Researchers at Beth Israel Deaconess Medical Center (BIDMC) have begun work on the AIR2 (Asthma Interventional Research) clinical trial, an international, multi-center trial exploring a new investigational asthma treatment that may change the course of asthma care.
The study focuses on a procedure called Bronchial Thermoplasty™ to treat asthma. The innovative procedure is being researched at BIDMC and other institutions in the United States, Canada, Brazil, Australia and the United Kingdom. This procedure is still under clinical investigation, but early patient data suggest it may hold some promise for moderate and severe asthmatic patients.
Asthma is one of the most common and costly diseases in the world. It affects more than 20 million people just in the United States with an estimated 2 million emergency room visits and 6,000 deaths per year. The prevalence of asthma is on the rise, and there is no cure.
Asthma is a disease involving greater than normal responsiveness of airways in the lungs to a variety of stimuli. This increased responsiveness can take the form of swelling of the airway wall, excess mucus production that can clog the airways, and significant narrowing of the airways when tiny muscles in the airway wall, called "airway smooth muscle," contract. Currently, medication is the only treatment available for asthma. But now, clinical research centers hope to open up a new avenue to alleviate the challenging symptoms of asthma - through Bronchial Thermoplasty™, an investigative procedure that may reduce the amount of airway smooth muscle that is responsible for the constriction of airways in asthma patients.
During Bronchial Thermoplasty,™, an outpatient bronchoscopic procedure, physicians will use the Alair® System to go into the airways with a flexible bronchoscope through the nose or the mouth and deliver thermal energy to the airway walls in an effort to reduce the presence of airway smooth muscle, and thereby reduce the ability of treated airways to constrict.
The Alair System, manufactured by Asthmatx, Inc., consists of a single-use device and a controller that delivers thermal energy to apply heat to the bronchial wall. The system consists of a catheter with an expandable wire basket at the tip. The four arms of the expanded basket come in contact with and fit snugly against the airway wall. The expanded basket then delivers controlled thermal energy for about 10 seconds to heat the airway smooth muscle. A contiguous series of thermal energy applications are needed to treat along the accessible length of the airways. Once the treatment session is completed, the device and the bronchoscope are removed. The controlled heat is designed to reduce the amount of airway smooth muscle in the airway wall, thereby reducing the ability of the airway walls to contract, narrow and spasm in response to irritation, infection, or inflammation.
During the clinical trial, physicians will treat one-third of the lungs in each treatment session for a total of three treatment sessions. The procedure is performed in a medical suite and takes about an hour to complete, followed by post-procedure observations for approximately four hours. The procedure will be performed as an outpatient procedure under conscious sedation. Also, patients who are currently highly medicated will stay on their medication for the duration of the study. The researchers are careful to point out that there is no expectation that this new investigational procedure will cure asthma. However, it is hoped that this procedure could be useful in reducing the severity and frequency of asthma symptoms and improving quality of life for patients with asthma. Thus, Bronchial Thermoplasty may become one of the many treatments that are available for the management of asthma.
The Alair System has been used successfully in 16 patients with asthma who were enrolled in a safety trial at two asthma centers in Canada. Two years following their last treatment, the 16 patients on average showed less airway narrowing after stimulation with a drug that causes contraction of airway smooth muscle. All patients surveyed indicated that they would be willing to undergo the Bronchial Thermoplasty procedure again, knowing now what the procedure involves. An additional 70 patients with moderate to severe asthma have been treated with this device in subsequent randomized clinical studies conducted outside the US (Canada, Brazil and Europe), and are continuing to be evaluated.
Armin Ernst, MD has no financial interest in Asthmatx, which is sponsoring the study.
Beth Israel Deaconess Medical Center is a patient care, teaching and research affiliate of Harvard Medical School, and ranks fourth in National Institutes of Health funding among independent hospitals nationwide. BIDMC is clinically affiliated with the Joslin Diabetes Center and is a research partner of Dana-Farber/Harvard Cancer Center. BIDMC is the official hospital of the Boston Red Sox. For more information, visit www.bidmc.harvard.edu.
Asthmatx is developing catheter-based medical devices for the treatment of asthma, a disease that affects over 20 million people in the United States. Asthmatx has developed the Alair® System to perform an outpatient procedure called Bronchial Thermoplasty™. Bronchial Thermoplasty involves the delivery of precisely controlled thermal energy to the airway wall, to reduce the amount of airway smooth muscle, and lessen these muscles' ability to narrow the airway. The results of three clinical studies of the Alair System suggest the procedure may offer significant benefits to patients with severe asthma.