Medivation and Astellas announce final results of Phase III enzalutamide trial in prostate cancer

US drug maker Medivation (Nasdaq: MDVN) and Japanese drug major Astellas Pharma (TYO: 4503) have announced final results on the primary and secondary efficacy endpoints from the Phase III PREVAIL trial of Xtandi (enzalutamide) in patients with chemotherapy-naïve metastatic prostate cancer who have failed androgen deprivation therapy and have few or no symptoms.

Study results

The PREVAIL study results in men with metastatic prostate cancer who have progressed on androgen deprivation therapy show that treatment with enzalutamide demonstrated a statistically significant overall survival benefit compared with placebo treatment. Enzalutamide reduced the risk of death by 29% compared with placebo. This benefit was observed despite substantial use of subsequent therapies (40% in the enzalutamide and 70% in the placebo groups).It was announced in October that the Independent Data Monitoring Committee (IDMC) recommended the study be stopped and patients treated with placebo be offered enzalutamide (The Pharma Letter October 23, 2013).