,2 However, EGPA relapsed even if serum eosinophil count was normal, and anti–IL-5 therapy may not be fully effective on EGPA manifestations.3, 4, 5 In this case series, we present 2 cases of new-onset and relapsed EGPA without eosinophilia and eosinophilic infiltration under benralizumab treatment, indicating that benralizumab may have potential masking effects by depleting eosinophil counts in patients with EGPA. This evidence concerns the gene IL5 and eosinophilic granulomatosis with polyangiitis.