Enzalutamide Outperforms Bicalutamide in Trial for Metastatic Castration-Resistant Prostate Cancer

The gist: In a clinical trial with metastatic, castration-resistant prostate cancer (CRPC) patients, the drug enzalutamide outperformed bicaluatmide. Men who took enzalutamide had about 10 more months without their disease worsening than men who took bicalutamide. 

“Medivation, Inc. MDVN, -3.90% and Astellas Pharma Inc. today announced topline results from the Phase 2 TERRAIN trial comparing enzalutamide with bicalutamide in men with metastatic castration-resistant prostate cancer. The study achieved its primary endpoint demonstrating a statistically significant increase in progression-free survival (PFS) for enzalutamide compared to bicalutamide (Hazard Ratio = 0.44; 95% Confidence Interval, 0.34-0.57; p < 0.0001). Median PFS was 15.7 months in the enzalutamide group compared to 5.8 months in the bicalutamide group.

“The median time on treatment in TERRAIN was 11.7 months in the enzalutamide group versus 5.8 months in the bicalutamide group. Serious adverse events were reported in 31.1% of enzalutamide-treated patients and 23.3% of bicalutamide-treated patients. Grade 3 or higher cardiac adverse events were reported in 5.5% of enzalutamide-treated patients versus 2.1% of bicalutamide-treated patients. Two seizures were reported in the enzalutamide group and one in the bicalutamide group. The most common side effects occurring during treatment and more common in the enzalutamide-treated versus bicalutamide-treated patients included fatigue, hot flush, hypertension, diarrhea, weight decreased and pain in extremity.

” ‘The results of this study showed that enzalutamide provides a longer duration of disease control in the studied patient population compared to bicalutamide,’ said Neal Shore, MD, co-principal investigator of the TERRAIN study and Medical Director, Carolina Urologic Research Center. ‘This robust data set adds to an impressive and consistent body of data for enzalutamide across multiple studies and stages of prostate cancer.’ “