Review of phase 2 studies utilizing the AIR® particle technology in the delivery of human insulin inhalation powder versus subcutaneous regular or lispro insulin in subjects with type 1 or type 2 diabetes

Insulin therapy is underutilized in the treatment of diabetes mellitus for many reasons, including both patient and provider resistance. Targeting postprandial blood glucose control in patients with either type 1 or type 2 diabetes has been demonstrated to improve overall glycemic control, but the reluctance to use injectable insulin demonstrates the need for the development of alternative routes for insulin delivery. The development of inhaled insulin systems was designed to improve the ease of insulin use for patients and help alleviate fears they may have with injectable insulin. Human insulin inhalation powder (HIIP) (Eli Lilly, Indianapolis, IN/Alk-ermes, Cambridge, MA) has been demonstrated in Phase 2 studies to have similar effects on glycemic profiles compared to both insulin lispro and regular insulin. Hypoglycemia during HIIP was similar to that of regular insulin but was associated with greater hypoglycemic risk compared to insulin lispro. In addition, the AIR (R) Inhaled Insulin system (Lilly/ Alkermes), which delivers HIIP, has been demonstrated to be easy to use and requires minimal patient education, which may improve overall medication compliance. Phase 3 studies are ongoing to further evaluate safety and efficacy of HIIP.