LAUSR

Abstract Objectives To assess the effectiveness and tolerability of dolutegravir (DTG)/lamivudine (3TC) among treatment-naive and virologically suppressed treatment-experienced individuals in the multicentre cohort of the Spanish HIV/AIDS Research Network (CoRIS) during the years 2018–2021. Methods We used multivariable regression models to compare viral suppression (VS) [HIV RNA viral load (VL) <50 copies/mL] and the change in CD4 cell counts at 24 and 48 (±12) weeks after initiation with dolutegravir/lamivudine or other first-line ART regimens. Results We included 2160 treatment-naive subjects, among whom 401 (18.6%) started with dolutegravir/lamivudine. The remaining subjects started bictegravir (BIC)/emtricitabine (FTC)/tenofovir alafenamide (TAF) (n = 949, 43.9%), DTG + FTC/tenofovir disoproxil fumarate (TDF) (n = 282, 13.1%), DTG/3TC/abacavir (ABC) (n = 255, 11.8%), darunavir (DRV)/cobicistat(COBI)/FTC/TAF (n = 147, 6.8%) and elvitegravir (EVG)/COBI/FTC/TAF (n = 126, 5.8%). At 24 and 48 weeks after starting dolutegravir/lamivudine, 91.4% and 93.8% of the subjects, respectively, achieved VS. The probability of achieving VS with dolutegravir/lamivudine was not significantly different compared with any other regimen at 24 or 48 weeks, with the exception of a lower chance of achieving VS at 24 weeks for DRV/COBI/FTC/TAF (adjusted OR: 0.47; 95% CI: 0.30–0.74) compared with dolutegravir/lamivudine. For the analysis of treatment-experienced virally suppressed subjects we included 1456 individuals who switched to dolutegravir/lamivudine, among whom 97.4% and 95.5% maintained VS at 24 and 48 weeks, respectively. During the first 48 weeks after dolutegravir/lamivudine initiation, 1.0% of treatment-naive and 1.5% of treatment-experienced subjects discontinued dolutegravir/lamivudine due to an adverse event. Conclusions In this large multicentre cohort, effectiveness and tolerability of dolutegravir/lamivudine were high among treatment-naive and treatment-experienced subjects.