Background: Tiotropium bromide is an effective therapy for COPD patients. Comparing across programs tiotropium Respimat Soft Mist inhaler was at least as efficacious as tiotropium HandiHaler, however, concerns have been raised about tiotropium's safety when given via Respimat.
Methods: The TIOSPIR trial (NCT01126437) compares the safety and efficacy of tiotropium Respimat 5 μg once daily (marketed) and 2.5 μg once daily (investigational) with tiotropium HandiHaler 18 μ once daily (marketed). The hypotheses to be tested are 1). that tiotropium Respimat 5 μg once daily and Respimat 2.5 μg once daily are non-inferior to HandiHaler in terms of all-cause mortality, and 2). that tiotropium Respimat 5 μg once daily is superior to HandiHaler in terms of time to first exacerbation. A spirometry substudy evaluates the bronchodilator efficacy. The trial is a randomized, double-blind, double dummy, event-driven, parallel group study. Participants can use any background treatment for COPD except inhaled anticholinergic agents. The study encompasses a wide range of COPD patients, e.g. patients with stable cardiac diseases including arrhythmia can be included. Clinical sites are international and include both primary care as well as specialists.
Results: To date, over 17,000 participants have been randomized from over 1200 sites in 50 countries with an anticipated treatment duration of 2-3 years.
Conclusion: TIOSPIR will provide precise estimates of the relative safety and efficacy of the Respimat and HandiHaler formulations of tiotropium, assess potential dose-dependence of important outcomes and provide information on the clinical epidemiology of COPD in a large international patient cohort.