Dendreon Presents Preclinical Data Validating Anti-Tumor Activity of D-3263, a Trp-P8 Agonist

SEATTLE and GENEVA, Oct. 23 /PRNewswire-FirstCall/ — Researchers from Dendreon Corporation today presented preclinical data on its lead small molecule candidate, D-3263, which targets Trp-p8 (a transmembrane cation channel protein also known as Trp-M8), supporting Trp-p8 as a therapeutic cancer target.

The poster, titled, “Preclinical Validation of the TrpM8 Ion Channel as a Cancer/ Benign Prostate Hyperplasia Target,” was presented at the European Organization for Research and Treatment of Cancer, National Cancer Institute and American Association for Cancer Research Symposium on molecular targets and cancer therapeutics taking place in Geneva, Switzerland, on October 23, 2008.

“These data provide us with additional evidence supporting the potential for D-3263 as an important new investigational therapy for cancer and also potentially for benign prostatic hyperplasia (BPH),” said David Urdal, Ph.D., chief scientific officer of Dendreon.

Results showed that in vitro, D-3263 selectively increases the influx of calcium into Trp-p8 expressing cells leading to cell death. In in vivo animal models, D-3263 significantly inhibited the growth of Trp-p8 expressing tumors in both CHO/TRP-P8 expressing tumors as well as a human prostate cancer xenograft tumor models using the LuCaP 35 prostate cancer cell line. The mean tumor volume in the LuCaP 35 model in animals treated with D-3263 was 123.7 mm3 compared to 207.6 mm3 in the control arm (p=0.004) In addition, D-3263 significantly reduced (p=0.004) the effects of androgen-induced BPH in animal models.

“We previously reported that D-3263 can selectively kill cells that over-express Trp-p8, and these data further substantiate its attractiveness as a molecule for treating cancer and potentially BPH,” said Dr. Urdal. “We look forward to filing an investigational new drug application with the U.S. Food and Drug Administration later this year to evaluate the compound in a Phase 1 dose escalation study in cancer.”

About Trp-p8

Trp-p8 (also known as Trp-M8) was identified through Dendreon’s in-house discovery efforts. It is an ion channel that is triggered by cold temperatures and small-molecule agonists. In normal human tissues Trp-p8 is expressed predominantly in the prostate where it is over-expressed in BPH and prostate cancer, as well as a range of other cancers including breast, lung and colon. Dendreon has synthesized bioavailable small molecule agonists that activate the Trp-p8 ion channel and induce cell death.

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 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 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 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, 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/.

Dendreon Corporation

CONTACT: Investors: Jennifer Williams, Investor Relations of DendreonCorporation, +1-206-829-1500, Media: Katherine Stueland of WeissComm Partnersfor Dendreon Corporation, +1-312-208-0320

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