New Clinical Data Analysis Shows Survival Benefit Three Years after Treatment with Sipuleucel-T

SEAL BEACH, Calif.--(BUSINESS WIRE)-- Dendreon Pharmaceuticals LLC, a commercial-stage biopharmaceutical company and pioneer in the development of immunotherapy, released results of a new retrospective analysis of clinical trial data showing a long-lasting survival benefit three years after treatment with PROVENGE^® (sipuleucel-T) in men with metastatic castrate-resistant prostate cancer (mCRPC). (abstract #222)

The analysis – which interpreted survival outcomes using number needed to treat to benefit (NNTB) – showed a favorable survival benefit for all men treated with sipuleucel-T compared to placebo, and a significantly greater survival benefit in African-American men over a three-year time period.

“African-American men see a much greater survival advantage with sipuleucel-T based on the findings of this analysis, which is critically important given these men tend to present with more aggressive disease and have greater than twice the mortality rate than that of Caucasian men,”¹ said Kelvin A. Moses, M.D., Ph.D., lead author of the analysis and associate professor in the Department of Urology at Vanderbilt University Medical Center. “These data underscore the survival benefit resulting from treatment with sipuleucel-T in all men and may help address the known survival disparity in African-American men with prostate cancer.”

The analysis pooled data from three placebo-controlled Phase 3 trials of sipuleucel-T involving 737 men with mCRPC and calculated the NNTB benefit at 12, 24 and 36 months for all patients treated with sipuleucel-T (n=488) and a cohort of African-American men (n=33). NNTB is the number of patients needed to be treated with a therapy to prevent one additional death at a given time compared to placebo. The lower the NNTB the more effective a treatment is. Results showed:

• At one year, the NNTB value (13) was the same for the pooled patients and the African-American cohort, showing that 13 men treated with PROVENGE prevented one additional death compared to placebo.
• At two years, NNTB values were 10 for the pooled patients and 5 for the African-American cohort.
• At three years, NNTB values were 8 for the pooled patients and 3 for the African-American cohort.

“This analysis reinforces earlier findings that sipuleucel-T provides an overall survival benefit to both African-American and Caucasian mCRPC patients,” said Bruce A. Brown, M.D., chief medical officer at Dendreon. “The enhanced survival outcomes in African-American men should serve as a call to action for urologists and oncologists to recommend immunotherapy to all African-American patients that stand to benefit from treatment.”

Additional findings presented in poster sessions at the 2019 ASCO GU Cancers Symposium include two analyses of data from Dendreon’s PROCEED registry:

• Experience with sipuleucel-T in mCRPC with visceral spread from PROCEED
  (abstract #174)

  A registry analysis of patients treated with PROVENGE in patients with visceral metastases, including of the liver and lung, found that, as expected and consistent with the literature for other treatments, these men had shorter median overall survival (OS) than men without visceral metastases (20.5 months vs. 31.2 months). The analysis also found that activation of antigen-presenting cells, a measure of immune activation and treatment potency, was similar in those with and without visceral metastases. These findings suggest that men with mCRPC and visceral spread of their disease can activate their immune cells to produce PROVENGE.

• Real-world registry data from PROCEED: sipuleucel-T in elderly men with mCRPC (abstract #177)

  A second analysis found that PROVENGE was generally well tolerated among an elderly cohort of 374 patients age 80 years and older. All grade and grade 3-5 serious adverse events were comparable between the elderly cohort and men younger than age 80 (n=1,528). PROVENGE was generally well-tolerated and may be considered a first-line option for elderly men with asymptomatic or minimally symptomatic mCRPC.

About PROVENGE^® (sipuleucel-T)

PROVENGE is the only FDA-approved immunotherapy made from a patient’s own immune cells for the treatment of prostate cancer. More than 30,000 men have been prescribed PROVENGE, and it has been clinically proven to extend life for men in advanced stages of the disease.

INDICATION

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

IMPORTANT SAFETY INFORMATION

Acute Infusion Reactions: Acute infusion reactions (reported within 1 day of infusion) may occur and include nausea, vomiting, fatigue, fever, rigor or chills, respiratory events (dyspnea, hypoxia, and bronchospasm), syncope, hypotension, hypertension, and tachycardia.

Thromboembolic Events: Thromboembolic events, including deep venous thrombosis and pulmonary embolism, can occur following infusion of PROVENGE. The clinical significance and causal relationship are uncertain. Most patients had multiple risk factors for these events. PROVENGE should be used with caution in patients with risk factors for thromboembolic events.

Vascular Disorders: Cerebrovascular events (hemorrhagic/ischemic strokes and transient ischemic attacks) and cardiovascular disorders (myocardial infarctions) have been reported following infusion of PROVENGE. The clinical significance and causal relationship are uncertain. Most patients had multiple risk factors for these events.

Handling Precautions: PROVENGE is not tested for transmissible infectious diseases.

Concomitant Chemotherapy or Immunosuppressive Therapy: Chemotherapy or immunosuppressive agents (such as systemic corticosteroids) given concurrently with the leukapheresis procedure or PROVENGE has not been studied. Concurrent use of immune-suppressive agents may alter the efficacy and/or safety of PROVENGE.

Adverse Reactions: The most common adverse reactions reported in clinical trials (≥ 15% of patients receiving PROVENGE) were chills, fatigue, fever, back pain, nausea, joint ache, and headache.

For full Prescribing Information, please visit www.dendreon.com/Products.

About Dendreon

Dendreon is a commercial-stage biopharmaceutical company and pioneer in the development of immunotherapy. Dendreon’s flagship product, PROVENGE (sipuleucel-T), was the first FDA-approved immunotherapy made from a patient’s own immune cells. More than 30,000 men with advanced prostate cancer have been prescribed PROVENGE in the U.S. since 2010. Dendreon also is evaluating the use of PROVENGE in early-stage prostate cancer, with the hope of curing more men of the disease. Dendreon is headquartered in Seal Beach, Calif. For more information, please visit www.dendreon.com.

¹ American Cancer Society. Cancer Facts and Figures for African American Men. Accessed 07Feb19. LINK

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