The authors were interested in the efficacy and safety of a two-drug compared with a three-drug regimen for the treatment of HIV-1 infection in antiretroviral (ART)-naive adults. They conducted two identical double-blind, randomised, non-inferiority, phase 3 trials. Participants were ≥18 years with HIV infection and a screening HIV viral load of ≤500,000 copies/mL and treatment-naive. Participants were randomised (1:1) to receive an OD two-drug regimen of dolutegravir (50 mg) plus lamivudine (300 mg), or an OD three-drug regimen of dolutegravir (50 mg), tenofovir disoproxil fumarate (300 mg) and emtricitabine (200 mg). The primary endpoint was the proportion of participants with HIV viral loads <50 copies/mL at week 48 in the intention-to-treat population. 1441 participants were enrolled into the first trial and by week 48, 90% of patients on the two-drug regimen and 93% on the three-drug regimen had achieved HIV viral loads of <50 copies/mL. In the second trial, 93% of two-drug regimen patients and 94% of three-drug had achieved viral suppression, demonstrating non-inferiority at a -10% margin in both studies. There were more drug-related adverse events with the three-drug than with the two-drug regimen (24% vs. 18%) but only 2% of participants in either arm discontinued due to these adverse events. Therefore efficacy and tolerability are similar when dolutegravir and lamivudine are used as a two-drug regimen compared with a guideline-recommended three-drug regimen at 48 weeks in ART-naive adults.
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