1. Patients with relapsed or refractory acute myelogenous leukemia (AML), Refractory anemia with excess blasts in transformation (RAEB-t), Refractory Anemia with Excess Blasts (RAEB), or chronic myelomonocytic leukaemia (CMML) who failed at least one previous chemotherapy course. Patients with accelerated CML Ph+ or myeloid blastic crisis are eligible. Patients in accelerated phase of non-Philadelphia chromosome + myeloproliferative disorders are also eligible: