LAUSR

Limited information is available on outcomes of haploidentical stem cell transplantation (haploSCT) with posttransplant cyclophosphamide using myeloablative conditioning regimens in children and adolescents. We report the results of a single-institution retrospective study of myeloablative haploSCT in 36 children and adolescents (median age, 8 y; range, 9 mo to 22 y) with high-risk hematologic malignancies. Donor engraftment occurred in 31 of 33 evaluable patients (94%). Recovery of neutrophils and platelets occurred at a median of 15 and 20 days. Cumulative incidence of acute graft-versus-host-disease (GVHD) grades II to IV and grades III to IV at 100 days was 36±8.7% and 10±5.4% and of chronic GVHD at 1 year was 55±9.2%, with 31±8.6% moderate to severe. Nonrelapse mortality was 16±6.1% and 22±6.9% at 100 days and 1 year. The cumulative incidence of relapse at 4 years was 32±8.8%. With a median follow-up of 57 months (range, 8 to 89 mo), the overall survival and event-free survival at 4 years was 55.6±8.7% and 44.8±8.5%. Myeloablative conditioning T-replete haploSCT with posttransplant cyclophosphamide is a viable alternative to matched unrelated transplantation for children and adolescents with high-risk hematologic malignancies. The high rates of nonrelapse mortality and chronic GVHD is a concern and deserves careful consideration.