Pathophysiological and Pharmacological Rationale for the Use of Exenatide Once Weekly in Patients with Type 2 Diabetes

A new formulation of exenatide has become available recently that is the first antidiabetic medication for type 2 diabetes mellitus (T2DM) dosed on a weekly schedule. This review summarizes the pharmacology, efficacy, and safety of exenatide once weekly (exenatide QW). The results are interpreted in terms of the pathophysiology of T2DM, as well as the pharmacology of the new formulation. Relevant literature on exenatide QW and diabetes was identified through PubMed database searches from inception until September 2013. In the new once-weekly formulation of exenatide, the exenatide molecule is dispersed in microspheres. Following subcutaneous injection, these microspheres degrade in situ and slowly release active agent. In clinical trials, therapy with exenatide QW as monotherapy or in combination with other antidiabetic treatments was associated with reductions in glycated hemoglobin (-1.3% to -1.9%), fasting plasma glucose (-32 to -41 mg/dL), and body weight (-2.0 to -3.7 kg). These outcomes were achieved without an associated increase in the rate of hypoglycemic episodes, except when exenatide QW was used in combination with sulfonylureas. The primary tolerability issues in the trials were gastrointestinal adverse events, particularly during the first weeks of use, although the rate of nausea during startup with exenatide QW was lower than that with the related agents, exenatide twice daily and liraglutide once daily. Exenatide QW may be particularly well suited to patients who desire the benefits associated with glucagon-like peptide-1 receptor agonists, including significant glycemic control, low risk of hypoglycemia, and moderate weight loss, but prefer the convenience of once-weekly dosing.