Efficacy and tolerability of dolutegravir/lamivudine versus dolutegravir/rilpivirine in switching from a three-drug regimen based on nonnucleoside reverse transcriptase inhibitors: A retrospective cohort study

Real-life comparisons of dolutegravir/rilpivirine (DTG/RPV) and DTG/lamivudine (3TC) regimens in people living with human immunodeficiency virus (PLWHIV) who switched from a standard three-drug regimen based on nonnucleoside reverse transcriptase inhibitors (NNRTIs) are missing. This study aimed to compare DTG/3TC and DTG/RPV in virologically suppressed patients (HIV-RNA < 50 copies/mL) coming from any NNRTI-based regimen in terms of discontinuation due to virologic failure (VF) discontinuation rates due to all causes, and adverse events. As a secondary outcome, we evaluated the difference in creatinine, total cholesterol, CD4, and triglycerides from baseline to weeks 48 after the switch. Of the 415 PLWHs included in the study, 278 (66.9%) switched to DTG/3TC, and 137 (33.1%) switched to DTG/RPV. Overall, 48 PLWHs (11.6%) discontinued the treatment:38 with DTG/3TC and 10 with DTG/RPV with similar discontinuation rates: 5.01 x 100 py (95% confidence interval [CI] 3.64-6.94) and 4.66 x 100 py (95% CI 2.51-8.67), respectively. The most common reason for discontinuation was toxicity (26 patients, 22/278 [7.9%] in the DTG/3TC group and 4/137 [2.9%] in the DTG/RPV group), mainly neurologic toxicity (never above grade 2). We found no differences in discontinuation rates due to treatment adverse events. Two study participants experienced virological failure in the DTG/3TC arm. We observed no significant difference in CD4 cell counts, lipid parameters, or renal function between the two groups at 48 weeks. This study demonstrated that, in clinical practice, a two-drug regimen with DTG/3TC or DTG/RPV is characterized by a low discontinuation rate and VF in virologically suppressed PLWHs switched from an NNRTI-based three antiretroviral drugs regimen.