[A case of complete remission from acute unclassified leukemia achieved by using a prodrug of ara C, stearyl-ara-CMP (YNK01)].

YNK01 (a daily oral dose of 450 mg) was administered for 22 days to a 58-year-old-female with Ph1-positive acute unclassified leukemia. Leukemia cells were negative for peroxidase and esterase, but were positive for CD19, CD13, CD34, CD9, HAL-DR, CD25, and TdT. Complete remission was obtained and continued for at least a month. The main side effects noted were diarrhea and melena. The administration of YNK01 resulted in plasma ara C levels that ranged between 15.4 to 23.0 ng/ml, which appear to be nearly equivalent to dose achieved during continuous IV infusion of a low dose (20 mg/m2/day) of ara C.