Study to Evaluate the Safety and Efficacy of ASC42 Tablets in Subjects With Primary Biliary Cholangitis

Inclusion Criteria: * Age ≥ 18 and ≤75 years old at screening. * Definite or probable PBC diagnosis, as demonstrated by the presence of ≥ 2 of the following 3 diagnostic factors: 1. Biochemical evidence of cholestasis based on ALP elevation. 2. Presence of AMA, or other PBC-specific autoantibodies, including sp100 or gp210, if AMA is negative. 3. Liver biopsy consistent with PBC. * Screening ALP ≥ 1.67× ULN * Taking UDCA for at least 6 months (stable dose for ≥ 3 months) prior to Day 0, or unable to tolerate UDCA (no UDCA for ≥ 3 months) prior to Day 0. Exclusion Criteria: * ALT or AST \> 5× ULN; ALP \>10× ULN * History or presence of other concomitant liver diseases * Child-Pugh grade B or C