Efficacy and safety of indacaterol and tiotropium in COPD patients according to dyspnoea severity

Abstract

BackgroundGuidelines for chronic obstructive pulmonary disease (COPD) recommend that treatment choices be based partly on symptoms. MethodsA post-hoc analysis of pooled data from clinical studies compared the efficacy and safety of once-daily inhaled bronchodilators indacaterol (150 and 300 μg) and open-label tiotropium (18 μg) according to baseline dyspnoea severity on the modified Medical Research Council (mMRC) scale in patients with COPD (mMRC scores <2 = ‘less dyspnoea’; scores ≥2 = ‘more dyspnoea’). Outcomes were assessed after 26 weeks. ResultsThe analysis included 3177 patients. In patients with less dyspnoea: indacaterol (both doses) improved 24-h post-dose (‘trough’) forced expiratory volume in 1 s (FEV1), transition dyspnoea index (TDI) and St George's Respiratory Questionnaire (SGRQ) total scores at week 26 and reduced the risk of COPD exacerbations vs placebo; and open-label tiotropium improved trough FEV1 and TDI total score vs placebo at week 26. In patients with more dyspnoea: indacaterol (both doses) improved trough FEV1, TDI and SGRQ total scores at week 26; indacaterol 300 μg was the only treatment to improve the TDI total score by more than the minimum clinically important difference (≥1 point) vs placebo; and open-label tiotropium improved trough FEV1, TDI total score at week 26 and decreased the risk of COPD exacerbations vs placebo. In both subgroups, all treatments were well tolerated. ConclusionsIn patients with less dyspnoea, all treatments had similar effects. Indacaterol 300 μg may be a useful treatment option for patients with COPD who experience more severe breathlessness.