Early discontinuation of DTG/ABC/3TC and BIC/TAF/FTC single-tablet regimens: a real-life multicenter cohort study

Background: Data regarding the efficacy and tolerability of DTG/ABC/3TC/and BIC/TAF/FTC in switching strategies are still scarce. The rates and reasons of early discontinuation within 24 weeks from the switch to dolutegravir (DTG) or bictegravir (BIC) single-tablet regimens (STRs) were compared.Methods: This is a multicenter cohort study. Persons living with HIV (PLWH) with HIV-1 RNA <50 copies/mL switching to BIC-STR or DTG-STR were included and followed-up 24 weeks. Major outcome was the analysis of (quantitative assessment of) discontinuation due to adverse events and self-suspension (EDAEs). Second, we assessed virologic failure (VF), and all-cause discontinuation (EDAC). Cox model for regression analysis was employed.Results: We included 786 PLWH: 524 with DTG, 262 with BIC. At week 24, we observed 70 EDAC: 5 for VF (1 with BIC and 4 with DTG; p = 0.6276), 10 simplifications, more frequently with BIC than DTG (n = 5, 1.9% and n = 5, 0.9%; p = 0.072) and 55 EDAEs, 7 (2.7%) with BIC, 48 (9.2%) with DTG (p = 0.0323). EDAEs due to neurological and gastrointestinal toxicity were similar (p = 0.2398 and p = 0.1160, respectively). There were no significant differences in the rates of VF and EDAC. EDAEs rate was significantly higher for DTG than for BIC. The adjusted HR for EDAEs in DTG group was 3.28 (95% CI: 1.34-8.00; p = 0.009). We identified an association between EDAE in the DTG group and having an age >60 and having switched from a regimen without ABC.Conclusions: PLWH who received DTG or BIC do not show differences in VF or EDAC rates. However, EDAEs is more frequent with DTG especially in the over-sixties and in those who come from regimens without abacavir.