The efficacy of bronchial thermoplasty, an endoscopic therapy that can reduce severe exacerbations in patients with uncontrolled asthma, was sustained for up to 10 or more years in patients with persistent asthma, according to clinical study results published in the Lancet Respiratory Medicine.
The international, multicenter BT10+ study (ClinicalTrials.gov Identifier: NCT03243292) was a follow-up study of participants with persistent asthma from the Asthma Intervention Research (AIR; ClinicalTrials.gov Identifier: NCT00214526) trial, Research in Severe Asthma (RISA; ClinicalTrials.gov Identifier: NCT00214539), and Asthma Intervention Research-2 (AIR2; ClinicalTrials.gov Identifier: NCT00231114) trials who had 10 or more years of follow-up since starting bronchial thermoplasty treatment or a sham control (n=192). At the 10-year outcomes study visit, investigators collected data on patient demographics, quality of life, lung function, computed tomographic (CT) scans in only the AIR2 participants, severe exacerbations, and health care use during the previous year.
Durability of the thermoplasty treatment effect, assessed by comparing participants who had severe exacerbations during years 1 and 5 after bronchial thermoplasty treatment with participants with severe exacerbations during the 12 months prior to the BT10+ visit, comprised the primary efficacy endpoint. Safety outcomes assessed for the primary safety endpoint included the absence of clinically significant posttreatment respiratory image changes following bronchial thermoplasty.
In total, 136 patients in the original trials received bronchial thermoplasty, while 56 patients were randomly assigned to a sham or control group. Approximately 32% (n=18) of participants randomly assigned to the sham or control group went on to receive bronchial thermoplasty following the conclusion of the trials. Participants were followed for 10.8 to 15.6 years (median, 12.1 years) following treatment.
A similar proportion of severe exacerbations were observed in patients treated with bronchial thermoplasty at the BT10+ visit (25%) compared with year 1 (24%; difference, 0.6%; 95% CI, -9.7% to 10.8%) and year 5 (22%; difference, 3.5%; -6.7% to 13.6%). There were 0.58 (95% CI, 0.33-0.83) severe exacerbations per participant during the 12-month period prior to the BT10+ visit. This per-participant number of severe exacerbations was significantly greater than during 5 years following treatment with bronchial thermoplasty (difference, 0.27; 95% CI, 0.01-0.56; P =.044) but was not different from 1 year following treatment (difference, 0.11; -0.19 to 0.42; P =.43).
The mean Asthma Quality of Life Questionnaire scores rose from 4.73 (95% CI, 4.53-4.94) to 5.86 (95% CI, 5.69-6.03) by 12 weeks of bronchial thermoplasty, an improvement that was still present for up to 10 years or more after treatment (5.78; 95% CI, 5.59-5.97).
A limitation of this study included the relatively large number of participants who were lost to follow-up.
The investigators concluded that their data suggest that bronchial thermoplasty is an effective nonpharmacological therapy, particularly for patients in whom asthma remains uncontrolled despite optimized medical therapy or among those whose asthma either does not qualify for or does not adequately respond to biologics.
Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.
Chaudhuri R, Rubin A, Sumino K, et al; on behalf of the BT10+ Study Group. Safety and effectiveness of bronchial thermoplasty after 10 years in patients with persistent asthma (BT10+): a follow-up of three randomised controlled trials. Lancet Respir Med. Published online January 29, 2021. doi:10.1016/S2213-2600(20)30408-2