Role of biological therapies targeting eosinophils in eosinophilic granulomatosis with polyangiitis: current evidence and future perspectives

BACKGROUND: Eosinophilic Granulomatosis with Polyangiitis (EGPA) is a systemic vasculitis classified among the antineutrophil cytoplasmic antibody (ANCA) associated vasculitides. Eosinophils play a key role in its pathogenesis, with interleukin-5 (IL-5) being the most potent stimulator of their proliferation and activation. In recent years, treatment strategies have evolved with the introduction of biological agents targeting IL-5 or its receptor. This review summarizes the current evidence on the efficacy and safety of anti-IL-5 therapies, focusing on mepolizumab and benralizumab. METHODS: A bibliographic search was conducted in PubMed, Web of Science, and Scopus, including studies of adults diagnosed with EGPA treated with anti-IL-5 therapies. The search was limited to articles published in the last 10 years in English or Spanish. RESULTS: Available data consistently show that these agents reduce corticosteroid requirements, lower eosinophil counts, and improve disease control. Regarding mepolizumab, real-world studies indicated that both 100 mg and 300 mg doses are equally effective, while the influence of ANCA status on treatment response remains controversial. Otorhinolaryngologic relapses have also been reported. Benralizumab 30 mg every 4 weeks showed remission rates comparable to mepolizumab, although further research is needed to determine the optimal dosing regimen. CONCLUSIONS: Overall, anti-L-5 therapies represent an effective and safe option for EGPA. Future research should focus on larger, multicenter trials to clarify the pathophysiology of the disease and facilitate the identification of predictive biomarkers, leading for personalized therapeutic strategies.