Astellas Pharma, Medivation announce topline results from enzalutamide Phase 2 STRIVE trial

Apr 2 2015

Astellas Pharma Inc. (TSE: 4503) and Medivation, Inc. (NASDAQ: MDVN) today announced topline results from the Phase 2 STRIVE trial comparing enzalutamide with bicalutamide in a study population of men with non-metastatic or metastatic castration-resistant prostate cancer. The study achieved its primary endpoint demonstrating a statistically significant increase in progression-free survival (PFS) for enzalutamide compared with bicalutamide (Hazard Ratio = 0.24; 95% Confidence Interval, 0.18-0.32; p<0.0001). Median PFS was 19.4 months in the enzalutamide group compared with 5.7 months in the bicalutamide group.

The median time on treatment in the STRIVE trial was 14.7 months in the enzalutamide group versus 8.4 months in the bicalutamide group. Serious adverse events were reported in 29.4% of enzalutamide-treated patients and 28.3% of bicalutamide-treated patients. Grade 3 or higher cardiac adverse events were reported in 5.1% of enzalutamide-treated patients versus 4.0% of bicalutamide-treated patients. One seizure was reported in the trial in the enzalutamide-treated group and none in the bicalutamide-treated group. The most common side effects noted more frequently in the enzalutamide-treated versus bicalutamide-treated patients included fatigue, back pain, hot flush, fall, hypertension, dizziness, and decreased appetite, consistent with the known safety profile of enzalutamide.

"These results demonstrate the potential for enzalutamide to provide a longer duration of disease control compared with bicalutamide in the studied patient population," said David Penson, M.D., MPH, co-principal investigator of the STRIVE study, Director of the Center for Surgical Quality and Outcomes Research and Chair of the Department of Urologic Surgery of Vanderbilt University Medical Center.

The STRIVE study is the second of two head-to-head studies of enzalutamide versus bicalutamide, the first of which was TERRAIN. Additional results from the STRIVE trial, including the secondary endpoints and safety data, will be submitted for presentation at upcoming medical conferences.

SOURCE Astellas Pharma Inc.