Mitoxantrone, etoposide, and intermediate-dose cytarabine: an effective and tolerable regimen for the treatment of refractory acute myeloid leukemia.

Thirty-two patients with refractory acute myeloid leukemia (AML) received salvage therapy with a single course of mitoxantrone 6 mg/m2 intravenous (IV) bolus, etoposide 80 mg/m2 IV for a period of 1 hour, and cytarabine (Ara-C) 1 g/m2 IV for a period of 6 hours daily for 6 days (MEC). Eighteen patients were primarily resistant to conventional daunorubicin and Ara-C induction treatment; eight patients had relapsed within 6 months from initial remission; six patients had relapsed after a bone marrow transplantation (BMT) procedure. Overall, 21 patients (66%) achieved a complete remission (CR), two (6%) died of infection during induction, and nine (28%) had resistant disease. Age greater than 50 years was the only factor predictive for a significantly lower response rate (P = .03). The median remission duration was 16 weeks; the overall median survival was 36 weeks. Severe myelosuppression was observed in all patients resulting in fever or documented infections in 91% of patients. Nonhematologic toxicity was minimal. We conclude that the MEC regimen has significant antileukemic activity and acceptable toxicity in salvage AML. Its benefit in front-line AML therapy is being investigated.