ONCOLOGYEDUCATION.COM ARTICLE SUMMARIES Enzalutamide in Metastatic Prostate Cancer Before Chemotherapy Beer T.M., et al., New England Journal of Medicine, doi: 10.1056/NEJMoa1405095

BACKGROUND The recently-published COU-AA-302 trial established the superiority of abiraterone/prednisone over placebo/prednisone in patients with metastatic CRPC prior to chemotherapy. The PREVAIL study tested enzalutamide in this setting. Beer T.M., et al., New England Journal of Medicine, doi: 10.1056/NEJMoa1405095

Enzalutamide 160mg po daily STUDY DESIGN Primary Outcome: Radiographic PFS and OS N = 1717 Enzalutamide 160mg po daily All had metastatic prostate cancer, and had progressed despite androgen suppression (with either an LHRH analog or surgical castration), ECOG 0/1 and had adequate organ function. Placebo Patients with bone or visceral METs were accepted. The use of previous antiandrogens, such as bicalutamide, was allowed but not required. Patients could not have received any previous ketoconazole, abiraterone, or cytotoxic chemotherapy. Beer T.M., et al., New England Journal of Medicine, doi: 10.1056/NEJMoa1405095

RESULTS - EFFICACY Enzalutamide Placebo Hazard Ratio p-Value 1 yr Radiographic PFS 65% 14% 0.19 (0.15-0.23) p < 0.001 mOS 32.4 mo 30.2 mo 0.71 (0.60-0.84) p < 0.0001 Beer T.M., et al., New England Journal of Medicine, doi: 10.1056/NEJMoa1405095

All-grade Hypertension RESULTS – SAFETY Enzalutamide Placebo All-grade Hypertension 13% 4% Fatigue 36% 26% Hot flushes 18% 8% Beer T.M., et al., New England Journal of Medicine, doi: 10.1056/NEJMoa1405095

COMMENTARY The PREVAIL study shows that enzalutamide is effective for patients with mCRPC in the pre-docetaxel setting. Both enzalutamide and abiraterone/prednisone have now shown that they are effective in improving OS in the pre-docetaxel setting. Beer T.M., et al., New England Journal of Medicine, doi: 10.1056/NEJMoa1405095