Introduction: The nuclear receptor FXR regulates the expression of genes involved in bile acids, glucose and lipid homeostasis. For its role as guardian of metabolism, FXR has been identified a promising pharmacological target in liver bile acid and lipid accumulation, such as cholestasis and non-alcoholic fatty liver disease (NAFLD). The field of FXR research is extremely competitive with a large number of patents and articles published in the last decades identifying promising hit compounds.
Areas covered: The present review summarizes recent patent activity (2014-to date) filing for synthetic and natural FXR ligands, including bile acid derivatives and non-steroidal compounds, alongside their in vitro and in vivo efficacy as well as their therapeutic applications.
Expert opinion: While the first FXR agonist, obeticholic acid, has gained approval, significant safety issues have been emerged. Today is unclear whether these safety issues are class related or restricted to the bile acid scaffold of this agent. Despite the significant number of patent applications claiming steroidal and non-steroidal FXR agonists, several questions on their therapeutic potential in cholestasis and NASH remain open leaving a space for the development of novel compounds.
Keywords: FXR; non-alcoholic steatohepatitis (NASH); non-steroidal agonists; primary biliary cirrhosis (PBC); steroidal agonists.