Tyrosine Kinase Inhibition to Treat Myeloid Hypereosinophilic Syndrome

The dosing regimen to be used initially (400 mg po qd in adults and 260 mg/m2/day in children with food and a glass of water) is identical to that recommended by the FDA for the treatment of the chronic phase of chronic myelogenous leukemia (CML) (Prod Info Gleevec ). In patients with ANC \<1500/mm3, platelet counts \< 75,000mm3 or abnormal liver function tests (ALT or AST \> 2.5 or bilirubin \> 3 times the upper limit of normal), the starting dose will be reduced to 300 mg po qD.

The dosing regimen to be used initially (15 mg po bid) is identical to that recommended by the FDA for the treatment of myelofibrosis with platelet counts of 100-200,000/mm3 (Prod Info ruxolitinib). In patients with platelet counts \<100,000/mm3, moderate renal impairment (CrCl \<60 mL/min) or abnormal liver function tests (ALT or AST \> 2.5 or bilirubin \> 3 times the upper limit of normal), the starting dose will be reduced to 10 mg bid. The recommended guidelines for dose adjustment during therapy and discontinuation of therapy in myelofibrosis will be followed.