Normalisation of airflow limitation in asthma: Post-hoc analyses of TRIMARAN and TRIGGER

Background: In asthma, persistent airflow limitation (PAL) is associated with poorer control, lung function decline and exacerbations. Using post-hoc analyses we evaluated: the relationship between post-salbutamol PAL at screening, airflow limitation (AL) during 52 weeks treatment with extrafine beclometasone dipropionate/formoterol fumarate/glycopyrronium (BDP/FF/G) versus BDP/FF and the risk of moderate/severe asthma exacerbations. Methods: TRIMARAN and TRIGGER were double-blind studies comparing BDP/FF/G with BDP/FF (TRIMARAN medium-dose ICS; TRIGGER high-dose) in adults with uncontrolled asthma. Patients were subgrouped according to post-salbutamol PAL status at screening, and AL over the 52-week treatment period. Results: Most patients with post-salbutamol PAL at screening had AL at all on-treatment visits (TRIMARAN 62.8%; TRIGGER 66.8%). A significantly higher proportion of patients had normalised airflow on ≥1 follow-up visit when receiving BDP/FF/G than BDP/FF (TRIMARAN 44.1 vs. 33.1% [p = 0.003]; TRIGGER 40.1 vs. 26.0% [p < 0.001]). In patients with post-salbutamol PAL at screening and normalised AL at ≥1 follow-up visit, exacerbation rates were 15% (p = 0.105) and 19% (p = 0.039) lower in TRIMARAN and TRIGGER versus those with AL on all visits. There was a trend to lower exacerbation rates in patients receiving BDP/FF/G than BDP/FF, particularly in patients in whom AL was normalised. Conclusion: In these analyses, AL in asthma was associated with an increased exacerbation incidence. Inhaled triple therapy with extrafine BDP/FF/G was more likely to normalise airflow, and was associated with a trend to a lower exacerbation rate than BDP/FF, particularly in the subgroup of patients in whom treatment was associated with airflow normalisation.