Real-World Effectiveness of Benralizumab in Severe Eosinophilic Asthma: A 32-Week Evaluation

Introduction: Benralizumab, an anti-IL-5 receptor monoclonal antibody, induces near-complete eosinophil depletion and has demonstrated significant clinical benefits in severe eosinophilic asthma (SEA). Real-world data remain essential for evaluating its effectiveness outside controlled trial settings. The aim of the study was to assess the clinical, laboratory, and functional outcomes of benralizumab over 32 weeks in a real-life cohort of SEA patients in Türkiye, following its recent national approval.

This retrospective study included biologic-naïve adults with SEA who initiated benralizumab between November 2023 and February 2025 and completed at least six consecutive doses. Peripheral blood eosinophil count (PBEC), clinically significant exacerbations (CSEs), Asthma Control Test (ACT) scores, and spirometric parameters were evaluated at baseline and week 32. Patients were classified as responders (ACT ≥20 and no CSE) or nonresponders.

Twenty-four patients (66.7% female; mean age 50.9 ± 13.1 years) were included. Median PBEC decreased from 800 (230-2,200) to 0 (0-100) cells/µL (p < 0.001). Median annual CSE frequency declined by 67% (p < 0.001). ACT scores improved from 9 (5-24) to 22 (9-25) (p < 0.001). Mean forced expiratory volume in 1 s (FEV₁) increased from 1,719 ± 768 mL to 2,165 ± 831 mL (p < 0.001), while forced vital capacity (FVC) showed significant improvement. Forced expiratory flow between 25% and 75% of the FVC (FEF_25-75) exhibited a nonsignificant trend toward increase. Sixteen patients (66.7%) were classified as responders. Responders had higher baseline PBEC, FEV₁, and FEF_25-75 values. Benralizumab was well tolerated, with only two mild adverse events observed.

Benralizumab provided substantial improvements in eosinophilic inflammation, exacerbation frequency, symptom control, and lung function over 32 weeks in a real-life SEA cohort. These findings support benralizumab as an effective and well-tolerated therapeutic option in routine clinical practice.