ViiV Healthcare reported Week 48 data from the phase IIIb VOGUE study showing that dolutegravir/lamivudine (Dovato) met a non-inferiority endpoint against Gilead Sciences' Biktarvy (bictegravir/emtricitabine/tenofovir alafenamide) in treatment-naïve adults with HIV-1. The results, presented at the 26th International AIDS Conference in Rio de Janeiro, mark the first randomised head-to-head trial comparing the two-drug regimen directly against the three-drug standard in this population.
The results potentially have commercial implications. Biktarvy is the dominant oral first-line regimen globally, and demonstrating equivalent viral suppression with one fewer antiretroviral drug gives ViiV a direct argument for prescribers weighing pill burden over decades of treatment. Dovato is already approved in the US and EU for treatment-naïve adults and for virologically suppressed patients switching regimens.
The VOGUE study enrolled 509 treatment-naïve adults living with HIV-1, randomised to dolutegravir/lamivudine (n=254) or bictegravir/emtricitabine/tenofovir alafenamide (n=255), with treatment initiated before baseline resistance results were available. The population included patients with high viral loads — 47% had HIV-1 RNA ≥100,000 copies/mL, 16% had ≥500,000 copies/mL — and 16% had a CD4+ cell count below 200 cells/mm³, a subgroup historically considered higher risk for two-drug initiation. At Week 48, virologic suppression (HIV-1 RNA <50 copies/mL) was achieved in 89% of the dolutegravir/lamivudine arm versus 92% in the bictegravir/emtricitabine/tenofovir alafenamide arm (adjusted difference: -3%, 95% CI [-8%, 2%]), meeting the non-inferiority margin. Median time to viral suppression was 4.1 weeks in both arms. No treatment-emergent resistance was identified in either group, and safety profiles were comparable with no new signals.
Dolutegravir inhibits HIV-1 integrase by blocking strand transfer of viral DNA into the host genome; lamivudine adds reverse transcriptase inhibition, terminating viral DNA chain elongation. The combination omits the nucleotide reverse transcriptase inhibitor backbone that underpins three-drug regimens including bictegravir/emtricitabine/tenofovir alafenamide.
The resistance finding carries particular weight. Prior concerns about two-drug initiation centred on whether a single NRTI backbone partner would provide sufficient coverage before baseline resistance results were available — a real-world scenario given that testing delays are common in many settings. Zero emergent resistance across both arms, including in patients with very high viral loads, directly addresses that concern.