After 10 or more years of follow-up in the BT10+ study, bronchial thermoplasty for uncontrolled asthma demonstrated sustained efficacy and an acceptable safety profile, researchers reported in The Lancet Respiratory Medicine.
“Data on long-term (more than 5 years) safety and efficacy of bronchial thermoplasty are lacking and studies designed to address this are needed,”Rekha Chaudhuri, MD, professor with the Asthma/COPD Clinical Research Centre at Gartnavel General Hospital and the Institute of Infection in the department of immunity and inflammation at the University of Glasgow, U.K., and colleagues wrote. “To our knowledge, the BT10+ study is the first to follow-up a large group of participants treated with bronchial thermoplasty beyond 5 years.”
The international, multicenter, follow-up study enrolled 192 patients with asthma who were previously enrolled in the AIR, RISA and AIR2 trials with 10 or more years of follow-up data since bronchial thermoplasty treatment. Researchers collected patient demographics, quality of life, lung function, CT scans, severe exacerbations and health care utilization in the previous year during the BT10+ 10-year outcomes study visit.
One hundred thirty six patients (mean age, 53.6 years; 60% women) received bronchial thermoplasty and 56 were considered sham or control participants. Bronchial thermoplasty was performed in 18 of the control participants (32%; mean age, 54.2 years; 39% women) after the conclusion of other previous trials. All participants in BT10+ were followed for a median of 12.1 years posttreatment.
The primary effectiveness endpoint was durability of bronchial thermoplasty treatment, which the researchers measured by comparing the proportion of participants with severe exacerbations from year 1 to 5 after treatment with those with severe exacerbations in the year before the 10-year follow-up visit. Of those who received bronchial thermoplasty, 25% experienced severe exacerbations at the BT10+ study visit compared with 24% 1 year and 22% at 5 years after treatment.
The researchers reported a reduction in severe exacerbations, including hospital ED visits or admissions to hospital for asthma, at the BT10+ study visit in participants treated with bronchial thermoplasty and participants in the control group compared with baseline.
The primary safety endpoint was the absence of clinically significant posttreatment CT scan changes after treatment at the BT10+ study visit. Bronchiectasis was observed in 13% of the 97 participants from the AIR2 trial. Among those who received bronchial thermoplasty and did not have bronchiectasis at baseline, six developed bronchiectasis after treatment (five mild, one moderate.
Researchers observed similar quality of life and spirometry measurements between years 1 and 5 and the BT10+ study visit.
“This suggests that bronchial thermoplasty is an effective nonpharmacological therapy for patients with asthma, particularly for those whose asthma remains uncontrolled despite optimized medical therapy and for those who do not qualify for or respond adequately to biologicals,” the researchers wrote.