CS27109, A Selective Thyroid Hormone Receptor-β Agonist Alleviates Metabolic-Associated Fatty Liver Disease in Murine Models

BACKGROUND/AIM: Thyroid hormone receptor-β (THR-β) agonists play crucial roles in dyslipidemia and metabolic associated fatty liver disease (MAFLD). We developed a novel oral and liver-targeted THR-β agonist, CS27109, and evaluated its efficacy in the treatment of metabolic disorders. MATERIALS AND METHODS: We evaluated in vitro and in vivo efficacy and/or safety of CS27109 along with MGL3196 (a phase III THR-β agonist). RESULTS: CS27109 showed pronounced activity and selectivity to THR-β and favorable PK properties, which was equivalent to MGL3196. In the hamster model, animals treated with a high dose of CS27109 showed equivalent reductions in serum TC and LDL-c with groups treated with MGL3196. In the rat model, CS27109 and MGL3196 reduced serum ALT, TC, TG, LDL-c, liver weight ratio, and liver steatosis. CS27109 simultaneously decreased liver TG and TC, and MGL3196 additionally reduced AST. In the mouse model, CS27109 dose-dependently reduced serum AST, ALT, liver inflammation, and NAS score, and also downregulated TC, LDL-c, liver steatosis, and fibrosis, but not in a dose-dependent manner. MGL3196 revealed an equivalent effect with CS27109 in that model. CS27109 also exhibited tolerable toxicity to the heart. CONCLUSIONS: CS27109 shows comparative in vitro and in vivo efficacy with MGL3196, suggesting its potential therapeutic application in the treatment of MAFLD such as dyslipidemia and steatohepatitis.