Timing of Initiation of Calcineurin Inhibitors in Pediatric Haploidentical Transplantation with Post-Transplantation Cyclophosphamide: Effects on Survival, Relapse, and Cytokine Release Syndrome
Abstract The use of unmanipulated haploidentical stem cell transplantations (haplo-HSCT) with post-transplant cyclophosphamide (PTCY) in children has emerged as an acceptable alternative to the patients without a matched donor. However, the timing of calcineurin inhibitors (CNI) used in combination with PTCY is increasingly becoming a topic of controversy. We evaluated 49 children with acute leukemia who underwent unmanipulated haplo-HSCT with PTCY according to the initiation day of CNIs (pre- or post-CY). There were no significant differences in the overall survival analysis between the two groups. The cumulative incidence of relapse at 2 years was 21.2% in the pre-CY group and 38.9% in the post-CY group (p = 0.33). Cytokine release syndrome (CRS) was observed more frequently in the post-CY group. Our study shows that the argument for starting CNI administration after CY is tenuous, and the rationale for not starting CNI before CY needs to be reconsidered.