Inclusion Criteria

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

PATIENT CHARACTERISTICS: Age: Over 16 Performance status: Karnofsky 60%-100% Life
expectancy: At least 6 weeks Hematopoietic: Not specified Hepatic: Bilirubin less than 2.5
mg/dL AST less than 3 times normal Alkaline phosphatase less than 3 times normal Renal:
Creatinine less than 2.0 mg/dL Cardiovascular: No NYHA class III/IV status Pulmonary: No
clinically significant pulmonary disease Other: No serious infection uncontrolled by
antibiotics No pregnant or nursing women Negative pregnancy test required of fertile women

PRIOR CONCURRENT THERAPY: Recovered from prior therapy Biologic therapy: No detectable
antibodies to M195 from prior monoclonal antibody M195 or HuM195 Chemotherapy: At least 2
days since hydroxyurea At least 3 weeks since other chemotherapy Endocrine therapy: Not
specified Radiotherapy: At least 3 weeks since radiotherapy Surgery: Not specified