The gist: Adding the drug abiraterone acetate (Zytiga) to treatment with prednisone helps patients with castration-resistant prostate cancer (CRPC) live longer. The treatment was tested in patients in a clinical trial. Patients in the trial were treated between April 2009 and June 2010. The treatment appeared to lengthen the amount of time that patients lived without their disease worsening. In 2011, these promising results convinced the U.S. Food and Drug Administration (FDA) to approve Zytiga for treating metastatic castration-resistant prostate cancer patients who had not yet received chemotherapy. Now, in final analysis of data from the trial, researchers have shown that Zytiga lengthens life for these patients.
“In the final analysis of overall survival in the COU-AA-302 trial, reported in The Lancet Oncology by Ryan et al, the addition of abiraterone acetate (Zytiga) to prednisone significantly prolonged survival in chemotherapy-naive patients with castration-resistant prostate cancer. Abiraterone had been approved for use in this setting on the basis of improved radiographic progression-free survival in COU-AA-302.
“In this double-blind trial, 1,088 asymptomatic or mildly symptomatic patients were randomly assigned between April 2009 and June 2010 to receive abiraterone at 1,000 mg once daily plus prednisone at 5 mg twice daily (n = 546) or prednisone plus placebo (n = 542). The coprimary endpoints were radiographic progression-free survival and overall survival…
“The investigators concluded: ‘In this randomised phase 3 trial with a median follow-up of more than 4 years, treatment with abiraterone acetate prolonged overall survival compared with prednisone alone by a margin that was both clinically and statistically significant. These results further support the favourable safety profile of abiraterone acetate in patients with chemotherapy-naive metastatic castration-resistant prostate cancer.’ ”