GZNL-P36 is an orally active inhibitor of SARS-CoV-2 papain-like protease (PLpro), with an IC50 of 6.45 nM. It effectively inhibits SARS-CoV and its variants, showing an EC50 ranging from 58.2 nM to 2.66 μM. In CD-1 mouse models, GZNL-P36 reaches a maximum plasma concentration (Cmax) of 549 ng/mL, with a half-life (T1/2) of 1.45 hours and a bioavailability of 74.7%. Additionally, GZNL-P36 exhibits antiviral activity in mice infected with SARS-CoV-2 XXB.1.