Obeticholic acid (OCA), sold under the brand name Ocaliva, is a semi-synthetic bile acid analogue which has the chemical structure 6α-ethyl-chenodeoxycholic acid. It is used as a medication used to treat primary biliary cholangitis. Intercept Pharmaceuticals Inc. hold the worldwide rights to develop OCA outside Japan and China, where it is licensed to Dainippon Sumitomo Pharma. Invention and development
The natural bile acid chenodeoxycholic acid was identified in 1999 as the most active physiological ligand for the farnesoid X receptor (FXR), which is involved in many physiological and pathological processes. A series of alkylated bile acid analogues were designed, studied and patented by Roberto Pellicciari and colleagues at the University of Perugia, with 6α-ethyl-chenodeoxycholic acid emerging as the most highly potent FXR agonist. FXR-dependent processes in liver and intestine were proposed as therapeutic targets in human diseases. Obeticholic acid is the first FXR agonist to be used in human drug studies. Clinical studies
Obeticholic acid is undergoing development in phase II and III studies for specific liver and gastrointestinal conditions. The U.S. Food and Drug Administration (FDA) approved obeticholic acid on May 27, 2016, for the treatment of primary biliary cholangitis. It was approved as an orphan drug based on its reduction in the level of the biomarker alkaline phosphatase as a surrogate endpoint for clinical benefit. It is indicated for the treatment of primary biliary cholangitis in combination with ursodeoxycholic acid in adults with an inadequate response to UDCA, or as monotherapy in adults unable to tolerate UDCA.
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This article incorporates public domain text from The U.S. National Library of Medicine and the National Institute of Neurological Disorders and Stroke. External links

GeneReviews/UW/NIH entry on Coffin–Lowry syndrome
Coffin-Lowry syndrome: MedlinePlus Genetics