This clinical trial is focused on studying the effectiveness and safety of the medication bezafibrate in patients with Primary Biliary Cholangitis (PBC), a liver disease. The study is specifically for those who have not had an optimal response to a standard treatment called ursodeoxycholic acid (UDCA). The trial will test two different doses of bezafibrate: 200 mg and 400 mg, and compare them to a placebo. The purpose of the study is to see if bezafibrate can help improve the condition of patients with PBC who are not responding well to UDCA.

The study will last for a total of 24 months. During the first 12 months, participants will receive either bezafibrate or a placebo in a double-blind manner, meaning neither the participants nor the researchers will know who is receiving the actual medication. After this period, there will be a 12-month extension phase where all participants will receive bezafibrate, but without the use of a placebo. This approach helps to ensure that the results are reliable and that any improvements can be attributed to bezafibrate.

Throughout the study, participants will be monitored for changes in their liver function and any side effects they may experience. The main goal is to determine if bezafibrate can lead to a complete biochemical response, which means normalizing certain liver enzyme levels. Additionally, the study will look at other factors such as the intensity of itching, which is a common symptom of PBC, and any serious adverse events that may occur. This research aims to provide more information on whether bezafibrate can be a beneficial addition to the treatment of PBC.