Study of Benralizumab (KHK4563) in Patients With Eosinophilic Chronic Rhinosinusitis

Inclusion Criteria: * Patients 20 years to 75 years of age * Eosinophilic chronic rhinosinusitis with a total score of ≥ 11 according to the diagnosis of eosinophilic chronic rhinosinusitis at enrollment * A minimum bilateral nasal polyp score of 3 out of the maximum score of 8 (with a score of at least 1 out of the maximum score of 4 for each nostril) at screening and at enrollment * Weight of ≥ 40 kg at screening Exclusion Criteria: * A Sino-Nasal Outcome Test-22 (SNOT-22) score of \< 7 at enrollment * Any nasal surgery (including polypectomy) within 1 year prior to the date of consent * Hospitalization for ≥ 24 hours for treatment of asthma exacerbation, within 12 weeks prior to the date of consent * Exposure to any commercially available (e.g., omalizumab) or investigational biologic agent within 16 weeks or 5 half-lives prior to enrollment, whichever is longer * Use of systemic corticosteroids (including oral corticosteroids) or corticosteroid nasal solution (except spraying) within 4 weeks prior to enrollment or planned use of such medications during the double-blind period * Prior treatment with benralizumab