Dual therapy with 3TC/DTG (lamivudine/dolutegravir) has shown satisfactory results in maintaining virological suppression and had its indication expanded in Brazil in 2021 to include all people living with HIV (PLHIV) under viral suppression. This study aimed to evaluate virological response after simplification to 3TC/DTG among PLHIV followed at a reference center in Bahia.

Prospective study on clinical application of 3TC/DTG combination therapy among PLHIV aged ≥ 18 years who simplified their regimen up to December 31, 2022, with available HIV viral load (VL) control data. VL < 50 copies/mL was considered therapeutic success (“virological success”) at weeks 48 (W48) and 96 (W96) after simplification. Adherence was assessed by ART dispensations and classified as “adequate” for refills >80%. Weight and BMI were evaluated before and after 96 weeks. Associations between variables were analyzed using chi-square and paired Student’s t-tests with p < 0.05 and 95% CI. The study was approved by the SESAB Research Ethics Committee.

The sample included 354 PLHIV, mean age 51.5 ± 13.5 years; 61.6% male; 84.7% Black or mixed-race; 84.2% residents of Salvador. Before simplification, mean CD4 count was 660 ± 323 cells/mm³. Participants had used an average of 3.0 ± 1.5 ART regimens, with mean treatment duration of 9.8 ± 5.7 years before simplification. Overall, 97.5% maintained virological suppression at W48 and 95.9% at W96. Adequate adherence was 89.2% (W48) and 90.4% (W96). A significant increase was observed in mean weight (69.1 ± 13.6 to 72.1 ± 14.8 kg; p < 0.01) and BMI (24.9 ± 5.5 to 26 ± 5.9 kg/m²; p < 0.01), with obesity prevalence rising from 17.5% to 23.4%. No difference in weight or nutritional status was found by sex or age. Only two participants switched regimens (one due to DTG adverse effect, one due to TB coinfection).

Simplification with DTG/3TC proved safe and effective for maintaining viral suppression, representing a viable strategy for the studied population. However, the observed increase in weight, BMI, and obesity highlights the need for continuous monitoring of these factors during treatment.