Real‐World Adverse Events After Type 2 Biologic use in Chronic Rhinosinusitis with Nasal Polyps

Objective To investigate the frequency and nature of adverse events related to type 2 biologic use in patients with chronic rhinosinusitis with nasal polyps (CRSwNP), including dupilumab and mepolizumab. Methods This is a single‐institution retrospective study of real‐world patient data. Patients were included if they have a diagnosis of CRSwNP, have undergone at least one endoscopic sinus surgery, and have taken at least two doses of dupilumab or mepolizumab between January 1, 2016, and July 1, 2023. Data collected include clinicodemographic information and past medical/surgical history. The primary outcomes are the incidence and types of adverse events. Adjusted odds ratio was calculated to compare the biologics using logistic regression. Risk factors for developing adverse events were investigated. Results Eighty‐seven patients on dupilumab and 51 patients on mepolizumab were included. Thirty‐nine (45%) and 10 (20%) patients respectively encountered adverse events, which differed from phase 3 trial data. The adjusted odds ratio for adverse event rates between these two treatment groups was 3.8 (95% CI, 1.5–10.5). The most common adverse events for dupilumab were arthralgia (16%), rash (14%), and conjunctivitis or xerophthalmia (10%). The main adverse events for mepolizumab were headache (6%) and fatigue (6%). Seven dupilumab and three mepolizumab patients discontinued therapy due to adverse events. The average duration of treatment was 22.5 (range: 1–77) months for mepolizumab and 15.9 (range: 1–35) months for dupilumab. Conclusion Dupilumab and mepolizumab have distinct adverse event profiles. This study contributes to informing clinicians' decisions regarding the use of type 2 biologics in CRSwNP patients. Level of Evidence 3 Laryngoscope, 134:3054–3059, 2024 In a real‐world study of chronic rhinosinusitis with nasal polyps (CRSwNP) patients, we investigated and compared adverse events associated with type 2 biologics. Dupilumab had a significantly higher adverse event rate (45%) compared with mepolizumab (20%) (p