Seladelpar in Subjects With Primary Biliary Cholangitis (PBC)

Primary: To evaluate the long-term safety and tolerability of seladelpar Secondary: To evaluate the long-term efficacy of seladelpar To evaluate the effect of seladelpar on patient-reported outcomes (pruritus) Exploratory To evaluate the effect of seladelpar on liver histology, additional measures of QoL, biomarkers of cholestasis, lipids, and liver fibrosis To evaluate the plasma concentrations of seladelpar and its metabolites

Inclusion Criteria:

1. Must have given written informed consent (signed and dated)
2. Participated in a PBC study with seladelpar
3. Females of reproductive potential must use at least one barrier contraceptive and a second effective birth control method during the study and for at least 90 days after the last dose. Male subjects who are sexually active with female partners of reproductive potential must use barrier contraception and their female partners must use a second effective birth control method during the study and for at least 90 days after the last dose

Exclusion Criteria:

Exclusion criteria are only applicable for subjects with a seladelpar interruption greater than 4 weeks prior to Day 1 of this study and for subjects who participated in CB8025-21838 irrespective of seladelpar interruption.

1. Treatment-related adverse event (AE) leading to seladelpar discontinuation in a previous PBC study with seladelpar (MBX-8025)
2. A medical condition, other than PBC, that in the investigator's opinion would preclude full participation in the study or confound its results (e.g., cancer)
3. AST or ALT above 3 × the upper limit of normal (ULN)
4. Total bilirubin above 2 × ULN
5. MELD score ≥ 15
6. Evidence of advanced PBC as defined by the Rotterdam criteria: albumin below 1× the lower limit of normal (LLN) AND total bilirubin above 1 × ULN)
7. eGFR below 60 mL/min/1.73 m2 (calculated by MDRD formula)
8. Auto-immune hepatitis
9. Primary sclerosing cholangitis
10. Known history of alpha-1-antitrypsin deficiency
11. Known history of chronic viral hepatitis
12. For females, pregnancy or breast-feeding
13. Use of colchicine, methotrexate, azathioprine, or long-term use of systemic steroids (e.g. prednisone, prednisolone, budesonide) (>2 weeks) within 2 months prior to Screening
14. Current use of fibrates or use of fibrates within 3 months prior to Screening
15. Current use of obeticholic acid or use of obeticholic acid within 3 months prior to Screening
16. Use of an experimental or unapproved treatment for PBC within 3 months prior to Screening
17. History of malignancy diagnosed or treated, actively or within 2 years, or active evaluation for malignancy; localized treatment of squamous or non-invasive basal cell skin cancers and cervical carcinoma in-situ is allowed if appropriately treated prior to Screening
18. Treatment with any other investigational therapy or medical device within 30 days or within 5 half-lives, whatever is longer, prior to Screening
19. Any other condition(s) that would compromise the safety of the subject or compromise the quality of the clinical study, as judged by the Investigator