B35-07 Sequential Application of Omalizumab, Mepolizumab, and Dupilumab in a Refractory Anca-Negative Eosinophilic Granulomatosis With Polyangiitis: Experience and Challenges

Background Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare systemic vasculitis characterized by asthma, eosinophilia, and multi-organ involvement. Treatment remains challenging in ANCA-negative and refractory cases. Case Summary A 42-year-old woman presented with a 6-year history of refractory asthma, eosinophilic sinusitis, and recurrent abdominal pain. She was diagnosed with ANCA-negative EGPA (Five-Factor Score = 1). Initial glucocorticoid and cyclophosphamide therapy achieved partial control but resulted in steroid dependence. Treatment and Outcome Sequential biologic therapy was administered: omalizumab (anti-IgE, 29 months) and mepolizumab (anti–IL-5, 12 months) provided partial benefit but failed to maintain remission or enable steroid withdrawal. Dupilumab (anti–IL-4/13) led to remarkable improvement in sinusitis and allowed complete steroid cessation for the first time. However, new-onset polyarthritis occurred during treatment, prompting discontinuation. Upon cessation, core EGPA symptoms (abdominal pain, rash) recurred, requiring temporary steroid reintroduction. Discussion This case highlights the therapeutic heterogeneity of biologics in refractory ANCA-negative EGPA. Dupilumab demonstrated superior efficacy in eosinophilic sinusitis, suggesting IL-4/IL-13 blockade as a potential precision approach for selected phenotypes. The emergence of arthritis raises questions about immune-shift phenomena and drug safety. This experience emphasizes the need for phenotype-driven biologic selection and individualized management in EGPA. This abstract is funded by: None