The FDA has approved a label update for abiraterone acetate (Zytiga) to include data showing that the drug is associated with significantly prolonged overall survival compared with placebo plus prednisone in men with chemotherapy-naïve metastatic castration-resistant prostate cancer.
The data, published recently in The Lancet Oncology (online ahead of print), showed that abiraterone treatment prolonged survival in mCRPC patients by a median of 4.4 months. Lead investigator Charles J. Ryan, MD, associate professor of medicine and urology at the University of California San Francisco, and colleagues stated that the study “strengthens the rationale for use of abiraterone acetate early” in the course of the disease.
For the study, researchers randomly assigned 1,088 asymptomatic or mildly symptomatic chemotherapy-naïve patients to receive oral abiraterone acetate (1,000 mg daily) with prednisone (5 mg twice daily) or placebo with the same dose of prednisone. After a median follow-up of 49.2 months, 65% of patients in the abiraterone group and 71% in the placebo group died.
The median survival time was 34.7 months in the abiraterone arm compared with 30.3 months in the placebo group, a survival difference that was “both clinically and statistically significant,” according to the investigators.