With the help of City of Hope physician Wei Feng and her colleagues, millions of people with diabetes can now take a breather -- and get their medication at the same time.
On Jan. 27, the United States Food and Drug Administration approved the first-ever inhaled insulin, called Exubera, for adults with type 1 or 2 diabetes. But what is now a welcome alternative to injection was once just an experimental insulin delivery method in testing at City of Hope.
"I'm excited about inhaled insulin getting out to those with diabetes," said Feng, principal investigator for the inhaled insulin trial at City of Hope. "It does give us more alternatives to treat patients; you can individually tailor it to patients' needs."
Feng led a three-year trial at the Leslie and Susan Gonda (Goldshmied) Diabetes and Genetic Research Center from 2000 to 2003, evaluating the delivery method among patients with type 1 diabetes. Nationwide, Exubera, a Pfizer Inc. product, was tested in about 2,500 adults with type 1 and 2 diabetes.
The inhaler delivers a puff of insulin as a dry powder directly to the lungs, organs rich with potential for drug delivery. If all the lungs' tiny alveoli were unfolded, the lungs would have nearly the surface area of a tennis court; and at about one-half micron thick, the lungs’ lining forms one of the body’s thinnest epithelial barriers.
"I've thought all along that this is a good product; not necessarily for type 1 as much as for type 2," Feng said. As she explained, people with type 1 diabetes need to fine-tune their insulin delivery. Injected insulin may be delivered in doses as precise as a half-unit, while inhaled insulin is provided in one-unit doses at the smallest.
Type 1 diabetes patients suffering from needle-phobia, however, may benefit, she said, "and our type 1 patients who used the inhaled insulin were happy with their glycemic control." The inhaled insulin might be helpful for type 1 patients as a replacement for short-acting insulin taken with meals, she added. However, patients with lung problems should not use the inhaler.
Physicians have had a hard time getting many people with diabetes to meet their blood-sugar control goals, but this medication may help, Feng noted. "Insulin has shown effectiveness in controlling diabetes, yet it has been a barrier for some of the diabetic patients to administrate injected medication," she said. "Inhaled insulin has showed equal effectiveness in controlling blood glucose as a regular insulin dose, but with improved quality of life."