A Pilot Phase 2 Study of Ruxolitinib for the Treatment of Steroid-Refractory Hypereosinophilic Syndrome

Although the approvals of mepolizumab and imatinib for treatment of hypereosinophilic syndrome (HES) have improved outcomes, responses vary and options for steroid-refractory, PDGFR-negative disease remain limited. Case reports suggest that JAK inhibitors may be effective in JAK2-associated myeloid HES and in steroid-resistant lymphocytic variant HES (LHES).