Metabolic Complications After Initiating BIC/FTC/TAF Versus DTG + 3TC in Antiretroviral-therapy-naive Adults With HIV: A Multicenter Prospective Cohort Study

BACKGROUND: Although antiretroviral therapy (ART) has become less toxic over time, its long-term adverse effects remain a concern. In ART-naive people, tenofovir alafenamide (TAF) is frequently prescribed to reduce the toxicity of tenofovir disoproxil fumarate (TDF). However, the metabolic impact of TAF remains a concern. This study aimed to evaluate the metabolic effects of TAF in ART-naive participants. METHODS: We analyzed data from the Cohort of the Spanish HIV Research Network (CoRIS). We included ART-naive participants who initiated either bictegravir/emtricitabine/TAF (BIC/FTC/TAF) or dolutegravir + lamivudine (DTG+ 3TC), matched by propensity score, after excluding those with hepatitis B. We compared changes in weight, metabolic biomarkers, and the incidence of metabolism-related clinical events over 96 weeks. RESULTS: In total, 340 participants were matched in each group. The median age was 34 years, 95% were male, and 62% were from Western Europe. The mean weight gain was 1.4 kg (95% confidence interval [CI]: 1.1, 1.8) after 96 weeks, with no significant differences between the BIC/FTC/TAF and DTG + 3TC groups. Changes in body mass index, lipid levels, hepatic steatosis index, and incidence of clinical events (hypertension, diabetes mellitus, dyslipidemia, and liver steatosis) were also similar between the groups. CONCLUSIONS: In this nationwide cohort of ART-naive individuals, initiation of BIC/FTC/TAF or DTG + 3TC resulted in similar modest increases in weight and lipid levels after 96 weeks, with no significant differences in metabolic outcomes or clinical events. These findings suggest that the metabolic profile of TAF should not be a deciding factor when choosing between 2- and 3-drug ART regimens.