Benralizumab Effect on Severe Chronic Rhinosinusitis With Eosinophilic Polyposis

Inclusion Criteria: * Adults aged 18-75 * Severe bilateral nasal polyps with average endoscopic score of at least 5 * Blood eosinophil count of at least 300/ul at screening * At least 1000mg prednisone (or equivalent) over the previous 12 months to control symptoms * At least one prior nasal surgical polypectomy * Informed Consent: Able to give written informed consent prior to participation in the study, which will include the ability to comply with the requirements and restrictions listed in the consent form. Subjects must be able to read, comprehend, and write at a level sufficient to complete study related materials. * Female subjects: Women of childbearing potential (WOCBP) must use an effective form of birth control (confirmed by the Investigator). Effective forms of birth control include: true sexual abstinence, a vasectomized sexual partner, Implanon, female sterilization by tubal occlusion, any effective Intra-uterine device (IUD) intrauterine device/ levonogestrel Intrauterine system (IUS), Depo-Provera(tm) injections, oral contraceptive, and Evra Patch(tm) or Nuvaring(tm). WOCBP must agree to use effective method of birth control, as defined above, from enrolment, throughout the study duration and within 16 weeks after last dose of IP, and have negative serum pregnancy test result on Visit 0. * Women not of childbearing potential are defined as women who are either permanently sterilized (hysterectomy, bilateral oophorectomy, or bilateral salpingectomy), or who ar…