Abrogation of the prognostic significance of low leukemic cell retention of cytosine arabinoside triphosphate by intensification of therapy and by alteration in the dose and schedule of administration of cytosine arabinoside.

The ability of leukemic cells to phosphorylate cytosine arabinoside (araC) and retain the triphosphate form of the drug (araCTP) is strongly predictive of remission duration for patients with acute nonlymphocytic leukemia who are treated with araC-based maintenance therapy. An increase in the intensity of therapy improves the overall median duration of remission, the increased intensity of therapy being especially beneficial for patients whose leukemic cells do not retain araCTP. This alteration in therapy reduces the prognostic significance of leukemic cell araCTP retention. Further, it seems that the use of high-dose araC as intensive consolidation therapy and the administration of conventional-dose araC by continuous infusion make it possible to further reduce or even abrogate the adverse prognostic significance of low leukemic cell retention of araCTP.