- Patients must have histologically MDS (including French-American-British [FAB] types refractory anemia [RA], refractory anemia with ringed sideroblasts [RARS], refractory anemia with excess blasts [RAEB], refractory anemia with excess blasts in transformation [RAEBT], or chronic myelomonocytic leukemia [CMMoL]); for the purpose of the study, all patients will be classified by World Health Organization (WHO) criteria