Post‐stem cell transplant maintenance in FLT3mut acute myeloid leukemia – A retrospective analysis: Outcomes are improved with midostaurin but not with gilteritinib

The FMS-like tyrosine kinase 3 (FLT3) domain is the most mutated gene in acute myeloid leukemia (AML), with FLT3 internal tandem duplication (ITD) mutations conferring adverse outcomes [1,2].Maintenance therapy after hematopoietic stem cell transplant (HSCT) may be essential, as FLT3 AML patients experience high rates of post-HSCT relapse and mortality [3].Terao et al. found that relapsed/refractory (R/R) FLT3 AML patients who received post-HSCT maintenance gilteritinib had improved overall survival (OS) (1-year OS, 100% vs. 45.5%,p = 0.0075) and cumulative incidence of relapse (CIR, 1-year CIR 0% vs. 68.8%,p = 0.0028) [4].However, the phase 3 MORPHO trial failed to reach the primary outcome of improved relapse-free survival (RFS) with post-HSCT maintenance gilteritinib compared to placebo in FLT3-ITD AML patients except in measurable residual disease (MRD) positive patients [5].As prospective data on FLT3 inhibitor maintenance therapy are evolving, there is a need to investigate real-life data and outcomes to guide clinical decisions.