Efficacy
Post chemotherapy populationr
The study was stopped after the planned interim analysis at the time of 250 deaths. The median OS was 18.4 months (95% CI 17.3 to not yet reached) in the enzalutamide group versus 13.6 months (95% CI 11.3 to 15.8) in the placebo group (HR 0.63; 95% CI 0.53 to 0.75; p<0.001).
Kaplan-Meier curve for OS (intention-to-treat population)r
© N Engl J Med 2012
Time to skeletal-related events (SRE) and HRQoL was later reported by Fizazi et al.r 37 % of 1199 patients reported one or more SRE, 36% (n=287) in the enzalutamide group and 40% (n=161) in the placebo group. Median time to first SRE was 16.7 months (95% CI 14.6 to 19.1) for those who received enzalutamide versus 13.3 months (9.9 to not yet reached).
© Lancet Oncol 2014
A significant number of patients receiving enzalutamide reported improvements in HRQoL and significantly longer time to HRQoL deterioration compared with those in the placebo group.r
© Lancet Oncol 2014
Further post hoc analysis demonstrated significantly improved outcomes in both younger and (under 75 years) and elderly patients (75 years and over) with comparable safety and tolerability.r
Chemotherapy naive populationr
At 12 months follow-up, radiographic PFS rate was 65% in the enzalutamide group and 14% in the placebo group. A hazard ratio of 0.19 (95% CI 0.15 to 0.23; p<0.0001) for radiographic progression or death was observed in the enzalutamide group compared with the placebo group. The median radiographic PFS was not reached in the enzalutamide group versus 3.9 months in those treated with placebo.
At planned interim analysis the median duration of follow up for survival was 22 months. Hazard ratio for OS in the enzalutamide group was 0.71 (95% CI 0.60 to 0.84; p< 0.0001). 241 of 872 patients (28%) receiving enzalutamide had died compared with 299 or 845 (35%) of the patients receiving placebo.
Kaplan-Meier curve for OS (intention-to-treat population)r
© N Engl J Med 2014