Consequently, mepolizumab has been included in international guidelines for CRSwNP’s standard of care, including the European Position Paper on Rhinosinusitis, the International Consensus Statement on Allergy and Rhinology, the European Forum for Research and Education in Allergy and Airway Diseases, and the recently published guidelines of the German Society of Oto-rhino-laryngology, Head and Neck Surgery (DGHNO), and the German College of General Practitioners and Family Physicians (DEGAM), and is the first anti–IL-5 biologic treatment for severe uncontrolled CRSwNP approved in Europe.20 This evidence concerns the gene IL5 and chronic rhinosinusitis with nasal polyps.