1. Diagnosis of myelofibrosis requiring therapy, including those previously treated and relapsed or refractory, or if newly diagnosed, with intermediate or high risk according to Lille scoring system (risk factors are: Hb < 10 g/dl, WBC < 4 or > 30 x 109/L; risk group: 0 factor(s) = low, 1 factor(s) = intermediate, 2 factor(s) = high) or with symptomatic splenomegaly