Assessing inhaled corticosteroid adherence and responsiveness in severe asthma using beclometasone dipropionate/formoterol NEXThaler™ dose-counting and nitric oxide monitoring

Abstract

Background: 65% of people with severe asthma and a FeNO ≥45 ppb are non-adherent to inhaled corticosteroids (ICS). Digital devices recording both time-of-use and inhaler technique identify non-adherence and ICS responsiveness but are not widely available. As the NEXThaler™ dose counter only activates at an inspiratory flow of 35 L/min, this may provide an alternative to identifying ICS responsiveness. Objective: To assess ICS adherence and responsiveness in severe asthma using beclometasone/formoterol (200/6 mcg) NEXThaler™ (BFN) dose-counting. Methods: Severe asthmatics with a FeNO ≥45 ppb were invited to use BFN in place of their usual ICS/long-acting β2-agonist (LABA). FeNO, ACQ6, lung function and blood eosinophil count were monitored for 3 months. A log10ΔFeNO ≥0.24 was used to define FeNO suppression as the primary marker of ICS responsiveness at day 28. Results: 27/48 (56%) patients demonstrated significant FeNO suppression at month 1 (median pre-114, post-48 ppb, p<0.001). A small but significant reduction occurred in FeNO non-suppressors. ACQ6 fell a median 1.2 units in FeNO suppressors (p<0.001) and 0.5 units in non-suppressors (p=0.025). These effects were sustained until month 3 in FeNO suppressors with a significant improvement in FEV1 and blood eosinophils. 67% (18/27) of those with baseline ICS/LABA prescription refills of ≥80% were FeNO suppressors suggesting prior non-adherence despite adequate prescription collection. 79% of FeNO suppressors did not require biologics within mean 11.4 months from initial dose counting. Conclusion: BFN dose counting identifies ICS responsiveness in severe asthma with the implication that these patients may not need to progress to biological therapies.