Bronchial Thermoplasty (BT) has been shown to result in significant improvements in a number of asthma control measures in three randomized clinical trials in patients with moderate-to-severe, persistent asthma. The Asthma Intervention Research 2 (AIR2) Trial, a double-blind, sham-controlled, randomized clinical trial of BT in patients with severe asthma, showed a 32% reduction in severe exacerbations, an 84% reduction in emergency room visits due to respiratory symptoms, and a 66% reduction in time lost from work due to asthma symptoms compared to a sham-treated group in the first year following the BT treatment period.
Wechsler at el describe their findings on the long-term safety and durability of BT out to 5 years post-treatment in BT-treated patients from the AIR2 Trial. They found that the reduction in the percentage of BT-treated patients experiencing severe exacerbations (compared to sham-treated patients) seen at 1 year was maintained out to 5 years with a 48% average decrease over 5 years in severe exacerbation event rates in BT-treated patients compared with the 12 months prior to BT treatment. There was a substantial reduction in the use of systemic corticosteroids associated with those exacerbations. Similarly, the reduction in the percentage of BT-treated patients having emergency room visits for respiratory symptoms (compared to sham -treated patients) seen at 1 year was maintained out to 5 years. There was no increase over 5 years in hospitalizations, respiratory adverse events, or asthma symptoms. In addition, one in 4 BT-treated patients (28%) saw a 50% or greater reduction from baseline average ICS dose at 5 years, with an average reduction of 18% from baseline for BT-treated patients at 5 year. The authors demonstrated long term safety based on the absence of clinically meaningful changes in lung function (FEV1) and no structural changes in the airways at 5 years.
This supports BT as an important option for patients with severe asthma who remain symptomatic despite taking current standard of care medications.