High Disease Burden and Oral Corticosteroid Use in Patients with Hypereosinophilic Syndrome and Eosinophilic Granulomatosis with Polyangiitis: Country-Level Insights into Real-World Management in Europe

<b>Objectives:</b> To analyze variations in patient characteristics, treatment patterns, clinical manifestations, clinical outcomes (i.e., response, flares and flare-free survival in HES; remission, relapses and relapse-free survival in EGPA; and overall survival), and healthcare resource utilization (HCRU) in patients with hypereosinophilic syndrome (HES) and eosinophilic granulomatosis with polyangiitis (EGPA) across five European countries. <b>Methods:</b> In two parallel, retrospective, non-interventional, longitudinal chart review studies (GSK ID: 214661 [EGPA] and 214657 [HES]), physicians collected data of patients they treated in France, Germany, Italy, Spain, and the UK from January 2015 to December 2019, with follow-up until August 2021. Country-level results are presented for each study; HES and EGPA data were pooled in a post hoc exploratory analysis. <b>Results:</b> Per-country, 22-26 HES- and 38-45 EGPA-treating physicians collected data from 52-62 (total 280) patients with HES and 80-85 (total 407) with EGPA. Patient sex and age at diagnosis differed across countries. Pooled HES/EGPA data revealed high oral corticosteroid (OCS) use in all countries (94.9% of patients; median [IQR] duration 20.7 [9.0, 33.8] months); immunosuppressive treatments and biologics use varied between countries (43.7-61.5% and 25.6-59.8%, respectively). The most frequent clinical manifestations were constitutional (51.6-78.8%) and lung (43.5-55.8%) in HES, and lung (41.3-67.9) and ENT (43.8-61.2) in EGPA. Pooled HCRU data showed country-level variation; 70.7-91.2% of patients had disease-related outpatient visits and 36.1-52.6% had ER visits or hospitalizations. <b>Conclusions:</b> Results demonstrate substantial disease burden, including high HCRU and extensive OCS use among patients with HES and EGPA in five European countries. The findings highlight the need for improved treatment strategies such as optimizing use of biologics to mitigate the reliance on corticosteroids.