A Randomised, Placebo-controlled, Double-blind, Two Period Crossover Study to Characterise the Exhaled Nitric Oxide Time Profile as a Biomarker of Airway Inflammation in Adult Asthma Patients Following Repeat Administration of Inhaled Fluticasone Furoate (FF)/ Vilanterol (VI) 100/25 mcg.

For asthmatic subjects, a combination of inhaled corticosteroid (FF) and long-acting beta2 receptor agonist (VI) is recommended for use (once daily) and fraction of exhaled nitric oxide (FeNO) is a non-invasive airway inflammation marker. In this randomised, double blind, placebo-controlled, two-period, crossover repeat dose study, the duration of action of fluticasone furoate (FF) will be determined by monitoring the return of FeNO levels to baseline, following the treatment with FF/vilanetrol (VI) in asthmatic subjects. Subjects who meet the eligibility criteria will participate in the following two treatment periods: FF/VI 100/25 mcg once-daily and placebo once-daily. Approximately 28 subjects will be enrolled in order to achieve 24 evaluable subjects. A 2-week treatment period will be followed by a 21-day monitoring/washout period before crossing over to the next treatment period. Total duration of each subject will be a maximum of 21 weeks. FeNO will be monitored up to 21 days after treatment with FF/VI together with FEV1 (up to 7 days).