AUA 2013: Data favorable for abiraterone in chemo-naïve men

The most recent data from the COU-AA-302 phase III trial support the efficacy and safety of abiraterone acetate (Zytiga) as a treatment for metastatic castration-resistant prostate cancer (mCRPC) in men who are chemotherapy-naive.

Fred Saad, MD, presented the findings from the prespecified interim analysis for the study that randomized 1,088 men 1:1 to treatment with abiraterone, 1 gram daily, plus prednisone, 5 mg twice daily, or placebo daily plus prednisone, 5 mg twice daily. Eligible patients had progressive mCRPC, were asymptomatic or mildly symptomatic, and had received no prior chemotherapy.

Radiographic progression-free survival and overall survival were analyzed as co-primary endpoints, and the results for both measures favored the abiraterone group over placebo-treated controls. Abiraterone reduced the risk of disease progression by 47% (p<.0001) and risk of death by 21% (p=.151). Secondary endpoint analyses showed abiraterone treatment significantly prolonged time to opiate use and time to chemotherapy initiation, as well as significantly improved time to ECOG performance status deterioration, time to PSA progression, and quality of life endpoints.

Safety analyses showed abiraterone was safe and well tolerated. Most grade 3/4 toxicities among abiraterone-treated men occurred at rates <10%.

“While this is an exciting time for patients with mCRPC, most new options are used in a post-chemotherapy setting. Unfortunately, chemotherapy is not an option for many patients, and we have been saying for many years that we need effective, well-tolerated alternatives for patients with mCRPC,” said Dr. Saad, of the University of Montreal.

“I believe abiraterone acetate is safe and effective hormonal therapy that will allow interested urologists the opportunity to be directly involved in the management of patients with CRPC.”

Dr. Saad has served as an adviser to and has conducted research for Johnson & Johnson.