Compared with placebo , evolocumab at both dosing schedules led to a significant reduction in mean LDL cholesterol at week 12 ( every-2-weeks dose : 592 % reduction [ 95 % CI 534-651 ] , monthly dose : 613 % reduction [ 536-690 ] ; both p < 00001 ) and at the mean of weeks 10 and 12 ( 602 % reduction [ 95 % CI 545-658 ] and 656 % reduction [ 598-713 ] ; both p < 00001 ) .