[Low-dose 4N-behenoyl-1-beta-D-arabinofuranosylcytosine (BHAC) in the treatment of atypical leukemia].

Four cases of hypoplastic leukemia, one of acute myelocytic leukemia (M2) and one of RAEB-t were treated with a low-dose 4N-behenoyl-1-beta-D-arabinofuranosylcytosine (LD-BHAC) regimen, in which 50 mg BHAC was administered daily intravenously by one-hour drip infusion for 14 days. Among the 6 cases, three (2 hypoplastic leukemia and one M2) obtained complete remission and one (hypoplastic leukemia), partial remission. Response rates were 66.6% of all cases, and 75% of cases of hypoplastic leukemia. During treatment, cytopenia was observed in all cases and a decrease in bone marrow nucleated cell counts was recognized in the aged M2 patient with remission. Although side effects of the drug on the digestive system such as anorexia and nausea were observed in some cases, they were all controllable by conventional treatments. The serum concentration of ara-C was measured in 4 cases. The peak level of serum ara-C concentration, 3.62-18.9 ng/ml (mean: 11.74 ng/ml), was observed at the time of cessation of infusion of BHAC, and an ara-C level of 2.75-4.89 ng/ml (mean: 3.54 ng/ml) was still present in the blood 6 hours after the cessation of infusion. It was concluded that LD-BHAC was useful in the clinical management of atypical leukemia and acute myelocytic leukemia in the aged.