A comparative study of idarubicin 12 mg/m2 and 8 mg/m2 combined with cytarabine as the first induction regimen for adult acute myeloid leukemia patients

OBJECTIVE This study aimed to explore a suitable dose of idarubicin (IDA) combined with cytarabine for the initial induction regimen for acute myeloid leukemia (AML) patients. PATIENTS AND METHODS A total of 100 adult patients with de novo AML aged between 14 years and 80 years were enrolled in the current study and randomized into two arms for the initial induction: an IDA 12 mg/m(2) arm and an IDA 8 mg/m(2) arm. All patients received the same consolidation chemotherapy. The follow-up period was January 1, 2009, to December 31, 2014. Overall survival (OS), disease-free survival (DFS), and morphology leukemia relapse (hematological and/or extramedullary) were recorded. RESULTS The complete remission rates were 80% and 75% in the IDA 12 mg/m(2) and IDA 8 mg/m(2) arms, respectively, after initial induction. High-dose IDA (12 mg/m(2)) resulted in a higher complete remission rate after two courses of induction therapy (96.4% vs 76.5%) in the cytogenetic intermediate-risk group (P=0.026). There were no differences in the number of units of infused red blood cells, agranulocytosis time, or infection rates between the two arms. Patients in the IDA 12 mg/m(2) arm received more platelet transfusions (P=0.047). In the intention-to-treat analysis, after a median follow-up of 13 months, high-dose IDA (12 mg/m(2)) resulted in improved OS (median OS, 54.0 months vs 26.7 months, P=0.021) and DFS (median DFS, 54.0 months vs 18.3 months, P=0.031), particularly in the cytogenetic intermediate-risk group (median OS, 54.0 months vs 29.5 months, P=0.009; median DFS, 54.0 months vs 15.3 months, P=0.014). IDA 12 mg/m(2) significantly improved OS and DFS in the cytogenetic intermediate-risk group (P=0.009 and P=0.018). CONCLUSION Our results suggest that a high dose of IDA (12 mg/m(2)) combined with cytarabine is a suitable and safe initial remission induction regimen that results in superior long-term survival of adult AML patients, particularly patients in the cytogenetic intermediate-risk group.