This study evaluated the safety and pharmacokinetics (PK) of a single dose of leritrelvir, a novel inhibitor of 3-chymotrypsin-like cysteine protease (3CLpro), in patients with hepatic impairment versus healthy participants with normal hepatic function. Eight participants with mild (Child-Pugh A) hepatic impairment, eight with moderate (Child-Pugh B) hepatic impairment, and eight healthy matched control participants were enrolled in this open-label, parallel clinical trial. After administration of leritrelvir of 400 mg, PK parameters were calculated and compared across groups. In total, 24 participants were enrolled and completed the study. Leritrelvir was generally well tolerated, with no serious adverse events or deaths reported during the study. Compared to the group with normal hepatic function, the geometric least-squares mean ratios (90% confidence intervals) for