Obeticholic acid for the treatment of primary biliary cirrhosis.

INTRODUCTION: There is significant unmet need in Primary Biliary Cholangitis (PBC) in patients under-responsive to the only approved therapy Ursodeoxycholic Acid (UDCA) who are at increased risk of progressing to end-stage liver disease. Obeticholic Acid (OCA) is a farnesoid X receptor (FXR) agonist which has been evaluated as a second line therapy in PBC and has recently been licenced by the FDA. Areas covered: The pharmacology and biology of OCA as an FXR agonist and its clinical benefits. A systematic review was undertaken of published literature, meeting abstracts and trial registries using the search terms FXR, FGF-19 (& FGF-15), Obeticholic Acid and INT-747. Expert commentary: OCA reduces exposure to toxic hydrophobic bile acids through reduction in bile acid synthesis (by direct and indirect (via enterocyte-released FGF19) actions on Cyp7A1-mediated bile acid synthesis) and bile acid excretion by hepatocytes. It significantly improves liver biochemical parameters strongly associated with risk of disease progression in UDCA under-responsive patients and the key side-effect of pruritus can be reduced by optimised dosing. OCA will be the first stratified therapy introduced in PBC, however confirmatory trial and real life data are needed to confirm that suggestive biochemical improvements are matched by improvement in key clinical outcomes.