Rilpivirine Versus Efavirenz with Emtricitabine/Tenofovir Disoproxil Fumarate in Treatment-Naïve HIV-1–Infected Patients with HIV-1 RNA ≤100,000 Copies/mL: Week 96 Pooled ECHO/THRIVE Subanalysis

The once daily, single-tablet regimen (STR) combining rilpivirine (RPV), emtricitabine (FTC), and tenofovir disoproxil fumarate (TDF) provides a simplified treatment option for antiretroviral therapy (ART)-naive patients with baseline HIV-1 RNA (BLVL) of ≤100,000 copies/mL. The aim of this analysis is to compare long-term efficacy, safety, and tolerability of RPV+FTC/TDF vs. efavirenz (EFV)+FTC/TDF as individual components in subjects with BLVL ≤100,000 copies/mL. Week 96 efficacy and safety data from subjects with BLVL ≤100,000 copies/mL, who received daily RPV 25 mg or EFV 600 mg with FTC/TDF in the phase 3, randomized, double-blind, double-dummy, active-controlled, registrational trials ECHO and THRIVE, were analyzed. Virologic response was evaluated by intent-to-treat, time to loss of virological response (ITT-TLOVR), and Snapshot algorithms. Through Week 96, RPV+FTC/TDF demonstrated non-inferior efficacy to EFV+FTC/TDF (84% vs. 81%, respectively; ITT-TLOVR) in 543 subjects with BLVL ≤100,000 copies/mL, and overall rates of virologic failure (VF) were 5.9% vs. 2.4%, respectively. Resistance development was lower in Year 2 than Year 1. Subjects in both arms with suboptimal adherence (≤95%) had lower virologic responses (63% vs. 62%, respectively). Treatment with RPV+FTC/TDF was associated with significantly fewer treatment-related adverse events (AEs), grade 2-4 AEs, neurological and psychiatric AEs (including dizziness and abnormal dreams/nightmares), and rash. Additionally, grade 2-4 treatment-emergent laboratory abnormalities and grade 1-3 lipid abnormalities were significantly less common with RPV+FTC/TDF than EFV+FTC/TDF. RPV+FTC/TDF demonstrated non-inferior efficacy to EFV+FTC/TDF in ART-naive subjects with BLVL ≤100,000 copies/mL and was associated with a higher rate of VF but a more favorable safety and tolerability profile through Week 96.