Treatment of acute leukemia in relapse with 4'(9-acridinylamino) methanesulfon-m-anisidide (AMSA) in combination with cytosine arabinoside and thioguanine.

Thirty-seven patients with acute leukemia in relapse were treated with a three-drug combination that included a 3- or 4-day course of AMSA with total doses ranging from 600 mg/m2 to 740 mg/m2 I.V., cytosine arabinoside 25 mg/m2 I.V. followed by 200 mg/m2 by continuous infusion daily for 5 days, and thioguanine 100 mg/m2 p.o. q 12h for 5 days. Eight of the 25 patients with acute nonlymphoblastic leukemia achieved a complete remission and 3 a partial remission. None of the five patients with acute lymphoblastic leukemia achieved a response and there was one partial remission in the seven patients with myelodysplastic syndrome or blastic CML. Reversible toxicity included nausea and vomiting (78%), alopecia (100%), pancytopenia (100%), mild stomatitis (63%), and hepatic dysfunction (24%). One patient developed seizures and cardiac arrhythmias. The activity of this combination in heavily treated patients with ANLL is comparable to that of the anthracycline-containing regimens, and its use in previously untreated patients with ANLL should now be explored.