Imatinib therapy for hypereosinophilic syndrome and eosinophilia-associated myeloproliferative disorders.
A pathogenetic mutation, FIP1L1-PDGFRA, that results from an interstitial chromosome 4q12 deletion, leads to a constitutive activation of the platelet-derived growth factor receptor-alpha (PDGFRA) tyrosine kinase as well as a disease phenotype that mimics both the hypereosinophilic syndrome (HES) and systemic mast cell disease associated with eosinophilia (SMCD-eos). Complete remissions, in response to treatment with low-dose imatinib mesylate (100 mg/day or less) have now been documented in all cases of FIP1L1-PDGFRA(+) eosinophilic disorder as well as other eosinophilic disorders that carry activation mutations of the PDGFRB gene that is located on chromosome 5q33. Furthermore, response to therapy has been rapid (within days) and durable. Interestingly, imatinib mesylate treatment, at a higher dose level (400 mg/day), might induce either partial or short-lived complete remissions in HES that is not associated with the aforementioned PDGFR mutations. These observations make it necessary to re-examine current disease classification and treatment algorithms in eosinophilic disorders.
Pardanani
Animesh
A
Division of Hematology and Internal Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
Tefferi
Ayalew
A
D001549:Benzamides; D004802:Eosinophilia / Q000145:classification / Q000188:drug therapy* / Q000209:etiology; D006801:Humans; D017681:Hypereosinophilic Syndrome / Q000145:classification / Q000188:drug therapy* / Q000209:etiology; D000068877:Imatinib Mesylate; D009154:Mutation; D009196:Myeloproliferative Disorders / Q000145:classification / Q000188:drug therapy / Q000209:etiology; D015514:Oncogene Proteins, Fusion; D010879:Piperazines / Q000627:therapeutic use*; D011743:Pyrimidines / Q000627:therapeutic use*; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000235:genetics; D016896:Treatment Outcome; D039221:mRNA Cleavage and Polyadenylation Factors / Q000235:genetics
D001549:Benzamides; D015514:Oncogene Proteins, Fusion; D010879:Piperazines; D011743:Pyrimidines; D039221:mRNA Cleavage and Polyadenylation Factors; D000068877:Imatinib Mesylate; C479819:FIP1L1-PDGFRA fusion protein, human; D020796:Receptor, Platelet-Derived Growth Factor alpha