Purpose: To evaluate the response rate, survival, and toxicity of mitoxantrone and cytarabine induction, high-dose cytarabine and etoposide intensification, and further consolidation/maintenance therapies, including bone marrow transplantation, in children with relapsed, refractory, or secondary acute myeloid leukemia (AML). To evaluate response to 2-chlorodeoxyadenosine (2-CDA) and etoposide (VP-16) in patients who did not respond to mitoxantrone and cytarabine.
Patients and methods: Patients with relapsed/refractory AML (n = 101) and secondary AML (n = 13) were entered.
Results: Mitoxantrone and cytarabine induction achieved a remission rate of 76% for relapsed/refractory patients and 77% for patients with secondary AML, with a 3% induction mortality rate. Cytarabine and etoposide intensification exceeded the acceptable toxic death rate of 10%. The response rate of 2-CDA/VP-16 was 8%. Two-year overall survival was estimated at 24% and was better than historical control data. Patients with secondary AML had similar outcomes to relapsed or refractory patients. Initial remission longer than 1 year was the most important prognostic factor for patients with primary AML (2-year survival rate, 75%), whereas for patients with primary AML, with less than 12 months of initial remission, survival was 13% and was similar to that of refractory patients (6%).
Conclusion: Mitoxantrone and cytarabine induction is effective with reasonable toxicity in patients with relapsed/refractory or secondary AML. The cytarabine and etoposide intensification regimen should be abandoned because of toxicity. Patients with relapsed AML with initial remissions longer than 1 year have a relatively good prognosis.