title: Sitagliptin, a DPP-4 inhibitor for the treatment of patients with type 2 diabetes: a review of recent clinical trials.
abstract: BACKGROUND
  Dipeptidyl peptidase-4 (DPP-4) inhibitors are a new class of oral antihyperglycemic agents that enhance the body's ability to regulate blood glucose by increasing the active levels of incretins, glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP). There are numerous DPP-4 inhibitors in development with sitagliptin as the first approved agent for the treatment of patients with type 2 diabetes.
  
  
  OBJECTIVE
  The purpose of this review is to provide an overview of the clinical trial results with sitagliptin.
  
  
  METHODS
  Clinical trials published between January 2005 (first sitagliptin publication) and November 2007 were included in this review. Medline was searched using the search terms: MK-0431 or sitagliptin.
  
  
  RESULTS
  Sitagliptin, an oral, once-daily, and highly selective DPP-4 inhibitor, has been evaluated in clinical trials as monotherapy, as add-on therapy, or as initial combination therapy with metformin. Sitagliptin provided effective fasting and postprandial glycemic control in a wide range of patients with type 2 diabetes. Markers of beta-cell function (HOMA-beta and proinsulin/insulin ratio) were improved with sitagliptin treatment. In these clinical trials, sitagliptin was generally well tolerated with an overall incidence of adverse experiences comparable to placebo, a low risk of hypoglycemia or gastrointestinal adverse experiences, and a neutral effect on body weight. The findings presented in this review are limited to the specific patient population enrolled in each clinical trial and for durations for up to 1 year. Future clinical studies should evaluate whether this class of agents has the potential to delay progression and/or prevent type 2 diabetes.
  
  
  CONCLUSIONS
  Sitagliptin has been shown to be effective and well-tolerated in various treatment regimens and may be considered for both initial therapy and as add-on therapy for patients with type 2 diabetes.
authors.affiliation: Chaim Sheba Medical Center, Tel Hashomer, Israel.
authors.forename: Avraham
authors.initials: A
authors.lastname: Karasik
authors.forename: Pablo
authors.initials: P
authors.lastname: Aschner
authors.forename: Harvey
authors.initials: H
authors.lastname: Katzeff
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Davies
authors.forename: Peter P
authors.initials: PP
authors.lastname: Stein
mesh_terms: D001786:Blood Glucose; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy*; D005749:Gastric Inhibitory Polypeptide; D052216:Glucagon-Like Peptide 1; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use*; D054795:Incretins / Q000627:therapeutic use; D050417:Insulin-Secreting Cells / Q000187:drug effects; D008687:Metformin / Q000627:therapeutic use; D011719:Pyrazines / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use*; D000068900:Sitagliptin Phosphate; D014230:Triazoles / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use*
chemical_list: D001786:Blood Glucose; D007004:Hypoglycemic Agents; D054795:Incretins; D011719:Pyrazines; D014230:Triazoles; D005749:Gastric Inhibitory Polypeptide; D052216:Glucagon-Like Peptide 1; D008687:Metformin; D000068900:Sitagliptin Phosphate