Clinical Efficacy of Inhaled Insulin
Published clinical data for Exubera, AIR, and AERx show that inhaled insulin was noninferior to injected mealtime insulin in most studies based on an average measurement of overall blood glucose control based on HbA1c, the generally accepted biomarker, glycosylated hemoglobin, formed when red blood cells are exposed to blood glucose. The extensive inhaled insulin clinical data also indicate improvement in terms of the following:
- • Greater patient preference. Most type 1 and type 2 diabetes patients strongly preferred inhaled insulin over injected insulin [12-15].
- • Lower blood glucose. Several phase 3 studies conducted by third parties showed lower fasting blood glucose with inhaled insulin, 8 h after a meal, and postmeal blood glucose, 2 h after a meal, which are real-time immediate blood glucose measures versus the average-over-time blood glucose measurement, HbAlc [18-20].
- • Fewer occurrences of hypoglycemia. Studies conducted by third parties found fewer occurrences of hypoglycemia in type 2 diabetes patients using inhaled insulin compared to injected insulin .
- • Less weight gain. Inhaled insulin resulted in less weight gain as seen in five phase 3 studies .
When Exubera received FDA approval, a collective analysis of 16 phase 3 controlled trials of inhaled insulin efficacy from 1999 to 2006 was published in 2006 in the Annals of Internal Medicine by the Tufts-New England Medical Center . This analysis, which included 4023 patients, concluded that inhaled insulin is similar to injected insulin in lowering blood glucose and showed superior efficacy compared to oral agents, as measured by reduction in HbA1c, for type 2 diabetes patients. In some of these trials inhaled insulin also demonstrated statistically significant improvements in fasting blood glucose relative to injectable insulin.