Cytosine arabinoside and 6-thioguanine in refractory acute lymphocytic leukemia

Combination therapy with cytosine arabinoside and 6-thioguanine has been found to be effective for remission induction in acute myelogenous leukemia (AML). The present study was undertaken to determine the efficacy of this combination in late refractory ALL; 19 children received Ara-C (100 nig/M2) given either subcutaneously or intravenously, and 6-TG (75-100 mg/M2) given orally in combination every 12 hours. The duration of therapy was variable (6-31 days) and determined by individual response. Complete remissions were obtained in 9 of 19 patients (47%). Severe marrow hypoplasia median 19 days, range (7–30 days) and pancytopenia occurred in all 9 patients who achieved remission. Two patients died during induction, 4 patients had no response to the combination, and 4 achieved marrow hypoplasia but no remission. The median remission duration was 28 days (range 11-127 days). In addition to severe myelosuppression, the majority of children experienced mild nausea, vomiting, and minimally abnormal liver function tests during therapy.