CP-320626

CP-320626 is an experimental small molecule inhibitor of glycogen phosphorylase, developed by Pfizer for potential use in metabolic diseases such as type 2 diabetes. It acts by binding to a novel allosteric site on the enzyme, distinct from the catalytic and other known regulatory sites, stabilizing the less active T-state of glycogen phosphorylase. This inhibition reduces glycogen breakdown (glycogenolysis), thereby lowering glucose production in liver and muscle cells. Preclinical studies have shown that CP-320626 can reduce blood glucose levels in diabetic animal models without altering plasma insulin concentrations. The compound has not advanced beyond preclinical or early clinical development[1][3][4][5][6].