Comprehensive up-to-date analysis on TCRαβ/CD19-depleted hematopoietic stem cell transplantation in pediatric hematological malignancies

This meta-analysis assesses the efficacy of TCR alpha beta+/CD19+ depleted hematopoietic stem cell transplantation (HSCT) in pediatric patients with hematological malignancies, bridging the gap in the heterogeneous results of published studies. We analyzed post-HSCT complications and survival outcomes in 1068 children across 14 studies, using both aggregated and patient-level data from acute myeloid leukemia/myelodysplastic syndromes (AML/MDS) and acute lymphoblastic leukemia (ALL) studies, employing the IPDfromKM technique for time-toevent data reconstruction. The analysis reveals a 95 % engraftment success rate (95 % CI: 93-97) and 6-year overall survival and disease-free survival (DFS) rates of 67.2 % and 66.3 %, respectively, with no significant differences in DFS between haploidentical and unrelated donors (hazard ratio = 0.9, 95 % CI: 0.53-1.55). Acute graft-versus-host disease (GvHD) grades III-IV and chronic GvHD incidences were 8 % (95 % CI: 6-11) and 17 % (95 % CI: 10-27). The relapse rate was 27 % (95 % CI: 21-33), with relapse-related mortality at 21 % (95 % CI: 15-28) and HSCT-related mortality at 12 % (95 % CI: 7-19). Relapse was significantly lower in patients (mostly ALL) receiving total body irradiation (risk ratio = 0.53, P = 0.04). These findings underscore TCR alpha beta/CD19depleted HSCT as a valuable option for patients without HLA-matched donors, highlighting the need for larger, multicenter studies.