At the preplanned interim overall survival analysis , which was performed after 77 % of the total number of expected events occurred , the overall survival rate at 12 months was 72 % ( 95 % confidence interval [ CI ] , 67 to 77 ) in the combination-therapy group and 65 % ( 95 % CI , 59 to 70 ) in the vemurafenib group ( hazard ratio for death in the combination-therapy group , 0.69 ; 95 % CI , 0.53 to 0.89 ; P = 0.005 ) .