DISEASE CHARACTERISTICS: Pathologically confirmed myeloid malignancies as follows: Acute myelogenous leukemia that is relapsed or refractory after at least 2 courses of standard induction chemotherapy Accelerated or myeloblastic chronic myelogenous leukemia Refractory anemia with excess blasts (RAEB) RAEB in transformation Chronic myelomonocytic leukemia More than 25% of bone marrow blasts positive for the CD33 antigen Clear signs of active leukemia following recovery from prior therapy required No rapidly accelerating blast count No clinically unstable disease No active CNS leukemia