Results from a new study in treatment-naïve HIV patients have shown that Merck Sharp & Dohme’s (MSD) Isentress is effective as first-line medication for reducing viral load and increasing CD4 cell counts.

Isentress (raltegravir), a first-in-class integrase inhibitor, was found to be as effective as efavirenz, a standard first-line medication, at suppressing viral load to undetectable levels when used in combination therapy.

At week 48, patients taking raltegravir had significantly fewer side effects compared to the efavirenz group and there were greater increases in mean CD4 cell count recorded for the raltegravir group, although this was not statistically significant.

Raltegravir and efavirenz were administered in combination with two other anti-HIV medicines, tenofovir and emtricitabine.

London Chelsea and Westminster Hospital consultant in HIV medicine Mark Nelson said that these findings show that a raltegravir-based regimen was as effective as an efavirenz-based regimen.

“This study suggests that raltegravir in combination therapy with other antiretroviral treatments may become an important new treatment option for a broader spectrum of patients, including those who have not been previously treated with HIV therapy,” Nelson said.

Raltegravir is approved in more than 80 countries across six continents for the treatment of HIV-1 infection in treatment-experienced adult patients in combination with other ARV agents.

MSD recently received a positive opinion from the European Union‘s Committee for Medicinal Products for Human Use recommending expanded marketing authorisation for raltegravir for the treatment of HIV-1 infection in all adult patients, including treatment-naïve and treatment-experienced patients.