Once-daily Extended Release Nevirapine (Viramune) Equals Twice-daily Immediate Release Formulation

SUMMARY: A once-daily extended-release formulation of nevirapine (Viramune) suppresses HIV viral load as well as the older immediate-release pill, and may cause fewer or milder side effects, according to a late-breaker presentation at the XVIII International AIDS Conference (AIDS 2010) last week in Vienna. The more convenient once-daily formulation is likely to be especially beneficial in resource-limited countries where the drug is still widely used.

The immediate-release formulation of nevirapine (Viramune IR) currently on the market is approved for twice-daily dosing. Once-daily medications, however, are more convenient and associated with better adherence.

As described by Anne-Marie Quinson from Boehringer-Ingelheim, the VERxVE trial compared the safety and efficacy of extended-release (Viramune XR) and immediate-release nevirapine formulations for first-line HIV treatment.

The study enrolled 1011 treatment-naive HIV positive adults, mostly from North America, Europe, and Australia. Most (85%) were men and the average age was 38 years.

The median pre-treatment viral load was about 50,000 copies/mL, and participants were stratified into high and low viral load groups (above or below 100,000 copies/mL). The average CD4 cell count was 228 cells/mm3. (Based on studies showing that people with better immune function are more likely to experience nevirapine hypersensitivity reactions, men with CD4 counts above 400 cells/mm3 and women with levels above 250 cells/mm3 were excluded.)

During a 14-day lead-in period -- done to bring nevirapine up to therapeutic levels in the body -- all participants took 200 mg Viramune IR once-daily. They were then randomly assigned (1:1) to receive either Viramune IR at a dose of 200 mg twice-daily or the new Viramune XR at a dose of 400 mg once-daily, both in combination with tenofovir/emtricitabine (Truvada).