Dr. Ryan on the COU-AA-302 Interim Analysis Results

Charles J. Ryan, MD, medical oncologist, University of California San Francisco Helen Diller Family Comprehensive Cancer Center, discusses results from an interim analysis of the COU-AA-302, randomized, phase III study of abiraterone acetate plus prednisone in chemotherapy-naive, asymptomatic or mildly symptomatic, patients with metastatic castration-resistant prostate cancer.

Many of the trial's primary endpoints had not been reached at the time of the interim analysis; however, Ryan points out that there is a clear expansion in the demonstrated clinical benefits of abiraterone acetate. In general, the drug is well tolerated, generally safe, and has shown clinical responses in 64% of patients.

Patients on the abiraterone acetate arm of the trial went a median of 25.2 months before the initiation of chemotherapy, compared to 16.8 months in the control arm, which combined placebo and prednisone. Additionally, performance status was maintained for 12.3 months for the investigational arm compared to 10.9 for the control and time to PSA progression was 11.1 months for abiraterone acetate compared to 5.6 for placebo.

Ryan adds that the results from the interim analysis suggest a new option may be available to use earlier in the treatment course.