Tropifexor ( LJN452 ) ,a novel and highly potent agonist of FXR
Tropifexor ( LJN452 ) is a novel and highly potent agonist of FXR with an EC50 of 0.2 nM in HTRF assay. It shows no significant off-target activity against a broad panel of enzyme, ion channel, nuclear receptor, and GPCR (>10000-fold selectivity for FXR). Robust induction of both BSEP and SHP genes is observed in primary cells by Tropifexor in a concentration-dependent manner. BSEP induction above vehicle (DMSO) control is observed at concentrations as low as 1 nM, while strong induction of SHP (15-fold above vehicle) is observed at 10 nM and modest induction of SHP at 1 nM (3-fold).Tropifexor demonstrates highly potent induction of SHP and FGF15 in the ileum as doses as low as 0.1 mg/kg. In the liver, robust induction of SHP is observed at 0.01 mg/kg of Tropifexor with maximal levels of gene induction achieved at 0.3 mg/kg. Expression of CYP8B1 mRNA following 14 day treatment with Tropifexor is already apparent at the lowest dose (0.003 mg/kg), and CYP8B1 gene expression is fully repressed at doses above 0.03 mg/kg. Treatment of rats with Tropifexor exhibits a clear dose-dependent increase in plasma FGF15 protein, with maximal levels of FGF15 detected at 7 h postdose. Treatment with Tropifexor for 14 days produces a robust dose-dependent reduction in serum triglycerides and reaches a maximal response with a 0.3 mg/kg dose, resulting in a decrease of triglyceride levels to approximately 79% below the vehicle control group.