Abstract
Cough is a major symptom in patients with asthma and poses a significant burden compared with other asthma symptoms. However, there are no approved treatments in Japan, developed to specifically treat cough in patients with asthma. We present the design of REACH, an 8-week real-life study, which will evaluate the efficacy of a combination of indacaterol acetate, glycopyrronium bromide and mometasone furoate (IND/GLY/MF) in asthmatic patients with cough refractory to medium-dose inhaled corticosteroid/long-acting β(2)-agonist (ICS/LABA). Patients with asthma (age ≥20 to <80 years) with a cough visual analogue scale (VAS) ≥40 mm will be randomised 2:1:1 to receive IND/GLY/MF medium-dose 150/50/80 μg once daily or step-up to a high-dose regimen of fluticasone furoate/vilanterol trifenatate (FF/VI) 200/25 µg once daily or budesonide/formoterol fumarate (BUD/FM) 160/4.5 µg four inhalations twice daily during the 8-week treatment period. The primary objective is to demonstrate the superiority of IND/GLY/MF medium-dose over high-dose ICS/LABA in terms of cough-specific quality of life after 8 weeks. The key secondary objective is to demonstrate the superiority of IND/GLY/MF in terms of subjective assessment of cough severity. Cough frequency (VitaloJAK cough monitor) and capsaicin cough receptor sensitivity will be evaluated in eligible patients. Cough VAS scores, fractional exhaled nitric oxide, spirometry and blood tests, and the Asthma Control Questionnaire-6, Cough and Sputum Assessment Questionnaire, and Japanese version of the Leicester Cough Questionnaire will be evaluated. REACH will provide valuable evidence on whether a switch to IND/GLY/MF medium-dose or step-up to high-dose ICS/LABA is beneficial for patients with persistent cough despite treatment with medium-dose ICS/LABA.