This study will evaluate the effects of elafibranor (the study drug) in participants with Primary Sclerosing Cholangitis (PSC). PSC is a rare disease of the liver that leads to injury and destruction of bile ducts. Damage to bile ducts leads to buildup of bile in the liver, which then causes further damage, and leads to disease progression. This study will compare elafibranor to a placebo, a dummy treatment. The main objective of the trial will be to study the safety and side effects of the study drug. The trial will also study the study drug's effects on blood tests and other tests related to PSC disease activity.

In this Phase II trial the efficacy of treatment in patients with clinically significant portal hypertension (CSPH), in compensated alcohol-related cirrhosis, will be assessed. This will be the first trial in the clinical development of the drug BI 685509 where patients will be treated for 24 weeks, and where the portal pressure will be assessed quantitatively via HVPG measurements. The trial will evaluate both short-term and long-term efficacy. The long-term assessment will be used to rule out any adaptation to sGC activation on portal pressure on chronic treatment. The trial will also provide supportive evidence for the planned Phase III development.