Pooled analysis of androgen synthesis inhibitors orteronel and abiraterone resulted in significantly increased overall and progression-free survival for anti-androgen agents, compared to placebo (hazard ratio for death: 0.76, 95% CI 0.67 to 0.87, P<0.0001; hazard ratio for radiographic progression: 0.7, 95% CI 0.63 to 0.77, P<0.00001).