Key clinical point: In patients with chemotherapy-naive metastatic castration-resistant prostate cancer (mCRPC), the overall survival (OS) benefit with enzalutamide is maintained in the long term.

Major finding: Median OS was 36 months in the enzalutamide group versus 31 months in the placebo group. Enzalutamide was associated with a 17% lower risk for mortality (hazard ratio, 0.83; P less than .001) versus placebo. Survival rates at 5 years were 42% with low risk, 24% with intermediate risk, and 5% with high risk.

Study details: Final 5-year OS analysis of the phase 3 PREVAIL trial involving 1,717 patients with chemotherapy-naive mCRPC randomly assigned to enzalutamide or placebo.

Disclosures: The PREVAIL trial and analyses were sponsored by Pfizer Inc. and Astellas Pharma Inc. Authors employed by the sponsors were involved in the design and conduct of the study. The authors reported ties with multiple pharmaceutical companies.

Commentary

“The introduction of newer generation androgen receptor blockers has had a significant impact on the treatment of advanced prostate cancer. Enzalutamide was the first of the newer generation, and data from various studies involving these agents continues to mature. Here, the authors report the 5-year survival analysis of the PREVAIL trial, where chemotherapy-naïve patients with metastatic castrate-resistant prostate cancer were randomized to enzalutamide versus placebo. Median overall survival was 36 months in the treatment group versus 31 months in the placebo group, despite allowing crossover in an extension. In addition, most patients in both arms received subsequent therapies. The survival benefits were maintained across risk groups. This survival analysis provides additional evidence to support the current and continued use of enzalutamide as one option in patients with metastatic castrate-resistant prostate cancer.”

Mark Klein, MD