This is a randomized, participant- and investigator-blinded, placebo-controlled, parallel group, multicenter study with two fixed-dose levels of CSJ117 (4 mg, 8 mg) administered once-daily via oral inhalation over 12 weeks in participants with COPD, prone for exacerbations and symptomatic at baseline despite background maintenance triple therapy (inhaled corticosteroids/long acting beta-2 agonist/long acting muscarinic antagonist (ICS/LABA/LAMA) combination, standard of care in this population) for at least three months prior to screening.
The study will include:
* Screening period of up to 2 weeks to assess eligibility.
* Run-in period of 4 weeks where participants will be placed on fixed-dose triple background therapy (ICS/LABA/LAMA) that will be used until the patient's last study treatment.
* Treatment period of 12 weeks. Participants will be stratified by eosinophil levels and then randomized 1:1:1 to either 4 mg CSJ117, 8 mg CSJ117, or placebo.
* Follow-up period of 55 days following the last dose of study drug. The primary objective of the study is to assess the effect of CSJ117 on disease/symptom burden after 12 weeks of treatment.
