Medivation and Astellas Announce New Enzalutamide Data Presented at the 2015 American Urology Association Annual Meeting

SAN FRANCISCO, CA and TOKYO, JAPAN--(Marketwired - May 17, 2015) - Medivation, Inc. (NASDAQ: MDVN) and Astellas Pharma Inc. (TSE: 4503) today announced data from the Phase 2 STRIVE trial comparing enzalutamide and bicalutamide in non-metastatic (M0) and metastatic (M1) prostate cancer patients whose disease progressed despite treatment with a luteinizing hormone-releasing hormone (LHRH) analogue therapy or following surgical castration. The data were presented during an oral plenary session at the 2015 American Urology Association (AUA) annual meeting in New Orleans, Louisiana.

Highlights of Key Enzalutamide Data

Title: A multicenter phase 2 study of enzalutamide versus bicalutamide in men with nonmetastatic or metastatic castration-resistant prostate cancer: STRIVE trial

• 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 (CI), 0.18-0.32; p < 0.0001). The median PFS was 5.7 months in the bicalutamide arm and 19.4 months in the enzalutamide arm;
• Treatment with enzalutamide also demonstrated significant improvement in the secondary endpoints of radiographic PFS, time to PSA progression, and PSA response rates compared to bicalutamide;
• For the subset of patients with M0 disease, the median PFS was 8.6 months in the bicalutamide arm and, at the time of analysis, had not yet been reached for patients in the enzalutamide arm with a Hazard Ratio (HR) of 0.24 (95% CI, 0.14-0.42; p < 0.0001). For patients with M1 disease, the median PFS was 5.5 months in the bicalutamide arm and 16.5 months in the enzalutamide arm with a HR of 0.24 (95% CI, 0.17-0.34; p < 0.0001).

• The safety profile of enzalutamide-treated patients in STRIVE was consistent with the known safety profile of enzalutamide:
  • The median duration of treatment was 14.7 months with enzalutamide and 8.4 months with bicalutamide.
  • Serious adverse events (AEs) were reported in 29.4% of enzalutamide-treated patients and 28.3% of bicalutamide-treated patients. Grade 3 or higher cardiac AEs were reported in 5.1% of enzalutamide-treated patients versus 4.0% of bicalutamide-treated patients. One seizure was reported in the enzalutamide group and none in the bicalutamide 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.

"Results from the STRIVE trial are of key interest to the medical community as they mark the second head-to-head trial of enzalutamide versus bicalutamide," said Celestia S. Higano, M.D., FACP, co-principal investigator of the STRIVE trial and professor, medicine and urology, University of Washington. "The analyses from STRIVE are in line with previous data from the TERRAIN trial demonstrating that patients treated with enzalutamide have improved clinical outcomes versus the common practice of adding bicalutamide to a luteinizing hormone-releasing hormone therapy."