Salvage therapy of imatinib-resistant hypereosinophilic syndrome with PDGFRB rearrangement

Hypereosinophilic syndrome (HES) has generally been defined as a peripheral blood eosinophil count greater than 1500/mm3 and may be associated with tissue damage. Imatinib is customarily used as the first-line therapy for HES with gene abnormalities, such as PDGFRA or PDGFRB. We presented a case where the patient was diagnosed with HES, with PDGFRB rearrangement. The patient began an imatinib regimen after diagnosis and then developed resistance to imatinib. The combination of dasatinib, methylprednisolone and hydroxyurea was administered to the patient as the salvage therapy.