Dendreon Announces Presentation of PROVENGE Data at the 2011 Genitourinary Cancers Symposium Annual Meeting

SEATTLE, Feb. 17, 2011 /PRNewswire/ -- Dendreon Corporation (Nasdaq: DNDN) today announced the following data presentations taking place at the 2011 Genitourinary Cancers Symposium annual meeting in Orlando, Florida.

• "Subsequent Treatment with APC8015F May Have Prolonged Survival of the Control Arm in Phase 3 Sipuleucel-T Studies," abstract #139.  Reception and General Poster Session B: Prostate Cancer (A33) from 4:50 to 6:20 p.m. ET on Thursday, February 17, 2011.
• "Characterization of Antigen-Specific T cell Activation and Cytokine Expression Induced by Sipuleucel-T," abstract #155. Reception and General Poster Session B: Prostate Cancer (A49) from 4:50 to 6:20 p.m. ET on Thursday, February 17, 2011.

Abstract #139: Subsequent Treatment with APC8015F May Have Prolonged Survival of the Control Arm in Phase 3 Sipuleucel-T Studies

This exploratory analysis evaluated the survival of patients who were randomized to the control arm in the three metastatic castrate resistant prostate cancer PROVENGE® (sipuleucel-T) Phase 3 clinical trials (D9901, D9902A, D9902B).  Control used in the trial was non-activated autologous peripheral blood mononuclear cells.  Patients in these trials who were randomized to receive control had the opportunity to participate in an open label Phase 2 protocol that allowed them to receive APC8015F, an investigational autologous cellular immunotherapy made from cryopreserved cells at the time of control generation.

Results from the exploratory analysis show patients treated with APC8015F (n=155) after their disease progressed had improved survival relative to the patients not treated in the control arm (n=61).  Following disease progression, the median survival of patients treated with APC8015F was 20.0 months compared to 9.8 months for control patients who did not receive APC8015F (HR=0.52 [95% CI: 0.37, 0.73]; P=0.0001).  While baseline prognostic factors tended to be more favorable in patients who received APC8015F, treatment with APC8015F remained associated with improved survival after adjusting for these factors (HR=0.55 [95% CI: 0.39, 0.78]; P<0.001).  The safety profile of APC8015F was consistent with that observed in the PROVENGE Phase 3 clinical trials.

Abstract #155: Characterization of Antigen-Specific T cell Activation and Cytokine Expression Induced by Sipuleucel-T

In PROVENGE (sipuleucel-T) Phase 2 and 3 clinical trials, patients underwent leukaphereses to collect peripheral blood mononuclear cells (PBMCs).  For the patients randomized to receive sipuleucel-T, the patient's PBMCs were cultured with PA2024, a recombinant fusion protein consisting of prostatic acid phosphatase (PAP) and granulocyte-macrophage colony-stimulating factor (GM-CSF), to generate the treatment (sipuleucel-T), which is then infused into the patient.

This presentation examined the role of GM-CSF in T cell activation and cytokine production in patients in the sipuleucel-T Phase 2 and 3 clinical trials (P07-2 ProACT and D9902B IMPACT).  For this analysis, a portion of PBMCs from each leukapheresis were cultured with GM-CSF and compared to sipuleucel-T (PBMCs cultured with PA2024) to evaluate T cell activation, cytokine production, and upregulation of the costimulatory molecules, CD54 and CD86.

The study showed a statistically significant increase in the production of a number of cytokines, including IL-2 (P<0.0001) and IFNγ (P=0.0019), from cells cultured with PA2024 compared to those cultured with GM-CSF.  Furthermore, CD54 upregulation was enhanced at week 2 in response to PA2024 but not GM-CSF.  The increased T cell activation and enhanced cytokine expression which occurred after the first infusion of sipuleucel-T also appeared to be PA2024-specific.  These data are consistent with sipuleucel-T generating in vivo priming of a T cell mediated immune response, and with these effects being independent of GM-CSF.

PROVENGE Indication and Safety

PROVENGE is an autologous cellular immunotherapy for the treatment of asymptomatic or minimally symptomatic metastatic castrate resistant (hormone refractory) prostate cancer.

PROVENGE is intended solely for autologous use and is not routinely tested for transmissible infectious diseases.

The safety evaluation of PROVENGE was based on 601 prostate cancer patients in four randomized clinical trials who underwent at least one leukapheresis procedure.  The most common adverse events (incidence greater than or equal to 15%) reported in patients in the PROVENGE group are chills, fatigue, fever, back pain, nausea, joint ache, and headache.  Serious adverse events reported in patients in the PROVENGE group include acute infusion reactions (occurring within 1 day of infusion) and cerebrovascular events.  In controlled clinical trials, severe (Grade 3) acute infusion reactions were reported in 3.5% of patients in the PROVENGE group.  Reactions included chills, fever, fatigue, asthenia, dyspnea, hypoxia, bronchospasm, dizziness, headache, hypertension, muscle ache, nausea, and vomiting.  No Grade 4 or 5 acute infusion reactions were reported in patients in the PROVENGE group.

To fulfill a post marketing requirement and as a part of the company's ongoing commitment to patients, Dendreon will conduct a registry of approximately 1,500 patients to further evaluate a small potential safety signal of cerebrovascular events.  In four randomized clinical trials of PROVENGE in prostate cancer patients, cerebrovascular events were observed in 3.5% of patients in the PROVENGE group compared with 2.6% of patients in the control group.

For more information on PROVENGE, please see the full Prescribing Information at www.provenge.com or call Dendreon ON Call at 1-877-336-3736

About Dendreon

Dendreon Corporation is a biotechnology company whose mission is to target cancer and transform lives through the discovery, development, commercialization and manufacturing of novel therapeutics.  The Company applies its expertise in antigen identification, engineering and cell processing to produce active cellular immunotherapy (ACI) product candidates designed to stimulate an immune response in a variety of tumor types.  Dendreon's first product, PROVENGE® (sipuleucel-T), was approved by the U.S. Food and Drug Administration (FDA) in April 2010 for the treatment of asymptomatic or minimally symptomatic metastatic castrate resistant (hormone refractory) prostate cancer.  Dendreon is exploring the application of additional ACI product candidates and small molecules for the potential treatment of a variety of cancers.  The Company is headquartered 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/.

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 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.

SOURCE Dendreon Corporation