Alogliptin is a selective, orally available inhibitor of dipeptidyl peptidase-4 being developed by Takeda Global Research & Development as a treatment for type 2 diabetes mellitus. Inhibition of dipeptidyl peptidase-4 (DPP-4) prolongs the action of 2 important incretin hormones, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP). These hormones are responsible for increasing insulin synthesis, regulating β-cell proliferation, inhibiting gastric emptying, and inhibiting glucagon secretion.