Washington, Oct 2 : Maraviroc, the first of a new class of HIV drugs called CCR5 receptor antagonists, can provide major benefits for certain patients who have become immune to existing medications, according to a new study.
Since it is from a new class of HIV medications known as HIV entry inhibitors, people living with HIV generally will not have resistance to maraviroc because they have not been exposed to any drugs from the class previously.
Unlike earlier HIV drugs that target the virus, maraviroc acts on the human T-cell, binding to it in such a way that prevents HIV from binding and subsequently infecting the T-cell.
"It is now possible to expect that a majority of treatment-experienced patients who experience failure on their current HIV drugs will regain control of their HIV infection with maraviroc combined with other newer antiretroviral drugs. This is an important step forward," says study principal investigator Dr. Roy Gulick, who is professor of medicine and director of the Cornell HIV Clinical Trials Unit of the Division of International Medicine and Infectious Diseases at Weill Cornell Medical College, and a practicing physician at NewYork-Presbyterian Hospital in New York City.
"Suppressing virus levels and increasing immune system T-cells with HIV treatment regimens helps HIV-infected people live longer, healthier lives," he added.
The double-blind study followed 1,049 of patients with advanced HIV and resistance to three antiretroviral drug classes.
Patients were randomized to receive maraviroc once-daily, twice-daily or placebo. Safety and efficacy were assessed at 48 weeks.
The researchers found that the drug, taken with an optimized standard HIV drug regimen, resulted in significantly greater suppression of the virus at 48 weeks, with concurrent increases in immune system T-cell counts, when compared with placebo.
Rates of side effects were not different between the maraviroc and placebo groups.
"Findings from the subgroup analyses show that maraviroc plus standard antiretroviral regimen provides consistent clinical benefit over placebo plus optimized background therapy for all subgroups analyzed," said Dr. Gerd Fatkenheuer, lead-author of the subgroup analyses and professor of medicine, Universit¤tsklinik Koln, Koln, Germany.
"Results highlight that maraviroc provides a valuable additional treatment option for a wide spectrum of treatment-experienced patients with R5 HIV-virus infection," Fatkenheuer added.
The study has been published in the October 2 issue of the New England Journal of Medicine (NEJM).