Sustained low disease activity during long-term mepolizumab treatment in FIP1L1::PDGFRA-negative hypereosinophilic syndrome: a multicenter real-world study.
Mepolizumab provided sustained long-term disease control with low glucocorticoid exposure in FIP1L1::PDGFRA-negative HES and EoLDAS offers a pragmatic measure of longitudinal disease control that warrants prospective validation and may inform future treat-to-target strategies.