CAPTAIN: Improvements in airflow obstruction in patients with uncontrolled asthma

Background: Airflow obstruction (FEV1/FVC ratio <0.7) is associated with increased lung function decline and exacerbation frequency in asthma. It is often considered irreversible. Aim: Analyse the impact of treatment escalation on airflow obstruction in asthma. Methods: CAPTAIN: Phase IIIA, randomised, double-blind, 24–52-week, parallel-group study in adults with uncontrolled asthma. Run-in/stabilisation: 3 weeks fluticasone propionate/salmeterol (250/50µg; DISKUS) BID followed by 2 weeks FF/VI (100/25µg; ELLIPTA) QD. Randomisation: FF/VI (100/25, 200/25μg) or FF/UMEC/VI (100/31.25/25, 100/62.5/25, 200/31.25/25, 200/62.5/25μg) QD (ELLIPTA). Outcomes: proportion of patients with pre-bronchodilator FEV1/FVC ≥0.7 at screening and randomisation, shift in FEV1/FVC from <0.7 at randomisation to ≥0.7 at Week 24 by treatment group (post hoc analysis). Only data for UMEC 62.5μg are shown. Results: The proportion of the total population with FEV1/FVC ≥0.7 increased from 24% (579/2423) at screening to 36% (867/2420) at randomisation. The proportion of patients with FEV1/FVC <0.7 at randomisation who shifted to FEV1/FVC ≥0.7 at Week 24 was higher in the FF/UMEC/VI 100/62.5/25 vs FF/VI 100/25 treatment group (13 vs 8%), and in the FF/UMEC/VI 200/62.5/25 vs FF/VI 200/25 treatment group (21 vs 11%) (Fig). Conclusions: Airflow obstruction may be reversible with treatment escalation in some patients with asthma. Funding: GSK (205715/NCT02924688).