In a per protocol analysis which excluded non-completers (i. e. patients who discontinued before the week 48 HIV RNA assessment) and patients with major protocol deviations, the proportion of patients with HIV RNA < 50 copies/ ml at week 48 was 86% (338/ 392) for REYATAZ/ ritonavir and 89% (332/ 372) for lopinavir/ ritonavir (difference estimate of ATV/ RTV-LPV/ RTV: -3% [95% CI, -7.6%, 1.5%].