August 2025
Eosinophils and EGPA: How Far Can Mepolizumab Go?
Article: Efficacy and Safety of Mepolizumab 300 mg in Eosinophilic Granulomatosis With Polyangiitis: A Meta-Analysis of Eight Retrospective Studies
Spataro F, Cacciapaglia F, Carlucci P, et al.
European Journal of Allergy and Clinical Immunology. 2025
Reviewed by Palma Carlucci, University of Bari Aldo Moro, Bari, Italy
This meta-analysis addresses a question that remains crucial for clinicians managing eosinophilic granulomatosis with polyangiitis (EGPA): to what extent can mepolizumab truly reduce corticosteroid dependence in this complex and heterogeneous disease? Read more
By pooling data from eight retrospective studies and covering 165 patients treated with mepolizumab 300 mg per month, this study confirms a consistent signal: an average daily reduction of about 6 mg of prednisone, which remains significant even when outliers are removed. Yet the marked heterogeneity highlights an important reality: not all patients benefit equally. Those with significant cardiac or peripheral nervous system involvement, for instance, show a more limited response, suggesting that IL-5 blockade alone may not suffice when vasculitic damage dominates the clinical picture.
The safety data are completely reassuring: mostly mild to moderate adverse events, with no therapy discontinuations due to toxicity, supporting mepolizumab as a tolerable option for patients burdened by long-term steroid exposure. However, this meta-analysis inevitably shares the limitations of its sources: small, retrospective studies with variable designs and tapering protocols, which calls for caution when translating these results into routine practice.
What clearly emerges is the need for better stratification tools. EGPA is not a uniform disease, and precise biomarkers that can predict who will benefit most from IL-5 inhibition are still lacking. As the field evolves, head-to-head comparisons with other biologics could help refine treatment strategies and define the best approach for each disease phenotype.
In summary, eosinophils remain a compelling therapeutic target, but they are not the sole driver of EGPA’s pathogenesis. Mepolizumab represents a valuable option for reducing steroid burden in carefully selected patients, but personalised approaches remain essential. This work is a reminder that even in 2025, EGPA continues to challenge both our understanding of eosinophils and our ambition to manage them wisely.
Palma Carlucci is a specialist in Allergy and Clinical Immunology, with particular expertise in respiratory and drug allergies, severe asthma, and eosinophilic disorders such as Hypereosinophilic Syndrome and Eosinophilic Granulomatosis with Polyangiitis. She graduated from the University of Pavia and completed her studies at the University of Bari.
Her clinical and research work focuses on advanced allergen immunotherapy, drug desensitization protocols and the integration of biologics into precision medicine for complex allergic conditions. She has authored several publications and meta-analyses in international journals and actively contributes to national scientific initiatives, including the SIAAIC consensus statement on managing Hypereosinophilic Syndrome.