Short-term randomized proof-of-principle trial of TMC278 in patients with HIV type-1 who have previously failed antiretroviral therapy

Abstract

Background

In vitro, TMC278, an investigational next-generation non-nucleoside reverse transcriptase inhibitor (NNRTI), has shown activity against wild-type and NNRTI-resistant HIV type-1 (HIV-1) and a higher genetic barrier to the development of resistance than efavirenz or nevirapine. This Phase II open-label trial evaluated the short-term (7-day) antiviral activity of TMC278 administered at three different doses replacing either the protease inhibitor (PI) or NNRTI of an ongoing failing treatment regimen in HIV-1-infected patients.

Methods

A total of 36 patients on failing antiretroviral therapy containing either an NNRTI or a PI (with evidence of ≥1 NNRTI resistance-associated mutation at screening for the PI group) and plasma viral load (VL)>1,000 copies/ml were randomized to one of three once-daily TMC278 doses (25 mg, 50 mg or 150 mg) for 7 days, while continuing NRTIs used at screening. The primary efficacy parameter was the change on day 8 in log₁₀ plasma VL from baseline.

Results

On day 8, median (min, max) changes from baseline in plasma VL were -0.87 (-2.3, 0.0), -0.95 (-1.8, 0.4) and -0.66 (-1.3, -0.2) log₁₀ copies/ml for the 25 mg, 50 mg and 150 mg once-daily TMC278 groups, respectively (P<0.001–<0.01). Overall, the median change from baseline was -1.19 log₁₀ copies/ml in the PI-substituted therapy group and -0.71 log₁₀ copies/ml in the NNRTI-substituted therapy group. TMC278 was generally safe and well tolerated with no apparent differences in safety among the three dose groups.

Conclusions

Once-daily TMC278 showed significant antiviral activity against HIV-1 in treatment-experienced patients with NNRTI failure and/or resistance, and was generally safe and well tolerated.