Infectious Diseases: Research and Treatment

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.