JAK2 Inhibitors RUXOLITINIB in Patients With Myelofibrosis

Inclusion Criteria: * Age between 18 and 69 years * No comorbidity contraindicating the transplantation : * Severe respiratory failure defined as dyspnea grade III or more * Severe cardiac failure defined as EF \< or = 30% * Severe renal failure defined as creatinine clearance \< 30 ml/min or dialysis * Dementia or non-ability to give informed consent for the protocol * Major alteration of performance status defined as ECOG \> 2 * Severe liver disease defined as a cirrhosis or bilirubin \> 2 x ULN, or AST/ALT \> 5 x ULN * Primary or secondary myelofibrosis diagnosed according to WHO definition (Tefferi, et al 2007) * Palpable splenomegaly or splenomegaly measured by any imagery (maximum size\> 15 cm by ultrasound scan, Magnetic Resonance Imaging or computer tomography) * Disease if intermediate or high risk according to published criteria and summarized as follows: At least one criterion among the following: * Haemoglobin \< 100 gr/L (unrelated to medication toxicity) * Leucocytes \< 4 G/L (unrelated to medication toxicity) or \> 25 G/L * Poor prognosis cytogenetics : complex karyotype, abnormalities of chromosomes 5, 7 or 17 , +8, 12p-, inv(3), 11q23 Two criteria among the following criteria : * General symptoms (weight lost \> 10% in less than 6 months, night swears, specific fever \> 37.5°C) * Peripheral blastosis \> 1% observed at least twice * Thrombocytopenia \< 100 G/L (unrelated to treatment toxicity) Exclusion Criteria: * Myelofibrosis transformed into acute leukaemia with 20% blasts of more in blood or bone marrow * Previous treatment with JAK2 inhibitor * Thrombopenia \< 50 G/L * Comorbidities contraindicating the transplantation * Comorbidity score Sorror \> 3 * Pregnant or lactating women