TKB272 is an orally active and selective antiviral agent targeting the main protease (Mpro) of SARS-CoV-2. It effectively blocks the infection and replication of various SARS-CoV-2 strains, including Omicron variants such as XBB.1.5 and EG.5.1. The enzymatic inhibitory activity of TKB272 shows an IC50 of 0.7 µM (against SARS-CoV-2WK-521 Mpro), and its antiviral activity at the cellular level reaches an EC50 as low as 2.6 nM (against BQ.1.1 strain in HeLahACE2-TMPRSS2 cells), with a cytotoxicity CC50 of 98 µM, indicating no apparent toxicity. In addition, TKB272 significantly suppresses the replication of SARS-CoV-2XBB.1.5 in B6.Cg-Tg(K18-hACE2)2-Prlmn/J transgenic mouse models. TKB272 holds promise for research in the field of SARS-CoV-2 infection.
