Clofarabine Can Replace Anthracyclines and Etoposide in Remission Induction Therapy for Childhood Acute Myeloid Leukemia: The AML08 Multicenter, Randomized Phase III Trial

To identify effective and less toxic therapy for children with acute myeloid leukemia, we introduced clofarabine into the first course of remission induction to reduce exposure to daunorubicin and etoposide. From 2008 through 2017, 285 patients were enrolled at eight centers; 262 were randomly assigned to receive clofarabine and cytarabine (Clo+AraC, n = 129) or high-dose cytarabine, daunorubicin, and etoposide (HD-ADE, n = 133) as induction I. Induction II consisted of low-dose ADE given alone or combined with sorafenib or vorinostat. Consolidation therapy comprised two or three additional courses of chemotherapy or hematopoietic cell transplantation. Genetic abnormalities and the level of minimal residual disease (MRD) at day 22 of initial remission induction determined final risk classification. The primary end point was MRD at day 22. Complete remission was induced after two courses of therapy in 263 (92.3%) of the 285 patients; induction failures included four early deaths and 15 cases of resistant leukemia. Day 22 MRD was positive in 57 of 121 randomly assigned evaluable patients (47%) who received Clo+AraC and 42 of 121 patients (35%) who received HD-ADE (odds ratio, 1.86; 95% CI, 1.03 to 3.41; = .04). Despite this result, the 3-year event-free survival rate (52.9% [44.6% to 62.8%] for Clo+AraC 52.4% [44.0% to 62.4%] for HD-ADE, = .94) and overall survival rate (74.8% [67.1% to 83.3%] for Clo+AraC 64.6% [56.2% to 74.2%] for HD-ADE, = .1) did not differ significantly across the two arms. Our findings suggest that the use of clofarabine with cytarabine during remission induction might reduce the need for anthracycline and etoposide in pediatric patients with acute myeloid leukemia and may reduce rates of cardiomyopathy and treatment-related cancer.