- Patients with Chronic Idiopathic Myelofibrosis (CIMF) requiring therapy, including those 1) previously treated by CIMF-directed therapy and relapsed, intolerant, or refractory to therapy; or 2) if newly diagnosed then with intermediate or high risk according to Lille scoring system (adverse prognostic factors are: Hb < 10 g/dl, WBC < 4 or > 30 x 10^9/L; risk group: 0 = low, 1 = intermediate, 2 = high), or with symptomatic spleen that is >/= 10cm below costal margin. However, patients with asymptomatic intermediate risk disease are not eligible.