This is a multicenter, open-label, parallel group, single-dose study to compare pharmacokinetics of GP681 after a single 40mg oral dose in eight healthy subjects and eight mild or eight moderate hepatic impairment subjects. Subjects with hepatic impairment will be enrolled into either mild (Child-Pugh A, score 5-6) or moderate (Child-Pugh B, score 7-9) hepatic impairment groups. The healthy subjects will match with impaired hepatic function patients on ethnic group, sex(+/- 1 subject), age (+/- 10 years) and weight (+/- 25%).~Participants will be admitted into the Clinical Research Units(CRU) on Day-1. On the morning of Day 1, subjects will receive a single 40 mg oral dose of GP681 following an overnight fast (i.e., at least 10 hours). Participants will be confined to the CRU until discharge on Day 12, with PK blood sample draws for measurement of GP681 and its main metabolites being taken throughout the confinement.~Safety assessments will include physical examinations, ECGs, vital signs, standard clinical laboratory evaluations (hematology, blood chemistry, urinalysis, coagulation), AE and serious adverse event (SAE) monitoring.~All participants will have a post-study safety follow-up contact conducted approximately 12 days after administration of study treatment. The study will be considered complete once all the participants have finished the required assessments, dropped out, or been lost to follow-up before completing the required assessments.
The primary objective of this study is to test whether mild (Child-Pugh A, score 5-6) and moderate (Child-Pugh B, score 7-9) hepatic impairment affects pharmacokinetics, safety and tolerability of GP681, compared with a control group with normal hepatic function following oral administration of GP681 as single dose.