Men with metastatic castration-resistant prostate cancer (mCRPC) who had not undergone previous chemotherapy reported delayed pain progression and prolonged health-related quality of life with abiraterone acetate plus prednisone compared with prednisone alone.
Abiraterone acetate plus prednisone is known to significantly improve radiographic progression-free survival over prednisone alone in asymptomatic or mildly symptomatic chemotherapy-naïve men with mCRPC. Ethan Basche, MD, director of the Cancer Outcomes Research Program at the University of North Carolina Lineberger Comprehensive Cancer Center in Chapel Hill, North Carolina, led an analysis of data on patient-reported pain and functional status in a preplanned interim analysis of a phase 3 trial comparing these two treatment regimens. The team reported its findings in The Lancet Oncology.
Between April 28, 2009, and June 23, 2010, men with progressive mCRPC who were asymptomatic or mildly symptomatic and had had no previous chemotherapy were randomized to receive oral abiraterone (1 g daily) plus prednisone (5 mg twice daily) (n=546), or placebo plus prednisone (n=542) in continuous 4-week cycles. At the time of the interim analysis, median follow-up was 22.2 months.
Median time to progression of mean pain intensity was longer among the abiraterone patients than among the prednisone-only patients, at 26.7 months vs 18.4 months, respectively. The abiraterone users also had a longer median time to progression of pain interference with daily activities (10.3 months vs 7.4 months) and a insignificantly longer median time to progression of worst pain (26.7 months vs 19.4 months).
Finally, median time to deterioration of health-related quality of life was longer in the men given abiraterone (12.7 months) than in the men given prednisone only (8.3 months) as assessed by the Functional Assessment of Cancer Therapy—Prostate (FACT-P) total score and by the score on its prostate-cancer-specific subscale (11.1 months vs 5.8 months).
Basche and coauthors asserted that these results provide further support for the efficacy of abiraterone in chemotherapy-naïve men with mCRPC.