The median progression-free survival was @ months ( @ % confidence interval -LSB- CI -RSB- , @ to @ ) with nivolumab plus ipilimumab , as compared with @ months ( @ % CI , @ to @ ) with ipilimumab ( hazard ratio for death or disease progression , @ ; @ % CI , @ to @ ; P < @ ) , and @ months ( @ % CI , @ to @ ) with nivolumab ( hazard ratio for the comparison with ipilimumab , @ ; @ % CI , @ to @ ; P < @ ) .