Poor graft function (PGF), defined by the presence of multilineage cytopenias in the presence of 100% donor chimerism, is a serious complication of allogeneic stem cell transplant (allo-HSCT). Emerging evidence demonstrates that the inadequate stem cells infusion, bone marrow microenvironment and immune dysregulation play a crucial role in maintaining and regulating hematopoiesis. Current therapies remain debatable, including selected CD34+ cells infusion, mesenchymal stromal cells infusion, prophylactic N-acetyl cysteine administration, etc. Thereafter, the investigators conduct a randomized trial aiming at validating the efficacy and safety of low-dose decitabine, together with umbilical cord blood in PGF post allo-HSCT patients.~Patients were eligible if they were diagnosed as PGF at day 28 post-HSCT or later. PGF was defined as two or three cytopenias, absolute neutrophil count ≤ 1.5 × 109/L, platelet count ≤ 30 × 109/L, hemoglobin ≤ 85g/L, lasting for more than 14 consecutive weeks, in the presence of full donor chimerism and primary disease in remission without severe graft-versus- host disease (GVHD) and relapse.~Patients with the following conditions or diagnoses were excluded: allergic to decitabine or any components of frozen preservation of umbilical cord blood; active infections; uncontrolled GVHD; severe organ dysfunction; relapse of underlying malignancies; graft failure. Patients were also excluded if they had received decitabine or participated in other clinical trials within one month before screening.~Hematological improvement is defined as recovery of two or three blood lineages: absolute neutrophil count>1.5 × 109/L, platelet count>30 × 109/L, hemoglobin>85g/L, without G-CSF, red blood cell or platelet infusion.~Hematological response is defined as recovery of three blood lineages: absolute neutrophil count>2.5 × 109/L, platelet count>60 × 109/L, hemoglobin>100g/L, without G-CSF, red blood cell or platelet infusion.~No response: failed to achieve hematological improvement or response.
This randomized trial aimed at validating the efficacy and safety of low-dose decitabine, together with umbilical cord blood in PGF post allo-HSCT patients.