At the preplanned interim overall survival analysis , which was performed after @ % of the total number of expected events occurred , the overall survival rate at @ months was @ % ( @ % confidence interval -LSB- CI -RSB- , @ to @ ) in the combination-therapy group and @ % ( @ % CI , @ to @ ) in the vemurafenib group ( hazard ratio for death in the combination-therapy group , @ ; @ % CI , @ to @ ; P = @ ) .