Multi-Center Study Shows Good Prognosis for Hematologic Malignancy Patients Undergoing MMUD Allogeneic Stem Cell Transplant with ATG

A multi-center retrospective study conducted in China has highlighted the promising results of mismatched unrelated donor (MMUD) allogeneic hematopoietic stem cell transplantation (allo-HSCT) for patients with hematologic malignancies. Published in Bone Marrow Transplantation, this study examines the effectiveness of combining MMUD allo-HSCT with antithymocyte globulin (ATG) for preventing graft-versus-host disease (GVHD). This approach has shown to deliver strong clinical outcomes, even with mismatches in human leukocyte antigen (HLA) compatibility between the donor and recipient.

The study enrolled 211 patients aged 14 or older, all diagnosed with hematologic malignancies and in complete remission prior to transplantation. Patients were split into two groups based on the number of HLA mismatches: Group A with one allele mismatch and Group B with two or more mismatches. All patients received peripheral blood stem cells and conditioning treatment with a marrow-clearing regimen, alongside GVHD prevention involving ATG.

Key results include a high cumulative engraftment rate of 96.2% for neutrophils and 93.4% for platelets within the first 28 days. The study also showed a relatively low incidence of severe acute GVHD, with III-IV grade GVHD occurring in 12.3% of cases, and moderate-to-severe chronic GVHD reaching 21% after three years. The three-year overall survival (OS) rate was 63.1%, with a disease-free survival (DFS) rate of 54.5%.

The findings also demonstrated that the number of HLA mismatches did not significantly affect survival rates, GVHD incidence, or viral reactivation. Additionally, the use of lower doses of ATG (≤6 mg/kg) improved engraftment rates and offered clinical advantages without impacting survival or relapse rates, providing a cost-effective treatment option.

This research is the largest multi-center study in China on MMUD allo-HSCT and underscores the potential of this transplantation approach for patients with high-risk hematologic cancers. It provides valuable insights into improving patient outcomes and refining transplant protocols, making it an important contribution to the field of blood cancer treatment.