A prospective study of allogeneic hematopoietic stem cell transplantation with post-transplantation cyclophosphamide and anti-thymoglobulin from HLA-mismatched related donors for non-malignant diseases

Abstract Allogeneic hematopoietic stem cell transplantation (HSCT) is performed as a curative treatment for children with non-malignant diseases, such as bone marrow failure syndromes and primary immunodeficiencies. As graft-versus-host-disease (GVHD) is a major factor affecting survival probability and quality of life after HSCT, availability of HLA-matched donors restricts opportunity for HSCT. Recently, HSCT with post-transplant cyclophosphamide (PTCy) has emerged as a potent method to prevent GVHD in HSCT from HLA-haploidentical donors, and some studies suggested the safety of PTCy-HSCT for non-malignant diseases. We conducted a prospective clinical trial, aiming to help confirm the safety of HSCT and further reduction of GVHD using a combination of PTCy and low-dose anti-thymocyte globulin (ATG) from HLA-mismatched related donors for children with non-malignant diseases. Six cases received HSCT, all cases achieved engraftment at a median of 14.5 days, and no cases developed severe acute GVHD. All cases had sustained donor chimerism without developing chronic GVHD at the last follow-up. In conclusion, HSCT with PTCy and low-dose ATG from HLA-mismatched related donors was feasible to control GVHD for non-malignant diseases in the children involved in our study.