The benefit of enzalutamide was shown with respect to all secondary end points , including the time until the initiation of cytotoxic chemotherapy ( hazard ratio , 0.35 ) , the time until the first skeletal-related event ( hazard ratio , 0.72 ) , a complete or partial soft-tissue response ( 59 % vs. 5 % ) , the time until prostate-specific antigen ( PSA ) progression ( hazard ratio , 0.17 ) , and a rate of decline of at least 50 % in PSA ( 78 % vs. 3 % ) ( P < 0.001 for all comparisons ) .