Gemtuzumab Ozogamicin in Treating Older Patients With Previously Untreated Acute Myeloid Leukemia (AML-19)

DISEASE CHARACTERISTICS: Histologically confirmed acute myeloid leukemia (AML) At least 20% bone marrow blasts by bone marrow aspiration or biopsy All subtypes except M3 (acute promyelocytic leukemia) are allowed Previously untreated primary or secondary disease (including AML after myelodysplastic syndromes) Ineligible for intensive chemotherapy, as defined by 1 of the following criteria: 61 to 75 years old AND WHO performance status > 2 AND/OR unwilling to receive intensive chemotherapy Over 75 years old No blast crisis of chronic myeloid leukemia No AML supervention after other myeloproliferative disease WBC < 30,000/mm^3 and meets 1 of the following criteria: WBC < 30,000/mm^3 at diagnosis AND had no prior treatment with hydroxyurea WBC ≥ 30,000/mm^3 at diagnosis AND received mandatory pretreatment with hydroxyurea (up to 14 days duration) until WBC < 30,000/mm^3 No active CNS leukemia PATIENT CHARACTERISTICS: Age See Disease Characteristics 61 and over Performance status See Disease Characteristics Life expectancy Not specified Hematopoietic See Disease Characteristics Hepatic Bilirubin ≤ 1.5 times upper limit of normal (ULN) Renal Creatinine ≤ 1.5 times ULN Cardiovascular No arrhythmia requiring chronic treatment No congestive heart failure No symptomatic ischemic heart disease No other severe cardiovascular disease Pulmonary No severe pulmonary dysfunction ≥ grade 3 Other No alcohol abuse No severe neurological or psychiatric disease No active uncontrolled infection or severe systemic infection No other malignancy No psychological, familial, sociological, or geographical condition that would preclude study compliance and follow-up HIV negative PRIOR CONCURRENT THERAPY: Biologic therapy No concurrent filgrastim (G-CSF) or sargramostim (GM-CSF) No concurrent antiangiogenic drugs Chemotherapy See Disease Characteristics Concurrent low-dose cytostatic agents (i.e., thioguanine or mercaptopurine) allowed for palliative care (standard supportive care arm only) Endocrine therapy Prior corticosteroids (duration ≤ 14 days ) for primary or secondary AML allowed Radiotherapy Not specified Surgery Not specified Other No other concurrent cytotoxic drugs No other concurrent experimental therapy No concurrent tyrosine kinase inhibitors