Discovery of an Orally Bioavailable Reversible Covalent SARS-CoV-2 M^pro Inhibitor with Pan-Coronavirus Activity

Resulting in several million deaths globally, the COVID-19 pandemic has highlighted the criticality of antiviral drugs during a viral pandemic. Herein, we describe our efforts toward targeting SARS-CoV-2 M^pro, a key viral protease, which led to the discovery of compound 18, a reversible covalent inhibitor with potent antiviral activity against several clinical variants of SARS-CoV-2. Compound 18 demonstrated dose-dependent efficacy in a mouse-adapted SARS-CoV-2 infection model, with favorable pharmacokinetic profiles in mice, rats, dogs, and monkeys.