Monoclonal Antibody Switching in Biologic Treatment of Chronic Rhinosinusitis with Nasal Polyps.

to evaluate our real-world data on the efficacy and safety of switching between two monoclonal antibodies in biologic treatment of uncontrolled chronic rhinosinusitis with nasal polyps (CRSwNP). All patients receiving biologic treatment for uncontrolled CRSwNP between April 2020 and March 2024 at a tertiary referral center who needed transitioning between biologic agents were retrospectively analyzed. The following parameters were investigated: patient's clinical characteristics, wash-out periods, treatment outcome, and switching-related side effects. Out of 91 CRSwNP patients who received biologic treatment, 4 patients (4.4%) necessitated switching to an alternative biologic agent. Three patients were switched to a different antibody because of insufficient symptom control with the initially prescribed biologic, while the other patient required switching to an alternative agent due to a side effect. Switching resulted in all four patients achieving a significant improvement in all outcome parameters. There were no switching-related side effects, and the switching procedure was performed in three cases without a wash-out period. CRSwNP patients under biologic therapy with an insufficient response or medication-related side effect may benefit from switching to an alternative biologic agent. Larger, prospective multicenter studies are warranted to further validate the effectiveness and safety of switching agents in the biologic treatment of CRSwNP.