Enzalutamide after docetaxel and abiraterone therapy in metastatic castration-resistant prostate cancer

Introduction: Enzalutamide is a novel antiandrogen which is approved for the treatment of metastatic, castration-resistant prostate cancer (mCRPC) after taxane-based chemotherapy. The efficacy of enzalutamide after the sequence docetaxel and abiraterone is not proven. Methods: Thirty-five mCRPC patients in the German compassionate use program, who received enzalutamide after progression with taxane-based chemotherapy and abiraterone were prospectively evaluated. The endpoints of the study were overall survival, radiologic progression-free survival and safety. Results: The median treatment duration on enzalutamide was 2.8 months. The median overall survival was 7.5 months [95% confidence interval (CI) 4.7-10.3] while median progression-free survival assessed by imaging was 3.1 months (95% CI 1.4-4.8). The most common toxicities of all grades were anemia and weight loss. Conclusion: Although the results are limited by a small patient number, the consecutive use of enzalutamide and abiraterone after taxane-based chemotherapy shows a modest clinical activity. Thus, sequence therapy alternating between chemotherapy and antihormonal drugs might be amore promising approach in mCRPC treatment.