Severe asthma: Eczema drug succeeds where others fail

Two new double-blind, randomized trials show that the eczema drug dupilumab is safer and more effective than current therapies for treating severe asthma.

Estimates suggest that up to 25 million people in the United States have asthma, and over 31 million have a form of eczema.

The link between eczema, or atopic dermatitis, and asthma has been the focus of much research.

For instance, it is known that children whose parents have asthma tend to develop eczema, and many of those who already have eczema go on to develop asthma — a phenomenon known as "atopic march."

Now, new research is suggesting that a drug used to treat one condition might also be effective in treating the other.

Dupilumab is an anti-inflammatory drug used to treat eczema, and two studies — recently published in The New England Journal of Medicine — demonstrate that it reduces symptoms and helps patients with difficult-to-control asthma to breathe more easily.

The first study was led by Dr. Mario Castro, the Alan A. and Edith L. Wolff Distinguished Professor of Pulmonology and Critical Care Medicine at Washington University School of Medicine in St. Louis, MO.

Dr. Castro was also a co-author of the second study, whose first author is Dr. Klaus F. Rabe, who is a professor of pulmonary medicine at the University of Kiel in Germany.

Dupilumab improves lung function

The first study comprised 1,902 participants with moderate to severe asthma, all of whom required three different kinds of inhaler to control their symptoms.

For 1 year, they were randomly divided into one of two groups: one that received dupilumab, or one that received a placebo. The group that received the drug was further divided, into either one that received a higher dose or one that received a lower dose.

Neither the doctors nor the participants knew which of the latter were taking the real drug, which made this a double-blind, randomized study.

Not only did those who took dupilumab have fewer symptoms, but they also fared better in a lung function test that examined the volume of air that a person can forcefully exhale.

Overall, those who took dupilumab had a better lung function by 130–240 milliliters than those who did not take the drug. No differences were noticed between high and low doses of the eczema drug.

Additionally, the participants who took the drug also registered fewer visits to the emergency room due to asthma. In fact, 3.5 percent of the intervention patients required such a visit, compared with 6.5 in the placebo group.

Why dupilumab is better than other drugs

The second study examined 210 participants who had severe asthma, all of whom used the same variety of inhalers to control their condition but took oral steroids, as well.

They were randomly assigned to receive either dupilumab as an additional drug or a placebo for 24 weeks.

As many as 50 percent of the patients who received dupilumab were weaned off the steroids completely, and 80 percent of the patients reduced their dose of steroids by half.

Chronic oral steroids such as prednisone can cause side effects including diabetes, cataracts, and osteoporosis, explains Dr. Castro. Also, people with asthma are required to take these drugs for decades.

"I have patients," explains Dr. Castro, "who have had to stop working and go on disability because their asthma symptoms are so severe they can no longer function in the workplace."

"I'm excited," he goes on, "about the potential of dupilumab because I have so many patients who have maxed out on available therapies and they still can't breathe. It can become a very disabling disease."

Dr. Castro also comments on the broader significance of these new findings, saying, "This drug not only reduced severe symptoms of asthma, it improved the ability to breathe."

"That's important because these patients have a chronic disabling disease that worsens over time with loss of lung function. So far, we do not have a drug for asthma that changes the course of the disease."

Dr. Mario Castro

He also mentions an extra benefit of dupilumab compared with existing therapies, saying, "Current drugs for severe asthma help reduce trips to the emergency room, for example, but they don't improve lung function."