Long-term efficacy of haploidentical hematopoietic stem cell transplantation in the treatment of pediatric acute leukemia

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the optimal treatment for pediatric patients with high-risk or intermediate-acute myeloid leukemia. Immunotherapies, such as CAR-T cellular therapy, have been rapidly developed, especially for refractory acute lymphoblastic leukemia. However, they are relatively expensive, limiting their widespread use. For patients lacking matched sibling donors, haploidentical donors are an option. This study analyzed the clinical outcomes of 119 pediatric acute leukemia patients who underwent haploidentical HSCT (n=68) or human leukocyte antigen (HLA)-matched HSCT (n=51). The 2-year overall survival (OS) and leukemia-free survival (LFS) in the haploidentical HSCT group were similar to those in the HLA-matched HSCT group (77.6% vs. 88.6%, P=0.076; 55.6% vs. 52.9%, P=0.497). The 3-year probability of total chronic graft-versus-host disease (GVHD) was 21.4% and 34.1% in the haploidentical and HLA-matched HSCT groups, respectively (P=0.526). Analysis of the 3-year cumulative recurrence rate suggested no significant difference between the haploidentical HSCT group and HLA-matched HSCT group (cumulative incidence, 32.7% vs. 31.2%, P=0.801). The cumulative incidence of acute GVHD, non-relapse mortality (NRM), and graft-versus-host relapse-free survival (GRFS) were similar in both groups. There was no difference in transplantation-related toxicity (TRT) in terms of infection, hepatic dysfunction, oral mucositis, and engraftment syndrome between the haploidentical HSCT and HLA-matched HSCT groups. The study suggests that haploidentical HSCT shows comparable OS, LFS, and GRFS to HLA-matched HSCT in pediatric patients with acceptable complications, and can therefore be recommended as an effective alternative for this population.