YYA-021 is a small-molecule CD4 mimic that inhibits HIV entry [1].
CD4 is a cell surface protein. The entry of human immunodeficiency virus type 1 (HIV-1) into target cells is initiated by the interaction of CD4 and viral envelope glycoprotein gp120. CD4 mimic inhibits the interaction between gp120 and CD4 and then inhibits HIV entry [1].
YYA-021 is a small-molecule CD4 mimic that inhibits HIV entry. YYA-021 competitively inhibited gp120-CD4 interaction [1]. In TZM-bl cells infected with simian-human immunodeficiency virus isolate MNA (SHIV MNA) or HIV-1 MNA pseudotyped viruses, YYA-021 inhibited the entry of Envs of SHIV MNA and HIV-1. KD-247 (the anti-V3 loop mAb, 50 μg) caused 50% neutralization of HIV-1 MNA. However, in the presence of 20 μM of YYA-021, KD-247 (<0.05 μg) caused 50% neutralization of HIV-1 MNA, which suggested that the synergistic neutralization effect of YYA-021 and KD-247. In the presence of YYA-021, SHIV MNA became more sensitive to IgG [2].
In Jcl:SD rats, the maximum tolerated dose of YYA-021.HCl was 2.5 mg. When administrated by tail vein injection, YYA-021 exhibited widespread tissue distribution due to its hydrophobicity. In a rhesus macaque, the maximum tolerated dose of YYA-021.HCl was 35.3 mg [1].
References:
[1]. Hashimoto C, Narumi T, Otsuki H, et al. A CD4 mimic as an HIV entry inhibitor: pharmacokinetics. Bioorg Med Chem, 2013, 21(24): 7884-7889.
[2]. Otsuki H, Hishiki T, Miura T, et al. Generation of a replication-competent simian-human immunodeficiency virus, the neutralization sensitivity of which can be enhanced in the presence of a small-molecule CD4 mimic. J Gen Virol, 2013, 94(Pt 12): 2710-2716.