Vicriviroc maleate is an investigational CCR5 receptor antagonist developed for the treatment of HIV infection. It functions by blocking the entry of HIV into human cells through inhibition of the CCR5 co-receptor, which is crucial for CCR5-tropic HIV-1 strains to infect cells. This makes it potentially effective against these specific viral strains. It has been explored in clinical trials, often in combination with other antiretroviral therapies, to improve the efficacy of HIV treatment regimens and reduce viral load while enhancing immune function in HIV-positive patients. As it is not approved for clinical use, it is primarily available as a research chemical or reagent.