Blais CM, et al. – The influence of single–dose glycopyrronium (long–acting muscarinic antagonist) and indacaterol (ultra–long acting β2 agonist), as monotherapy and in combination, on the methacholine dose–response curve of mild asthmatics, was determined. In addition, experts planned to compare these findings with a non–asthmatic control curve. The bronchoprotective mechanisms triggered by different classes of asthma medications were differentiated by methacholine dose–response curves. When performing superiority, equivalence, or non–inferiority trials, assessment of bronchoprotection using methacholine dose–response curves appeared to be useful during clinical development of respiratory medications.