The long-awaited action by the U.S. Food and Drug Administration means millions of people with both type 1 and type 2 diabetes may have the option of avoiding the needles and countless injections that have marked their lives so far.
"This is the first new insulin delivery option introduced since the discovery of this drug in 1920s," said Dr. Steve Galson, director of the FDA Center for Drug Evaluation and Research. "There are more than 5 million Americans who take insulin injections every day, and Exubera may be an option for many of these patients. It will not replace all injectable insulin. . . It's a very highly innovative product that has the potential to improve the quality of life of millions of Americans with diabetes."
"This is highly positive. It will be a major advance for individuals with diabetes, both children and adults," said Dr. Robert Rapaport, director of the division of pediatric endocrinology at Mount Sinai School of Medicine in New York City. "I think there will be some longstanding questions about its ultimate safety because it's the first inhaled medication that will be used like this. But, assuming the safety profile will be good, it will be a major advance."
Added Dr. Stuart Weiss, an assistant clinical professor of medicine at New York University School of Medicine: "There are still some questions as to lung function and diffusion capacity, and smokers can't use it. There are all sorts of things to be concerned about. It's going to take a few years to see whether or not it's as safe as all that."
The announcement follows European regulators' approval of Exubera on Thursday. A U.S. Food and Drug Administration advisory panel recommended approval of the drug in the United States on Sept. 8.
Type 2 diabetes has become a global epidemic, affecting some 12 million people in the United States alone. The condition, which develops when the pancreas does not produce enough insulin or the body cannot use the hormone efficiently, is strongly associated with overweight and obesity. While some people can manage their type 2 diabetes through diet and exercise, others must rely on insulin injections.
Type 1 diabetes, in which the body's insulin-producing capabilities are limited or non-existent, is not linked to body weight.
Insulin is the hormone that converts blood sugar, called glucose, into energy for cells in the body.
If left uncontrolled, either type of diabetes can lead to a multitude of complications, including amputations, blindness, kidney disease, heart attack and strokes.
The first commercial insulin hit the market in the 1920s. Since then, the gold standard for treatment of type 1 diabetes and more advanced type 2 diabetes has been insulin, injected before meals.
In the intervening years, new types of insulin formulations and devices have made the process more efficient.
"Needles are way, way smaller, syringes are easier to use, pen devices are very discreet, all sorts of delivery devices are very impressive," Weiss said. But the premise has remained the same -- delivery by injection.
Exubera, on the other hand, is a dry powder formulation of insulin inhaled into the lungs through the mouth. Like injectable insulin, it is administered before meals using a small, hand-held device.
Studies on safety and effectiveness were done on more than 2,500 adults with type 1 and type 2 diabetes. The drug, manufactured by Pfizer Inc., was as effective as injectable insulin for control of blood sugar, the company stated. Pfizer apparently delayed Exubera's application for U.S. approval for three years to finish safety studies.
"Because this is a new way to deliver insulin to patients, it has been extensively studied with respect to safety and efficacy," said Dr. Robert Meyer, director of the FDA Office of Drug Evaluation II, which oversees the division of Metabolic and Endocrine Drugs. "We have a large amount of data from the clinical trials speaking to the safety of this product overall, and safety in the lungs as well. In addition, there are ongoing, continuing trials to monitor safety that will be reported after approval."
"We feel that there is an extensive and reasonable safety database to allow us to make a determination of efficacy and safety for patients without underlying lung disease and who do not smoke," Meyer said.
In those clinical studies, Exubera reached peak insulin concentration more quickly than some insulins, called regular insulin, administered by injection. Peak insulin levels were achieved at 49 minutes, on average, with Exubera, compared to 105 minutes, on average, with regular insulin, the FDA said.
Prescriptions for Exubera will be accompanied by a "Medication Guide" containing FDA-approved information written especially for patients, the agency said.
Like any insulin product, low blood sugar is a side effect of Exubera and diabetics should carefully monitor their blood sugar regularly. Other side effects associated with Exubera in clinical trials included cough, shortness of breath, sore throat and dry mouth, the FDA said.
Exubera shouldn't be used by smokers or someone who quit smoking within the last six months. The drug is also not recommended in people with asthma, bronchitis or emphysema. Baseline tests for lung function are recommended before beginning treatment, six months after that, and then repeated annually, according to the FDA.
Inhaled insulin is unlikely to completely replace injectable insulin. But, for many people, it may greatly improve glucose control.
"It's very hard to predict what the impact will be," Weiss said. "A lot of people who need to be on insulin are not on insulin. For that type 2 diabetic who is afraid of needles or will not take a shot, this is an ideal product. The problem is it doesn't address the root cause of diabetes. It could become another treatment that will cause people to overeat and under-exercise."
Exubera is also unlikely to be the only inhaled insulin on the market for long. Eli Lilly and Co., Kos Pharmaceuticals Inc., MannKind Corp. and Novo Nordisk A/S all are developing their own versions.
More information
Visit the American Diabetes Association for more on this disease.
