Low-dose arabinosyl cytosine in acute leukemia after a myelodysplastic syndrome and in elderly leukemia.

Low-dose arabinosyl cytosine (ARA-C) was tested in 15 patients with acute leukemia after a myelodysplastic syndrome (MDS) and in six elderly patients with acute nonlymphoid leukemia (ANLL). The drug was given subcutaneously at 10 mg/m2, every 12 hr for 2 weeks, every 28 days. The overall response rate was 19% (one complete remission, three partial responses), and the median duration of response was 4 months. No particular features at diagnosis were predictive of response. Pancytopenia and marrow hypoplasia occurred after 44 (78%) of 56 courses of therapy and were more severe in nonresponders. Four patients died during the aplasia following ARA-C therapy. Subcutaneous low-dose ARA-C was of limited benefit and bore a noticeable hematologic toxicity.