are designed to stimulate a tumor-directed immune response. Dendreon is also developing an orally-available small molecule that targets TRPM8 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 www.dendreon.com.

This news release contains forward-looking statements that are subject to risks and uncertainties. Factors that could affect these forward-looking statements include, but are not limited to, developments affecting Dendreon's business and prospects, including progress on the commercialization efforts for PROVENGE and requisite receipt of FDA licensure for marketing and the risk that additional capital could be needed in the future for the potential commercialization of PROVENGE. 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 www.sec.gov. Dendreon cautions investors not to place undue reliance on the forward-looking statements contained in this press release. All forward-looking statements are based on information currently available to Dendreon on the date hereof, and Dendreon undertakes no obligation to revise or update these forward-looking statements to reflect events or circumstances after the date of this press release, except as required by law.

Contact Information:
Katherine Stueland
Vice President, Corporate Communications and Investor Relations
206-829-1522
kstueland@dendreon.com