Bronchial Thermoplasty for Adults With Severe Asthma in the Biologic Era

Rationale: For patients with severe asthma that remain uncontrolled with exacerbations despite biologics or patients who are not eligible for biologics, there is no reimbursed treatment other than pulmonary rehabilitation in the Netherlands. Pulmonary rehabilitation is known to have a limited effect for a limited amount of time. Bronchial thermoplasty or bronchial ablation (BT) is a non-pharmacological treatment for asthma aiming to restore abnormal airway function by using an endobronchial approach. Previous RCT's reported efficacy on exacerbations and asthma related quality of life (AQLQ), but were performed before large availability of biologic treatments. Although a single BT treatment is not without costs, these costs seem to outweigh the costs that can be saved by the long-term (\>5 years) lowering effect of BT on the frequency of exacerbations and hospitalizations and omitting long term use of trials and switches of biologics. Therefore, the investigators hypothesize that BT, in the era of biologics, is superior (in terms of exacerbations and quality of life) over standard care and cost-effective in patients whose asthma remains uncontrolled despite optimal anti-inflammatory treatments including biologics, and the investigators propose to test this hypothesis in a RCT.

Objective: To investigate the impact of BT as compared to standard of care in severe asthma patients that remain uncontrolled despite standard treatment including adequate doses of inhaled preventer therapies with or without biologics on:

1. rate of exacerbations 2. asthma related quality of life (AQLQ) 3. 1-year and 5-year cost-effectiveness and cost utility Study design: Investigator-initiated randomized, multicenter, parallel-group interventional RCT of severe asthma patients undergoing either BT (active arm) or standard care (control arm).

Study population: Adult, uncontrolled severe asthma patients despite optimal medical therapy including one or more trials of treatment with a biologic or ineligible for biologic treatment AND 2 or more severe asthma exacerbations in the previous year AND FEV1 ≥ 50% predicted.

Intervention: BT (active arm) versus standard care (control arm). Main study parameters/endpoints: The primary endpoint of this study is the between group difference in severe exacerbation rate after 12 months of follow-up. The main secondary endpoints are between group differences after 12 months of follow-up and within group differences before and after intervention or standard care. Parameters that will be explored are: AQLQ (minimal clinically important difference \>0.5), ACQ (minimal clinically important difference \>0.5), exacerbation rate (before and after BT) and hospitalizations (rate and % subjects).