MK-8666 is a partial GPCR (G-protein-coupled receptor) agonist that is coordinated with the action of GPR40. GPR40, also known as free fatty acid (FFA) receptor 1 modulates fatty acid-induced insulin secretion in pancreatic beta cells and in intestinal enteroendocrine cells. Thus, MK-8666 has been investigated for treatment of type 2 diabetes mellitus and has been shown to robustly lower glucose without negative effects.

AK-42 is a novel potent and specific inhibitor of CLC-2, displaying unprecedented selectivity over CLC-1, the closest CLC-2 homolog, and exhibiting no off-target engagement against a panel of 61 common channels, receptors, and transporters expressed in brain tissue.