Efficacy of etoposide and mitoxantrone in patients with acute myelogenous leukemia refractory to standard induction therapy and intermediate-dose cytarabine with amsidine. Dutch Hematology-Oncology Working Group for Adults (HOVON).

Thirty-seven newly diagnosed patients with acute myeloid leukemia (AML) who were not in complete remission (CR) after induction chemotherapy with cytarabine and daunorubicin followed by intermediate-dose cytarabine and amsacrine, were treated with mitoxantrone and etoposide in a prospective, open multicenter study. The aim was to examine the efficacy and the toxicity of mitoxantrone and etoposide in a patient population with bad prognosis because of refractoriness to two standardized induction courses. Twelve patients attained CR (32.4%). Responders were found only among the patients with documented susceptibility (i.e. partial remission) to the previous therapy. In responding patients the median remission duration and disease-free survival was 15+ months (range 3-52+). Toxicity was mainly hematologic and characterized by prolonged hypoplasia; one patient died in aplasia. Granulocytes and platelets recovered unexpectedly early in six of 22 non-responders. This study suggests that AML patients refractory to two standardized chemotherapy courses can still attain a durable CR after an additional course, here with mitoxantrone and etoposide, provided they show some responsiveness to the previously given cytostatic drugs.