Nidufexor

Farnesoid X Receptor (FXR), a pivotal member of the nuclear receptor superfamily, plays a central role in the regulation of crucial physiological processes. These processes encompass bile acid homeostasis, inflammatory responses, fibrosis, as well as lipid and glucose metabolism. Given its extensive physiological functions, FXR has become an extremely promising therapeutic target for bile acid metabolism disorders. In recent years, the progress in medicinal chemistry has significantly expedited the development of FXR agonists. In 2016, obeticholic acid (OCA) received approval from FDA for marketing. As the first small-molecule drug targeting FXR for primary biliary cholangitis (PBC), its approval has spurred the advancement of multiple FXR agonists with diverse chemical structures into clinical trials. Notable candidates include Tropifexor (for non-alcoholic steatohepatitis, NASH), Cilofexor (for PBC), and Nidufexor (for diabetic nephropathy). This review delineates the structural features and biological functions of FXR, analyzes molecular mechanisms underpinning its signal transduction pathways and disease pathogenesis, and highlights molecular design strategies and structure-activity relationship (SAR) advancements in FXR agonists. These insights aim to provide a theoretical foundation for rationally designing novel, potent FXR agonists.

Farnesoid X receptor (FXR) is a promising target for drug discovery against nonalcoholic fatty liver disease (NAFLD). However, no FXR agonist has been approved for NAFLD so far. The R & D of FXR agonists are somewhat hindered by the lack of effective and safe chemotypes. To this end, we developed a multi-stage computational workflow to screen the Specs and ChemDiv chemical library for FXR agonists, which consisted of machine learning (ML)-based classifiers, shape-based and electrostatic-based models, a FRED-based molecular docking protocol, an ADMET prediction protocol and substructure search. As a result, we identified a novel chemotype that has never been reported before, with compound XJ02862 (ChemDiv ID: Y020-6413) as the representative. By designing an asymmetric synthesis strategy, we were able to prepare four isomers of compound XJ02862. Interestingly, one of the isomers, 2-((S)-1-((2S,4R)-2-methyl-4-(phenylamino)-3,4-dihydroquinolin-1(2H)-yl)-1-oxopropan-2-yl)hexahydro-1H-isoindole-1,3(2H)-dione (XJ02862-S2), showed potent FXR agonistic activity in HEK293T cells. The molecular docking, molecular dynamics simulations and site-directed mutagenesis suggested the hydrogen bond between compound XJ02862-S2 and HIS294 of FXR is essential for ligand binding. We further demonstrated that compound XJ02862-S2 had no agonistic effect on TGR5. Further biological experiments have shown that compound XJ02862-S2 could ameliorate hypercholesterolemia, hepatic steatosis, hyperglycemia, insulin resistance (IR) in high-fat-diet induced obese (DIO) mice. In term of molecular mechanism, compound XJ02862-S2 regulates the expression of FXR downstream genes involved in lipogenesis, cholesterol transport and bile acid biosynthesis and transport. Taken together, we have discovered a novel chemotype as potent FXR agonists for NAFLD by computational modeling, chemical synthesis and biological evaluation.