UPDATE: Dendreon Announces Prelim. Data for PROVENGE Shows Positive Immune Response

Dendreon Corporation (NASDAQ: DNDN) announced today that fourabstracts featuring PROVENGE^® (sipuleucel-T) data from ongoing Phase IIsequencing studies and the PROCEED registry, and two abstracts highlightingpreliminary Phase II data of DN24-02, an investigational active cellularimmunotherapy in patients with surgically resected HER2+ urothelial cancer,will be presented at the 49^th Annual Meeting of the American Society ofClinical Oncology (ASCO) from May 31-June 4, 2013 in Chicago, IL.Data from an open-label study demonstrate the presence of existingimmunological memory in advanced prostate cancer patients retreated withPROVENGE several years after initial treatment for androgen dependent prostatecancer (ADPC) in the Phase III PROTECT study. In addition, the retreatmentappeared to boost product potency compared with prior treatment. Separately,data from two Phase II studies indicate that PROVENGE can be combined withandrogen deprivation therapy (ADT) or abiraterone acetate plus prednisone.“These studies help us understand how PROVENGE may be combined or sequencedwith other advanced prostate cancer treatments,” said Mark Frohlich, M.D.,executive vice president of research and development and chief medical officerat Dendreon. “We are also pleased with the preliminary data demonstrating thatthe antigen-presenting cell activity of DN24-02 for HER2+ urothelial cancer issimilar to that of PROVENGE. The data highlight the promise of our activecellular immunotherapy platform and furthers Dendreon's position as a leaderin personalized cancer therapies.”Studies evaluating PROVENGE and DN24-02 data at ASCO include:PROVENGE: * A Randomized Phase II Study Evaluating the Optimal Sequencing of Sipuleucel-T and Androgen Deprivation Therapy (ADT) in Biochemically-Recurrent Prostate Cancer (BRPC): Immune Results (Abstract 5016). Data suggest that combining ADT with sipuleucel-T may augment adaptive immunity. PROVENGE is not indicated for the treatment of biochemically-recurrent prostate cancer.Poster discussion session: Genitourinary Cancer, Saturday, June 1, 12:00 PM –1:00 PM CDT., E Arie Crown Theater Lead Author: Emmanuel StylianosAntonarakis, M.D., Sidney Kimmel Comprehensive Cancer Center at John HopkinsUniversity, Baltimore, MD * A Randomized Phase II Trial of Sipuleucel-T with Concurrent or Sequential Abiraterone Acetate (AA) Plus Prednisone (P) in Metastatic Castrate-Resistant Prostate Cancer (mCRPC) (Abstract 5047). In a Phase II clinical study, the data suggest sipuleucel-T can be successfully manufactured during concurrent AA plus P with no significant changes in peripheral immune responses or alterations in adverse event profiles.General poster session: Genitourinary Cancer, Monday, June 3, 8:00 AM – 11:45AM CDT., S Hall A2 Lead Author: Eric J. Small, M.D., Department of Medicine,University of California San Francisco, San Francisco, CA * Impact of Prior Docetaxel on Sipuleucel-T Product Parameters in PROCEED Patients (Abstract 5034). In an ongoing, Phase IV registry of patients administered sipuleucel-T regardless of prior docetaxel use, the data suggest that antigen presenting cell activation in sipuleucel-T is not impaired following docetaxel treatment.General poster session: Genitourinary Cancer, Monday, June 3, 8:00 AM – 11:45AM CDT., S Hall A2 Lead Author: Celestia S. Higano, M.D., FACP Seattle CancerCare Alliance, Seattle, WA * Open-Label, Multicenter Study of Sipuleucel-T in Men with Metastatic Castration-Resistant Prostate Cancer (mCRPC) Previously Treated with Sipuleucel-T: Evaluation of Antigen Presenting Cell (APC) Activation and ELISPOT Data (Abstract 5053). In a study designed to evaluate the product potency in the retreatment of patients with sipuleucel-T, the data indicate the presence of existing immunological memory to sipuleucel-T years following initial treatment, and retreatment appeared to boost product potency compared with prior treatment. The patients were initially treated with sipuleucel-T when they had ADPC, and were retreated after they developed mCPRC. PROVENGE is not indicated for the treatment of ADPC and the safety and effectiveness of retreatment have not been established.General poster session: Genitourinary Cancer, Monday, June 3, 8:00 AM – 11:45AM CDT., S Hall A2 Lead Author: Tomasz M Beer, M.D., Oregon Health & ScienceUniversity Knight Cancer Institute, Portland, ORDN24-02: * Preliminary Safety, Product Parameters, and Immune Response Assessments From A Phase II Randomized, Open-Label Trial of DN24-02, an Autologous Cellular Immunotherapy (ACI), In Patients with Surgically Resected HER2+ Urothelial Cancer at High Risk for Recurrence (Abstract 4547). In an ongoing Phase II study, preliminary data on the adverse events and immune response of DN24-02 indicate that antigen presenting cell activity is comparable to that of sipuleucel-T and positive immune responses were observed.General poster session: Genitourinary (Nonprostate) Cancer, Monday, June 3,8:00 AM – 11:45 AM CDT., S Hall A2 Lead Author: Dean F. Bajorin, M.D.,Memorial Sloan-Kettering Cancer Center, New York, NY * Preliminary HER2 Expression Data from NeuACT, the Phase II Randomized, Open-Label Trial of DN24-02 in Patients with Surgically Resected HER2+ Urothelial Cancer (UC) at High Risk for Recurrence (Abstract 4527). In an ongoing Phase II study, preliminary data on HER2 expression in urothelial cancer suggest a high incidence of HER2 expression (>74%) in urothelial cancer primary tumor and lymph node specimens from patients, with higher expression observed in lymph node specimens.Poster discussion session: Genitourinary (Nonprostate) Cancer, Tuesday, June4, 11:30 AM – 12:30 PM CDT., E354a Lead Author: Michael Press, M.D.,University of Southern California Norris Comprehensive Cancer Center, LosAngeles, CA