A Novel Dual Incretin Agent, Tirzepatide (LY3298176), for the treatment of Type 2 Diabetes Mellitus and Cardiometabolic Health

Abstract: The incretin hormone system is the target of multiple type 2 diabetes mellitus (T2DM) treatments because defects in this system play major roles in the pathogenesis of diabetes. Currently, the glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are recommended for patients with atherosclerotic cardiovascular (CV) disease and those at high risk for atherosclerotic CV disease. In addition to the favorable CV effects, GLP-1 RAs also provide robust lowering of hemoglobin A1c and weight. Although these factors make GLP-1 RAs attractive options for T2DM, the currently available agents have no effect on glucose-dependent insulinotropic polypeptide (GIP). Patients with T2DM are known to have GIP defect which is significant due to its profound insulinotropic effects. Tirzepatide is a novel incretin agent currently recently approved by the Food and Drug Administration for the treatment of T2DM. This first-in-class agent serves as a coagonist for both the GLP-1 and GIP receptors. In this review, we report on the pharmacologic mechanism of GLP-1, GIP, and coagonist effects on the cardiometabolic system. In addition, we review the glycemic lowering, weight loss effects, and other cardiometabolic outcomes of tirzepatide based on phase 2 and 3 data. The safety profile of tirzepatide is consistent across all phase 3 trials. The most common adverse effects are gastrointestinal symptoms, but they generally have a low risk for discontinuation. Overall, preliminary data suggest that tirzepatide is an efficacious and safe agent for the treatment of T2DM.