The present study will be a multicenter, prospective phase II-study comparing efficacy of allogeneic SCT for patients with myelofibrosis who have a suitable stem cell donor after a 3 months Ruxolitinib induction therapy with patients who lack a suitable stem cell donor and will continue to receive Ruxolitinib.

This study is a multicenter, prospective phase II-study compares efficacy of allogeneic SCT for patients with myelofibrosis who have a suitable stem cell donor after a 3 months Ruxolitinib induction therapy with patients who lack a suitable stem cell donor and will continue to receive Ruxolitinib.

In this study will further assess and compare the safety and efficacy of study treatments/ induction therapy in both study arms on spleen reduction, improvement of constitutional symptoms, QOL, toxicity, fibrosis regression, development of GvHD as well as chimerism, engraftment, relapse incidence, disease related mortality, outcome and overall survival.

Inclusion Criteria:

1. Symptomatic primary myelofibrosis or myelofibrosis post polycythaemia vera or essential thrombocythemia stage intermediate 2- or high-risk according to IPSS or DIPSS [46] or intermediate 1-risk with high risk cytogenetics, other than normal karyotype, sole del 20q, del 13q, or sole+9, or transfusion-dependency
2. Patients age: 18 - 70 years at time of inclusion (female and male)
3. Patients understand and voluntarily sign an informed consent form
4. Platelet count ≥ 50 x 109/L
5. No prior Ruxolitinib treatment
6. ECOG ≤ 2

Exclusion Criteria:

1. Severe renal, hepatic, pulmonary or cardiac disease, such as:

   • Total bilirubin, SGPT or SGOT > 3 times upper the normal level
   • Left ventricular ejection fraction < 30 %
   • Creatinine clearance < 30 ml/min
   • DLCO < 35 % and/or receiving supplementary continuous oxygen

2. Positive serology for HIV

3. Pregnant or lactating women (positive serum pregnancy test)

4. Age < 18 and ≥ 71 years.

5. Uncontrolled invasive fungal infection at time of screening (baseline)

6. Serious psychiatric or psychological disorders

7. Participation in another study with ongoing use of unlicensed investigational product from 28 days before study enrollment

8. Transformation to AML