The integrase inhibitor raltegravir (Isentress) has taken a key step towards approval for use in first-line HIV therapy in Europe. The EMEA's Committee for Medicinal Products for Human Use (CHMP) has recommended expanding its marketing authorisation as part of combination antiretroviral therapy by individuals initiating such treatment. Currently its European licence restricts its use to treatment-experienced patients.
This recommendation comes days after the International AIDS Society’s conference in Cape Town was presented with trial data about the safety and efficacy of the drug in treatment-naive patients. Interim three-year results from an ongoing study showed that raltegravir was as effective as efavirenz as part of antiretroviral therapy for patients starting HIV treatment.
In the study, 198 patients were randomised to receive raltegravir or efavirenz (Sustiva) in combination with FTC and tenofovir (Truvada). The study is a phase 2 dose-ranging study. After 48 weeks, all the raltegravir-treated patients were taking a 400mg dose of the drug twice daily.
After 144 weeks, 78% of individuals taking raltegravir had a viral load below 50 copies/ml compared to 76% of those taking efavirenz. Mean CD4 cell counts increases at this time point were also comparable in the two arms of the study (252 vs 233 cells/mm3).
Fewer of the patients taking raltegravir reported side-effects (54% vs 76%), and the lipid profiles of individuals taking this drug were more favourable than those seen amongst the patients taking efavirenz.
Raltegravir has already been approved for first-line use in the US. This was based upon 48-week results from the STARTMRK study.