Integrated Analysis of Genomics, Molecular Responses, and Outcomes of CBF-AML with FLAG-Based Therapy on a Phase II...

Fludarabine, cytarabine, and G-CSF-based therapy (FLAG) yields approximately 60% 5-year overall survival (OS) in core-binding factor (CBF) acute myeloid leukemia (AML), with potential added benefit with gemtuzumab ozogamicin (GO). Although measurable residual disease (MRD) status via optimal quantitative polymerase chain reaction (qPCR) response (OPR; qPCR <0.1% at the end of induction and <0.01% during/after consolidation) of fusion transcripts predicts survival, the impact of baseline myeloid mutations on OPR and survival with FLAG remains uncertain. We interrogated these factors in 219 first-line patients with CBF-AML (median age 52 years; range, 19-80) treated on a phase II trial (NCT00801489); 51% received FLAG-GO and 49% FLAG idarubicin. Baseline mutations included 49% kinase pathways (non-MAP kinase), 44% MAP kinase, 11% DNMT3A-ASXL1-TET2, and 7% transcription factors. Five-year relapse-free survival and OS were 67% and 74% overall, respectively, 77% and 80% with FLAG-GO. On multivariate analysis, baseline mutations did not affect OPR or survival, whereas FLAG-GO favored both. In CBF-AML, FLAG-based therapy possibly attenuates the prognostic impact of concurrent baseline genomics.

In CBF-AML treated with conventional intensive chemotherapy, usually 7 + 3, baseline mutations in KIT, chromatin modulators, cohesin complex, etc., garner suboptimal MRD clearance and survival. In our analysis, FLAG-based therapy abrogated the impact of baseline mutations on OPR and survival in CBF-AML, while showing promising long-term survival using FLAG-GO.