Comparison of efficacy, safety and durability of a switch to co-formulated RPV/TDF-TAF/FTC or DTG/ABC/3TC in virologically suppressed HIV-1-infected patients in a single Italian center: a cohort data analysis.

OBJECTIVES To evaluate the efficacy, safety and durability of a simplification to single tablet with RPV/TDF-TAF/FTC (RPV-STR) or DTG/ABC/3TC (DTG-STR) in virologically-suppressed HIV-positive patients in a single Italian teaching hospital. METHODS All HIV-infected, ART experienced switching to RPV-STR or DTG-STR with HIV-RNA level <50 copies/mL were included. The outcomes were incidence rate and rate ratios for discontinuation due to all causes (DAC), discontinuation due to virologic failure (VF), and adverse events after four years of follow-up. RESULTS We included 402 patients (244 on RPV-STR, 158 on DTG-STR). At the fourth year of follow-up, 124 (30.4%) patients discontinued for any cause (71 on RPV-STR and 53 on DTG-STR). Fifteen patients experienced VF, 13 (5.3%) on RPV-STR and 2 (1.2%) on DTG-STR (long rank: p=0.4413). Overall, 46 (11.4%) had adverse events (23 with RPV-STR and 23 with DTG-STR,). Nausea/diarrhea were more frequent with DTG-STR (4.4% vs. 0%), and neurological toxicity with RPV-STR (4.5% vs 2.5%). The discontinuation rate for all causes within the first three months was significantly higher with STR-DTG (aRR 5.88 [95%CI: 3.20-10.81; p<0.001]; similarly, the discontinuation rate due to adverse events was significantly higher with STR-DTG compared to STR-RPV (aRR 12.89, 95%CI 5.48 - 30.32; p<0.001). No difference in VF rate was observed between the two groups [RR 0.47 95%CI 0.10- 2.14; p=0.335] CONCLUSIONS: : Undetectable patients switched to DTG-STR or RPV-STR maintained virologic suppression with a low risk of VF. A higher discontinuation rate was observed with DTG-STR compared to RPV-STR in particular within 3 months from the switch.