A study to test whether different doses of BI 1291583 help people with bronchiectasis. This study is being done to test the study drug, BI 1291583, for safety, effectiveness, and side effects, when compared to taking a placebo, in subjects with bronchiectasis and find the recommended dose of the study drug, BI 1291583 that can be used in future clinical research studies. Different doses of the study drug will be tested to see which dose has less unacceptable side effects and is more effective in subjects with bronchiectasis.

Main inclusion criteria:
? ≥18 and ≤85 years
? Clinical history consistent with bronchiectasis and investigator
confirmed diagnosis by computed tomography (CT) scan
? History of 2 pulmonary exacerbations requiring antibiotic
treatment in the last 12 months, or 1 exacerbation if SGRQ
Symptoms score is >40
? Current sputum producers with a history of chronic
expectoration, able to provide spontaneous sputum at Screening

Main exclusion criteria:
? Cystic fibrosis, hypogammaglobulinemia, common variable
immunodeficiency, α1-antitrypsin deficiency treated with
augmentation therapy, current allergic bronchopulmonary
aspergillosis
? Acute infections
? Unstable dose regimen of maintenance bronchiectasis treatment