Introduction We performed a comprehensive assessment of the effect of tiotropium Respimat® (tio R) add-on therapy on episodes of asthma worsening in adult patients with symptomatic asthma despite inhaled corticosteroid (ICS)/long-acting beta2-agonist (LABA) treatment.
Methods The PrimoTinA-asthma® studies (NCT00772538/NCT00776984) were two replicate 48-week, Phase III trials, investigating the effect of tio R 5 μg or placebo on episodes of asthma worsening and exacerbations when added onto ICS ≥ 800 μg budesonide equivalent/day + at least LABA. Endpoints included time to first episode of asthma worsening during the 48-week treatment period and number of episodes of asthma worsening per patient. Time to first asthma worsening was also analysed by baseline patient characteristics, and number of episodes was analysed by month to determine any seasonality effect.
Results In pooled data from the two studies (N = 912), time to first asthma worsening was longer in the tio R group compared with placebo, with a 31% risk reduction (hazard ratio 0.69; 95% CI 0.58, 0.82; P < 0.0001). The total number of all episodes of asthma worsening was lower in patients receiving tio R vs. placebo (rate ratio 0.76; 95% CI 0.63, 0.91; P = 0.0031). Improvements in time to first episode following tio R treatment compared with placebo were consistent across multiple subgroups, defined by baseline characteristics such as age, sex, lung function, Asthma Control Questionnaire score at randomisation and allergic status. Additionally, when the number of episodes of asthma worsening was plotted by month, tio R add-on treatment was shown to reduce episodes compared with placebo across all seasons, particularly during the fall/autumn peak.
Conclusion Tiotropium Respimat® add-on therapy reduced the rate of episodes of asthma worsening in adults with severe symptomatic asthma, irrespective of several baseline characteristics, allergic characteristics and across seasons, including the fall/autumn peak.
