Real-World Study of 6,000+ Medicare Patients with Advanced Prostate Cancer Shows Adding PROVENGE® (sipuleucel-T) to Treatment Regimen Reduced Risk of Death by 45%

– New Data Presented at ASCO Genitourinary Cancers Symposium Finds Adding PROVENGE to Commonly Prescribed Oral Therapies Extends Median Survival by 14.5 Months

SEAL BEACH, Calif.–(BUSINESS WIRE)–#gu20–Dendreon Pharmaceuticals, a commercial-stage biopharmaceutical company and pioneer in the development of immunotherapy, today released results of a first-of-its-kind study examining survival outcomes in men with metastatic castrate-resistant prostate cancer (mCRPC) who were treated with PROVENGE^® (sipuleucel-T) and oral agents in a real-world treatment setting.

According to a retrospective analysis of medical and pharmacy claims data from more than 6,000 Medicare Fee for Service beneficiaries, the addition of PROVENGE to either Zytiga^® (abiraterone acetate) or Xtandi^® (enzalutamide), at any point in a patient’s mCRPC treatment regimen, reduced the risk of death by 45% and extended median overall survival (OS) by 14.5 months.¹ These findings were presented in a poster session at the 2020 ASCO Genitourinary (GU) Cancers Symposium in San Francisco (abstract #42, Poster Session A, 11:30 a.m. PST).

“Based on our analysis of these real-world data, men with mCRPC who had immunotherapy added to their treatment regimen had a significant reduction in the risk of death at three years, regardless of the sequencing,” said Rana R. McKay, M.D., lead study author, and medical oncologist and assistant professor of medicine at Moores Cancer Center, University of California, San Diego. “This magnitude of risk reduction is a compelling finding, and additional analyses are underway looking at other variables that could impact outcomes.”

Based upon the real-world use and survival outcomes associated with the utilization of PROVENGE and oral agents Zytiga or Xtandi in men receiving treatment for mCRPC, the study authors found that:

• In mCRPC patients treated with Zytiga or Xtandi, the median OS was significantly higher among men who also were treated with PROVENGE (35.2 months vs. 20.7 months; p<0.0001).
• Three-year survival rates were significantly higher in men who received PROVENGE in any line of treatment compared to men who never received treatment with PROVENGE (48% vs. 28%; p<0.0001).
• More than 150 variations of mCRPC treatment sequences were identified in the analysis, underscoring the importance of developing a structured approach to managing mCRPC patients.
• Further statistical analysis of these treatment cohorts is underway.

“These findings underscore the importance of using complementary MOAs to maximize patient survival outcomes, and highlights the critical role immunotherapy plays in the mCRPC treatment regimen,” said Bruce A. Brown, M.D., chief medical officer at Dendreon. “These real-world data contribute to a growing body of evidence that PROVENGE continues to deliver on its promise of helping men with advanced prostate cancer live longer.”

Additional findings on the use of immunotherapy in earlier stage prostate cancer and the potential impact of the treatment on cell death were presented today in poster sessions at the 2020 ASCO GU Cancers Symposium:

• A comparison of sipuleucel-T (sip-T) product parameters from two phase III studies: ProVent in active surveillance prostate cancer and IMPACT in metastatic castrate-resistant prostate cancer (mCRPC) (abstract #321, Poster Session A, 11:30 a.m. PST)

This study compared the final product parameters (CD54 upregulation, CD54+ cell count and total nucleated cell [TNC] count) in 313 men on active surveillance (AS) enrolled in the ongoing Phase 3 ProVent clinical trial and 341 men with mCRPC treated with sip-T in the randomized, pivotal Phase 3 IMPACT trial. Results showed that men enrolled in ProVent yielded higher apheresis TNC and CD54+ cell counts than men in IMPACT, possibly a reflection of a healthier immune system in patients in the ProVent trial. Additionally, final product CD54+ cell counts, CD54 upregulation and TNC cell counts were statistically higher in men enrolled in ProVent than in men enrolled in IMPACT.

• The association of humoral antigen spread (AgS) with cytotoxic T lymphocyte (CTL) activity after sipuleucel-T (sip-T) treatment in two phase II clinical studies: STAMP and STRIDE (abstract #112, Poster Session A, 11:30 a.m. PST)

One mechanism of action of cancer immunotherapy is to induce an immune response to specific antigen-bearing tumor cells. The resultant destruction of the tumor cells by the immune system’s T cells leads to the release of additional tumor-associated antigens. These secondary antigens prime subsequent immune responses – a process called antigen spread. This immunological phenomena was previously shown to correlate with survival benefit in the IMPACT study. Sip-T has been shown in clinical trials to induce lytic T cell responses against the immunizing antigen (PA2024) and/or the target antigen (prostatic acid phosphatase or PAP), with responses correlating with overall survival. In this analysis, researchers demonstrated that antigen spread observed after sipuleucel-T treatment correlated with observed lytic T cell responses, concluding that treatment with sip-T in men with mCRPC appears to invoke the tumor immunity cycle, in which tumor cell death releases secondary antigens resulting in antigen spread.

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 certain 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.

Click here for full Prescribing Information.

About Dendreon

Dendreon is a commercial-stage biopharmaceutical company and pioneer in the development of treatments that harness the power of the immune system to extend life. 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 Results are based on a retrospective analysis of Medicare Parts A, B and D claims data (2013-2017). Results do not reflect controlling for known differences in the two treatment groups. Therefore, the findings are limited by their exploratory nature.

Contacts

Leslie Bryant
[email protected]
T +1.562.505.9290