Sitagliptin: Profile of a novel DPP-4 inhibitor for the treatment of type 2 diabetes

Novel therapeutic strategies for type 2 diabetes are needed, since the current treatment options neither address all pathophysiological mechanisms nor achieve the glycemic target goals. A general islet-cell dysfunction including insulin- and glucagon-secretion defects contributes to the pathophysiology of type 2 diabetes. Improving islet function by incretin hormone action is a novel therapeutic approach. Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) are important incretin hormones contributing to 50-70% of the stimulation of insulin secretion after a meal. Dipeptidyl-peptidase IV (DPP-4) inhibitors inhibit the degradation of GLP-1 and GIP as well as that of other regulatory peptides. Sitagliptin, a DPP-4 inhibitor, is orally active and has been shown to be efficacious and safe in clinical studies. Sitagliptin has received approval in Mexico, the United States and other countries. Like other DPP-4 inhibitors, sitagliptin reduces hemoglobin A1c (HbA1c), fasting and postprandial glucose by glucose-dependent stimulation of insulin secretion and inhibition of glucagon secretion. Sitagliptin is weight neutral. Indirect measures show a possible improvement of beta-cell function. Sitagliptin does not cause a higher rate of hypoglycemia in comparison to metformin or placebo. This article gives an overview of the mechanisms of action, pharmacology and clinical trial results of sitagliptin. (c) 2007 Prous Science. All rights reserved.