this is a phase II study to evaluate the safety and tolerability of 2 doses of elafibranor in participants with Primary Sclerosing Cholangitis (PSC), and its potential effect on the change in serum alkaline phosphatase (ALP) and other hepatic markers of PSC during 12 weeks of treatment in the double-blind period (DBP) compared to placebo. This will be followed by a 96-week open-label extension (OLE) period (no placebo) to assess long-term safety and maintenance of effects of elafibranor. After the first dose of the study intervention on Day 1, the participants will have study visits every 4 weeks through Week 12 of the DBP to assess efficacy and safety. In the OLE period, the study visits for each participant will occur after 4 weeks of entering the OLE, then every 12 weeks up to Week 52, followed by every 22 weeks up to Week 96 which will be the end of treatment (EOT). All participants will have a safety follow-up 4 weeks after the last dose of study intervention.

There will be 2 screening visits followed by 4 visits during the double blind/placebo part of the trial, followed by visits every 3 months for the open label part of the study. All visits will be in person. Blood will be drawn at every visit. Urine will be collected at most visits. ECG's (recording of your heart activity) will be done on a regular basis. Additional procedures include fibroscans (scan of your liver to determine liver stiffness) and ultrasound exams of your abdomen and bladder. Multiple questionnaires will be competed throughout the trial period.