BACKGROUND: Rabbit anti-thymocyte globulin (rATG) decreases the risk of graft failure and graft-versus-host disease (GVHD) in a setting of allogenic hematopoietic cell transplantation (HCT) but has highly variable pharmacokinetics. Recently, it was shown that a dosing nomogram based on recipient bodyweight and absolute lymphocyte count reduced rATG overexposure, which led to faster immune reconstitution. The aim of this study is to evaluate the feasibility and benefits of using an rATG dosing nomogram to achieve early CD4 METHODS: The rATG dosing nomogram in pediatric patients with IEM receiving an umbilical cord blood transplant with busulfan-based myeloablative conditioning at the University of Minnesota Masonic Children's Hospital was used prospectively since 2017. The primary endpoint was CD4 RESULTS: A total of 27 patients were included in the study. Median follow-up time was 31 months (interquartile range [IQR], 22-38) and median age was 1.5 years (IQR, 0.7-3.9). The underlying disease was Hurler syndrome in 17 (63%), Hunter syndrome in 4 (15%), and cerebral adrenoleukodystrophy in 4 (15%) patients
2 patients were transplanted for other IEM. The CD4 CONCLUSION: In patients with IEM, individualized dosing of rATG was associated with a robust and early CD4