Treatment of Philadelphia Chromosome Positive (Ph +) Chronic Myelogenous Leukemia in Blast Crisis and Ph + Acute Leukemia with High Dose Cytosine Arabinoside (HDARAC).

High dose cytosine arabinoside (HDARAC) was administered to eleven patients in the blastic phase of Philadelphia (Ph) chromosome positive chronic myelogenous leukemia (CML). Four patients presented in blastic phase and in seven patients blastic transformation had evolved from a previous chronic phase. All patients had been heavily pretreated with chronic phase drugs (hydroxyurea, myleran) or a protocol designed to treat the chronic phase (L-5 protocol) and with blastic phase regimens (anthracycline/araC combination or vincristine/prednisone). One of 11 patients achieved a complete remission (365 + days) and two patients achieved a partial response. No cytogenetic remissions were observed. The other patients were considered treatment failures with 3/8 surviving less than one month after therapy. Blasts were, at least temporarily, eliminated in all patients receiving at least 7 doses of HDARAC, although repopulation was rapid. HDARAC may be satisfactory therapy for accelerated phase CML but is minimally active in blastic phase CML.