TMC278-C204 (NCT00110305), a 96-week trial of the nonnucleoside reverse transcription inhibitor (NNRTI) rilpivirine (RPV, TMC278) in 368 HIV-1-infected, treatment-naive patients, was extended to investigate long-term safety and efficacy. Week 192 analysis results are presented. This was a long-term follow-up of a Phase IIb, randomized trial. No significant RPV dose-response relationships with respect to the primary endpoint (composite ITT-TLOVR algorithm) were observed at week 48 or 96. All RPV-treated patients were switched to open-label 75 mg qd at week 96 and then to 25 mg qd, the Phase III dose, at approximately week 144 as it gave the best benefit-risk balance. All control patients continued receiving open-label efavirenz (EFV) 600 mg qd. At week 192, 59% of RPV- and 61% of EFV-treated patients maintained confirmed viral load <50 copies/ml (ITT-TLOVR algorithm). The mean changes from baseline in CD4 cell count were similar in both groups (RPV: 210 cells/mm(3) vs. EFV: 225 cells/mm(3)). No new safety concerns were noted between week 48 and 192. In the week 192 analysis, RPV compared with EFV was associated with a lower overall incidence of grade 2-4 adverse events (AEs) at least possibly related to treatment, including rash (p<0.001) and neurologic AEs (p<0.05 Fisher's exact test, post hoc analyses) Incidences of serious AEs, grade 3 or 4 AEs, and discontinuations due to AEs were similar across groups. Increases in total cholesterol, LDL-cholesterol, HDL-cholesterol, and triglycerides were significantly lower with RPV than with EFV. RPV continued to show sustained efficacy similar to EFV at week 192 with a generally more favorable safety profile.