Dolutegravir/Lamivudine Efficacy and Safety Outcomes in People With HIV-1 With or Without Historical Resistance Results at Screening: 48-Week Pooled Analysis.

Background Drug resistance testing aids in appropriate antiretroviral therapy selection to improve treatment success but may not be readily available. We evaluated the impact of switching to dolutegravir/lamivudine (DTG/3TC) using pooled data from the TANGO and SALSA trials in adults who were virologically suppressed with or without historical resistance results at screening. Methods Adults who were virologically suppressed (HIV-1 RNA <50 copies/mL for >6 months) with no prior virologic failure were randomized to switch to DTG/3TC (TANGO, n = 369; SALSA, n = 246) or continue their current antiretroviral regimen (CAR; TANGO, n = 372; SALSA, n = 247). Week 48 HIV-1 RNA ≥50 and <50 copies/mL (Snapshot algorithm, Food and Drug Administration; intention-to-treat exposed), CD4+ cell count, and safety were analyzed by availability of historical resistance results. Results Overall, 294 of 615 (48%) participants in the DTG/3TC group and 277 of 619 (45%) participants in the CAR group had no historical resistance results at screening. At week 48, proportions with Snapshot HIV-1 RNA ≥50 copies/mL were low (≤1.1%) and similar across treatment groups and by historical resistance results availability. High proportions (91%–95%) maintained virologic suppression through week 48, regardless of results availability. Across both subgroups of results availability, greater increases in CD4+ cell count from baseline to week 48 occurred with DTG/3TC vs CAR. No participants taking DTG/3TC had confirmed virologic withdrawal, regardless of historical resistance results availability. One participant undergoing CAR without historical resistance results had confirmed virologic withdrawal; no resistance was detected. Overall, DTG/3TC was well tolerated; few adverse events led to withdrawal. Conclusions Findings support DTG/3TC as a robust switch option for adults who are virologically suppressed with HIV-1 and no prior virologic failure, regardless of historical resistance results availability. Clinical trial registration TANGO: NCT03446573, https://clinicaltrials.gov/study/NCT03446573. SALSA: NCT04021290, https://clinicaltrials.gov/study/NCT04021290 [ABSTRACT FROM AUTHOR]