Maraviroc.

Maraviroc, first in a new pharmacological class of antiretroviral agents known as CCR5 antagonists, has been approved by the U.S. Food and Drug Administration for the treatment of HIV-infected adult patients who are infected with only CCR5-tropic HIV-1 virus and who have HIV-1 strains resistant to multiple antiretroviral agents. Maraviroc has demonstrated in vitro activity against a wide range of CCR5 tropic clinical isolates, including those resistant to the four currently existing drug classes of antiretroviral agents. In the two pivotal phase III studies, MOTIVATE-1 and -2, maraviroc, in combination with optimized background therapy (OBT), demonstrated superior virologic and immunologic treatment outcomes than OBT alone in treatment-experienced patients infected with CCR5-tropic HIV-1. In these studies, maraviroc also demonstrated acceptable safety and tolerability profiles with adverse events and discontinuation rates in general comparable to those noted in the placebo arms.