FDA Panel Urges Approval of Inhaled Insulin

Exubera Offers People With Diabetes an Alternative to Insulin Injections

Medically Reviewed by Brunilda Nazario, MD on September 08, 2005
From the WebMD Archives

Editor's Note: The FDA approved Exubera in 2006, but in October 2007 the drug company Pfizer said it was halting sales of the drug because of financial reasons.

Sept. 8, 2005 (Washington) -- A government advisory panel has backed approval of the first insulin inhaler. The device offers people with diabetes an alternative to insulin injections for controlling their blood sugar.

Experts recommended FDA approval of the drug for adults who use insulin by a 7-to-2 vote despite what many said were serious concerns about its long-term safety and ease of use by patients.

If approved, the drug, known as Exubera, would represent the first major shift away from needles and syringes for millions people with diabetes who now take daily injections to control blood sugar. The FDA is not required to follow its advisors' recommendations, but it usually does.

The product works much like inhalers already used by asthma and allergy sufferers. It delivers a fine, dry, powdered insulin breathed in through a handheld plastic device. It delivers a short-acting insulin preparation that could be used for the treatment of type 1 and type 2 diabetes.

Companies have long sought to offer diabetes patients an alternative to painful jabs of insulin doses. Exubera has been in development for a decade and is backed by a joint venture between Pfizer, Sanofi-Aventis, and Nektar Therapeutics. Pfizer and Sanofi-Aventis are WebMD sponsors.

An estimated 18 million Americans -- more than 6% of the population -- have diabetes. Most suffer from type 2 diabetes, in which the body fails to react normally to the blood-sugar-lowering effect of the insulin it produces. About 1.5 million people have type 1 diabetes; they must inject insulin because their immune systems have damaged or destroyed the ability to make the hormone to lower blood sugar levels.

Up to two-thirds of all people with diabetes don't adequately control their blood sugar, according to the American Academy of Clinical Endocrinologists. Poor control over the long term can lead to blood vessel and organ damage, blindness, kidney failure, and foot ailments.

Exubera vs. Injections

Pfizer presented several studies showing that Exubera controlled blood sugar as well as insulin shots for up to two years in patients with both types of diabetes.

Still, FDA officials said they were concerned that less than 30% of type 1 patients using the drug lowered their blood sugar to recommended levels after six months of use.

"Questions remain about whether adult type 1 diabetics can expect to achieve tight glycemic control with Exubera," said Karen M. Mahoney, MD, an FDA safety official.

Though Exubera could result in far fewer injections for some patients, many will still be using needles even if regulators approve it.

Many people who use insulin need multiple daily injections. Exubera does not replace longer-acting insulin that many people now use. In addition, patients who smoke will be excluded from taking Exubera because of evidence that damage from cigarettes boosts patients' exposure to insulin, leading to the potential of dangerously low blood sugars.

At the same time, several experts said they worried that the drug's sponsors had not done enough to prove that it is safe in people with diabetes exposed to secondhand smoke or those with lung diseases like asthma or emphysema.

That was a particular concern in light of evidence that the drug led to minor but consistent reductions in lung function in most patients who used it for more than a few months.

The company committed to a 12-year study of Exubera's effects in patients with lung disease once the drug hits the market. "We understand the need to continue to assess the long-term effects on pulmonary function," said Pfizer official Neville Jackson, MD.

Proper Use a Concern

The FDA should also require the companies to come up with a detailed training program instructing doctors and patients on using the inhaler, several advisors said. Many pointed to decades of experience with asthma inhalers, which often frustrate doctors because improper or spotty use by patients compromises their effectiveness.

"I think the use of insulin without a needle, the siren call of that is almost irresistible," said Rebecca W. Killion, the panel's patient representative, herself a diabetes patient. "The practicality issue, though … is huge."

Jackson said that patients and doctors would get "intensive training" on using the inhaler properly.

The companies did not seek approval of the drug for adolescents and children, two groups that could benefit greatly from a needle-free product. Earlier studies on children were stopped because of uncertainly about the drug's effect on breathing.

"We intend to restart pediatric studies after consultation with the agency," Jackson told advisors.

Show Sources

SOURCES: Karen M. Mahoney, MD, FDA safety official. Neville Jackson, MD, Pfizer. Rebecca W. Killion, member, FDA expert advisory panel.

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