September 27, 2013 - Dendreon Corporation (NASDAQ: DNDN) announced today the presentation of data from clinical studies featuring PROVENGE® (sipuleucel-T), an autologous cellular immunotherapy for metastatic castrate-resistant prostate cancer (mCRPC), at the 2013 European Cancer Congress in Amsterdam, September 27-October 1, 2013. Preliminary Phase II data surrounding DN24-02, an investigational autologous cellular immunotherapy for patients with surgically resected HER2+ urothelial cancer, will also be presented.

Preliminary data from a Phase II combination study demonstrated that PROVENGE product potency and immunological prime-boost responses are maintained when administered concurrently or sequentially with abiraterone acetate (AA) plus prednisone. Additionally, preliminary data from an ongoing open-label study of PROVENGE treatment in men with mCRPC who were previously treated with PROVENGE in the androgen dependent prostate cancer (ADPC) setting suggest long-lived immunological memory to PROVENGE years following initial treatment.

"The data presented at this Congress surrounding PROVENGE and DN24-02 further our understanding of the potential benefits of these personalized immunotherapies," said Mark Frohlich, M.D., executive vice president of research and development and chief medical officer at Dendreon. "The ability to sequence treatments such as PROVENGE with other therapies has the potential to transform the treatment of advanced prostate cancer, particularly in the current oncology landscape with the encouraging results from immunotherapy combination regimens."

Studies evaluating PROVENGE and DN24-02 data at the 2013 European Cancer Congress include:

PROVENGE:

  • A Phase II Trial of Sipuleucel-T in Combination with Concurrent or Sequential Abiraterone Acetate (AA) in Patients with Metastatic Castrate-Resistant Prostate Cancer (mCRPC) [Abstract 2860]. Data from a Phase II study suggested that PROVENGE can be successfully manufactured during concurrent AA plus prednisone treatment without affecting PROVENGE product potency and immunological prime-boost responses.
    Poster Discussion Session: Genitourinary Malignancies - Prostate Cancer, Monday, September 30, 11:30 AM CEST, Hall 7.2 Lead Author: Eric Small, M.D., University of California, San Francisco, CA
  • P10-1, an Open-Label, Multicenter Study of Sipuleucel-T in Men with Metastatic Castrate-Resistant Prostate Cancer (mCRPC) Previously Treated with Sipuleucel-T: Analysis of Immunological Data [Abstract 2909]. Preliminary data from an open-label study designed to evaluate the product potency and immune response to retreatment with PROVENGE suggested immunological memory to PROVENGE several years following initial treatment, and retreatment appeared to boost immunological measures. The patients were initially treated with PROVENGE when they had ADPC, and were retreated after they had progressed to mCPRC. The safety and effectiveness of PROVENGE has not been established for treatment of ADPC.
    General Poster Session: Genitourinary Malignancies - Prostate Cancer, Monday, September 30, 9:30 AM - 12:00 PM CEST, Hall 4 Lead Author: Tomasz Beer, M.D., Oregon Health & Science University, Knight Cancer Institute, Portland, OR
  • Preliminary Product Parameters from P11-1, a Phase II, Open-Label Trial of Sipuleucel-T in European Men with Metastatic Castrate-Resistant Prostate Cancer (mCRPC) [Abstract 2900]. Preliminary data demonstrated the manufacture of PROVENGE can be performed successfully by a European facility that serves multiple nations and resulted in a similar product parameter profile as PROVENGE manufactured in the U.S.
    General Poster Session: Genitourinary Malignancies - Prostate Cancer, Monday, September 30, 9:30 AM - 12:00 PM CEST, Hall 4 Lead Author: Peter Mulders, M.D., Radboud University Nijmegen Medical Centre, Netherlands
  • Metastatic Disease Detection is an Important Cause of Screen Failures in a Phase II Trial Evaluating the Optimal Sequence of Androgen Deprivation Therapy and Sipuleucel-T in Hormone-Naïve Patients with Biochemically-Recurrent Prostate Cancer (BRPC) [Abstract 2903]. Data analysis from the Phase II study indicated a high frequency of radiographic metastatic disease in the setting of hormone-naïve BRPC, which highlights the importance of screening for metastases in this early-stage patient population.
    General Poster Session: Genitourinary Malignancies - Prostate Cancer, Monday, September 30, 9:30 AM - 12:00 PM CEST, Hall 4 Lead Author: Adam Kibel, M.D., Dana-Farber Cancer Institute, Boston, MA

DN24-02:

  • NeuACT, a Phase II Randomised, Open-Label Trial of DN24-02 in Patients with Surgically Resected HER2+ Urothelial Cancer at High Risk for Recurrence: Updated Analysis of Product Parameters and Safety [Abstract 2907]. A preliminary analysis demonstrated positive immune responses to DN24-02, and suggested that antigen presenting cell activation is comparable to that of PROVENGE.
    General Poster Session: Genitourinary Malignancies - Prostate Cancer, Monday, September 30, 9:30 AM - 12:00 PM CEST, Hall 4 Lead Author: Dean Bajorin, M.D., Memorial Sloan-Kettering Cancer Center, New York, NY
  • HER2 Tissue Expression in NeuACT, a Phase II, Randomised, Open-Label Trial of DN24-02 in Patients with Surgically Resected HER2+ Urothelial Cancer (UC) at High Risk for Recurrence [Abstract 2928]. An interim analysis demonstrated a high prevalence of HER2 protein expression in high-risk UC, which is consistent with prior studies noting a higher incidence in UC lymph node tumors compared with primary tumors.
    General Poster Session: Genitourinary Malignancies - Prostate Cancer, Monday, September 30, 9:30 AM - 12:00 PM CEST, Hall 4 Lead Author: Michael Press, M.D., University of Southern California Norris Comprehensive Cancer Center, Los Angeles, CA

"These preliminary data are encouraging, and suggest that combining sipuleucel-T and abiraterone acetate plus prednisone is possible. It is not known if the potential for an immunostimulatory effect from low testosterone levels achieved with abiraterone may be offset by the potentially immunosuppressive effects of prednisone," said Eric J. Small, M.D., professor of medicine and chief, Division of Hematology and Oncology, University of California San Francisco and deputy director, Helen Diller Family Comprehensive Cancer Center. "This study demonstrated that the co-administration of sipuleucel-T with abiraterone acetate and prednisone was generally well tolerated, and did not affect the product characteristics of sipuleucel-T nor its capacity to show an immune response."

The European Commission (EC) recently granted marketing authorization for PROVENGE (autologous peripheral blood mononuclear cells activated with PAP-GM-CSF or sipuleucel-T) dispersion for infusion in the European Union (EU) for the treatment of asymptomatic or minimally symptomatic metastatic (non-visceral) castrate-resistant prostate cancer in male adults in whom chemotherapy is not yet clinically indicated.

About PROVENGE

U.S. Indication and Important Safety Information

PROVENGE® (sipuleucel-T) is an autologous cellular immunotherapy indicated 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. The most common adverse events (incidence greater-than or equal to 15%) are chills, fatigue, fever, back pain, nausea, joint ache, and headache. Serious adverse events reported 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 1500 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 the FDA approved full prescribing information, please visit http://www.provenge.com.

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. 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/.

Statements in this press release that are not strictly historical in nature constitute "forward-looking statements." Such statements include, but are not limited to, statements regarding the expected benefits of the restructuring, the timing and elements of the restructuring, the timing and form of related charges, the expected annual operating expense reduction, expectations and beliefs regarding Dendreon's financial position, profitability and Dendreon's ability to breakeven and achieve improved performance as a result of the restructuring, statements regarding sequencing studies, statements regarding studies to advance understanding of immunotherapy and the treatment of advanced prostate cancer, statements regarding biomarkers, expectations about the early detection study, expectations about advancing our pipeline, expectations regarding reductions of cost of goods sold, expectations regarding the presentation of clinical data, developments affecting Dendreon's U.S. and global business and prospects, beliefs and expectations regarding potential revenue and earnings from product sales, including beliefs regarding Dendreon's ability to grow sales, expectations regarding market size, target market, and market opportunity, beliefs regarding the impact of our direct to consumer advertising, expectations with respect to our sales force execution and effectiveness, progress generally on commercialization efforts for PROVENGE, and expectations about clinical trial enrollments. Such forward-looking statements involve known and unknown risks, uncertainties and other factors which may cause Dendreon's actual results to be materially different from historical results or from any results expressed or implied by such forward-looking statements. These factors include, but are not limited to, our inability to achieve and sustain commercial success for PROVENGE; the identification of efficacy, safety or other issues with PROVENGE; a slower than anticipated adoption by treating physicians of PROVENGE for the treatment of patients with advanced prostate cancer for a variety of reasons, including competing therapies, instability in our sales force, the risk that we cannot replace vacant sales positions on a prompt basis, perceived difficulties in the treatment process, delays in obtaining reimbursement or for other reasons; any promotional limitations imposed by the FDA on our ability to commercialize and market PROVENGE; unexpected difficulties and costs associated with the rapid expansion of our commercial operations to support the commercial launch of PROVENGE; the impact of competing therapies on sales of PROVENGE, manufacturing difficulties, disruptions or delays and other factors discussed in the "Risk Factors" section of Dendreon's Annual Report on Form 10-Q for the quarter ended June 30, 2013. All forward-looking statements are qualified in their entirety by this cautionary statement. Dendreon is providing this information as of the date of this press release and does not undertake any obligation to update any forward-looking statements contained in this release as a result of new information, future events or otherwise.

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