A multicenter, prospective, observational study on montelukast monotherapy or montelukast-based combinations treating cough variant asthma

Background: Evidence of treatment against cough variant asthma (CVA) is insufficient for the clinical practice in China. We aimed at evaluating the real-world effectiveness of montelukast (MONT) alone or in combination with low-dose inhaled corticosteroids (ICS) and low-dose ICS plus long-acting beta-2-agonists (LABA) for Chinese CVA patients in a multicentre, prospective, cohort study. Methods: Adult patients diagnosed with CVA defined as chronic cough >8 weeks with a positive bronchial provocation test and normal chest X-ray findings were enrolled at respiratory clinics. Study treatment followed routine clinical practice. The investigators initiated MONT by 10 mg/day alone or in combination with a low-dose ICS +/- LABA and followed up treatment outcomes for 4 weeks. The primary outcome measure was the change in cough score (CS) from baseline. Results: The study enrolled 247 patients (MONT =146, MONT + ICS =38, MONT + ICS/LABA =63). In the primary analysis, the mean change (95% CI) in CS at the end of the study was -1.2 (-1.6, -0.9), -0.9 (-1.5, -0.4), and -1.3 (-1.7, -0.8) in the three groups, respectively. MONT monotherapy had a satisfactory rate of weekly asthma control at the end of the study (83.5%, 95% CI: 75.1%, 89.4%) in the per-protocol analysis. Rates of weekly asthma control were similar in two MONT-based combination regimens (83.9%, 81.4%). Short-acting beta-2-agonist (SABA) user (>= 2 times per week) was 16.8% in the MONT group. Conclusions: The real-world effectiveness of MONT alone or in combination with ICS or ICS and LABA was acceptable for CVA short-term control.