Phase II study of mitoxantrone and cytarabine in acute myeloid leukemia.

Thirty-eight patients with acute myeloid leukemia (AML) were treated with mitoxantrone (Mto) combined with cytarabine (Ara-C). Five patients had received no previous treatment for acute myeloid leukemia, seven were refractory to treatment with standard first-line chemotherapy, eight had relapsed during treatment, and 18 had relapsed after treatment was stopped. Eleven of these relapses were early (within 6 months of stopping treatment). Mto was given for 5 days by iv bolus injection at a dose of 10 mg/m2 to 12 patients and at 12 mg/m2 to 26. Ara-C was given at a dose of 1 g/m2 twice daily by a 2-hour infusion for 3 days to 37 patients. One patient received Ara-C at a dose of 500 mg/m2 twice daily for 3 days. Toxicity was acceptable except for cerebellar toxicity in two patients, which was irreversible in one. Twenty-two patients (56%) achieved complete remission (CR), and four achieved partial remission (10%). Seventy-five percent of the patients who had relapsed during treatment and 58% of those who had relapsed after treatment was stopped achieved CR. Eleven patients remain in CR at a median time of 10 months (range, 3-17) after treatment. In five patients remissions have lasted greater than 1 year, one in a patient treated in second relapse and one in a patient treated in third relapse. Mto and Ara-C appear to be effective salvage therapy in acute myeloid leukemia and should be considered for incorporation into first-line induction regimens.