Continuous infusion of intermediate-dose cytarabine and fludarabine with idarubicin for patients younger than 60 years with resistant acute myeloid leukemia: a prospective, multicenter phase II study.

We assessed continuous infusion (CI) of fludarabine and cytarabine (FLAG) plus idarubicin for patients under 60-years old with resistant acute myeloid leukemia (AML). Induction chemotherapy consisted of idarubicin (12 mg/m(2) iv infusion over 30 min on Days 1-3), plus fludarabine (30 mg/m2/day) and cytarabine (1,000 mg/m(2)/day) on Days 1-5 as a 24-hr CI. G-CSF was added on Days 1-5. The 29 patients enrolled were of median age 40 years (range, 18-57 years); of these, 8 (27.6%) had primary refractory disease, 19 (65.5%) were in early relapse, and 1 each (3.4%) was in multiple relapse and relapse after SCT. In response to induction, 8 patients (27.6%) achieved CR, 2 (6.9%) achieved CRp, and 19 (65.5%) failed treatment; of the latter, 14 had aplasia, three had an indeterminate course, and two showed resistance. Seven patients remain alive, while two were lost to follow-up. Nineteen patients died, 14 of infection, one of toxicity during consolidation, three of relapse after SCT, and two of persistent disease. These findings indicate that although CI of FLAG plus idarubicin was effective for eradicating blasts, it carried a high risk of toxicity. Reduced doses are recommended for CI of FLAG plus idarubicin.