# Comparative effectiveness of dolutegravir + lamivudine versus three‐drug regimens in Swedish clinical practice: a nationwide study

## TL;DR

A nationwide study in Sweden found that switching HIV patients to a two-drug regimen of dolutegravir and lamivudine was as effective as three-drug regimens in maintaining viral suppression.

## Contribution

This study provides real-world evidence on the long-term effectiveness of switching to a two-drug regimen in routine clinical practice.

## Key findings

- Adjusted virologic failure rates were low and comparable between DTG+3TC and 3DR groups.
- Treatment-emergent resistance rates remained low in both treatment groups.
- Switching to DTG+3TC was associated with significantly lower odds of virologic failure at 24, 36, and 42 months.

## Abstract

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.