Addition of Cladribine to Idarubicin and Cytarabine during Induction Increases the Overall Efficacy Rate in Adult Patients with Acute Myeloid Leukemia: A Matched-Pair Retrospective Comparison.

Objectives: The aims of this study were to evaluate a novel induction regimen composed of idarubicin (IDA), cytarabine (Ara-C) and cladribine (IAC regimen) for acute myeloid leukemia (AML) patients, and to identify the prognostic factors affecting treatment outcomes.

Methods: The clinical data of 27 untreated AML patients who received the IAC regimen as primary induction therapy in our hospital between April and November 2014 were analyzed retrospectively. The treatment outcomes of the IAC regimen were compared with two IA (IDA + Ara-C) regimens (IDA 10 mg/m² and IDA 12 mg/m²) in a pair-matched analysis.

Results: The complete remission (CR) rate in the IAC arm was higher compared to the IA(L) arm (p = 0.002) as was the overall efficacy rate (p = 0.017). There was no significant difference in outcomes between the IAC and IA(H) (Ara-C with high-dose IDA) arms. The IAC arm contained significantly higher CR rates than the IA(L) (Ara-C with low-dose IDA) arm in both the intermediate group (p = 0.050) and the unfavorable group (p = 0.013). Toxicity did not differ between the IAC group and the other two arms. High WBC at diagnosis (p = 0.022) and an unfavorable karyotype (p = 0.026) were related to a poorer response. The IAC regimen (p = 0.013) had greater superiority over the IAL regimen on efficacy than over the IA(H) regimen (p = 0.041).

Conclusions: The IAC regimen achieved a more significant advantage over the IA(L) regimen without increasing the risk of adverse events. The efficacy of induction therapy is associated with WBC at diagnosis, karyotype and induction regimen.