Comparative effectiveness of dolutegravir + lamivudine versus three-drug regimens in Swedish clinical practice: a...

HIV guidelines recommend switching from a three-drug regimen (3DR) to dolutegravir + lamivudine (DTG+3TC) for eligible individuals. This retrospective national cohort study used Swedish InfCareHIV registry data to evaluate long-term outcomes of adults with HIV RNA <50 copies/ml who switched to DTG+3TC or a guideline-recommended 3DR between July 2019 and May 2023 in routine clinical care.

Demographic and clinical data were obtained from InfCareHIV at baseline, 6, 12, 24, 36 and 42 months post-switch. The primary endpoint was virologic failure (VF) rates at each time point; secondary endpoints included VF rates in prespecified subgroups, time to VF, and incidence of viral blips and treatment-emergent resistance. Generalized estimating equations modelling was used to assess the effects of clinical predictors on VF.

A total of 1125 individuals (46%) switched to DTG+3TC, and 1336 (54%) switched to 3DR. Adjusted VF rates post-switch were 0.1-2.9% in the DTG+3TC group and 0.3-2.2% in the 3DR group in the intent-to-treat analysis (0-0.4% and 0.3-2.3% in the on-treatment [OT] analysis, respectively). In the OT set, the odds of VF were significantly lower for DTG+3TC versus 3DR at 24, 36 and 42 months (p<0.001). Treatment-emergent resistance rates were low in both groups.

In this long-term, real-world, national cohort, switching to DTG+3TC was associated with low rates of VF and antiretroviral therapy resistance, indicating that eligible individuals can be switched to DTG+3TC without increased risk of VF.