A Phase IIb, Randomized, Double-Blind, Placebo-Controlled, Multicenter, Dose-Ranging Study to Assess the Efficacy and Safety of MSTT1041A in Patients With Uncontrolled Severe Asthma

This is a Phase IIb, randomized, placebo-controlled, double-blind, multicenter, multi-arm study which will evaluate efficacy, safety, and pharmacokinetic of MSTT1041A compared with placebo as add-on therapy in participants with severe, uncontrolled asthma who are receiving medium- or high-dose inhaled corticosteroid (ICS) therapy and at least one of the following additional controller medications: long-acting beta-agonists (LABA), leukotriene modifier (LTM), long-acting muscarinic antagonist (LAMA), or long-acting theophylline preparation. The total duration of this study for each participant is approximately 70 weeks including screening, run-in, treatment, and follow-up.