Final overall survival results from EORTC 1333/PEACE-3 trial of enzalutamide plus radium-223 in metastatic castration-resistant prostate cancer

BACKGROUND: The primary analysis of the European Organisation for Research and Treatment of Cancer (EORTC) 1333/PEACE-3 study demonstrated that enzalutamide plus radium-223 (Ra223) improved radiological progression-free survival (rPFS) compared with enzalutamide alone in patients with metastatic castration-resistant prostate cancer (mCRPC). The primary endpoint was rPFS, while overall survival (OS) was a key secondary endpoint. Interim OS results were reported at the time of primary analysis. Here, we report the final OS analysis. PATIENTS AND METHODS: From November 2015 to March 2023, 446 patients were randomly assigned to receive enzalutamide alone or enzalutamide combined with six cycles of Ra223. Co-administration of bone-protecting agents (BPAs) became mandatory for all patients from March 2018. Final analysis of OS was triggered on 1 May 2025. RESULTS: With a median follow-up of 58 months and 317 reported deaths, the hazard ratio (HR) was 0.76 [95% confidence interval (CI) 0.60-0.96, P = 0.0096] for OS in favor of the enzalutamide + Ra223 arm, reaching the predefined level of statistical significance of