Mitoxantrone in refractory acute leukemia in children: A phase I study

Summary Nine children with acute non-lymphocytic leukemia (ANLL), ages 16 months to 16 years (median 7 years), and 15 children with acute lymphocytic leukemia (ALL), ages 10 months to 18 years (median 5 years), were treated with 5-day courses of mitoxantrone (Novantrone®; dihydroxyanthracenedione) as induction therapy. All the children had leukemia which was resistant to conventional therapy and all but one patient had received anthracycline therapy prior to the initiation of this trial. Three patients (two with ANLL, one with ALL) received the drug at a dose of 6 mg/m²/day i.v. for 5 days. Both patients with ANLL achieved partial remissions (PR) (105 and 87 days duration). The child with ALL failed to respond to two courses of the drug, and died of progressive disease 45 days after the institution of therapy. Twenty-one patients (14 with ALL, seven with ANLL) were treated with 8 mg/m²/day i.v. mitoxantrone for 5 days. There were three early deaths (all ALL) which were not felt to be secondary to drug toxicity. Four of the 18 children achieved complete remission (CR) (one ANLL — 35 days; three ALL — 39, 31 and 13 days). One child with ANLL achieved a PR (13 days) and one child with ALL showed improvement in his bone marrow status. Twelve children failed to respond to this therapy.Dose-limiting toxicity was not seen among the patients who received 6 mg/m²/day for 5 days. There were five patients who had mucositis and one patient who had nausea and vomiting among those patients who received 8 mg/m²/day for 5 days. Four of these children had significant decreases in the myocardial shortening fraction as measured by echocardiography. None of these patients had clinical signs of cardiotoxicity.The CR plus PR rate for both dose levels is 33%. Mitoxantrone appears to be an effective agent for remission induction in children with late stage ALL and ANLL. Toxicity was not a significant problem at the doses used in this trial.