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

• DOI: 10.1097/qai.0b013e3181aa12d5
• Publication Date: 2009-06-22T09:07:16Z
• Authors: Esteban Martínez; José A Arranz; Daniel Podzamczer; Montserrat Loncá; José Sanz; Patricia Barragán; Esteban Ribera; Hernando Knobel; Victor Roca; Félix Gutiérrez; José L Blanco; Josep Mallolas; Josep M Llibre; Bonaventura Clotet; David Dalmau; Ferran Segura; José R Arribas; Jaime Cosín; Pilar Barrufet; Esperanza Casas; Elena Ferrer; Adrià Curran; Alicia González; Judit Pich; Ana Cruceta; Joan A Arnaiz; José M Miró; José M Gatell
• Keywords: Adult; Male; Anti-HIV Agents; Organophosphonates; HIV Infections; Deoxycytidine; tenofovir/emtricitabine; 03 medical and health sciences; 0302 clinical medicine; Emtricitabine; Humans; Treatment Failure; Tenofovir; reverse transcriptase inhibitors; abacavir/lamivudine; Adenine; simplification; clinical trial; Middle Aged; Dideoxynucleosides; 3. Good health; Treatment Outcome; Lamivudine; Spain; HIV-1; Reverse Transcriptase Inhibitors; Drug Therapy, Combination; Female

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.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.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.In HIV-1-infected patients with virological suppression, abacavir/lamivudine did not meet the noninferiority outcome for treatment efficacy compared with tenofovir/emtricitabine.