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.

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.

Efficacy and safety of switching from boosted lopinavir to boosted atazanavir in patients with virological suppression receiving a LPV/r-containing HAART: the ATAZIP study.

OBJECTIVES: To evaluate the efficacy and safety of switching from boosted lopinavir (LPV/r) to boosted atazanavir (ATV/r) in virologically suppressed HIV-1-infected patients versus continuing LPV/r. METHODS: Forty-eight weeks analysis of a randomized, open-label, noninferiority trial including patients with virological suppression (< or = 200 copies/mL for > or = 6 months) on LPV/r-containing triple highly active antiretroviral therapy. Patients (n = 248) were randomized 1:1 either to continue LPV/r twice a day (n = 127) or to switch to ATV/r every day (ATV/r; n = 121), with no change in nucleoside reverse transcriptase inhibitor backbone. Those known to have >4 protease inhibitor (PI)-associated mutations and/or who had failed >2 PI-containing regimens were excluded. RESULTS: Baseline characteristics were balanced. 30% harboured > or = 1 PI-associated mutation (10% harboured > or = 1 major mutation). Treatment failure at 48 weeks (primary end point) occurred in 20% (25 of 127) of the LPV/r arm and in 17% (21 of 121) of the ATV/r arm (difference -2.3%; 95% confidence interval: -12.0 to 8.0; P = 0.0018). Virological failure occurred in 7% (9 of 127) of the LPV/r arm and in 5% (6 of 121) of the ATV/r arm (difference -2.1%; 95% confidence interval: -8.7% to 4.2%, P < 0.0001 for noninferiorating). CD4 changes from baseline were similar in each arm (approximately 40 cells/mm). Adverse event rate leading to study drug discontinuation was 5% in both arms. Median fasting triglycerides and total cholesterol decreased significantly in the ATV/r arm (-53 and -19 mg/dL, respectively versus -4 and -4 mg/dL in the LPV/r arm; P < 0.001 in both comparisons). Alanine aminotransferase/aspartate aminotransferase hepatic abnormalities were similar in the 2 arms. CONCLUSIONS: Switching to ATV/r in virologically suppressed patients who were receiving a LPV/r-containing highly active antiretroviral therapy provided comparable (noninferior) efficacy and a safety profile with improved lipid parameters [ISRCTN24813210].

Substitution of nevirapine, efavirenz, or abacavir for protease inhibitors in patients with human immunodeficiency virus infection.

BACKGROUND: We assessed the strategy of substituting nevirapine, efavirenz, or abacavir for a protease inhibitor in patients infected with human immunodeficiency virus type 1 (HIV-1) in whom virologic suppression had been achieved. METHODS: We randomly assigned 460 adults who were taking two nucleoside reverse-transcriptase inhibitors and at least one protease inhibitor and whose plasma HIV-1 RNA levels had been less than 200 copies per milliliter for at least the previous six months to switch from the protease inhibitor to nevirapine (155 patients), efavirenz (156), or abacavir (149). The primary end point was death, progression to the acquired immunodeficiency syndrome, or an increase in HIV-1 RNA levels to 200 copies or more per milliliter. RESULTS: At 12 months, the Kaplan-Meier estimates of the likelihood of reaching the end point were 10 percent in the nevirapine group, 6 percent in the efavirenz group, and 13 percent in the abacavir group (P=0.10 according to an intention-to-treat analysis). HIV-1 RNA could be amplified in 21 of the 29 patients in whom virologic failure developed during treatment with study medication (72 percent), and resistance mutations to the study medication and to at least one of the nucleoside reverse-transcriptase inhibitors in the regimen that failed were detected in all but 1 of the 21 patients. Twenty-three of the 29 patients with virologic failure during treatment with study medication had received prior suboptimal therapy with nucleoside reverse-transcriptase inhibitors. Fewer patients in the abacavir group (6 percent) than in the nevirapine group (17 percent) or the efavirenz group (17 percent) discontinued the study medication because of adverse events (P=0.01). The proportion of patients with fasting lipid levels warranting therapeutic intervention decreased significantly in the abacavir group, but the prevalence of clinical lipodystrophy did not change significantly in the three groups. CONCLUSIONS: When therapy was switched from a protease inhibitor to nevirapine, efavirenz, or abacavir in patients with virologic suppression, there was a trend toward a higher rate of virologic failure among those given abacavir.