Merck today reported initial results from the Phase III study investigating the efficacy and safety of a treatment regimen including ISENTRESS® (raltegravir) Tablets once daily in treatment-naïve adult patients infected with HIV-1. ISENTRESS is indicated in combination with other antiretroviral agents for the treatment of HIV-1 infection in treatment-naïve and treatment-experienced adults. In the study, although the treatment regimen that included ISENTRESS once daily enabled more than 80 percent of patients to achieve viral suppression, ISENTRESS once daily did not demonstrate non-inferiority to the treatment regimen that included ISENTRESS twice daily. Merck said that based on the initial results and following the recommendation of an independent Data Monitoring Committee, Merck will end the study. Merck is notifying clinical investigators of this decision this week and is recommending that patients enrolled in the once-daily dosing arm of the study be switched to ISENTRESS twice daily, the FDA-approved dose. Results from this study will be submitted for presentation at an appropriate scientific meeting in 2011.
This Phase III study evaluated the safety and efficacy of an investigational once-daily dose of raltegravir (800 mg once daily) versus the approved twice-daily dose (400 mg twice daily), each given in combination with a once-daily fixed-dose combination of emtricitabine and tenofovir disoproxil fumarate, in adult treatment-naïve HIV-1-infected patients. In this study, 775 patients were randomized, and 770 patients received study drug and are included in the current analyses.
The overall treatment difference observed between the once-daily and twice-daily groups was primarily due to results in patients with high viral load. Among patients with more than 100,000 copies/mL of HIV-RNA, 74.3 percent.