Abstract Background We aim to assess the efficacy, safety and tolerability of DTG+3TC as a switch regimen after 10 years of its introduction in clinical practice. Methods An observational study was conducted with virologically suppressed PLWH switching to DTG+3TC in a multicenter cohort. Exclusion criteria included HBsAg+ status and M184V resistance mutation. We employed Kaplan-Meyer survival analysis for virological failure (VF) and treatment discontinuation (TD), Cox-regression for VF or TD predictors, and linear mixed models for immunological and metabolic parameter changes. Results We enrolled 2430 PLWH: 1587 (65.3%) were males, with a median age of 54.5 yrs. Full population characteristics are shown in Table1. During 9199 PYFU, we observed 82 VF (0.9 per 100 PYFU); no emergent resistance mutations were registered among VF. Estimated probabilities of maintaining virological suppression (VS) at 240 and 480 wks were 96.2% and 92.8%, respectively. At a multivariate analysis, a history of at least one previous VF before switch (vs no event, aHR 2.09, p=0.005) and a time of VS 8 years before switch (vs VS 8 years, aHR 1.82, p=0.021) were significantly associated with a higher risk of VF. During 9287 PYFU, we observed 339 TD (3.7 per 100 PYFU). Estimated probabilities of maintaining DTG/3TC were 83.8% at 240 wks and 79.4% at 480 wks. Discontinuations for toxicity were 78 (23.0% of all TD), with CNS toxicity accounting for 25 cases. Other frequent reasons for TD were: switch to CAB+RPV (64, 18.9%) and treatment intensification (32, 9.4%). At a multivariate analysis, we found that a HIV-RNA peak 500.000 cps/mL (aHR 1.55, p=0.006) and the presence of HBcAb (aHR 1.60, p=0.002) were significantly associated with a higher risk of TD; meanwhile, the presence of DTG in the ARV regimen before switch, (aHR 0.51, p=0.001) was inversely correlated with TD risk. After 240 weeks, we registered a significant improvement in both CD4+ count (+59, p 0.001) and CD4/CD8 ratio (+0.1, p 0.001). As to metabolic parameters, we observed significant improvement in total cholesterol, tryglicerides and HDL cholesterol at both 240 and 480 weeks (p 0.02 for all). Conclusion We assessed the efficacy and safety of DTG+3TC in the long term while also showing neutral impact on metabolic parameters. Disclosures All Authors: No reported disclosures
Baldin et al. (Thu,) studied this question.