Randomized Trial of Intermediate-dose Cytarabine in Induction and Consolidation Therapy in Adults with Acute Myeloid Leukemia.

Abstract

Cytarabine, 100-200 mg/mE+2/day, is commonly used in induction therapy of acute myelogenous leukemia (AML). Whether a higher dose of cytarabine would be more effective is unknown. Also, there is controversy whether high-dose cytarabine is better than an intermediate-dose combined with other drugs for post-remission therapy. In this open-label, randomized controlled, parallel group study, roles of intermediate-dose cytarabine were investigated. Subjects with AML age 15-55 years were randomized to receive daunorubicin, omacetaxine mepesuccinate, and conventional- or intermediate-dose cytarabine. Subjects achieving complete remission were randomized to receive 3 courses of high-dose cytarabine or 2 courses of intermediate-dose cytarabine with daunorubicin in the 1^st and mitoxantrone in the 2^nd course. The primary endpoint was disease-free survival (DFS). 591 subjects were randomized to intermediate- (<i>N</i> = 295) or conventional-dose (<i>N</i> = 296) cytarabine group. Three-year DFSs were 67% [95% confidence interval (CI), 61-73] in the intermediate-dose cohort compared with 54% (95% CI, 48-61) in the conventional-dose cohort [Hazard Ratio (HR), 0.67; 95%CI, 0.51-0.89; <i>P</i> = 0.005). Three-year survivals were 68% (95%CI, 63-74) and 59% (95%CI, 53-65; HR, 0.720; 95%CI, 0.56-0.94; <i>P</i> = 0.014). Two courses of intermediate-dose cytarabine with daunorubicin or mitoxantrone resulted in similar DFS and survival as three courses of high-dose cytarabine when used for post-remission therapy. Induction therapy with intermediate-dose cytarabine with daunorubicin and omacetaxine mepesuccinate increases DFS and survival in persons with AML ages 15-55 years compared with conventional-dose cytarabine.<i>See related commentary by Watts and Bradley, p. 3073</i>.