Comparisons between rilpivirine (RPV) and integrase strand transfer inhibitors (INSTIs) in antiretroviral therapy (ART)-naïve HIV-infected individuals are currently lacking. Aim of the study was to compare, in an observational cohort setting, the durability of treatment of RPV- and INSTI-based first-line regimens.
Patients who started first-line ARTs based on RPV or on INSTIs, with HIV-RNA 200 cells/μL, were included. The primary endpoint was the cumulative probability of treatment failure (TF = virological failure [confirmed HIV-RNA >50 copies/mL] or discontinuation of the anchor drug in the regimen), as assessed by Kaplan-Meier method. A multivariable Cox regression was used to control for potential confounding.
Of 1991 patients included, 986 started ART with a RPV- and 1,005 with an INSTI-based regimen. The median (IQR) follow-up was 20 (10, 35) months. The cumulative two-years probability of TF with RPV (9.1% [95% 7.2, 11.1]) was lower than that observed in the INSTI group (16.6% [13.8, 19.4], p=0.0002) but not when comparing with dolutegravir (DTG) alone. Starting ART with an INSTIs-based regimen vs. RPV was associated with a higher risk of TF after controlling for potential confounding factors (AHR [95%CI]: 1.64 [1.28, 2.10]; p<0.001). Results were similar when restricting the analysis to STR regimens, although the probability of virological success was higher for INSTI and for DTG.
In ART-naïve patients with low viral load and high CD4 count, the risk of treatment failure was lower in patients who started RPV- vs. INSTIs-based regimens other than DTG-based ones.

Copyright © 2021. Published by Elsevier Ltd.