Dendreon Awarded Patent for Monoclonal Antibody Therapy Targeting HLA-DR Positive Malignancies.

Business Editors, Health/Medical Writers

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Dendreon Corporation (Nasdaq:DNDN) today announced that it has been awarded U.S. patent No. 6,416,958 "Selective Apoptosis of Neoplastic Cells by an HLA-DR specific Monoclonal Antibody."

The patent covers all monoclonal antibody therapies that target the HLA-DR molecule on tumor cells and induce cell death (apoptosis) in those cancer cells.

"This patent gives Dendreon broad protection for our monoclonal antibody product candidates aimed at treating leukemias and lymphomas," said Reiner Laus, M.D., vice president of research at Dendreon. "The claims not only cover our lead monoclonal antibody candidate, DN1924, but any antibody that induces programmed cell death in HLA-DR positive malignant cells."

There are an estimated 386,000 patients with HLA-DR positive hematologic malignancies and approximately 83,000 new cases annually. HLA-DR is expressed in a number of different hematologic cancers including Non-Hodgkin's and Hodgkin's lymphomas, chronic lymphocytic leukemia and multiple myeloma, as well as in certain epithelial malignancies. In preclinical studies to date, DN1924 has been shown to induce apoptosis in cancer cells expressing HLA-DR but has no effect on normal cells and is not immunosuppressive. Monoclonal antibodies have been proven to be an effective form of therapy for treating cancer and autoimmune diseases, with annual sales estimated to exceed $2 billion in 2002.

"This patent will position us to become the dominant player in antibodies directed against HLA-DR positive malignancies. We are pleased that DN1924 is in line to be one of the first monoclonal antibodies from Dendreon's pipeline to enter clinical development," said Christopher S. Henney, Ph.D., D.Sc., chief executive officer. "Other antibodies are already undergoing preclinical testing for the potential treatment of soft tissue malignancies such as prostate, breast and colon cancer and autoimmune diseases such as rheumatoid arthritis. We believe we now have one of the most diverse and robust antibody programs and are working hard to advance these exciting opportunities into the clinic as soon as possible."

Dendreon Corporation is dedicated to the discovery and development of novel products for the treatment of cancer through its innovative manipulation of the immune system. Dendreon's product pipeline includes therapeutic vaccines, monoclonal antibodies and a pathway to small molecules. 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 the potential for a successful challenge to Dendreon's intellectual property by a third party, the company's dependence upon intellectual property rights, risks that the company may be unable to develop a successful product Dendreon's limited operating history, risks associated with the completing or failing to complete clinical trials, the risk that the safety and/or efficacy results of a clinical trial will not support an application for a biologics license, the risk the company may not satisfy regulatory requirements or that the FDA will not be satisfied with the data we provide or approve a product for which a biologics license has been applied, the uncertainty of Dendreon's future access to capital, the failure by Dendreon to secure and maintain relationships with collaborators and dependence on the efforts of third parties. 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 US. Securities and Exchange Commission, including the Company's annual report on Form 10-K for the year ended December 31, 2001, which are available at www.sec.gov.