Study was terminated as a precautionary measure due to histological findings in a nonalcoholic steatohepatitis (NASH) study (CB8025-21730, NCT03551522).

The objectives of this study are to evaluate the effect of seladelpar treatment compared to placebo on efficacy, safety, and tolerability in patients with primary sclerosing cholangitis (PSC).

Key Inclusion Criteria:

1. Confirmed diagnosis of primary sclerosing cholangitis (PSC) based on any two of the following three criteria:

   • Historical evidence of an elevated alkaline phosphatase (AP) > upper limit of normal (ULN) from any prior laboratory result
   • Liver biopsy consistent with PSC
   • Abnormal cholangiography consistent with PSC as measured by magnetic resonance cholangiopancreatography (MRCP), endoscopic retrograde cholangiopancreatography (ERCP), or percutaneous transhepatic cholangiography (PTC)

2. Individuals must have the following specific additional laboratory parameters measured by the Central Laboratory at Screening:

   • AP ≥ 1.5 × ULN and < 8 × ULN
   • Total bilirubin ≤ 2 × ULN
   • Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 5 × ULN
   • Estimated glomerular filtration rate (eGFR) > 60 mL/min/1.73 m^2
   • Platelets ≥ 140 × 10^3/µL
   • International Normalized Ratio (INR) ≤ 1.3 (in the absence of warfarin or other anticoagulant therapy)
   • Albumin ≥ 3.5 g/dL

3. Patients taking ursodeoxycholic acid (UDCA) will be allowed to enroll if meeting the following criteria:

   • Total daily dose of ≤ 20 mg/kg/day
   • A minimum of 6 months of stable treatment
   • Minimum of 12 weeks off treatment prior to Screening if UDCA is recently discontinued

Key Exclusion Criteria:

1. Clinically significant acute or chronic liver disease of an etiology other than PSC

2. Patients with a diagnosis of overlapping autoimmune hepatitis (AIH) and PSC

3. Secondary or immunoglobulin G4 (IgG4) related sclerosing cholangitis

4. Small duct PSC

5. Presence of a cholangiocarcinoma on cholangiography or MRI at Screening as determined by the central radiologist and the principal investigator (PI) or medical monitor

6. Bile duct stent or percutaneous bile duct drain placement, or balloon dilatation procedure of a stricture within 12 weeks of Screening

7. History, evidence, or high suspicion of cholangiocarcinoma or other hepatobiliary malignancy based on imaging, screening laboratory values, and/or clinical symptoms

8. Presumptive or diagnosed acute cholangitis within 12 weeks of Screening and through Day 1

9. Evidence of compensated or decompensated cirrhosis based on histology, relevant medical complications, or laboratory parameters:

   • Historical liver biopsy demonstrating cirrhosis (eg, Ludwig Stage 4 or Ishak Stage 5)

   • Current or prior history of decompensated liver disease, including ascites, hepatic encephalopathy, variceal bleeding or other clinical conditions consistent with cirrhosis and/or portal hypertension,

   • Liver stiffness > 14.4 kPa by FibroScan, or

   • Combined low platelet count (< 140 × 10^3/µL ) with one of the following:

     • Serum albumin < 3.5 g/dL,
     • INR > 1.3 (not due to antithrombotic agent use), or
     • Total bilirubin > ULN

10. Prior or actively listed for liver transplantation

11. Prior exposure to seladelpar

Note: Other protocol defined Inclusion/Exclusion criteria may apply.

Dose masking

After conclusion of the study and without prior written approval from Gilead, investigators in this study may communicate, orally present, or publish in scientific journals or other media only after the following conditions have been met:

• The results of the study in their entirety have been publicly disclosed by or with the consent of Gilead in an abstract, manuscript, or presentation form; or
• The study has been completed at all study sites for at least 2 years