In the per protocol analysis , the difference in virological failure for HIV-1 RNA > 400 copies/mL ( 0 of 39 patients in the PI group and two of 45 patients in the NRTI group ) and for HIV-1 RNA > 50 copies/mL ( two of 39 and three of 45 patients , respectively ) was +4.4 percentage points ( 95 % CI -2.1 to +11.0 percentage points ) and +1.5 percentage points ( 95 % CI -8.6 to +11.7 percentage points ) , respectively , also showing noninferiority .