Trends in prevalence, treatment use, and disease burden in patients with eosinophilic granulomatosis with polyangiitis in Japan: Real-world database analysis.

Objectives: We report the prevalence of eosinophilic granulomatosis with polyangiitis (EGPA) and describe oral corticosteroid (OCS) use and disease burden before and after the mepolizumab approval in 2018 for EGPA in Japan.
Methods: Two retrospective studies (GSK IDs: 218083 and 218084) used two databases: (1) the JMDC insurer database (Japanese health insurer claims) was used to report annual EGPA prevalence and OCS use in mepolizumab-treated patients and (2) Medical Data Vision database was used to report annual treatment use, OCS dose, relapses, and healthcare resource utilization in patients with EGPA.
Results: EGPA prevalence (95% confidence interval) increased from 4.2 (0.1, 23.4) in 2005 to 58.6 (53.2, 64.5) per 1,000,000 in 2020. Median OCS dose (mg/day) decreased from a range of 4.8-7.7 during 2010-2017 to 4.5-4.8 during 2018-2020 (lowest dose in 2020). The proportion of patients with prednisolone-equivalent daily OCS dose >10 mg decreased from 2017 (11.9%) to 2020 (10.3%), while the median dose halved. The proportion of patients with EGPA relapses (64.3% to 41.6%) and hospitalization (27.8% to 23.6%) decreased from 2010 to 2020.
Conclusions: EGPA prevalence increased between 2005 and 2020. With the introduction of mepolizumab for EGPA in 2018, real-world OCS use, relapses, and healthcare resource utilization decreased.
(© Japan College of Rheumatology 2023. Published by Oxford University Press.)