SEATTLE, Aug. 28, 2006 – Researchers at Swedish Medical Center recently began recruitment for the AIR2 (Asthma Interventional Research) international, multi-center clinical trial to explore a new investigational asthma treatment that may significantly change the course of asthma care. Swedish is one of 18 medical centers in the United States taking part in this randomized trial and the only site in the Pacific Northwest
The study focuses on a procedure called Bronchial Thermoplasty™ to treat asthma. The innovative procedure is still under clinical investigation, but early patient data suggest it may hold promise for moderate and severe asthmatic patients.
Asthma is a common disease in which the airways in the lung become inflamed, excess airway mucus is produced, and airways narrow when muscles within the airway walls contract. During an asthmatic attack, in response to an asthma trigger such as an allergen or irritant, the airway smooth muscle may contract leading to airway narrowing and breathing difficulties.
Nationally, asthma currently affects more than 20 million U.S. residents, with an estimated 2 million emergency-room visits and 5,000 deaths per year. Closer to home, on average, one in 10 women and one in 14 men in Washington state currently have asthma. Between 1999 and 2003, the number of adults with asthma in Washington state increased by 30 percent. About 9 percent of Washington state adults (400,000 people) currently have asthma. More than 5,000 Washington state residents are hospitalized each year from asthma, and the condition costs more than $400 million every year in medical expenditures and lost productivity for the state.
Currently, if someone suffers from asthma, medication is the only treatment available for relief. But now, clinical research centers around the globe hope to open up a new avenue to alleviate the challenging symptoms of asthma – through Bronchial Thermoplasty™, an investigative, minimally invasive procedure that reduces the amount of airway smooth muscle responsible for the constriction of airways in asthma patients.
As part of this randomized trial, physicians will access the airways with a flexible bronchoscope through the nose or mouth, which is a routine procedure, and by generating and applying thermal energy with the device, it will reduce areas of underlying smooth muscle in the small to medium size airways. The Alair® System – which is manufactured by Asthmatx, Inc. – consists of a single-use device and a controller that delivers radiofrequency energy (RF) to apply heat to the bronchial wall during the outpatient bronchoscopic procedure Bronchial Thermoplasty™.
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 RF energy for about 10 seconds to heat the airway smooth muscle.
A contiguous series of RF 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.
"The thermal energy that's applied to the airway through this procedure reduces the amount of muscle in the airway walls, which reduces the ability for it to constrict. Less constriction in the airways may result in reducing the severity and frequency of asthma symptoms," said thoracic surgeon Brian Louie, M.D., F.R.C.S.C., Swedish's principal investigator on the AIR2 Trial. "This could have a significant impact on how we manage asthmatic patients in the future."
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 is performed as an outpatient procedure under conscious sedation. No general anesthesia is used, no incision is necessary, and there is no need to stay overnight. Also, patients who are currently highly medicated will stay on their medication for the duration of the study.
"The smooth muscle in your airway serves no identifiable purpose. It's kind of like your appendix," said Seattle-area interventional pulmonologist Linda Anderson, M.D., who is co-investigator of the AIR2 Trial at Swedish. "But when something does go wrong with it, it can cause problems. It can constrict, tighten and narrow the airway considerably causing real health consequences for asthmatics."
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. As a result, the hope is that Bronchial Thermoplasty™ may become one of the many treatments available for the management of asthma.
Dr. Louie is hopeful that Swedish will be able to enroll up to 20 patients over the next year as part of the 300-patient trial being conducted at various sites around the world.
To participate in this study, a person must have asthma, be between 18 and 65 years of age, and be a non-smoker.
About Swedish Medical Center
Swedish Medical Center is the largest, most comprehensive, nonprofit health provider in the Pacific Northwest. Founded in 1910, it now has more than 7,000 employees and a medical staff of more than 2,000 physicians, most of which are private practitioners. Swedish now encompasses three hospital campuses (First Hill, Providence and Ballard) totaling 1,245 licensed beds, a new community-based emergency room and specialty center in Issaquah, Swedish Home Care Services and Swedish Physicians – a network of 12 primary-care clinics located throughout the Greater Seattle area. In addition to general medical and surgical care, Swedish is known as a regional referral center, providing specialized treatment in areas such as cardiovascular care, cancer care, orthopedics, high-risk obstetrics, neurological care, sleep medicine, pediatrics, organ transplantation and clinical research. For more information, visit www.swedish.org
Asthmatx designs, develops and manufactures medical devices for the treatment of asthma, a condition that affects over 20 million people in the United States. Asthmatx has developed the Alair System®, which consists of a single-use device and a controller that delivers radiofrequency energy during an outpatient bronchoscopic procedure known as Bronchial Thermoplasty. The Alair System provides a novel investigational treatment approach that uses radiofrequency energy to apply controlled heat to the airway wall to reduce the amount of airway smooth muscle and restrict its ability to narrow the airway. Bronchial Thermoplasty has been shown to reduce the narrowing of airway passages in response to bronchoconstrictors, and may potentially improve asthma symptoms in patients with this condition. Asthmatx is currently conducting a pivotal study investigation to establish the safety and efficacy of the Alair System for the treatment of asthma. For more information, visit, www.air2trial.com.
About the Alair System
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. NOTE: The Alair System is an Investigational device. It is limited by Federal (United States) law to investigational use. To be used by Qualified Investigators only.
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- To read the transcript and/or view the video of a related story that the CBS affiliate in Pittsburg, PA -- KDKA Television -- aired on Jan. 9, 2007, click here.