Relapses and treatment status in elderly and non-elderly patients with eosinophilic granulomatosis with polyangiitis: A retrospective observational study using Japanese nationwide claims data

Objectives: This study aimed to better understand the relapse rate for eosinophilic granulomatosis with polyangiitis, a rare, debilitating form of vasculitis, in Japanese elderly and non-elderly patients, along with their treatment statuses. Methods: This retrospective, observational study used claims data from April 2019 to March 2022 representing approximately 8 million insured individuals in Japan. Patients aged >= 18 years were identified and stratified into elderly (>= 65 years) and non-elderly (<65 years) groups. The proportion of patients experiencing relapses and their treatment statuses were assessed during a 1-year follow-up period. Results: Among the 651 eligible patients with eosinophilic granulomatosis with polyangiitis enrolled, 38.86% experienced a relapse during the follow-up period. This proportion was similar between the elderly (36.34%) and non-elderly (42.59%) groups. Moreover, fewer elderly than non-elderly patients were prescribed biologics (22.16% vs. 37.26%) and immunosuppressants (20.36% vs. 29.28%), despite having higher percentages of corticosteroid-related comorbidities. Conclusions: The disease burden of eosinophilic granulomatosis with polyangiitis in Japan remains substantial, with over one-third of patients experiencing a relapse, regardless of age. Age-specific management strategies optimizing biologics and immunosuppressant use while minimizing adverse events are needed to improve the outcomes of these patients in Japan.