Objectives: Week 96 efficacy and safety of the non-nucleoside reverse transcriptase inhibitor (NNRTI) rilpivirine (RPV) was compared to efavirenz (EFV) in subset of 1,096 subjects who received emtricitabine/tenofovir disoproxil fumarate (FTC/TDF) in pooled data from 2 phase 3 studies.
Methods: ECHO and THRIVE are double-blind, double-dummy, randomized, active-controlled, non-inferiority phase 3 studies of RPV versus EFV plus 2 NRTIs in antiretroviral-naïve adult subjects. The primary and secondary endpoints were the proportion of subjects with HIV-1 RNA <50 copies/ mL using an intent-to-treat, time to loss of virologic response (ITT-TLOVR) analysis at weeks 48 and 96, respectively. Safety, tolerability, immunologic response, adherence level, and other measures were also evaluated.
Results: At week 48, noninferior efficacy of RPV+FTC/TDF over EFV+FTC/TDF was established, and at week 96 RPV+FTC/TDF remained noninferior (77% overall response rate in both groups). Through week 96, rates of virologic failure were higher in the RPV+FTC/ TDF group, with low and similar rates of virologic failure and resistance mutations occurring during the second year of follow-up. Treatment with RPV+FTC/TDF was associated with a lower rate of discontinuation due to adverse events and grade 2-4 adverse events including dizziness, abnormal dreams/nightmares, rash, and lipid abnormalities.
Conclusions: The pooled ECHO and THRIVE studies demonstrated noninferiority of RPV+FTC/TDF in achieving virologic response with safety and tolerability advantages over EFV+FTC/TDF through 96 weeks. Higher rates of virologic failure in the RPV+FTC/TDF group were balanced with higher rates of discontinuations due to adverse events in the EFV+FTC/TDF group.