Background: The MERIT study evaluated maraviroc versus efavirenz, both with zidovudine/lamivudine, in treatment-naïve patients with CCR5-tropic (R5) HIV-1. Post hoc analyses previously assessed week 48 outcomes in patients rescreened with R5 virus by a more sensitive tropism assay. Methods: Week 96 efficacy (post hoc, n = 614) and safety (n = 721) were assessed. Results: Proportions of subjects <50 copies/mL (58.8% maraviroc, 62.7% efavirenz) and time to loss of virologic response (TLOVR) responders (<50 copies/mL: 60.5% vs 60.7%) were similar. Maraviroc recipients had greater CD4 increases (+ 212 vs + 171 cells/mm3) and fewer adverse event discontinuations (6.1% vs 15.5%), malignancies, and category C events. Conclusion: Week 96 data confirm week 48 observations in MERIT. © 2010 Thomas Land Publishers, Inc.