Insulin delivered through an inhalant might be able to mimic natural insulin release while avoiding the lung worries that helped sink previous inhalants.

Earlier this month, MannKind Corporation presented long-term data on its AFRESA insulin inhalant at the 45th Annual Meeting of the European Association for the Study of Diabetes. Results from the four-year study, which investigated about 200 people, raise hopes that AFRESA could succeed where earlier inhalers failed.

"The big advantage is that we can give the insulin in a way that more closely follows the pattern of insulin if you don't have diabetes," Dr. Peter Richardson, CSO of MannKind and a lead researcher on this study, tells DOTmed News.

Dr. Richardson says that unlike conventional insulin, which spikes around 40 minutes to one hour after injection, AFRESA takes effect in about 10 minutes. This can help patients avoid some of the weight gain that often comes with injected insulin use, Dr. Richardson claims. "We can get overall as good of blood sugar [response] as the best treatment available, while getting less of a change in blood sugar after a meal," he says.

Going where others have gone before

More important, Dr. Richardson hopes his product has two advantages that will let it outlast its now defunct rivals: small size and no effect on the lungs.

Two years ago, Pfizer dropped Exubera, its inhaled insulin product, after the bulky device attracted only meager sales and amid fears that it could disrupt lung function or even cause lung cancer. And last year, Eli Lilly washed their hands of a similar project, Air Insulin, made in partnership with Alkermes, for similar reasons.

But AFRESA fits in the palm of one's hand and is easy to carry around -- tiny, disposable single-use inhalers are also in the works -- and it appears to be lung safe. Although insulin is a cell growth promoter, from which much of the cancer fear derives, Dr. Richardson says AFRESA uses unmodified human insulin (grown from bacteria), which does not carry the same risks.

And he says no lung function deterioration was seen in animal tests, and in humans none was detected in the four-year study "above and beyond what we'd see getting older. That's really quite reassuring," he says.

He claims the reason for the better lung response is that insulin powder dissolves rapidly in the lungs. The powder, made of what his company calls Technospheres, is designed to dissolve on contact with the neutral pH environment of the lung.

The real question, though, is will the data convince the FDA, which is set to release their review of the product in January. But Dr. Richardson says the results suggest mandatory lung tests aren't needed. "From the experts we've spoken with, and looking at the data, pulmonary function testing doesn't improve the safety of patients," he says.

Nonetheless, he acknowledges that AFRESA will not be right for everyone. Many of the subjects in the trial got a mild cough, though it cleared up on its own after only a few uses, and less than 3 percent discontinued because of it, Dr. Richardson says. Still, those with lung disease, such as chronic bronchitis, and smokers should stick with injections.

Even though the Technosphere is pharmacologically inert -- it doesn't interact with the body's cells -- Dr. Richardson also doesn't recommend it for patients with severe renal failure.

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