Real-World Experience with Selinexor -Containing Regimens in Post-Transplant AML/MDS Patients Who MRD Still Positive after First-Line Preemptive Treatment

Background: Hematopoietic stem cell transplantation (HSCT) is the only cure for acute myeloid leukemia (AML), but relapse is the most important cause of transplant failure. Patients with remission but measurable residual disease (MRD) positive have a higher probability of hematologic relapse. The MRD-directed preemptive treatments can spare some patients in remission from further therapy. The conventional first-line preemptive treatment has been ineffective in some patients, so it's necessary to find a new preemptive treatment to prevent relapse and improve the prognosis. Our study aimed to evaluate the efficacy and safety of selinexor-containing regimens in the preemptive treatment of MRD positive in post-transplant patients with AML or myelodysplastic syndrome (MDS). Methods: The study was conducted in Tongji Hospital from March 2022 to May 2023. The inclusion criteria of post-transplant AML/MDS patients included the followings: (a) Persistent MRD positive. (b) MRD turned negative after first-line preemptive treatment but was positive again. (c) Patients at high risk for hematologic relapse after transplantation; (d) AML-M4/5. The end of the follow-up was in June 2023. Bone marrow aspiration was assessed for MRD using multiparameter flow cytometry (MFC) combined with real-time quantitative polymerase chain reaction (RT-qPCR) as follows: 1) MRD assessed by MFC: MRD negativity was defined as