OUTLINE: Patients continue retinoid therapy until 30 days after documentation of clinical complete remission. Patients begin treatment within 10 days of documentation of clinical complete remission, or after RT-PCR-confirmed molecular relapse, or 3-6 weeks after chemotherapy. Patients receive HuM195 IV over 60 minutes twice a week for 6 doses. Patients with unacceptable toxicity, in first complete remission, or ineligible for bone marrow transplant (BMT) proceed to the next regimen. Patients receive idarubicin IV over 15 minutes on days 1-3 and cytarabine IV continuously over days 1-5. Patients then receive 2 more courses, given at 4-6 week intervals, consisting of idarubicin IV over 15 minutes on days 1-2 and cytarabine IV continuously on days 1-4. Patients begin maintenance therapy after toxicity resolves or 1 week after the last dose of HuM195. This consists of HuM195 IV over 60 minutes for 2 doses (72-96 hours apart). Treatment repeats once a month for 6 courses. Patients who have an initial molecular response but are positive on the RT-PCR assay, or who achieve complete remission following clinical relapse of disease during treatment are eligible for retreatment. Patients are followed every 3 months.