Cytarabine for acute leukemia in adults. Effect of schedule on therapeutic response

Adults with acute leukemia were randomized between two schedules of cytarabine administered by continuous intravenous infusion: schedule 1, 800 mg/sq m for 48 hours; schedule 2, 1,000 mg/sq m for 120 hours. The duration of infusion time remained constant for each patient, although the total dose during subsequent courses was modified depending on the severity of myelosuppression. Courses were repeated for a minimum of three courses at 14-day intervals until remission or treatment failure. Response rate was 20% for schedule 1 and 38% for schedule 2 (P<.05), showing that response rate to cytarabine is related to schedule of administration. Median duration of complete remissions was 62 weeks for schedule 1 and 51 weeks for schedule 2. Twenty-three percent of patients who achieved complete remissions had remissions lasting more than two years; 21% are still in remission.