Low-Dose Ara-C by Continuous Infusion in the Treatment of Acute Non-Lymphocytic Leukemia (ANLL) and Myelodysplastic Syndrome (MDS)

Thirteen patients with acute non-lymphocytic leukemia (ANLL) or myelodysplastic syndrome (MDS) were treated with low-dose cytosine arabinoside (Ara-C) 20 mg/m2/day by continuous intravenous infusion for 21 days. Seven patients attained complete remissions (CR) and two patients had partial remissions (PR). Two patients required two courses of treatment before attaining CR. Two of four patients with abnormal cytogenetics also achieved complete response with reversion of cytogenetic abnormalities to normal. All patients who responded showed profound pancytopenia with marked hypoplasia of bone marrow. The universal occurrence of pancytopenia and reversion of cytogenetic abnormalities to normal suggests that low-dose Ara-C is cytotoxic and may not act as a differentiating agent.