DISCUSSION
transplantation-associated, AML, GVHD, Post-transplantation, transplantation-associated toxicities, hepatic dysfunction, myelosuppression
AML, SECONDARY, REMISSION, CARDIAC EVENTS, GVHD
The emergence of FLT3-targeted therapies administered in frontline or R/R settings enables patients with This post hoc analysis shows that bridging treatment with either gilteritinib or SC led to equivalent post-transplantation survival. Patients who resumed gilteritinib after HSCT had low relapse rates and longer OS compared with those who did not. However, we caution against interpretation of any definitive treatment effects of gilteritinib maintenance therapy from ADMIRAL. The number of patients who received gilteritinib was small and a pretransplantation response of CRc was more common among patients who restarted gilteritinib, which might have contributed to the observed differences in survival. Additionally, neither secondary randomization to determine definitive treatment effects of maintenance therapy nor routine bone marrow evaluation for gilteritinib arm patients who did not resume gilteritinib were incorporated into the study design. However, patients who resumed gilteritinib experienced no new safety signals during the post-transplantation period. Grade ≥3 AEs in patients receiving post-transplantation gilteritinib were related primarily to myelosuppression; a low risk for grade ≥3 AEs related to hepatic dysfunction and cardiac events persisted. Rates of grade ≥3 GVHD after gilteritinib resumption and GVHD-related mortality were low.Post-transplantation maintenance therapy with FLT3 inhibitors in patients with AML remains off-label in the United States but is a growing area of interest. The randomized, placebo-controlled, double-blind SORMAIN trial showed that up to ~2 years of post-transplantation sorafenib therapy in patients with The aforementioned studies mainly examined HSCT in first remission, when the risk of relapse may be lower and the risk/benefit ratio for post-transplantation maintenance therapy may differ from that in the R/R AML setting of ADMIRAL. The phase 3 QuANTUM-R trial of quizartinib versus SC in patients with R/R As is typical of secondary analyses, our study has several limitations. The small number of patients who underwent HSCT during the trial precluded rigorous statistical comparisons between HSCT and non-HSCT groups. In addition, our statistical analyses were not adjusted for multiple comparisons. Because patients who received high-intensity SC discontinued study treatment after 1 or 2 treatment cycles, long-term follow-up was restricted to a very small number of SC arm patients, and post-transplantation AEs were not rigorously monitored. The gilteritinib arm patients did not participate in routine study visits during the transplantation period prior to restarting gilteritinib, and thus it is plausible that patients who restarted gilteritinib therapy likely experienced fewer transplantation-associated toxicities than patients who did not restart gilteritinib, and cross-arm comparisons of transplantation-associated AEs were not possible. Patients who underwent HSCT were younger (<65 years) and considered eligible for high-intensity chemotherapy, which likely predisposed them to better survival outcomes. Post-transplantation use of another FLT3 inhibitor also might have affected OS in both arms. Furthermore, a smaller proportion of patients who underwent HSCT had a high Our analysis demonstrates that patients with 