BMS-663068 is an HIV-1 attachment inhibitor in development for the treatment of HIV-1 infection. BMS-663068 is a prodrug for BMS-626529 which binds to the viral envelope glycoprotein gp120 and interferes with attachment of the virus to the cellular CD4 receptor. Administration of BMS-663068 for 8 days with or without ritonavir resulted in substantial declines in plasma HIV-1 RNA levels and was generally well tolerated. Longer-term clinical trials of BMS-663068 as part of combination antiretroviral therapy are warranted.