Sequential therapy with decitabine and an XPO-1 inhibitor followed by allogeneic hematopoietic stem cell transplantation in MDS with biallelic TP53 inactivation patients : a preliminary case series.

Myelodysplastic syndrome with biallelic TP53 inactivation (MDS-biTP53) patients represents an ultra-high-risk subgroup with dismal outcomes. Even after allogeneic hematopoietic stem cell transplantation (allo-HSCT), relapse rates remain extremely high and survival is poor. This preliminary case series reports the outcomes of 8 consecutive patients with MDS-biTP53 who received a novel sequential therapy of decitabine (DAC) combined with the XPO-1 inhibitor selinexor, followed by allo-HSCT at a single center between September 2024 and December 2025. At a median follow-up of 7.3 months (95% CI, 4.2-10.4 months) from HSCT, median overall survival (OS) and relapse-free survival (RFS) were not reached. At last follow-up, 7/8 patients remained alive (OS 87.5%) and 6/8 were relapse-free (RFS 75%), with one relapse (12.5%). This patient successfully achieved a second complete remission following preemptive therapy with low-dose decitabine combined with donor lymphocyte infusion and remained in remission at the last follow-up. Two patients developed serious infections during the peritransplant period. One patient with pre-transplant intestinal colonization of carbapenem-resistant Enterobacteriaceae (CRE) ultimately died due to CRE bloodstream infection followed by intestinal graft-versus-host-disease (GVHD). Overall treatment-related toxicity was deemed manageable, and the incidence of grade III-IV acute GVHD was 25% (2/8). This preliminary study provides encouraging evidence that sequential decitabine and selinexor therapy followed by allo-HSCT may improve outcomes with acceptable toxicity in patients with ultra-high-risk MDS-biTP53. However, these findings are limited by the small sample size, relatively short follow-up, and retrospective, single-center design. Confirmation in larger prospective trials is warranted.