Gemtuzumab Ozogamicin in Treating Older Patients With Previously Untreated Acute Myeloid Leukemia

Overview

RATIONALE: Monoclonal antibodies such as gemtuzumab ozogamicin can locate cancer cells and either kill them or deliver cancer-killing substances to them without harming normal cells. It is not yet known whether gemtuzumab ozogamicin is more effective than standard supportive care in treating older patients who have acute myeloid leukemia. PURPOSE: This randomized phase II/III trial is studying two different gemtuzumab ozogamicin regimens to see how well they work compared to standard supportive care in treating older patients with previously untreated acute myeloid leukemia.

OBJECTIVES: * Compare the feasibility, toxicity, and antileukemic activity of two different dosing regimens of gemtuzumab ozogamicin (GO) vs standard supportive care in older patients with previously untreated acute myeloid leukemia who are not candidates for intensive chemotherapy. (phase II) * Compare the efficacy and toxicity of the best dosing regimen of GO selected from phase II vs standard supportive care, in terms of overall survival, in these patients. (phase III) OUTLINE: This is a randomized, open-label, multicenter phase II study followed by a phase III study. Patients are stratified according to age (61 to 75 vs 76 to 80 vs 81 and over), CD33-positivity of bone marrow blasts (\< 20% vs 20-80% vs \> 80% vs unknown), initial WBC before hydroxyurea administration (\< 30,000/mm\^3 vs ≥ 30,000/mm\^3), WHO performance status (0-1 vs 2 vs 3-4), and participating center. * Phase II: Patients are randomized to 1 of 3 treatment arms. * Arm I: Patients receive gemtuzumab ozogamicin (GO) IV over 2 hours on days 1 and 8. Patients with stable or responding disease at day 36 receive GO IV over 2 hours every 4 weeks for up to 8 courses in the absence of disease progression or unacceptable toxicity. * Arm II: Patients receive GO IV over 2 hours on days 1, 3, and 5. Patients with stable or responding disease at day 36 receive GO IV over 2 hours every 4 weeks for up to 8 courses in the absence of disease progression or unacceptable toxicity. * Arm III: Patients receive standard supportive care. * Phase III: Patients are randomized to 1 of 2 treatment arms. * Arm I: Patients receive the selected treatment (arm I or arm II) from phase II. * Arm II: Patients receive standard supportive care. Patients who receive GO treatment are followed monthly for 1 year and then every 3 months thereafter. Patients who receive standard supportive care are followed at least every 4 weeks. PROJECTED ACCRUAL: A total of 259 patients (75 for phase II \[25 per treatment arm\] and 184 for phase III \[92 per treatment arm\]) will be accrued for this study within 2.5 years.