PURPOSE In patients with acute myeloid leukemia (AML), induction chemotherapy is based on standard doses of anthracyclines and cytarabine. High doses of cytarabine have been reported as being too toxic for patients older than age 50 years, but few studies have evaluated intensified doses of anthracyclines. PATIENTS AND METHODS In this randomized Acute Leukemia French Association 9801 (ALFA-9801) study, high doses of daunorubicin (DNR; 80 mg/m(2)/d x 3 days) or idarubicin (IDA4; 12 mg/m(2)/d x 4 days) were compared with standard doses of idarubicin (IDA3; 12 mg/m(2)/d x 3 days) for remission induction in patients age 50 to 70 years, with an event-free survival (EFS) end point. After two consolidation courses based on intermediate doses of cytarabine, patients in continuous remission were randomly assigned to receive or not receive maintenance therapy with recombinant interleukin-2 (rIL-2; 5 x 10(6) U/m(2) x 5 days each month) for a total duration of 12 months. A total of 468 patients entered the study (median age, 60 years). Results Overall complete remission rate was 77% with significant differences among the three randomization arms (83%, 78%, and 70% in the IDA3, IDA4, and DNR arms, respectively; P = .04). However, no significant differences were observed in relapse incidence, EFS, or overall survival among the three arms. In the 161 patients randomly assigned for maintenance therapy, no difference in outcome was observed between the rIL-2 and the no further treatment arms. CONCLUSION Neither intensification of anthracycline doses nor maintenance with rIL-2 showed a significant impact on AML course, at least as scheduled in this trial.