May 18 2009
Chronic asthma sufferers may find new relief in a simple, minimally invasive outpatient procedure known as bronchial thermoplasty, which uses controlled radiofrequency-generated heat to treat the muscles of the airways, preventing them from constricting and narrowing.
The study, which was approved by the Food and Drug Administration (FDA), marks the most recent phase of investigational trials of the Alair System, the device used in the bronchial thermoplasty procedure. If approved, it would become the first non-pharmaceutical therapy to effectively treat severe asthma.
Results of the multi-center study of Alair, which is manufactured by Asthmatx, will be presented on Monday, May 18, during the 105th International Conference of the American Thoracic Society in San Diego.
"The research we will be presenting was part of the pivotal clinical study designed for submission to the FDA, which provides evidence supporting the effectiveness and safety of the Alair system when used in the bronchial thermoplasty procedure," said lead author Mario Castro, M.D., M.P.H., professor of medicine and pediatrics at Washington University School of Medicine.
Researchers at 30 sites in six countries enrolled 297 patients with severe asthma to participate in the trial. Participants—all of whom continued to experience asthma symptoms, despite high doses of asthma medications—were split into two subgroups. Patients in the control group were randomly assigned to receive a placebo or "sham" treatment, meaning that while they underwent the procedure, no heat was applied. Researchers used a quality-of-life scale to measure the results at six months, nine months and one year. Overall, 79 percent of the patients in the experimental group who were treated with bronchial thermoplasty experienced a statistically significant and clinically meaningful improvement in their quality-of-life measurements.
"Following a procedure, patients treated with bronchial thermoplasty experience persistent asthma control over the year following treatment, based on improvement in the asthma quality of life, a significant reduction in rates of severe asthma attacks and a reduction of emergency room visits for respiratory symptoms," Dr. Castro noted.
According to the American Lung Association, more than 20 million Americans have asthma, and asthma attacks result in about ten million unscheduled doctor office visits, two million emergency room visits, and 4,000 deaths annually.
Dr. Castro said the high level of continued commitment from all study participants underscores the need for effective asthma control in patients who suffer from severe forms of the disease.
"Our high compliance rate and the fact that initially over 580 patients consented to participate in a study that included three potential sham bronchoscopy procedures certainly confirmed that this group of severe asthma patients is a very needy population for whom current therapies are inadequate," he noted. "Bronchial thermoplasty addresses an unmet medical need, offering significant advantages over the existing standard of care for patients suffering from severe asthma."
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