Treatment of “poor risk” acute nonlymphocytic leukemia with continuously infused low‐dose cytosine arabinoside

There is currently little experience using a continuous intravenous infusion of low‐dose cytosine arabinoside (LDARA‐C) in the treatment of acute nonlymphocytic leukemia (ANLL). We report the results in 12 patients with ANLL described as either relapsed ANLL, ANLL with a preceding myelodysplastic phase, or ANLL in the elderly treated with 14 days of continuous intravenous LDARA‐C (20 mg/m²/day). Complete responses (CR) were seen in five patients (42%) and partial responses (PR) in three patients (25%). Treatment resulted in overall and clonal cytoreduction, which was evident by serial bone marrow exams and bone marrow cytogenetic analysis. The ability to obtain a CR correlated with the finding of a low initial marrow cellularity (P < .05). This study finds that continuous intravenous infusion of LDARA‐C for ANLL can achieve response rates comparable to standard induction programs in a subset of patients traditionally defined as having a poor prognosis.