Abiraterone

Recent research has shown that drugs that target the hormone synthesis pathway can be clinically active in patients with castrate-resistant prostate cancer. Abiraterone is a potent and irreversible inhibitor of CYP17 that has shown clinical activity in patients. In patients who had disease progression after docetaxel chemotherapy, overall survival was significantly longer in patients who received abiraterone-prednisone compared to the placebo-prednisone group (14.8 months vs 10.9 months; hazard ratio (HR) = 0.65; 95% confidence interval (CI), 0.54 to 0.77; P <0.001).4All secondary endpoints, including time to PSA progression (10.2 vs 6.6 months; P <0.001), progression free survival (PFS) (5.6 months vs 3.6 months; P <0.001), and PSA response rate (29% vs 6%, P <0.001), favoured the treatment group. In addition, there were significant benefits compared with prednisone alone in terms of pain relief, delayed pain progression, prevention of skeletal-related events, and patient reported health-related quality of life.5,6In chemotherapy-nave patients, radiographic PFS was significantly increased with abiraterone-prednisone compared with placebo-prednisone (median 16.5 vs 8.2 months, HR = 0.52; 95% CI, 0.45 to 0.61).7At a median follow-up of 49.2 months (IQR 47.0 to 51.8), overall survival was increased with abiraterone-prednisone compared to the placebo-prednisone group (median 34.7 vs 30.3 months, HR = 0.81; 95% CI, 0.70 to 0.93; P = 0.0033).8

There have been no cost-effectiveness analyses on abiraterone performed using local cost data and Singaporean societal norms. Based on NICE appraisal, 9the manufacturers base-case incremental cost-effectiveness ratio (ICER) for abiraterone plus prednisolone compared with prednisolone alone is USD $71,756 per quality adjusted life-year (QALY) gained for the one prior chemotherapy subgroup. The NICE committee determined that the most plausible ICER was likely to be higher than the manufacturers base-case estimate for the one prior chemotherapy subgroup, but would be less than USD $76,645 per QALY gained.