Concurrent use of indacaterol plus tiotropium in patients with COPD provides superior bronchodilation compared with tiotropium alone: a randomised, double-blind comparison

BackgroundCurrent guidelines recommend treatment with one or more long-acting bronchodilators for patients with moderate or more severe chronic obstructive pulmonary disease (COPD). The authors investigated the approach of dual bronchodilation using indacaterol, a once-daily long-acting β2 agonist, and the long-acting muscarinic antagonist tiotropium, compared with tiotropium alone.MethodsIn two identically designed, double-blind, 12-week studies, patients with moderate to severe COPD were randomised to indacaterol 150 μg once daily or matching placebo. All patients concurrently received open-label tiotropium 18 μg once daily. The primary outcome was standardised area under the curve of forced expiratory volume in 1 s (FEV1) from 5 min to 8 h post dose at week 12. The key secondary outcome was 24 h post-dose (‘trough’) FEV1 at week 12. Resting inspiratory capacity (IC) was measured in a subgroup.Results1134 and 1142 patients were randomised in studies 1 and 2; 94% and 94% completed. Compared with monotherapy, concurrent therapy increased FEV1 (area under the curve by 130 and 120 ml, trough by 80 and 70 ml; all p