Benralizumab as a steroid-sparing rescue therapy in ANCA-negative eosinophilic granulomatosis with polyangiitis: real-world experience from three cases and review of the literature.

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare small-vessel vasculitis driven by type 2 inflammation, frequently associated with severe asthma, eosinophilia, and multiorgan involvement. Despite conventional immunosuppressive therapy, many patients remain steroid-dependent or refractory. Benralizumab, an anti-IL-5 receptor monoclonal antibody inducing rapid eosinophil depletion, has emerged as a promising therapeutic option. We present a real-world case series of three patients with severe, antineutrophil cytoplasmic antibodies (ANCA)-negative EGPA treated with benralizumab. Clinical manifestations, laboratory parameters, organ involvement, eosinophil kinetics, glucocorticoid use, and treatment outcomes were retrospectively analyzed. All patients exhibited marked peripheral eosinophilia, severe asthma or respiratory involvement, and multisystem disease. Prior glucocorticoid and immunosuppressive therapy failed to achieve sustained disease control or steroid sparing. Benralizumab administration resulted in rapid, profound, and sustained eosinophil depletion in all cases. Significant clinical improvement was observed, including improved asthma control, resolution of sinonasal and cutaneous manifestations, and better quality of life. In one patient with predominant skin involvement, clinical response was evident within hours after the first dose. In another patient, complete resolution of cardiac lesions documented on cardiac MRI was observed after six months of benralizumab therapy. Glucocorticoids were discontinued in two patients and reduced to a low maintenance dose in one. No serious adverse events occurred during follow-up. This exploratory real-world case series suggests that benralizumab may represent a promising steroid-sparing therapeutic option in selected patients with severe, steroid-dependent, ANCA-negative eosinophilic EGPA. The observed rapid eosinophil depletion and early clinical improvement should be interpreted as preliminary findings requiring confirmation in larger prospective studies.