The data demonstrated the absence of clinical complications and the maintenance of stable lung function over a five year period post-BT in patients with moderate to severe asthma. The data was presented in a poster at the annual meeting of the American Thoracic Society (ATS) in New Orleans.

The AIR Trial was a multicenter, randomised, controlled clinical study that evaluated the safety and effectiveness of BT in patients with moderate to severe asthma. Positive safety and effectiveness data at one year post-BT were published in the New England Journal of Medicine (NEJM) in March 2007. BT-treated patients have been followed for five years post-procedure to evaluate longer-term safety.

BT, which is the first device-based asthma treatment approved by the FDA, is a novel outpatient procedure that delivers precisely controlled thermal energy to reduce excess airway smooth muscle that is associated with airway constriction in patients with asthma. By decreasing the ability of the airways to constrict, the new treatment has been shown to help patients with severe asthma gain substantially better control over their disease.

According to the study, the data showed that over five years, the percent of patients reporting respiratory adverse events remained stable, hospitalisations and emergency room visits for respiratory symptoms remained stable, pulmonary function (FEV1) remained stable, no incidences of pneumothorax, intubation, mechanical ventilation, cardiac arrhythmias or death as a result of BT treatment over the five year follow-up.

In the period immediately following BT, there was an expected transient increase in the frequency and worsening of respiratory-related symptoms, which were of the type expected following bronchoscopy in patients with asthma. The events typically occurred within a day of the procedure and resolved on average within seven days with standard care.

Glen French, CEO of Asthmatx, said: “This demonstration of long-term safety, combined with the therapeutic benefits demonstrated in a series of three randomised controlled clinical studies, is extremely uncommon for a medical device at the time of FDA approval. It provides strong support for the adoption of BT as a new therapeutic option for the treatment of severe asthma in adults.”