Race as a factor in donor selection and survival of children with hematologic malignancies undergoing hematopoietic stem cell transplant in Florida

Background Previous studies have explored posthematopoietic cell transplant (HCT) outcomes by race in adults; however, pediatric data addressing this topic are scarce. Procedure This retrospective registry study included 238 White (W) and 57 Black (B) children with hematologic malignancies (HM) receiving first allogeneic HCT between 2010 and 2019 at one of the five Florida pediatric HCT centers. Results We found no differences between W and B children in transplant characteristics, other than donor type. There was a significant difference in use of human leukocyte antigen (HLA)‐mismatched donors (HLA‐MMD) (53% W, 71% B, p = .01). When comparing HLA‐MMD use to fully HLA‐matched donors, B had relative risk (RR) of 1.47 (95% CI 0.7–3) of receiving a mismatched unrelated donor (MMUD), RR of 2.34 (95% CI 1.2–4.4) of receiving a mismatched related donor (MMRD), and RR of 1.9 (95% CI 0.99–3.6) of receiving a mismatched cord blood donor (MMCBD) HCT, respectively. There was no significant difference in the incidence of aGVHD (48% W, 35% B), p = .1, or cGVHD (19% W, 28% B, p = .1), or primary cause of death. Overall 24‐month survival was 61% (95% CI 55%–68%) for W, and 60% (95% CI 48–75) for B children, log‐rank p = .7. While HLA matching improved survival in W children, the number of B children receiving HLA‐matched HCT was too small to identify the impact of HLA matching on survival. Conclusions In this contemporary cohort of children with HM, we found that B children were more likely to receive HLA‐MMD transplants, but this did not adversely affect survival or GVHD rates

Early mixed chimerism‐based preemptive immunotherapy in children undergoing allogeneic hematopoietic stem cell transplantation for acute leukemia

This retrospective analysis comprises 10-year experience with early posttransplant mixed chimerism-based preemptive intervention. Out of 104 patients, 51 received preemptive immunotherapy. Their outcomes were similar to patients achieving full donor chimerism spontaneously. Among patients receiving intervention, 5-year event-free survival was identical in patients with and without pretransplant residual disease, respectively (68% [95% confidence interval (CI) 38-98%] vs. 69% [95% CI 54-85%] log-rank = 0.4). In patients who received preemptive immunotherapy, chimerism status and residual disease prior to transplant were no longer predictors of poor outcome; however, 41% of the patients with residual disease prior to transplant relapsed early and did not benefit from this strategy

Florida Pediatric Bone Marrow Transplant and Cell Therapy Consortium (FPBCC) Pediatric Outcomes Analysis Using Enhanced Data Back to Centers (eDBtC) Platform

Florida, with 4.1 million children, has six small pediatric BMT programs which are distributed across the state facilitating access to transplant. However, the literature indicates a survival advantage when transplants are done in a larger center with disease-specific expertise. In addition to lack of expertise across all diseases, it is more difficult for smaller centers to use their experience to improve patient outcomes as each center's analyses are skewed due to small number of transplants. In 2018, five Florida Pediatric BMT centers formed a consortium (Florida Pediatric BMT and Cell Therapy Consortium – FPBCC) with the goal of sharing data, clinical collaboration, and increasing patient base for retrospective and early stage clinical trials. The ultimate goal is to increase knowledge about utilization of pediatric BMT and its outcomes in a geographically defined population of children. This knowledge will help develop interventions for practice improvement. After signing a memorandum of understanding for FPBCC and data use agreements, and after obtaining IRB approvals for retrospective data analyses, we gathered data from all pediatric BMT transplants performed in 5 Florida Pediatric BMT centers between 2014 and 2016. We utilized the CIBMTR eDBtC (enhanced data back to center) platform to gather data reported to the CIBMTR. De-coded CIBMTR data were downloaded by each center and forwarded to the FPBCC for analysis. Four hundred and fifteen transplants were done in the five Florida centers over the 3-year study period. However, we present 377 transplants performed in 301 children who were ≤18 years at the time of transplant. The majority (58%) of first transplant recipients were male, 28% were ≤3 years of age and 68% were ≤10 years of age at time of transplant. By race, the majority of recipients were Caucasians (70%) followed by AA (21%). The majority of transplants (61%) were allogeneic with 81% of them being first, and 9% being second or a subsequent transplant. Unrelated donor was the most common donor type (64%). Among related transplant donors, 25% were mismatched. Bone marrow was used as a stem cell source in 58% of first allogeneic transplants, cord blood in 26%, and PBSCs in 16%. Among autologous transplants, 38% were second or subsequent transplant. The most common indications for allogeneic transplant were acute lymphoblastic leukemia (33%), myelogenous leukemia (20%) sickle cell disease (8%) and primary immune deficiencies (5%). In the autologous group, the most common indication for transplant was neuroblastoma (37%), followed by medulloblastoma and other brain tumors (18% each). We showed that data obtained through collaboration of programs using the eDBtC platform could lead to better understanding of activity and trends in transplant in a defined patient population. This consortium will continue with data validation and analyses in order to identify areas for improvement

Pediatric HCT in Florida (2014 ‐2016): A report from the FPBCC

FPBCC was formed in 2018 by five pediatric transplant programs in Florida. One of the key objectives of the consortium is to provide outcome analyses by combining HCT data from all the participating centers in order to identify areas for improvement. In this first FPBCC landscape report we describe the patient and transplant characteristics of pediatric patients undergoing first allo and auto HCT between 2014 and 2016 in Florida. The source of data was eDBtC of the CIBMTR. Over the span of 3 years, a total of 230 pediatric patients underwent allo-HCT and 104 underwent auto-HCT at the participating centers. The most significant predictor of survival in allo-HCT recipients with malignant disorders was the degree of HLA- match, while in the recipients of allo-HCT with non-malignant disorders the predictors of survival included age, donor relationship and degree of HLA match. Our analyses identified the need to improve reporting of primary cause of death and improve on donor selection process given that the degree of HLA match remains the most important predictor of survival. This first FPBCC-wide review describes the trends in pediatric HCT activity between 2014 and 2016 among the participating centers in Florida and confirms feasibility of using eDBtC data platform and collaborative approach in order to identify areas for improvement in outcomes