This study is testing a medicine called **AZD0292** for people aged 12 and up who have a lung condition called **bronchiectasis** and a type of bacteria called **Pseudomonas Aeruginosa (PsA)** in their lungs. **Bronchiectasis** is when the airways in the lungs are wider than normal and can get infected easily. The study will check if AZD0292 is safe and works well to prevent lung problems. It will also compare AZD0292 to a placebo, which looks like the medicine but doesn't have any active ingredients. Participants must have a history of lung problems, be stable without symptoms for 4 weeks before starting, and have a positive test for PsA. People with other lung diseases, recent cancer, or certain infections can't join. The study includes two groups: one with chronic PsA and another exploratory group with cystic fibrosis (CF). **Key Points:** - Study includes multiple visits over a period of time. - Participants must be over 12 years old and meet specific health criteria. - Compensation may be provided for participation and travel. This study aims to find better treatments to improve life quality and reduce lung problems for those affected by bronchiectasis and PsA.