Rilpivirine efficacy, virology and safety in ARV treatment-naïve patients with viral load ≤100,000 HIV-1 RNA c/mL: ECHO and THRIVE 96-week results

Background : In the ECHO and THRIVE Phase III, randomised, double-blind trials, rilpivirine (RPV, TMC278, EDURANT) 25 mg qd showed non-inferiority compared to efavirenz (EFV) 600 mg qd in antiretroviral (ARV) treatment-naive, HIV-1-infected adults at Weeks 48 and 96. In Europe, RPV combined with other ARVs is approved for the treatment of ARV-naive adults with a viral load (VL) ≤100,000 c/mL. We present results from a pooled analysis of Week 96 data from this patient subgroup. Methods: Patients received RPV 25 mg qd or EFV 600 mg qd, both with TDF/FTC (ECHO) or TDF/FTC, AZT/3TC or ABC/3TC (THRIVE). Response rate (% VL <50 c/mL, intent-to-treat-time-to-loss-of-virologic response [ITT-TLOVR]), virologic failure in the resistance analysis (VF res ) and resistance development, as well as safety and tolerability were evaluated. Results : Baseline characteristics were similar between the 368 RPV and 329 EFV patients with baseline VL ≤100,000 c/mL. At Week 96, response rates (RPV 84% vs EFV 80%; difference 4.0% [95% CI: -1.7%, 9.7%]) and VF res percentages (8% vs 6%, respectively; p=0.46) (Table) were similar in each treatment group. A comparable proportion of VF res developed NNRTI resistance-associated mutations (RAMs) in each group. More RPV than EFV VF res developed N(t)RTI RAMs (p=0.02). The increase in mean (95% CI) CD4+ cell count from baseline to Week 96 was 224 (208; 240) cells/mm 3 for RPV and 206 (188; 225) cells/mm 3 for EFV. Treatment-related grade 2-4 overall AEs, any rash, and neurologic AEs, including dizziness were less frequent for RPV than EFV (all p<0.0001, Fisher's Exact test) (Table). Conclusions : At Week 96, in ARV treatment-naive adults with baseline VL ≤100,000 c/mL, RPV demonstrated sustained antiviral efficacy similar to EFV. There were similar frequencies of RPV and EFV VF res , and RPV had a more favourable safety/tolerability profile than EFV. (Published: 11 November 2012) Citation: Abstracts of the Eleventh International Congress on Drug Therapy in HIV Infection Molina J-M et al. Journal of the International AIDS Society 2012, 15 (Suppl 4):18250 http://www.jiasociety.org/index.php/jias/article/view/18250 | http://dx.doi.org/10.7448/IAS.15.6.18250