(HealthDay)—For chemotherapy-naive patients with metastatic castration-resistant prostate cancer, abiraterone acetate correlates with improved radiographic progression-free survival, according to a study published online Dec. 10 in the New England Journal of Medicine to coincide with the U.S. Food and Drug Administration's recent approval for expanded use of the drug.
Charles J. Ryan, M.D., from the University of California in San Francisco, and colleagues randomly allocated 1,088 patients with metastatic castration-resistant prostate cancer who had not received previous chemotherapy to receive abiraterone acetate (1,000 mg) plus prednisone or placebo plus prednisone.
The researchers found that the median radiographic progression-free survival was significantly improved for abiraterone-prednisone versus placebo-prednisone (16.5 versus 8.3 months; hazard ratio, 0.53). Overall survival improved with abiraterone-prednisone over a median follow-up of 22 months (median not reached versus 27.2 months with placebo-prednisone; hazard ratio, 0.75), but the efficacy boundary was not crossed. Abiraterone-prednisone was also superior with respect to time to initiation of cytotoxic chemotherapy, opiate use for pain related to cancer, prostate-specific antigen progression, and performance status decline. Abnormalities on liver-function testing and grade 3 or 4 mineralocorticoid-related adverse events were more common with abiraterone-prednisone.
"In summary, the results show benefit from the use of abiraterone in patients with asymptomatic or mildly symptomatic metastatic castration-resistant prostate cancer who have not received previous chemotherapy," the authors write. "These findings include increased rates of radiographic progression-free survival and overall survival, as well as clinically meaningful secondary end points."
The study was funded by Janssen Research and Development, which manufacturers abiraterone acetate; several authors disclosed financial ties to pharmaceutical companies, including Janssen.
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