Final results from the STARTMRK study, a Phase III trial evaluating Isentress (raltegravir), from Merck Inc, in combination therapy in previously untreated adult HIV-1 patients, indicate that virologic efficacy was better than the efavirenz-based regimen at 240 weeks. In the study, 563 previously untreated HIV-1 infected adult patients with HIV-1 RNA greater than 5000 copies/mL received either 400 mg Isentress orally twice daily (n=281) or 600 mg efavirenz orally once daily (n=282), each in combination with tenofovir/emtricitabine. The primary endpoint of the study was a reduction in HIV-1 viral load to less than 50 copies/mL at week 48. Results show the regimen containing Isentress was better than the regimen containing efavirenz at reducing HIV-1 viral load to undetectable levels (less than 50 copies/mL) at follow-up at weeks 192 and 240 in these pre-specified exploratory analyses. The 240-week analysis showed a greater immunologic response, as well as a proven safety and tolerability profile. At all pre-specified time points, the regimen containing Isentress had fewer drug-related adverse events versus the comparator. Results were presented by Dr. Jürgen Rockstroh, University of Bonn, Bonn-Venusberg, Germany, at the 19th International AIDS Conference.