Inhaled Insulin Efficacious in Study, but Lung Function Drops

Tendency to cause a slight but significant decline in breathing ability, but new Exubera™ studies conclusively proved the drug’s safety Inhale Therapeutic Systems Inc. on Thursday said that data from a new study re-affirmed its experimental inhaled form of insulin controls blood sugar as well as injections of insulin, although the inhaled form again caused a slightly greater decline in lung function.

San Carlos, California-based Inhale, which has licensed its inhaled product to Pfizer Inc. and French drugmaker Aventis, released the data at the annual scientific meeting of the American Association of Clinical Endocrinologists.

Earlier trials of the inhaled insulin, called Exubera, have also suggested its equivalent effectiveness to injected insulin as well as its tendency to cause a slight but significant decline in breathing ability. The unfavorable lung-function trend, in fact, prompted Pfizer last year to delay its US marketing application for Exubera until other studies conclusively proved the drug’s safety. Some analysts expect Pfizer to seek approval from the US Food and Drug Administration by late 2002, which would represent a one-year delay.

The latest phase III trial lasted six months and involved 335 patients ages 12 to 65 with Type 1 diabetes. One group of patients in the study took Exubera prior to meals and also took a single injection of long-acting insulin at bedtime. Another group took two to three daily insulin injections. Both groups were evaluated by the end of the trial to measure their levels of glycated hemoglobin (HbA1c).

"The percentage of patients achieving an HbA1c of less than 8% or less than 7% was…similar in both groups," Inhale said.

Patients taking the inhaled insulin showed significantly greater decreases in glucose levels before breakfast and two hours after taking meals compared with patients who only took injected insulin, Inhale said.

Inhale’s share price has fallen sharply during the past year on lingering concerns about the possible long-term side effects from inhaled insulin. Overall, Inhale said the frequency and nature of side effects were comparable among the two groups in the latest trial. But mild to moderate cough was also seen more frequently in patients taking Exubera, although the coughing "decreased in incidence and prevalence" over the course of the study, Inhale said.