Median PFS was 21.4 weeks for E+P ( n = 26 ; 95 % confidence interval [ CI ] , 12.7-39 .6 ) and 23.4 weeks for P ( n = 29 ; 95 % CI , 17.1-29 .9 ) , with a hazard ratio of 1.0 ( 95 % CI , 0.6-1 .7 ) .