This study investigates the effects of an investigational medication in people with chronic rhinosinusitis with nasal polyps (CRSwNP). CRSwNP is a condition where growths in the nasal passage cause congestion and other symptoms. The study aims to assess how well the investigational medication works when added to standard nasal steroid treatments in reducing symptoms in adults aged 18 and older.

Participants will be randomly assigned to one of three study arms, receiving either the investigational medication or a placebo, in addition to their usual nasal steroid treatment. The study involves a series of medical evaluations and treatments over a period of time to monitor the safety and effectiveness of the treatment. A placebo is an inactive substance that looks like the investigational medicine but does not contain any active ingredients.

• Who can participate: Adults aged 18 and older with a history of chronic rhinosinusitis with nasal polyps for at least one year can participate. Key eligibility includes prior sinonasal surgery for nasal polyps or recent treatment with systemic corticosteroids due to worsening symptoms.
• Study details: Participants will be required to attend site visits and complete phone or home visits as part of the study. They will receive either the investigational medication or a placebo along with their regular nasal steroid treatment. A placebo is an inactive substance that looks like the investigational medicine but does not contain any medicine.
• Study timelines and visits: The study will last up to 76 weeks. The study requires 9 site visits and 20 phone/home visits.