Raltegravir: in treatment-naive patients with HIV-1 infection

Raltegravir, a first-in-class, oral HIV type-1 (HIV-1) integrase inhibitor, blocks the covalent integration of HIV-1 complementary DNA into the host genome. In a large, randomized, double-blind, multinational, ongoing trial in treatment-naive patients with HIV-1 infection, raltegravir 400 mg twice daily was noninferior to efavirenz 600 mg once daily in achieving plasma HIV-1 RNA viral levels of <50 copies/mL after 48 weeks' treatment (primary endpoint), when used as part of an antiretroviral therapy (ART) combination regimen. The time to achieve a virological response was significantly shorter in the raltegravir group than in the efavirenz group. Furthermore, significantly more raltegravir than efavirenz recipients achieved HIV-1 RNA viral levels of <50 copies/mL at weeks 2-16. The efficacy of raltegravir in achieving HIV-1 RNA levels of <50 copies/mL was also demonstrated in subgroups of patients separated according to baseline viral levels, CD4+ cell counts and viral subtypes. Preliminary evidence suggests that both virological and CD4+ cell count improvements were maintained at 96 weeks for treatment-naive recipients of raltegravir 400 mg twice daily. As part of an ART combination regimen, raltegravir treatment was generally well tolerated and was associated with significantly fewer drug-related adverse events than efavirenz treatment. Moreover, after 96 weeks, raltegravir treatment was associated with a significantly lower impact on serum lipid levels than efavirenz treatment.