In vitro activity: YYA-021 enhances the neutralization sensitivity of simian-human immunodeficiency virus (SHIV) carrying the envelope from the clade B clinical human immunodeficiency virus type 1 (HIV-1) isolate MNA.

Kinase Assay: YYA-021 is a small-molecule CD4 mimic that inhibits HIV entry, with high anti-HIV activity and low cytotoxicity. IC50 value: 8.4 μM

Cell Assay: HIV IC50 (=8.4 μM) value of YYA-021 is determined by a single round assay using cYTA48P virus and TZM-bl cells. YYA-021 is broadly distributed in tissues, probably as a result of its hydrophobicity. The plasma concentrations of YYA-021 in both species remained at micromolar levels for several hours post-injection.