Discovery of Potent and Orally Bioavailable GPR40 Full Agonists Bearing Thiophen-2-ylpropanoic Acid Scaffold.

The free fatty acid receptor GPR40 is predominantly expressed in pancreatic β-cells and enhances insulin secretion in a glucose dependent manner. Therefore, GPR40 agonists are possible novel insulin secretagogues with reduced or no risk of hypoglycemia for the treatment of type 2 diabetes mellitus (T2DM). Chemically and structurally diverse GPR40 agonists with high safety are pursued for the clinical development of GPR40-based pharmacotherapeutics. Herein we report our design and discovery of a new chemotype of GPR40 agonists free of the typical phenylpropanoic acid scaffold. The thiophen-2-ylpropanoic acid containing GPR40 modulators functioned as full agonists with high-efficacy response (Emax) and reduced lipophilicity. Significantly, the lead compound in this series, (R)-7k, exhibited more potent in vitro glucose-stimulated insulin secretion and in vivo glucose-lowering effects (10 mg/kg, po) than the GPR40 partial agonist TAK-875, which was once in phase III clinical trials, and high selectivity over the relevant receptors GPR120 and PPARγ.