Background: Atazanavir seems to be a protease inhibitor (PI) with a more favourable metabolic profile. Information regarding the potential benefit of replacing lopinavir/ritonavir by atazanavir in HIV-infected patients with prolonged viral suppression is scarce. If proved, this strategy could be particularly attractive for the subset of patients with greater cardiovascular risk.
Methods: SLOAT was a prospective, open, comparative trial in which patients receiving lopinavir/ritonavir-based regimens and having undetectable plasma HIV-RNA for longer than 24 weeks were randomized to continue on the same therapy or switch to atazanavir. Outcomes in viral rebound, CD4 counts, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides and glucose were compared in both groups of patients at 48 weeks of follow-up.
Results: A total of 189 patients were recruited and took at least the first dose of the assigned treatment arm. Overall, 102 switched to atazanavir (49 on 400 mg once daily, and 53 on 300 mg plus 100 mg of ritonavir once daily due to concomitant tenofovir use) and 87 continued on lopinavir/ritonavir. All patients received the PI along with two nucleoside analogues. Virological failure occurred in 12 patients switched to atazanavir and 9 continuing on lopinavir/ritonavir. A reduction (P < 0.001) in median total cholesterol (-19 mg/dL) and triglycerides (-80 mg/dL) was observed after 48 weeks of atazanavir switching, whereas no significant changes occurred in the lopinavir/ritonavir arm. Greater reductions in total cholesterol and triglycerides were seen in patients switched to atazanavir without ritonavir boosting.
Conclusions: The replacement of lopinavir/ritonavir by atazanavir provides an overall significant reduction in total cholesterol and triglycerides, without increased risk of virological failure.