Median recurrence-free survival was @ months ( @ % CI @-@ ) in the ipilimumab group versus @ months ( @ % CI @-@ ) in the placebo group ( hazard ratio @ ; @ % CI @-@ ; p = @ ) ; @-year recurrence-free survival was @ % ( @ % CI @-@ ) in the ipilimumab group versus @ % ( @-@ ) in the placebo group .