The Food and Drug Administration approved a thermal device that ablates airway smooth muscle to treat severe, persistent asthma that is not well controlled with medication alone.
The device uses a radiofrequency (RF) generator and a single-use catheter with an electrode basket at the tip to deliver RF energy to the airway wall to reduce smooth muscle. The procedure is performed as outpatient bronchoscopy.
Asthmatx Inc. will market the device as the Alair Bronchial Thermoplasty System. The thermoplasty system is the first medical device to use RF energy to treat severe and persistent asthma “in certain adults,” according to the FDA statement announcing the April 27 approval.
The RF energy “heats the lung tissue in a controlled manner, reducing the thickness of smooth muscle in the airways and improving a patient's ability to breathe,” the FDA statement noted, adding that multiple treatment sessions to target different parts of the lungs are required for patients to benefit from treatment.
The FDA based its approval decision on a randomized, double-blind, controlled trial of 297 patients with severe, persistent asthma who experienced symptoms despite treatment with inhaled corticosteroids and long-acting beta agonists (Am. J. Respir. Crit. Care Med. 2010;181:116–24).
In that study, patients treated with the Alair system had improvements in asthma-specific quality of life and a reduction in severe exacerbations, as well as improvements in asthma-related quality of life.
Possible side effects during treatment include chest tightness or pain, atelectasis, hemoptysis, anxiety, headaches, and nausea. Other risks associated with treatment include acute asthma attacks and wheezing, according to the FDA statement.
The FDA also noted that the device is designed to reduce the number of severe asthma attacks on a long-term basis.
As a condition of approval, the FDA will require Asthmatx to conduct a 5-year postmarketing study to evaluate the long-term safety and effectiveness of the device.
That requirement reflects concerns by an FDA advisory panel that reviewed the device in October 2009. The panel agreed that there was reasonable evidence that the device was safe and effective, and it recommended approval. However, panel members recommended a postmarketing study to assess the device's long-term safety and efficacy.
For that postmarketing study, Asthmatx will enroll many of the patients who were enrolled in the clinical trial, as well as 300 new patients in the United States, according to the FDA.
Patients with asthma who have an implantable electronic device, such as a pacemaker, and those who are known to be sensitive to lidocaine, atropine, or benzodiazepines should not be treated with the thermal device, according to the FDA.
In addition, the procedure should not be performed in asthma patients who have an active respiratory infection or coagulopathy, or in those who are having an asthma exacerbation and those who have had changes to their corticosteroid regimen within 14 days prior to treatment.
In addition, areas of the lung that have been treated with the device should not be retreated, according to the FDA.