Beyond eosinophil depletion: long-term clinical trajectory and durability of response to benralizumab in patients with severe eosinophilic asthma and CRSwNP: an 18-month real-world study (the BANDOR study)

Background The management of patients with severe eosinophilic asthma and chronic rhinosinusitis with nasal polyps requires therapies capable of inducing stable remission. While benralizumab is an established treatment for severe asthma, randomized controlled trials in nasal polyposis have failed to reach primary clinical endpoints or showed inconsistent results. Consequently, there is a lack of evidence regarding its performance in clinical practice. The primary objective of this study was to evaluate the kinetics of response across different symptom domains and to identify predictors of clinical improvement in a Real-World setting in patients affected by severe eosinophilic asthma and chronic rhinosinusitis with nasal polyps. Methods This retrospective observational study analyzed a cohort of patients with a United Airways Disease phenotype treated with benralizumab for a continuous period of 18 months. We mapped the longitudinal trajectory of specific SNOT 22 subdomains and lung function. Patients were stratified into early and late responders based on the timing of clinical improvement to identify baseline predictors of rapid versus gradual response. Results Analysis revealed that SNOT 22 subdomains exhibit distinct recovery patterns. Nasal and physical symptoms showed a significant improvement within the first months of therapy despite the limited success reported in previous clinical trials. In contrast, functional and emotional domains required a longer period of treatment to reach a stable plateau. Early responders were characterized by a significantly higher baseline eosinophil count (median 885 vs 530 cells per microliter) and greater bronchial obstruction at baseline compared to late responders. Functional stability in FEV1 and a reduction in oral corticosteroid use were maintained throughout the observation. Conclusions The BANDOR study demonstrates that benralizumab can induce durable clinical remission in a specific subset of patients who maintain treatment adherence. The speed of response is domain specific, with physical symptoms improving before emotional and functional ones. A high initial eosinophilic burden is the primary determinant of a rapid response. These findings suggest that while randomized trials showed limited efficacy, Real-World data identifies a high disease burden phenotype that derives significant long term benefit from receptor targeted eosinophil depletion.