Antileukemic activity of 5-aza-2'-deoxycytidine and cytarabine against intracerebral L1210 murine leukemia.

The effect of different doses of 5-aza-2'-deoxycytidine (5-aza-dCyd) or cytarabine (ara-C) on the survival time of mice with intracerebral (ic) L1210 leukemia was compared. CD2F1 mice were given ic inoculation of 10(3) L1210 cells, and chemotherapy was given as a 12-hour iv infusion at various days thereafter. Treatment on Day 6 with increasing doses of 5-aza-dCyd reached a mean maximal percent increase in lifespan (ILS) of 118% at 20 mg/kg, whereas the mean maximal ILS reached for ara-C was about 60% at 1000 mg/kg. When these equitoxic doses of each drug, as determined by body weight loss, were given on Day 3, 4, or 5, 5-aza-dCyd gave greater ILS and more 60-day survivors than ara-C. These data indicate that 5-aza-dCyd is more effective than ara-C against the ic L1210 leukemia.