A 45-year-old man with severe persistent asthma has blood eosinophil count of 520 cells/µL despite high-dose ICS/LABA therapy. He has 4 exacerbations per year requiring oral corticosteroids. Which biologic agent targets the IL-5 receptor alpha subunit on eosinophils to reduce exacerbations?
- A Benralizumab ✓
- B Mepolizumab
- C Dupilumab
- D Omalizumab
Correct answer: A. Benralizumab
Explanation
Benralizumab is a monoclonal antibody directed against the IL-5 receptor alpha chain (IL-5Rα) on eosinophils and basophils, inducing antibody-dependent cell-mediated cytotoxicity and causing rapid near-complete eosinophil depletion. Mepolizumab and reslizumab target the IL-5 ligand itself. Dupilumab targets the IL-4Rα subunit shared by IL-4 and IL-13 receptors, approved for eosinophilic and non-eosinophilic severe asthma. Omalizumab is anti-IgE used in allergic asthma (elevated total IgE, sensitisation to perennial allergen).
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.