Merck's investigational once-daily formulation of Isentress meets primary and secondary endpoints in pivotal Phase III study

Merck (MSD) has announced top-line results from the company’s Phase III pivotal trial, ONCEMRK. ONCEMRK is evaluating an investigational once-daily formulation of Isentress (raltegravir), known as raltegravir 600 mg (to be given as 2 x 600 mg once-daily), for previously untreated HIV-1 infected adults. The study met its primary efficacy endpoint: 1200 mg raltegravir (given as 2 x 600 mg once-daily) was statistically non-inferior to the marketed formulation approved dose of Isentress 400 mg twice-daily, each in combination therapy with Truvada, as assessed by the proportion of patients achieving HIV-1 RNA <40 copies/mL at Week 48. In addition, the secondary endpoints of tolerability and immunologic efficacy (as measured by change from baseline in CD4 cell counts at Week 48) were comparable. Later this year, Merck plans to present detailed findings of the study at an upcoming scientific conference, and to submit applications for licensure to the FDA and the EMA for this investigational new formulation.