Vicriviroc maleate is primarily used in the treatment of HIV infection. It functions as a CCR5 receptor antagonist, blocking the entry of HIV into human cells by inhibiting the CCR5 co-receptor, which is essential for certain strains of the virus to infect cells. This mechanism makes it particularly effective against CCR5-tropic HIV-1 strains. It is often explored in combination with other antiretroviral therapies to enhance the overall efficacy of HIV treatment regimens. Additionally, its potential application in reducing viral load and improving immune function in HIV-positive patients has been a focus of clinical research.