Imatinib mesylate use in refractory eosinophilic granulomatosis with polyangiitis: a literature review and a case report.

Recent advances in pharmacology have greatly expanded the drug repertoire for treatment of anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis. Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare multisystemic disorder, a type of the ANCA-associated vasculitis. Important features of this disease are eosinophilia and anti-myeloperoxidase ANCA presence in around 30-70% of patients. Primary therapy of EGPA includes steroids and cytotoxic drugs, e.g., cyclophosphamide, azathioprine, or methotrexate. Nevertheless, some patients are refractory to this therapy. Alternative approaches include rituximab, mepolizumab, and intravenous immunoglobulin. Accumulating evidence highlight a new promising drug in EGPA therapy-imatinib mesylate (IM), tyrosine kinase inhibitor. This drug is a key pharmacological agent in treating various types of hematological malignancies and FIP1L1/PDGF-RA-positive hypereosinophilia. In this article, we present a case demonstrating successful treatment of EGPA with IM; we also discuss possible mechanisms of IM efficacy in EGPA treatment and future perspectives of this therapeutic approach.