William K. Oh, MD, from the Tisch Cancer Institute at Mount Sinai Medical Center, discusses the third interim analysis of the COU-AA-302 trial that examined abiraterone acetate before chemotherapy in mCRPC.
William K. Oh, MD, Chief of the Division of Hematology and Medical Oncology, the Tisch Cancer Institute at Mount Sinai Medical Center, discusses the third interim analysis of the COU-AA-302 trial that examined abiraterone acetate before chemotherapy in men with metastatic castration-resistant prostate cancer (mCRPC).
The study evenly randomized 1088 patients with mCRPC to receive treatment with abiraterone plus prednisone or prednisone and a placebo. Overall, the study showed a robust improvement in radiographic progression-free survival (rPFS) with a clear trend toward an overall survival benefit (OS), Oh explains. At the interim analysis, rPFS was 16.5 months for abiraterone compared to 8.3 with prednisone alone (HR = 0.53; P < .0001). The OS for patients receiving abiraterone was 35.3 months compared to 30.1 (HR = 0.79; P = .0151).
Oh notes that many criticized the timing of the unblinding event in the COU-AA-302 trial, since OS had not yet been demonstrated. However, the trial continues to show many positive secondary endpoints and was approved by the FDA based on secondary endpoints, Oh explains.