Maraviroc in Antiretroviral-Naïve HIV-1 Patients

New antiretroviral agents that are better tolerated with less side effects and novel resistance patterns are needed at all lines of human immunodeficiency virus (HIV) therapeutic strategies. The CC-chemokine receptor 5 (CCR5) antagonist maraviroc is a member of the novel class of “antiretroviral agents” that prevents the entry of HIV-1 into host cells by blocking the CCR5 coreceptor. In the MERIT (Maraviroc versus Efavirenz in Treatment-Naïve Patients) study in antiretrovial-naïve patients aged ≥16 years with CCR5-tropic HIV-1 infection, maraviroc showed noninferiority to efavirenz for virological endpoints. Evidences from trials suggest that maraviroc is effective at reducing HIV-1 viral load in antiretroviral-experienced and -naïve patients with CCR5-tropic virus, as well as in those with CCR5-tropic virus who have developed HIV-1 resistance to existing antiretroviral regimens. Recent in vitro study demonstrated that maraviroc was also active against CCR5-tropic HIV-2 strains.