Dendreon anti-Her-2/neu Cancer Vaccine Shown to Eradicate Tumors and Prolong Survival; Preclinical Results of APC8024 Published in International Journal of Cancer.

Business Editors & Health/Medical Writers

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SEATTLE--(BUSINESS WIRE)--Nov. 6, 2002

Researchers at Dendreon Corporation (Nasdaq:DNDN) have demonstrated that a version of their anti-Her-2/neu cancer vaccine APC8024, currently being tested in patients with breast, ovarian and colon cancer, is effective in the treatment of cancer in mice.

The results are published in the current issue of the International Journal of Cancer.

Results demonstrated that all tumor-bearing mice treated with three injections of the vaccine showed greatly prolonged survival and remained healthy throughout the period of study. In contrast, 80 percent of control-treated mice died from tumor within 7 weeks. The vaccine was shown to induce potent T-cell immunity in mice and protect mice from injection with Her-2 expressing tumors.

The publication, "Antitumor Vaccination with Her-2 Derived Recombinant Antigens," details Dendreon's vaccine approach to treating tumors that express the Her-2/neu marker. In humans, Her-2/neu is overexpressed in approximately 25 percent of metastatic breast, ovarian, pancreatic and colon cancers.

"Our approach provides a powerful, reproducible way to stimulate the immune system to attack Her-2/neu positive tumor cells," said Reiner Laus, M.D., vice president of research. "Our method of genetically engineering proteins to optimize their uptake and processing by antigen presenting cells is the same approach we have used in the development of Provenge(TM), our therapeutic prostate cancer vaccine that recently produced promising results in a Phase III clinical trial. We are currently investigating this approach in Phase I clinical trials of APC8024 and look forward to presenting initial results later this year."

To create the vaccine, researchers first selected intra-cellular and extra-cellular portions of the Her-2/neu protein and combined them to form a genetically engineered fusion protein. The engineered protein was then added to antigen presenting cells or dendritic cells, powerful immune system stimulators, and injected into cancer bearing mice.

"This research further strengthens Dendreon's expanding therapeutic vaccine platform," said David Urdal, Ph.D., president and chief scientific officer. "Our APC8024, anti-Her-2/neu, vaccine combined with our Provenge program allows Dendreon to target potential markets valued at more than $4 billion."

For more information on Dendreon's clinical trials, please visit the "Clinical" section at www.dendreon.com.

Dendreon Corporation is a biotechnology company developing targeted therapies for cancer. Dendreon currently has three therapeutic vaccines in clinical trials. Dendreon's product pipeline also includes monoclonal antibodies and a pathway to small molecules. Dendreon has established important alliances with industry leaders Genentech, Johnson & Johnson Pharmaceutical Research & Development, L.L.C. and Kirin Brewery Co., Ltd. For more information, visit www.dendreon.com.

Except for historical information contained herein, this news release contains forward-looking statements that are subject to risks and uncertainties that may cause actual results to differ materially from the results discussed in the forward-looking statements, particularly those 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 a difference include risks relating to the efficacy of Provenge, risks and uncertainties surrounding the presentation of data to the FDA and approval of product applications by the FDA, risks related to Dendreon's limited operating history, risks associated with completing our clinical trials, including 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 will not be satisfied with the data we provide for Provenge or 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, 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 SEC reports, which are available at www.sec.gov.