Exenatide in type 2 diabetes: treatment effects in clinical studies and animal study data

The therapeutic options for treating type 2 diabetes have been widened by the introduction of exenatide as the first incretin mimetic. Incretins are gut hormones that contribute to the stimulation of insulin secretion after a carbohydrate rich meal. The incretin hormone glucagon-like peptide-1 (GLP-1) not only stimulates insulin secretion under hyperglycaemic conditions, but also suppresses glucagon secretion, slows gastric emptying, induces satiety and improves beta cell function in type 2 diabetes. These beneficial effects have awakened the interest to use GLP-1 for the treatment of type 2 diabetes. Because of its short biological half-life, GLP-1 itself is not practical for type 2 diabetes therapy. Exenatide is a peptide found in the lizard Heloderma suspectum and has a high similarity to GLP-1. Exenatide belongs to the novel class of incretin mimetics because of its incretin-like action. It has a much longer biological half life than GLP-1 and is a GLP-1 receptor agonist that can be used for therapeutic purposes by twice daily injection. Clinical studies and clinical experience with exenatide have shown a significant reduction in HbA1c, fasting- and postprandial glucose and a marked reduction in body weight in type 2 diabetic patients. Animal studies reveal an improvement of beta cell function and an increase in beta cell mass after exenatide treatment. This review gives an overview on exenatide, its pharmacological profile and its role and potential in the therapeutic setting of type 2 diabetes. Furthermore, future developments concerning exenatide application are highlighted.