BMS-626529 is a member of the new drug class of HIV-1 attachment inhibitors currently in development. BMS-663068 is the phosphonooxymethyl prodrug of BMS-626529, a novel small-molecule attachment inhibitor that targets HIV-1 gp120 and prevents its binding to CD4(+) T cells. The activity of BMS-626529 is virus dependent, due to heterogeneity within gp120. Research result suggest that BMS-626529 should be active against the majority of HIV-1 viruses and support the continued clinical development of the compound.