A simplification trial switching from nucleoside reverse transcriptase inhibitors to once-daily fixed-dose abacavir/lamivudine or tenofovir/emtricitabine in HIV-1-infected patients with virological suppression.

Author(s): Martinez E, Arranz JA, Podzamczer D, Lonca M, Sanz J, Barragan P, Ribera E, Knobel H, Roca V, Gutierrez F, Blanco JL, Mallolas J, Llibre JM, Clotet B, Dalmau D, Segura F, Arribas JR, Cosin J, Barrufet P, Casas E, Ferrer E, Curran A, Gonzalez A, Pich J, Cruceta A, Arnaiz JA, Miro JM, Gatell JM, BICOMBO Study Team

Affiliation(s): Hospital Clinic-Institut d'Investigaciones Biomediques August Pi i Sunyer, University of Barcelona, 08036 Barcelona, Spain. esteban@fundsoriano.es

Publication date & source: 2009-07-01, J Acquir Immune Defic Syndr., 51(3):290-7.

Publication type: Multicenter Study; Randomized Controlled Trial; Research Support, Non-U.S. Gov't

BACKGROUND: Data comparing abacavir/lamivudine versus tenofovir/emtricitabine in antiretroviral-naive patients are controversial. We compared 48-week efficacy and safety of these combinations as substitutes of nucleosides in patients with virological suppression. METHODS: We randomly assigned 333 HIV-1-infected patients on lamivudine-containing triple regimens with <200 copies per milliliter for at least 6 months to switch their nucleosides to either abacavir/lamivudine (n = 167) or tenofovir/emtricitabine (n = 166). The primary outcome was treatment failure ["switching = failure" intention to treat (ITT) analysis, noninferiority margin 12.5%]. Secondary outcomes were time to treatment failure, virological failure, adverse events, and changes in CD4 count, fasting plasma lipids, lipodystrophy, body fat, bone mineral density, and renal function. RESULTS: Treatment failure occurred in 32 patients (19%) on abacavir/lamivudine and 22 patients (13%) on tenofovir/emtricitabine [difference 5.9%; (95% confidence interval -2.1% to 14.0%), P = 0.06]. Four patients in the abacavir/lamivudine group versus none in the tenofovir/emtricitabine group developed virological failure [difference 2.4; (95% confidence interval 0.05 to 6.0), P = 0.04]. Twenty-three patients (14%) assigned to abacavir/lamivudine and 10 (6%) to tenofovir/lamivudine experienced grade 3 or 4 adverse effects (P = 0.03). CD4 counts and plasma lipids showed higher increments in the abacavir/lamivudine group than in the tenofovir/emtricitabine group. CONCLUSIONS: In HIV-1-infected patients with virological suppression, abacavir/lamivudine did not meet the noninferiority outcome for treatment efficacy compared with tenofovir/emtricitabine.