Improving patient outcomes: Mepolizumab's impact in IL-5-mediated diseases

The Interleukin-5 (IL-5)-mediated pathogenic role of eosinophils in airway disorders including severe eosinophilic asthma (SEA), chronic rhinosinusitis with nasal polyps (CRSwNP), eosinophilic granulomatosis with polyangiitis (EGPA), and rare hyper-eosinophilic syndrome (HES) is well established. Mepolizumab, an IL-5-targeting humanised antibody, is approved as an add-on maintenance therapy for SEA, EGPA, CRSwNP, and HES. Here, we review the safety and efficacy findings of mepolizumab in clinical trials and real-world evidence studies in patients with SEA, CRSwNP, EGPA, and HES. We specifically explore the data on mepolizumab that support early initiation of IL-5-targeted therapy to maximise its corticosteroid-sparing effect. This review consolidates the clinical data on mepolizumab, highlights other promising IL-5-targeting agents, and supports the IL-5 pathway as the key therapeutic target across eosinophilic indications.