Switching to Dolutegravir/Lamivudine Two-Drug Regimen: Durability and Virologic Outcomes by Age, Sex, and Race in Routine US Clinical Care

Purpose: Two-drug regimens (2DR) may address drug-drug interactions and toxicity concerns.Dolutegravir/lamivudine (DTG/3TC) 2DR was approved in the US for both treatment-naïve and treatment-experienced individuals with a viral load <50 copies/mL.This study describes real-world DTG/3TC 2DR treatment outcomes among treatment-experienced individuals, stratified by age, sex, and race.Methods: From the OPERA ® cohort, people with HIV with a viral load <50 copies/mL who switched from a commonly used threedrug regimen to DTG/3TC 2DR as per the label between April 8, 2019 and April 30, 2021 were included.Incidence rates (Poisson regression) for loss of virologic control (first viral load ≥50 copies/mL), confirmed virologic failure (2 viral loads ≥200 copies/mL or discontinuation after 1 viral load ≥200 copies/mL), and DTG/3TC 2DR discontinuation were estimated overall and stratified by age, sex, and race.Results: The 787 individuals included were followed for a median of 13.6 months (IQR: 8.2, 22.3).Confirmed virologic failure occurred in ≤5 individuals.Loss of virologic control occurred at a rate of 14.0 per 100 person-years (95% CI: 11.7, 16.8).DTG/3TC 2DR discontinuation occurred at a rate of 17.5 per 100 person-years (95% CI: 15.0, 20.3); 4% discontinued for treatment-related reasons (viremia, adverse diagnosis, side effect, lab abnormality).For all outcomes, incidence rates were comparable across strata of age, sex, and race.Conclusion: This descriptive study demonstrates that DTG/3TC 2DR is an effective and well-tolerated treatment option for people with HIV with a viral load <50 copies/mL at switch, regardless of their age, sex, or race.