Primary biliary cholangitis (PBC) - formerly known as primary biliary cirrhosis - is a chronic, slowly progressive autoimmune liver disease. PBC mainly affects women (90%) and, typically, is diagnosed between the ages of 35 - 60. It is characterized by inflammation and destruction of small bile ducts, accompanied by fibrosis (excess fibrous connective tissue) and eventually cirrhosis (extensive scarring of the liver). Another key feature is the presence of specific anti-mitochondrial antibodies in the blood in over 90% of the patients.

PBC is a relatively rare disease and occurs worldwide. The incidence and prevalence in various countries and regions differ considerably  and have been reported to vary from  0.33 to 5.8  and and 1.91 to 40.2 cases  per 100 000 inhabitants, respectively.

Many PBC patients do not experience any symptom at diagnosis  or during the course of the disease and are diagnosed after the finding of abnormal liver tests at screening or testing for other conditions. However, a significant proportion of patients do have symptoms that can markedly influence the quality of life. The most common symptoms are  fatigue and itching.

Ursodeoxycholic acid (UDCA) is the accepted standard treatment. . UDCA has clear favorable effects by improving biochemical cholestasis, delaying histological progression and improving liver transplantation-free survival. This therapy is virtually free of adverse effects. Unfortunately up to 50% of patients show no, or a suboptimal, response and would therefore be candidate for additional treatment. To date, UDCA is the only approved treatment for PBC. Potential second line treatments include obeticholic acid, fibrates and budesonide. Currently, these drugs are undergoing extensive clinical evaluation.