High-dose cytosine arabinoside and daunorubicin as primary therapy in elderly patients with acute myelogenous leukemia. A phase I-II study of the Southeastern Cancer Study Group.

We undertook a phase I-II trial in elderly (age greater than or equal to 60 years) untreated acute myelogenous leukemia (AML) patients using brief, intensive therapy to improve induction rates and overall survival in older AML patients. Twenty-one patients ranging in age from 60 to 81 years (median, 66 years) were treated using either a 4- or 5-day course of high-dose cytosine arabinoside, 3 g/m2 intravenously (IV) every 12 hours; followed by daunorubicin, 45 mg/m2/d IV bolus for 3 consecutive days. Thirteen patients were entered at the first dose level (a 4-day course or eight doses of cytosine arabinoside), whereas eight patients underwent therapy at the second dose level (a 5-day course or ten doses). Patients who achieved a complete remission received a repeat course of high-dose cytosine arabinoside and daunorubicin within 4 weeks of attaining remission. Seven patients had an antecedant history of a myelodysplastic syndrome. Infection was the major complication experienced by this elderly patient group, and included ten episodes of bacteremia or fungemia (four of which were fatal) and five cases of pneumonia (one fatality). Nine of the 21 patients (three of 13 at the first dose level and six of eight at the second dose level) achieved a complete remission. Median remission duration was 9 months (range, 4-19+ months). Although high-dose cytosine arabinoside plus daunorubicin was an effective antileukemic therapy, it is too toxic to recommend for most elderly leukemic patients.