PF-04279405

PF-04279405 is a small molecule glucokinase activator (GKA) that was under development by Pfizer for the treatment of type 2 diabetes. Glucokinase is a key enzyme that functions as a glucose sensor in pancreatic beta cells and the liver, where it regulates insulin secretion and hepatic glucose uptake. By allosterically activating this enzyme, PF-04279405 was intended to improve glycemic control. However, preclinical studies in mice, rats, dogs, and monkeys revealed significant safety concerns, including severe and prolonged hypoglycemia. This hypoglycemia was associated with brain neuronal necrosis, peripheral neuropathy, and cardiac arteriopathy, likely mediated by counterregulatory catecholamine release or endothelial dysfunction. Due to these severe adverse effects, the development of PF-04279405 and several related GKAs was discontinued.