Retrospective comparison of survival and responses to Fludarabine, Cytarabine, GCSF (FLAG) in combination with gemtuzumab ozogamicin (GO) or Idarubicin (IDA) in patients with newly diagnosed core binding factor (CBF) acute myelogenous leukemia: MD Anderson experience in 174 patients

Fludarabine, cytarabine, GCSF (FLAG)-based induction/consolidation results in high remission rates in core binding factor (CBF) acute myelogenous leukemia. We treated 174 consecutive patients with newly diagnosed CBF-AML in a prospective clinical trial of FLAG-based induction/consolidation in combination with gemtuzumab ozogamicin (FLAG-GO; N = 65) or in combination with idarubicin (FLAG-IDA; N = 109). The 5 year RFS in the FLAG-GO cohort was significantly better than the FLAG-IDA cohort, 78% versus 59%, respectively (p-value =.02). In multivariate analysis for RFS, age (p =.0001), FLAG-GO regimen (p =.04), 4 log reduction in CBF-related fusion transcript by quantitative polymerase chain reaction (qPCR) in bone marrow samples at end of consolidation therapy (p =.03), and additional cytogenetic abnormalities (p =.03) were significant variables. Lower age (p =.0001) and 3 log or more transcript reduction at end of induction (p =.04) were significant variables predicting for better overall survival (OS), while there was strong trend for better OS with FLAG-GO (p =.06) regimen. FLAG-GO regimen was superior in optimal disease specific fusion transcript reduction at end of induction (p =.002), mid-consolidation (p <.01), and end of consolidation (p <.001) therapy. Induction/consolidation with FLAG-GO regimen results in better clinical outcomes in newly diagnosed patients with CBF-AML compared to FLAG-IDA and achieves deeper molecular clearance by qPCR assessment of the fusion transcripts.