A Study to Evaluate Efficacy and Safety of an Investigational Drug Named Volixibat in Patients With Itching Caused by Primary Sclerosing Cholangitis (PSC)

Inclusion Criteria:

1. Provide freely signed informed consent and assent (as applicable) and be willing tocomply with all study visits and requirements through end of study, including thefollow-up period.

2. Subjects aged ≥12 years for eligible regions; otherwise ≥18 years

3. Confirmed diagnosis of large duct or small duct PSC based on American Associationfor the Study of Liver Disease (AASLD) guidelines.

4. Pruritus associated with PSC as assessed by Adult ItchRO.

5. Ursodeoxycholic acid (UDCA) and anti-pruritic medication use will be allowed ifmeeting additional criteria.

6. Concomitant Inflammatory Bowel Disease (IBD) is allowed if meeting additionalcriteria.

Exclusion Criteria:

1. Pruritus associated with an etiology other than PSC

2. Evidence or clinical suspicion of decompensated cirrhosis, or a history ofdecompensation events

3. History of ileostomy or small bowel surgery/resection or other surgeries that mayhave disrupted the enterohepatic circulation

4. Evidence, history, or suspicion of other liver disease; PSC patients with AIH arenot excluded.

5. Bile duct stent or percutaneous bile duct drain placement, or balloon dilatationprocedure of a stricture within 12 weeks of Screening

6. Exceeding pre-defined biochemical values for alanine aminotransferase/aspartateaminotransferase (ALT/AST), estimated glomerular filtration rate (eGFR),serumcreatinine (sCr), platelet count, international normalized ratio (INR) and totalbilirubin

7. History of liver transplantation