Article Text
Abstract
Background We evaluated the effect of once-daily tiotropium Respimat® 5 µg on lung function, asthma exacerbation and asthma symptom control among patients with symptomatic asthma receiving inhaled corticosteroids (ICS; ≥800 μg/day budesonide or equivalent) + long-acting β2-agonist (LABA).
Methods Data were pooled from two replicate, double-blind, placebo-controlled, 48-week, parallel-group studies of once-daily tiotropium 5 µg versus placebo, both delivered via the Respimat® SoftMist™ inhaler (PrimoTinA-asthma®: NCT00772538, NCT00776984). Eligible patients had: ≥5-year history of asthma diagnosed before the age of 40 years; seven-question Asthma Control Questionnaire (ACQ-7) score of ≥1.5; experienced ≥1 exacerbation during the previous year. Patients were either lifelong non-smokers, or ex-smokers (<10 pack-years) who quit smoking ≥1 year before study enrolment. Exclusion criteria included diagnosis of chronic obstructive pulmonary disease. Co-primary end points in individual trials: peak forced expiratory volume in 1 second (FEV1) within 3 h post-dose (0–3 h) and trough FEV1. A co-primary end point in pooled data was time to first severe exacerbation; secondary end points included time to first episode of asthma worsening and ACQ-7 response. Post hoc efficacy analyses were performed.
Results 912 patients were randomised to receive tiotropium Respimat® (n = 456) or placebo Respimat® (n = 456). At Week 48, tiotropium Respimat® was associated with statistically significant improvements versus placebo Respimat® in peak FEV1(0–3h) (adjusted mean difference 100 mL; 95% confidence interval: 52, 148; p < 0.0001) and trough FEV1 (adjusted mean difference 62 mL; 95% confidence interval: 18, 106; p = 0.006). Time to first severe asthma exacerbation was significantly longer with tiotropium Respimat® versus placebo Respimat® (282 vs 226 days, respectively; hazard ratio 0.79; p = 0.034), as was time to first episode of asthma worsening (315 vs 181 days, respectively; hazard ratio 0.69; p < 0.0001). At Week 24, ACQ-7 responder rate was significantly higher with tiotropium Respimat® (53.9%) versus placebo Respimat® (46.9%; odds ratio 1.32; p = 0.0427).
Conclusion Once-daily tiotropium Respimat® add-on to ICS + LABA improves lung function, reduces risk of severe asthma exacerbation and asthma worsening, and significantly improves asthma symptom control compared with placebo Respimat® in patients with symptomatic asthma.