The purpose of this study is to evaluate the effectiveness and safety of an investigational medication compared to a placebo in patients with cystic fibrosis (CF) who have a chronic lung infection caused by methicillin-resistant Staphylococcus aureus (MRSA). Cystic fibrosis is a genetic condition that affects the lungs and makes it difficult to breathe due to thick, sticky mucus. MRSA is a type of bacteria that is resistant to many antibiotics, making infections hard to treat.

Participants in the study will be randomly assigned to one of two study arms. One group will receive the investigational medication, while the other group will receive a placebo, which is an inactive substance that looks like the investigational medication but does not contain any medicine. The study will compare the effects of the investigational medication and the placebo on lung function and overall health.

• Who can participate: This study is open to individuals aged 18 and older diagnosed with cystic fibrosis who have a chronic MRSA lung infection. Participants must meet specific health criteria related to their condition.
• Study details: Participants will be randomly assigned to receive either the investigational medication or a placebo. A placebo is an inactive substance that looks like the investigational medicine but does not contain any medicine.