Treatment of relapsed acute myeloid leukemia with idarubicin and intermediate-dose cytarabine.

High-dose cytarabine (HDARA-C) is an effective but toxic treatment for acute myeloid leukemia (AML). In order to reduce the incidence of severe complications noted with HDARA-C-containing regimens, we used a combination of intravenous (IV) idarubicin (IDARUB) at optimal dosage and cytarabine (ARA-C) at intermediate dosage. Thirty-five patients aged 23 to 78 years (median, 56) with AML in first relapse received IDARUB, 8 mg/m2/d for five days, and ARA-C, 1 g/m2 every 12 hours for six doses. Of the 35 patients, 21 achieved a complete remission (CR), four had a partial remission (PR), four died in aplasia, and six were nonresponders. The only factor influencing the CR rate was the duration of the first CR (35% for patients relapsing before 16 months v 83% for patients relapsing after 16 months, P = .003). Mucositis was the most significant extrahematologic side effect. Diarrhea, skin toxicity, and hepatic disturbances were rare and mild. There was no cerebellar toxicity, even in 25 patients greater than 50 years of age. This regimen is effective and well tolerated even in elderly patients, and could be used either as induction or consolidation therapy for the treatment of AML.