Long term data on the efficacy and tolerability of lamivudine plus dolutegravir as a switch strategy in a multicenter cohort of HIV1-infected, virologically suppressed patients

Abstract Background. Results from clinical trials and observational studies suggest that lamivudine plus dolutegravir could be an effective and tolerated option for simplification in HIV-1 positive patients. Materials and Methods. This was an observational study enrolling HIV-1-infected, virologically suppressed patients switching to lamivudine plus dolutegravir. We performed Kaplan-Meyer survival analysis to evaluate time to virological failure (VF, defined by a single HIV-RNA ≥1,000 copies/mL or by two consecutive HIV-RNA ≥ 50 copies/mL) and treatment discontinuation (TD, defined as the interruption of either 3TC or DTG), Cox-regression to assess predictors and linear mixed model for repeated measures to measure changes in immunological and metabolic parameters. Results. Five-hundred fifty-six patients were eligible for the analysis: median CD4+ count at baseline was 668 cell/mm3, while median time of virological suppression was 88 months. Estimated probabilities of maintaining virological suppression at weeks 96 and 144 were 97.5% (SD ±0.8) and 96.5% (SD ±1.0). Years from HIV diagnosis were the only predictor of VF. In patients with time of virological suppression <88 months, the rate of VF was higher in the presence of the M184V mutation. Estimated probabilities of remaining on 3TC+DTG at 96 and 144 weeks were 79.2% (SD ±1.9) and 75.2% (SD ±2.2). A significant increase in CD4 cell count (+44 cell/mm3, p=0.015), CD4/CD8 ratio (+0.10, p=0.002) and HDL cholesterol (+5.4 mg/dl, p=0.036) was found after 144 weeks; meanwhile total cholesterol (-9.1 mg/dl, p=0.007) and triglycerides (-2.7, p=0.009) significantly decreased. Conclusions. Our findings confirm the efficacy and tolerability of 3TC+DTG in virologically suppressed patients.