Rheumatoid Arthritis Drug Could Fight Problem Asthma

THURSDAY, Feb. 16, 2006 (HealthDay News) -- Using a well-known rheumatoid arthritis drug to reduce high levels of an inflammatory protein could be a new means of fighting severe asthma, British researchers report.

Their study found that people with severe asthma have higher-than-normal concentrations of an inflammation-linked cytokine called tumor necrosis factor alpha (TNFa). Reducing the levels using a TNF-inhibiting drug, etanercept, reduced asthma symptoms in people with refractory -- hard to manage -- disease.

"Open-label use of etanercept for three months in patients with refractory asthma improved airflow measures and symptoms scores, and reduced bronchial hyperresponsiveness," wrote Dr. Serpil Erzurum, from the Cleveland Clinic, in an editorial accompanying the study in the Feb. 16 issue of the New England Journal of Medicine.

However, Erzurum also cautioned against widespread use of TNF inhibitors in the treatment of asthma until more studies are done, because these medications can have serious side effects. Potential side effects include a boost in risk for serious infections such as pneumonia, as well as an increased cancer risk.

Asthma, which affects about 20 million Americans, is a chronic disease of the airways that can cause wheezing, difficulty breathing and shortness of breath, according to the National Heart, Lung, and Blood Institute. Numerous medications are available to treat the disorder, and with proper treatment most people can keep it under control.

However, according to Erzurum, in about 10 percent of the cases, asthma becomes very hard to control, severely impacting on quality of life. Many patients must make chronic use of oral steroids, which can have significant side effects. These hard-to-manage cases account for about half of the health-care costs linked to asthma. They also represent a large portion of asthma complications and deaths.

Etanercept, sold under the brand name Enbrel, is a TNF-inhibitor drug already prescribed for autoimmune diseases such as rheumatoid arthritis or ankylosing spondylitis.

The first phase of the current study compared 10 people who didn't have asthma to 10 people with mild-to-moderate asthma and another 10 people with tough-to-treat disease. British researchers from the National Health Service looked for differences in the levels of TNFa between these three groups.

They found that people with severe asthma had about twice the TNFa activity as people without asthma. Severe asthmatics also had higher levels than people with mild-to-moderate asthma.

Dr. Jonathan Field, director of the allergy and asthma clinic at New York University Medical Center/Bellevue in New York City, said he wasn't surprised by the findings.

"TNF is one of the many inflammatory cytokines linked to allergy and autoimmune diseases. This is one of the times it has been well-documented, however," he said.

To further examine the role of TNF in refractory asthma, the researchers tested the known TNF inhibitor, etanercept, on participants with hard-to-control disease. Half began the study taking etanercept twice a week for 10 weeks, while the other half received a placebo. After a one-month rest, the groups were switched and those that had received the placebo were now given the drug and vice-versa. During the study, neither the researchers nor the patients knew who was receiving the medication.

Asthma severity, measured by lung function tests, was significantly reduced for those taking the medication, the study found. On a quality-of-life scale of seven points, scores improved by an average of nearly one point when people were taking etanercept compared to the placebo.

The authors point out that their findings are only applicable to those with severe asthma, and not for those with mild-to-moderate asthma. That's because these milder cases don't have the high levels of TNF seen in people with severe asthma.

"For people with severe, refractory asthma, this may be a hopeful adjunct therapy, but we have to be very aware of the potential side effects," said Field.

Field added that more studies need to be done on much larger groups of people before this could possibly become a standard treatment.

Dr. Malourdes de Asis, chief of allergy at Nyack Hospital in New York, echoed Field's sentiments.

"This is a promising therapy for people with refractory asthma, but it's expensive and we still need more studies and a multi-center trial," she said.

More information

For more on asthma control, head to the U.S. National Heart, Lung, and Blood Institute.