Seladelpar (MBX-8025) in Subjects With Primary Biliary Cholangitis (PBC)

Primary:

To evaluate the safety and efficacy of MBX-8025 2 mg, 5 mg, and 10 mg over 8 weeks of
treatment

Secondary:

To evaluate the safety and efficacy of MBX-8025 2 mg, 5 mg, and 10 mg over 12 and 26 weeks of
treatment

To evaluate the safety and efficacy of MBX-8025 2 mg, 5 mg, and 10 mg over 52 weeks of
treatment

To evaluate the pharmacokinetics (PK) of MBX-8025

Exploratory:

To evaluate the effect of MBX-8025 on bile acids, additional markers of inflammation and
renal function

MBX-8025 doses of 1 mg and 15 mg may be evaluated if dose adjustment occurs

Inclusion Criteria:

1. Must have given written informed consent (signed and dated) and any authorizations
required by local law

2. 18 to 75 years old (inclusive)

3. Male or female with a diagnosis of PBC, by at least two of the following criteria:

- History of AP above ULN for at least six months

- Positive AMA titers (>1/40 on immunofluorescence or M2 positive by enzyme linked
immunosorbent assay (ELISA) or positive PBC-specific antinuclear antibodies

- Documented liver biopsy result consistent with PBC

4. On a stable and recommended dose of UDCA for the past twelve months or intolerant to
UDCA

5. AP ≥ 1.67 × ULN

6. 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:

1. 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 on active
treatment)

2. AST or ALT > 3 × ULN

3. Total bilirubin > 2.0 mg/dL

4. Total bilirubin > ULN AND albumin < LLN with the exception to subjects with Gilbert's
Syndrome. Subjects with Gilbert's syndrome are excluded if Direct Bilirubin > ULN.

5. Auto-immune hepatitis

6. Primary sclerosing cholangitis

7. Known history of alpha-1-Antitrypsin deficiency

8. Known history of chronic viral hepatitis

9. Creatine kinase above ULN

10. Serum creatinine above ULN

11. For females, pregnancy or breast-feeding

12. Use of colchicine, methotrexate, azathioprine, or systemic steroids in the two months
preceding screening

13. Current use of fibrates or simvastatin

14. Current use of obeticholic acid

15. Use of an experimental or unapproved treatment for PBC

16. Use of experimental or unapproved immunosuppressant

17. Adverse event leading to MBX-8025 discontinuation from CymaBay's phase 2 PBC study
(CB8025-21528)

18. 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