• Subjects aged between 18 and 75 years, inclusive, of either sex.

• Body Mass Index (BMI) calculated as weight in kilograms divided by the square of height in meters (kg/m²), with a BMI of at least 18.5.

• Subjects must meet the diagnostic criteria for chronic rhinosinusitis as defined in the Chinese Chronic Rhinosinusitis Diagnosis and Treatment Guidelines (2024), with a disease duration exceeding 12 weeks.

• During the screening period, nasal endoscopy must reveal bilateral pathological changes in the nasal mucosa, such as edema and purulent discharge, or a CT scan must show bilateral sinus involvement.

• During the screening period, a CT scan must demonstrate bilateral sinus involvement, with at least one sinus on each side scoring ≥ 1 point on the Lund-MacKay (LMK) scale.

• During the screening period, the Nasal Congestion Score (NCS) must be ≥ 2 points.

• During the screening period, the Composite Symptom Score (CSS) for nasal congestion, rhinorrhea, and facial pain/pressure must be ≥ 5 points.

• During the screening period, the Sino-Nasal Outcome Test-22 (SNOT-22) total score must be ≥ 20 points.

• Subjects must have been on a stable daily dose of mometasone furoate nasal spray (MFNS) for at least 4 weeks prior to enrollment.

⁃ Subjects with asthma or chronic obstructive pulmonary disease (COPD) must have had stable conditions without exacerbations in the 3 months prior to screening (e.g., no emergency room visits, hospitalizations, or systemic corticosteroid use). The use of inhaled corticosteroids must have been at a stable dose, with continuous use for at least 3 months prior to screening, and planned continuation throughout the study period.

⁃ Subjects must fully understand the purpose, nature, methodology, and potential adverse events of the trial, voluntarily participate in the trial, and provide written informed consent, or have an authorized legal representative provide informed consent.