Sustained Efficacy and Low Rate of Adverse Events of Dupilumab in Type‐2 <scp>CRSwNP</scp> Over 48 Months

ABSTRACT Objective Dupilumab is a fully humanized monoclonal antibody that interferes with the inflammatory cascade in type‐2 Chronic Rhinosinusitis with Nasal Polyps (CRSwNP). Studies evaluating its safety and efficacy in the long term are still few. Our study analyzed outcomes and adverse events after 1, 3, 6, 12, 24, 36, and 48 months of dupilumab administration in patients affected by CRSwNP. Materials and Methods A monocentric, retrospective study assessing blood eosinophil (BEC) and total IgE count, Sinonasal Outcome Test‐22 (SNOT‐22), Nasal Polyps Score (NPS), sniffin’ sticks identification test (SSIT‐16), and Lund‐Mackay score (LMS) in patients receiving subcutaneous Dupilumab 300 mg/2 weeks for at least 1 year and up to 4 years. Results Seventy patients were enrolled, of whom 70, 38, 25, and 12 completed a 12, 24‐, 36‐, and 48‐month follow‐up period, respectively. Patients showed a very rapid and long‐lasting statistically significant improvement in their SNOT‐22, NPS, and SSIT after 1 month, and this trend was kept in the following 48 months. The total IgE count has been constantly reducing over the study period. BEC increased in the first 6 months and then gradually decreased over time, reaching an even smaller value than baseline at 36 and 48 months. Four patients (5.9%) complained of severe adverse events within 6 months, with two interrupting treatment due to hypereosinophilia. Conclusion Dupilumab was safe and effective in extinguishing the symptomatologic burden of CRSwNP as early as 1 month and up to 48 months, with side events limited to the first 6 months of administration. Level of Evidence 4.