Fludarabine, cytarabine, granulocyte-colony stimulating factor and amsacrine: an effective salvage therapy option for acute myeloid leukemia at first relapse.

Improved therapeutic options for relapsing patients with acute myeloid leukemia (AML) are urgently needed. Poor outcomes following salvage therapy have been reported in those with short initial remission duration, adverse risk karyotype, prior allograft, older age, FLT3-internal tandem duplication (ITD) AML and prior high-dose cytarabine (HiDAC) induction therapy. We present a cohort of 58 patients (aged 18-70) treated with fludarabine, cytarabine, granulocyte-colony stimulating factor (G-CSF) and amsacrine (FLAG-amsacrine) as salvage chemotherapy for AML at first relapse. 83% had received prior HiDAC-based therapy. The overall complete remission (CR/CR with incomplete blood count recovery [CRi]) rate was 59%, with median event-free survival (EFS) and overall survival (OS) of 6.9 and 10.6 months, respectively. FLAG-amsacrine was an effective bridge to allogeneic transplant with 38% successfully transplanted with excellent outcomes (median OS not reached). FLAG-amsacrine was also effective in elderly patients (≥ 60 years), with 61% achieving second remission. The regimen was well tolerated, with 30- and 42-day treatment-related mortality of 3.4% and 13.8%, respectively. Outcomes remained poor in those with short initial remission duration (<6 months). We conclude that FLAG-amsacrine is a useful salvage option for AML at first relapse.