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

Gerald Pierone Jr,1 Laurence Brunet,2 Jennifer S Fusco,2 Cassidy E Henegar,3 Supriya Sarkar,3 Jean Van Wyk,4 Vani Vannappagari,3 Michael B Wohlfeiler,5 Gregory P Fusco2 1Department of Adult Primary Care, Whole Family Health Center, Vero Beach, FL, USA; 2Department of Epidemiology, Epividian, Raleigh, NC, USA; 3Epidemiology and Real World Evidence, ViiV Healthcare, Research Triangle Park, NC, USA; 4Global Medical, ViiV Healthcare, Brentford, UK; 5Department of Medicine, AIDS Healthcare Foundation, Miami, FL, USACorrespondence: Laurence Brunet, Epividian, 150 Fayetteville Street, Suite 2300, Raleigh, NC, 27601, USA, Tel +1-919-827-0010, Email laurence.brunet@epividian.comPurpose: 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 three-drug 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