Outcome Of Hematopoietic Cell Transplantation Research Articles

The role of donor type and pre-transplant immunosuppression on outcomes of hematopoietic stem cell transplantation in children and young adults with severe aplastic anemia.

The goal of this study was to assess the effect of donor type and pre-transplant immunotherapy (IST) on outcomes of hematopoietic stem cell transplantation (HSCT) for children and young adults with severe aplastic anemia (SAA). This retrospective, multi-center study included 52 SAA patients, treated in 5 pediatric transplant programs in Florida, who received HSCT between 2010 and 2020 as the first- or second-line treatment. The median age at HSCT for all 52 patients was 15 years (range 1-25). The 3-year overall survival (OS) by donor type were as follows: 95% [95% CI 85.4-99] for matched related donors (MRD) (N = 24), 84% [95% CI 63.5-99] for haploidentical (N = 13), and 71% [95% CI 36-99] for matched unrelated donors (MUD) (N = 7). The 3-year OS was 81% [95% CI 69.7-99] for all patients, 90.5% [95% CI 79.5-99] for non-IST patients (N = 27), and 70% [95% CI 51-99] for IST patients (N = 24) (log-rank p = .04). Survival of haploidentical HSCT (haplo-HSCT) recipients with post-transplant cyclophosphamide (PTCy) (N = 13) was excellent for both groups: 100% for non-IST patients (N = 3) and 80% for IST patients (N = 10). The 3-year OS for patients with previous IST by donor type in groups where >5 patients were available was 78.8% [95% CI 52.3-99] for haplo-HSCT (N = 10) and 66.7% [95% CI 28.7-99] for MUD (N = 6). Although it appears that patients receiving HSCT ≥6 months after the start of IST had worse survival, the number of patients in each category was small and log-rank was not significant(p = .65). Patients receiving MUD and haplo-HSCT with PTCy had similar outcomes, suggesting that haplo-HSCT with PTCy could be included in randomized trials of upfront IST versus alternative donor HSCT.

Hematopoietic Stem-Cell Transplantation: Exploring the Latest Advances and Gaps in Disparities, Psychosocial and Symptom Management Interventions, and Chronic Graft-Versus-Host Disease Care.

Although allogeneic hematopoietic cell transplantation (HCT) offers a potential for cure for many patients with advanced hematologic malignancies and bone marrow failure or immunodeficiency syndromes, it is an intensive treatment and accompanied by short- and long-term physical and psychological symptoms requiring specialized care. With substantial advances in therapeutic approaches for HCT and supportive care, HCT survivors experience less morbidity and mortality. However, disparities in both HCT access and outcomes persist, and HCT survivors and their caregivers often lack access to much-needed psychosocial care. Additionally, more medical and psychosocial resources are needed to holistically care for HCT survivors with chronic graft-versus-host disease (GVHD). Hence, this chapter focuses on three areas pertaining to advances and gaps in HCT care: disparities in access to and outcomes of HCT, psychosocial and physical symptom management with supportive care interventions, and GVHD prevention and management.

Pathobiological signatures of dysbiotic lung injury in pediatric patients undergoing stem cell transplantation.

Hematopoietic cell transplantation (HCT) uses cytotoxic chemotherapy and/or radiation followed by intravenous infusion of stem cells to cure malignancies, bone marrow failure and inborn errors of immunity, hemoglobin and metabolism. Lung injury is a known complication of the process, due in part to disruption in the pulmonary microenvironment by insults such as infection, alloreactive inflammation and cellular toxicity. How microorganisms, immunity and the respiratory epithelium interact to contribute to lung injury is uncertain, limiting the development of prevention and treatment strategies. Here we used 278 bronchoalveolar lavage (BAL) fluid samples to study the lung microenvironment in 229 pediatric patients who have undergone HCT treated at 32 children's hospitals between 2014 and 2022. By leveraging paired microbiome and human gene expression data, we identified high-risk BAL compositions associated with in-hospital mortality (P = 0.007). Disadvantageous profiles included bacterial overgrowth with neutrophilic inflammation, microbiome contraction with epithelial fibroproliferation and profound commensal depletion with viral and staphylococcal enrichment, lymphocytic activation and cellular injury, and were replicated in an independent cohort from the Netherlands (P = 0.022). In addition, a broad array of previously occult pathogens was identified, as well as a strong link between antibiotic exposure, commensal bacterial depletion and enrichment of viruses and fungi. Together these lung-immune system-microorganism interactions clarify the important drivers of fatal lung injury in pediatric patients who have undergone HCT. Further investigation is needed to determine how personalized interpretation of heterogeneous pulmonary microenvironments may be used to improve pediatric HCT outcomes.

Racial, Ethnic and Socioeconomic Diversity and Outcomes of Patients with Graft-versus-Host Disease: A CIBMTR Analysis

Socioeconomic status (SES) and race/ethnicity have been associated with outcomes of allogeneic hematopoietic cell transplantation (allo-HCT). Certain aspects of GVHD management such as the need for long term care, prolonged immunosuppressive treatment, and need for close follow up for complications may exacerbate disparities. Adults (≥ 18 years) reported to the Center for International Blood and Marrow Transplant Research (CIBMTR) who underwent a first alloHCT for acute leukemia, myelodysplastic syndrome, or myeloproliferative neoplasm between 2008 - 2018 were included. Endpoints for those developing GVHD included overall survival (OS), transplant related mortality (TRM), and disease relapse. Models were adjusted for patient and transplant related variables. A two-sided p-value < 0.01 was considered significant. Among the 14,825 allo-HCT recipients, 6,259 (42.2%) and 6,675 (45.0%) patients developed aGVHD and cGVHD, respectively. In patients with aGVHD, non-Hispanic Blacks had increased TRM (HR 1.50, 95% CI 1.24-1.83, p=0.0001) and overall mortality (HR 1.31, 1.14-1.50, p=0.0002) compared with non-Hispanic Whites, an association that disappeared when severity of aGVHD was included in the model. Lower SES was associated with increased risk of disease relapse (p=0.0016) but not OS or TRM. In patients who developed cGVHD, race and ethnicity were not associated with OS, TRM and disease relapse. However, the highest quartile of annual household income (≥ $80,000) had improved OS (HR 0.77, 0.69-0.85, p<0.0001) and reduced TRM (HR 0.86, 0.67-0.87, p<0.0001) compared with lowest quartile, adjusting for race and ethnicity. Race/ethnicity and SES are associated with outcomes after GVHD. Optimizing health care resources available to low SES patients and strategies to minimize the risk of severe GVHD in non-Hispanic Blacks may improve long-term outcomes.

Allogeneic haematopoietic cell transplantation for chronic myeloid leukaemia in Switzerland in the face of rapid development of effective drugs.

Until the year 2000, allogeneic haematopoietic cell transplantation (HCT) was the standard treatment for young and fit chronic myeloid leukaemia (CML) patients. CML was the main indication for allogeneic HCT. The introduction of tyrosine kinase inhibitors changed the treatment of CML patients dramatically. Allogeneic HCT was rapidly replaced by tyrosine kinase inhibitors as first-line treatment for CML, and the indication shifted to the treatment of non-responders, patients intolerant to tyrosine kinase inhibitors and patients whose CML is transforming to the accelerated phase and blast crisis. This paper describes changes in the use of transplantation technology for CML patients in the face of rapid drug development. All patients receiving a transplant for CML between 1997 and 2021 in Switzerland were included in the study. For the purpose of this analysis, time periods were analysed in quinquennia, 1997-2001 (Q1), 2002-2006 (Q2), 2007-2011 (Q3), 2012-2016 (Q4) and 2017-2021 (Q5), as the observation period spanned 25 years. Overall, 239 patients received a transplant. These included 96 in Q1, 56 in Q2, 25 in Q3, 34 in Q4 and 28 in Q5. Patient characteristics changed over time: recent patients were older and had a longer interval from diagnosis to transplantation because of tyrosine kinase inhibitor treatment. However, the proportions of patients receiving transplants during an early versus advanced disease stage differed little. Transplant technology changed, as well. Patients received intensive conditioning regimens less often due to higher age and more commonly had peripheral blood as opposed to bone marrow transplants. However, the type of stem cell donor selected did not differ. In a univariable analysis, there were no significant differences in survival, progression-free survival, non-relapse mortality, relapse incidence or incidences of acute and chronic graft-versus-host disease among the five quinquennia. In a multivariable analysis, older age, donors other than HLA-identical siblings and more advanced disease stage, but not the quinquennium, were associated with higher risk of death. Since the introduction of tyrosine kinase inhibitors haematopoietic cell transplantation has been used less frequently to treat CML. Patients in recent cohorts received transplants at an older age and later in the disease course; despite these higher risks, the outcome of allogeneic HCT has not worsened over time but has not improved, either. As the outcome is worse in advanced phases, it is important to conduct transplants before disease progression. Therefore, patients with advanced disease should be monitored closely and receive transplants in time.

Health professional attitudes and perceptions of prehabilitation and nutrition before haematopoietic cell transplantation.

Nutritional prehabilitation may improve haematopoietic cell transplantation (HCT) outcomes, although little evidence exists. The present study aimed to understand healthcare professional (HCP) perceptions of prehabilitation and nutritional care pre-HCT in UK centres. An anonymous online survey (developed and refined via content experts and piloting) was administered via email to multidisciplinary HCPs in 39 UK adult centres, between July 2021 and June 2022. Data are presented as proportions of responses. Routine provision denotes that care was provided >70% of time. Seventy-seven percent (n = 66) of HCPs, representing 61.5% (n = 24) of UK adult HCT centres, responded. All HCPs supported prehabilitation, proposing feasible implementation between induction chemotherapy (60.4%; n = 40) and first HCT clinic (83.3%; n = 55). Only 12.5% (n = 3) of centres had a dedicated prehabilitation service. Nutrition (87.9%; n = 58), emotional wellbeing (92.4%; n = 61) and exercise (81.8%; n = 54) were considered very important constituents. HCPs within half of the HCT centres (n = 12 centres) reported routine use of nutrition screening pre-HCT with a validated tool; 66.7% of HCPs (n = 36) reported using the malnutrition universal screening tool (MUST). Sixty-two percent (n = 41) of HCPs reported those at risk, received nutritional assessments, predominantly by dietitians (91.6%; n = 22) using the dietetic care process (58.3%; n = 14). Body mass index (BMI) was the most frequently reported body composition measure used by HCPs (70.2%, n = 33). Of 59 respondents, non-dietitians most routinely provided dietary advice pre-HCT (82.4%; n = 28 vs. 68%; n = 17, p = 0.2); including high-energy/protein/fat and neutropenic diet advice. Prophylactic enteral feeding pre-HCT was rare, indicated by low BMI and significant unintentional weight loss. Just under half (n = 25 of 59, 42.4%) HCPs reported exercise advice was given routinely pre-HCT. Nutrition and prehabilitation pre-HCT are considered important and deliverable by HCPs, but current provision in UK centres is limited and inconsistent.

Effects of total body irradiation on hematopoietic cell transplantation outcomes in pediatric acute myeloid leukemia with prior central nervous system involvement

BackgroundThe implications of previous central nervous system (CNS) involvement in children with acute myeloid leukemia (AML) undergoing hematopoietic cell transplantation (HCT) remain inadequately understood. Patients with CNS disease require more upfront CNS directed intrathecal therapy, but little is known about whether transplant conditioning regimens should be intensified or if previous CNS involvement impacts post HCT outcomes. While total body irradiation (TBI) remains standard for pediatric acute lymphoblastic leukemia myeloablative conditioning, it has been largely replaced with chemotherapy-only myeloablation in pediatric AML, primarily due to toxicity and late effects associated with TBI. In the setting of previous CNS involvement, it has been suggested that TBI-based myeloablation may have advantages due to superior CNS tissue penetration and thus decreased rates of AML relapse post HCT. ObjectiveWe analyzed a publicly available dataset derived from the Center of International Blood and Marrow Transplantation Research (CIBMTR) registry to characterize the impact of TBI in HCT preparative regimens in pediatric AML patients with a history of CNS involvement. MethodsThe study dataset was obtained from the CIBMTR data repository. The study cohort included patients aged ≤21 years who underwent initial allogeneic HCT with myeloablative conditioning for de novo AML in the first or second complete remission between 2008 and 2016, who provided consent for research. Patients with mismatched related donor transplant and non-calcineurin inhibitor graft-versus-host disease (GVHD) prophylaxis were excluded. The dataset was further modified by excluding patients with missing disease site data or those with non-CNS extramedullary disease. Patients were categorized as CNS-positive or -negative AML (AML-CNS(+) and AML-CNS(-), respectively) based on the disease status at diagnosis. Cox regression model and Fine Grey methods were employed to delineate the effects of TBI and CNS disease on key HCT outcomes. ResultsThe study cohort comprised 550 pediatric AML patients, of which 25% (n =136) were AML-CNS(+). CNS involvement was more prevalent in patients aged 0-3 years, patients who were in the second complete remission, and those with a mismatched unrelated donor or umbilical cord blood. AML-CNS(+) patients demonstrated a lower relapse rate (hazard ratio [HR]: 0.50, 95% confidence interval: 0.33-0.76) compared to AML-CNS(-) patients, with comparable disease-free survival (DFS) and overall survival (OS) (p =0.10 and 0.20, respectively) in the two cohorts. The entire TBI treated cohort showed an association with increased risks of Grade 2-4 acute GVHD, bloodstream infections, and endocrine dysfunction. TBI use within the AML-CNS(+) cohort was associated with a lower relapse rate but increased risks of non-relapse mortality and a trend of higher grade 3-4 acute GVHD. ConclusionIn this population-based analysis of pediatric patients with de novo AML undergoing HCT, TBI-based conditioning regimens did not confer an advantage in DFS or OS compared to non-TBI regimens, irrespective of CNS disease status. However, TBI use was associated with increased risks of short- and long-term comorbidities. These findings underscore the need for careful consideration of TBI in pediatric AML.

Hemophagocytic Lymphohistiocytosis Gene Variants in Severe Aplastic Anemia and Their Impact on Hematopoietic Cell Transplantation Outcomes

Hemophagocytic Lymphohistiocytosis Gene Variants in Severe Aplastic Anemia and Their Impact on Hematopoietic Cell Transplantation Outcomes

Impact of prior COVID-19 infection on allogeneic hematopoietic stem cell transplantation outcomes.

There are limited data on outcomes of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in recipients with prior COVID-19 infection. This single-center retrospective study included 54 adult patients who received allo-HSCT from July 2020 to September 2021 after previous COVID-19 infection and 122 control group patients without a history of COVID-19 who underwent HSCT during the same period, with a median follow-up of 17 months. Median time from COVID-19 to allo-HSCT was 211 days. The incidence of main complications in the post-transplant period was not significantly different between the two groups: deep vein thrombosis (p =.85), TMA (p=.8), VOD (p=.25), bloodstream infections (p=.21), pneumonia of any etiology (p=.41), viral infections (p=.85), invasive fungal disease (p=.08). The 2-year non-relapse mortality, relapse incidence, overall survival, and progression-free survival also were comparable in the study and the control groups: 22% (95% CI 10.5-36.2) versus 26.3% (95% CI 18.7-34.6) p =.4; 15.6% (95% CI 7.3-26.9) versus 23.6% (95% CI 16.0-32.3) p =.39; 67.9% (95% CI 50.4-80.3) versus 59.8% (95% CI 50.2-68.1) p =.24 and 62.3% (95% CI 45.5-75.3) versus 49.9% (95% CI 40.0-59.1) p =.18, respectively. The history of previous COVID-19 infection did not affect the results of allo-HSCT.

Outcome of Allogeneic Hematopoietic Stem Cell Transplantation in a Child with Myelodysplastic Neoplasm with Complex Karyotype and ETV6 Variant: Challenges in Treatment

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only treatment with the potential for cure in patients with myelodysplastic neoplasm (MDS). Nevertheless, disease relapse is the main cause of treatment failure. Due to the rarity of childhood MDS (cMDS), there are few studies showing the impact of cytogenetic alterations and genetic variants on outcomes of allo-HSCT, mainly focusing on clonal chromosomal evolution (CCE) during relapse post-transplant. Here, we describe a 3-year-old boy with cMDS-IB, who evolved to MDS/AML. At diagnosis, the patient showed a complex karyotype with chromosomal abnormalities not yet reported together in the same clone, and likely a pathogenic variant in the ETV6 gene. The patient was treated with HLA-matched sibling HSCT, but unfortunately relapsed after HSCT with clonal cytogenetic evolution. This unfavorable outcome suggests that the treatment of pediatric MDS associated with predictive factors of poor prognosis, such as complex karyotype and ETV6 variant remains a challenge.

The impact of pre-transplant respiratory virus detection on post-transplant outcomes in children undergoing hematopoietic cell transplantation.

Pre-transplant respiratory virus (RV) infections have been associated with negative transplant outcomes in adult hematopoietic cell transplantation (HCT) recipients. In the era of HCT delay due to high-risk RVs, we examined the impact of pre-transplant RV detection on transplant outcomes in a pediatric HCT recipients. This retrospective cohort study included myeloablative allogeneic HCT recipients from 2010 to 2019. All patients were screened for RV at least once within 90 days before HCT using RT-PCR, regardless of symptoms. Post-transplant outcomes included days alive and out of hospital (DAOH) and progression to lower respiratory tract infection (LRTI). Among 310 patients, 134 had a RV detected in the 90 days prior to HCT. In univariable analysis, transplant factors including younger age, total body irradiation, umbilical cord blood transplantation, lymphocyte count less than 100/mm3, and HCT comorbidity index score ≥3, and viral factors including symptomatic infection, human rhinovirus (HRV) as a virus type, and symptomatic pre-transplant upper respiratory tract infection (URTI) were associated with fewer DAOH. In multivariable analysis, transplant factors remained significant, but not viral factors. There was a higher incidence of progression to post-transplant LRTI with the same pre-transplant RV if the last positive PCR before HCT was ≤30 days compared to >30 days (p=0.007). In the setting of recommending HCT delay for high-risk RVs, symptomatic URTI, including HRV infections, may lead to increased duration of hospitalization and early progression to LRTI when transplantation is performed within 30 days of the last positive PCR test.

Neutrophil antigen antibodies affect engraftment and secondary graft failure in hematopoietic progenitor cell transplantation.

Research is limited on the role of antibodies against human neutrophil antigen (HNA) in hematopoietic progenitor cell (HPC) transplantation outcomes. A retrospective review was conducted on medical records of patients at the NIH Clinical Center enrolled in six research protocols. This case-control study included 21 patients tested for HNA antibodies from January 2010 to March 2022 who underwent HPC transplantation. In addition, 42 patients following the same research protocols were randomly selected as a control group. The cumulative incidence of time to neutrophil engraftment was significantly impacted by the patients' anti-HNA status (p = .042), with the patients with anti-HNA experiencing delayed engraftment. Secondary graft failure occurred in 4 out of 42 patients (9.52%; 95% confidence interval [CI]: 3.7-22.1) of the control group, while 5 out of 9 patients (55.5%; 95% CI: 26.7-81.1) with anti-HNA experienced secondary graft failure (p = .005). Furthermore, patients with anti-HNA had a lower proportion (p = .008 for full and p = .002 for partial chimerism) and cumulative incidence (p = .016 for full and p = .010 for partial chimerism) of achieving donor chimerism compared to the control group. The study reveals a potential link between anti-HNA and HPC transplantation outcomes not previously reported. Patients with anti-HNA had a lower proportion and cumulative incidence of achieving donor chimerism. Additionally, anti-HNA status affected the time for neutrophil engraftment, with a slower rate of neutrophil engraftment and increased risk of secondary failure in patients with anti-HNA.

Outcomes of allogeneic haematopoietic cell transplantation for myelofibrosis in children and adolescents: the retrospective study of the EBMT Paediatric Diseases WP

AbstractThis retrospective study evaluated 35 children (median age 5.2 years; range 0.4–18) with myelofibrosis (MF), including 33 with primary myelofibrosis and 2 with secondary myelofibrosis transplanted from matched sibling donor (MSD) (n = 17) or non-MSD (n = 18) between 2000 and 2022. Conditioning was usually chemotherapy-based (n = 33) and myeloablative (n = 32). Fifteen patients received bone marrow (BM), 14 haematopoietic cells (HC) from peripheral blood (PB), and 6 from cord blood (CB). Day +100 acute GvHD II–IV incidence was significantly lower after MSD-haematopoietic cell transplantation (MSD-HCT) than after non-MSD-HCT [18.8% (4.3–41.1) vs 58.8% (31–78.6); p = 0.01]. Six-year non-relapse mortality (NRM) was 18% (7.1–32.8), relapse incidence was 15.9% (5.6–30.9), progression-free survival (PFS) was 66.1% (47–79.7), GvHD-free relapse-free survival was 50% (30.6–66.7), and overall survival (OS) was 71.1% (51.4–84). Six-year PFS and OS were significantly higher after BM transplantation compared to HCT from other sources [85.1% (52.3–96.1) vs 50.8% (26.3–71), p = 0.03, and 90.9% (50.8–98.7) vs 54% (28.1–74.2), p = 0.01, respectively], whereas NRM was significantly lower [0% vs 32% (12.3–53.9); p = 0.02]. This first multicentre study on outcomes of allogeneic HCT in children with myelofibrosis proves feasibility and curative effect of transplantation in these children, suggests that bone marrow transplantation is associated with better outcomes, and indicates the need for further studies.

Upfront allogeneic hematopoietic stem cell transplantation for adult T-cell acute lymphoblastic leukemia/lymphoma in first complete remission: a single-center study.

Real-world data on outcomes of upfront allogeneic hematopoietic stem cell transplantation (allo-HCT) for adult T-cell acute lymphoblastic leukemia/lymphoma (T-ALL) patients in first complete remission (CR1) is still lacking. A single center retrospective study was conducted from 94 consecutive patients received their first allo-HCT between 2010 and 2021, which include 76 patients received upfront allo-HCT and 18 patients received allo-HCT in non-upfront settings. There were no significant differences in most variables. In the upfront allo-HCT group, 52 (68%) patients achieved CR1 with one cycle of induction regimen. 24 (32%) patients achieved CR1 with more than one cycle. In the non-upfront group, there were 14 patients with active disease and 4 patients in second CR before transplant. The majority of patients received antithymocyte globulin-based graft-versus-host disease prophylaxis. Median follow-up time was 51 months for both groups. 5-year overall survival (OS) was 54% in the upfront allo-HCT group. While, in the non-upfront group, 5-year OS were 19% (P = 0.013). 5-year progression free survival in the upfront group was higher than that in the non-upfront group (50% versus 20%, P = 0.02). 5-year cumulative incidence relapse rate was significantly higher in non-upfront group (64% vs. 32%, P = 0.006). While, there was no difference in the 5-year non-relapse mortality (NRM) rate (19% versus 16%, P = 0.56). The most common cause of death was disease progression. In multivariable analysis, non-upfront allo-HCT (hazard ratios (HR) 2.14, P = 0.03) and HCT-CI (≥ 2) (HR 6.07, P = 0.002) were identified to be associated with worse OS. Non-upfront allo-HCT and HCT-CI (≥ 2) were also found to be independent risk factors for higher relapse rate. While, haploidentical-HCT was found to be associated with increased NRM. Our study indicated that allo-HCT remains an important curative treatment for adult patients with T-ALL, especially when it was performed in the upfront setting.

Comparable outcomes of allogeneic peripheral blood versus bone marrow hematopoietic stem cell transplantation from a sibling donor for pediatric patients.

Traditionally, bone marrow (BM) has been preferred as a source of stem cells (SCs) in pediatric hematopoietic SC transplantation (HSCT); however, the use of peripheral blood SCs (PBSC) has recently increased. With advancing graft-versus-host disease (GVHD) prophylaxis, whether the BM is still a better SC source than PB in sibling donor HSCT remains controversial. Here, we compared the results of BM transplantation (BMT) and PBSC transplantation (PBSCT) in pediatric patients with malignant or non-malignant diseases receiving sibling HSCT using a total of 7.5mg/kg of anti-thymocyte globulin (ATG). We retrospectively reviewed children who received HSCT from a sibling donor between 2005 and 2020 at Seoul National University Children's Hospital. Of the 86 patients, 40 underwent BMT, and 46 underwent PBSCT. Fifty- six patients had malignant diseases, whereas thirty patients had non-malignant diseases. All conditioning regimens comprised ATG. Busulfan-based myeloablative conditioning regimens were administered to patients with malignant diseases and approximately half of those with non-malignant diseases. The remaining half of the patients with non-malignant diseases were administered cyclophosphamide-based reduced- intensity conditioning regimens. According to studies conducted at our center, all BM donors received G-CSF before harvest to achieve early engraftment. In all 86 patients (47 males and 39 females), the median age at the time of HSCT was 11.4 (range, 0.7 - 24.6) years. The median follow-up period was 57.9 (range, 0.9-228.6) months, and the corresponding values for those with BM and PBSC were 77 (range, 2.4-228.6) months and 48.7 (range, 0.9-213.2) months, respectively. Engraftment failure occurred in one patient with BM and no patient with PBSC. The cumulative incidence of acute GVHD with grades II-IV was higher in PBSC (BM 2.5%, PBSC 26.1%, p = 0.002), but there was no significant difference in those with grades III-IV acute GVHD (BM 0%, PBSC 6.5%, p = 0.3703) and extensive chronic GVHD (BM 2.5%, PBSC 11.6%, p = 0.1004). There were no significant differences in treatment-related mortality (TRM) (BM 14.2%, PBSC 6.8%, p = 0.453), 5-year event-free survival (EFS) (BM 71.5%, PBSC 76.2%, p = 0.874), and overall survival (OS) rates (BM 80.8%, PBSC 80.3%, p = 0.867) between BM and PBSC in the univariate analysis. In the multivariate analysis, which included all factors with p < 0.50 in the univariate analysis, there was no significant prognostic factor for EFS or OS. There was no significant difference in the relapse incidence between BM and PBSC among patients with malignant diseases (BM 14.2%, PBSC 6.8%, p = 0.453). Additionally, there were no significant differences in the TRM, 5-year EFS, and OS rates between malignant and non-malignant diseases nor between the busulfan-based myeloablative regimen and reduced-intensity chemotherapy using cyclophosphamide. In this study, we showed no significant differences in EFS, OS, TRM, and GVHD, except for acute GVHD grades II-IV, between BMT and PBSCT from sibling donors, using ATG (a total of 7.5mg/kg). Therefore, PB collection, which is less invasive for donors and less labor-intensive for doctors, could also be considered an acceptable SC source for sibling donor HSCT in children.

Abstract LB066: Acute systemic beta-adrenergic receptor activation to improve graft composition and outcomes in hematopoietic stem cell transplantation

Abstract Background: Graft-versus-host disease (GvHD) and relapse persist as significant hurdles in achieving successful outcomes following allogeneic hematopoietic cell transplantation (alloHCT). The composition of the graft plays a substantial role in influencing transplant outcomes. Higher numbers of naïve CD4 and naïve CD8 T cells correlate with increased GvHD risk, conversely, elevated numbers of NK cells are associated with enhanced graft-versus-leukemia (GvL) effects. Acute systemic β-adrenergic receptor activation triggers the mobilization of favorable effector lymphocytes into the bloodstream, leading to a significant alteration in the composition of circulating immune cells. Aim: This study investigated whether infusion with the non-selective beta-agonist isoproterenol (ISO), following granulocyte colony-stimulating factor (G-CSF) mobilization, would enhance human peripheral blood hematopoietic cell (PBHC) grafts and improve transplant outcomes in NSG mice. Methods: Ten healthy volunteers received ISO infusion (50 ng/kg/min) for 20 minutes after 5 days of G-CSF. Blood samples were collected before and during the last 5 minutes of ISO infusion. Results: ISO infusion increased the total number of G-CSF-mobilized CD34 cells (28±13 cell/µl to 32±13 cells/µl) and significantly improved G-CSF-mobilized PBHC composition, increasing favorable graft cell subsets—NK cells (9.5% to 27.9%) and γδ T cells (5.0% to 7.5%)—and reducing unfavorable graft components—B cells (12.6% to 7.7%), naïve CD4 (18.1% to 11.2%), and naïve CD8 (8.9% to 5.8%) T cells (all p&amp;lt;0.05). NSG mice receiving G-CSF+ISO mobilized grafts exhibited lower GvHD (P=0.012) and extended survival (median survival: G-CSF alone = 45 days, G-CSF+ISO = 78 days) compared to mice receiving grafts mobilized by G-CSF alone. No difference in human CD45 engraftment was observed between the groups, with ~50% engraftment in both groups of mice. Upon challenge with the K562 chronic myeloid leukemia cell line, 42% of NSG-Tg(Hu-IL15) mice receiving G-CSF+ISO mobilized grafts were alive with low tumor burden at day 40, compared to 15% of mice receiving G-CSF mobilized grafts. In vitro, PBHC mobilized by G-CSF+ISO demonstrated an 8-fold increase in cytolysis against K562 compared to PBHC mobilized by G-CSF only (P=0.0002). Conclusion: ISO infusion post-G-CSF treatment favorably enhances graft composition, mitigates GvHD, prolongs survival, and augments GvL effects. Our findings suggest that acute systemic beta-adrenergic receptor activation could be a valuable strategy to enhance outcomes in alloHCT. Citation Format: Helena Batatinha, Grace M. Niemiro, Nicole Pena, Giovannah Hoskin, Preteesh Mylabathula, Forrest Baker, Tiffany Zuniga, Kyle Smith, Douglass Diak, Michael Seckeler, Emmanuel Katsanis, Richard Simpson. Acute systemic beta-adrenergic receptor activation to improve graft composition and outcomes in hematopoietic stem cell transplantation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB066.

Impact of Early Cytomegalovirus Reactivation After Allogeneic Hematopoietic Stem Cell Transplantation on Relapse in Patients With Myelodysplastic Syndrome: A Nationwide Retrospective Study From Adult Myelodysplastic Syndrome Working Group of the JSTCT

Cytomegalovirus (CMV) reactivation is a prominent complication associated with adverse outcomes in allogeneic hematopoietic stem cell transplantation (HSCT). However, CMV reactivation after allogeneic HSCT may be associated with a lower incidence of relapse in some hematological malignancies. This study analyzed the Japanese registry data from 1082 patients with myelodysplastic syndrome (MDS) who underwent their first allogeneic HSCT and survived for 100 days after transplantation without graft failure or disease relapse to investigate this association. Patients who received cord blood transplants, demonstrated in vivo T cell depletion, underwent prophylactic anti-CMV treatment, or diagnosed with secondary MDS were excluded. CMV reactivation measured by pp65 antigenemia within 100 days after allogeneic HSCT was observed in 57.5% of patients, with a median time of 46 days from transplant. The 5-yr overall survival and cumulative incidence of relapse (CIR) in the cohort were 60.5% and 15.6%, respectively. The 5-yr CIR showed no significant difference between patients with and without CMV reactivation (14.4% versus 17.2%; P = .185). Interestingly, CMV reactivation within 100 days was significantly associated with a lower 5-yr CIR (7.6% versus 16.4%; P = .002) in patients with <5% myeloblasts in the bone marrow (BM) just before HSCT. Furthermore, this relevancy confirmed even when excluding patients with Grade II to IV acute GVHD (Hazard ratio: 0.38; 95% confidential intervals: 0.18–0.801; P = .011). Our findings indicate a correlation between early CMV reactivation and MDS relapse, based on the proportion of myeloblasts in the BM. These results may contribute to the development of effective CMV prophylaxis post-HSCT.

Improving outcomes of hematopoietic stem cell transplant for leukemia in children and young adults in resource-limited setting

IntroductionAllogeneic hematopoietic stem cell transplantation (HSCT) is a curative approach in patients with relapsed and high-risk leukemia. This retrospective analysis aimed to investigate outcomes and risk factors associated with HSCT in children and young adults with hematological malignancies in a resource-limited setting. MethodsWe retrospectively evaluated 48 pediatric and young adult patients diagnosed with hematological malignancies who underwent HSCT at our institution between April 2017 and Jan 2023. ResultThe median age of the cohort was 10 years (6 months - 21 years), and the majority of patients underwent transplants for acute lymphoblastic leukemia (ALL) (n = 24; 50 %) and acute myeloid leukemia (n = 18; 37.5%). Median time to neutrophil and platelet engraftment were 15 days (range 9–28) and 18 days (range 9–40), respectively. One patient had primary graft failure. Cytomegalovirus reactivation occurred in 21 patients (43.8%). Seventeen patients received escalated donor lymphocyte infusion (DLI). With a median follow-up of 902 days (52–2490), the probability of event free survival and overall survival (OS) was 65.9% and 69.4%. OS for lymphoid and myeloid malignancies were 64.7% and 75.2%, respectively. Kaplan-Meier probabilities of OS for patients in first complete remission (CR), CR2, CR3, or with refractory disease were 80%, 76.2%, 0%, and 40%, respectively (p = 0.02). OS of the patients undergoing matched sibling donor (n = 17) or haploidentical HSCT (n = 31) was 70.6% and 69%, respectively (p = 0.989). ConclusionsOur study demonstrates excellent outcomes of patients with hematological malignancies undergoing allogeneic HSCT with similar outcomes in HLA-identical sibling donors and haploidentical first-degree family donors. Prophylactic DLI might be considered in patients with high-risk leukemia to prevent relapse, including ALL.

Pretransplant Blinatumomab Improves Outcomes in B Cell Acute Lymphoblastic Leukemia Patients Who Undergo Allogeneic Hematopoietic Cell Transplantation

BackgroundBlinatumomab, a bispecific monoclonal antibody, effectively controls refractory B cell acute lymphoblastic leukemia (ALL) and promotes measurable residual disease (MRD) negativity. This study investigated the impact of pretransplant blinatumomab on allogeneic hematopoietic cell transplantation (HCT) outcomes in B cell ALL patients. MethodsWe analyzed the effect of pretransplant blinatumomab on transplant outcomes of 117 adults undergoing allogeneic HCT for B cell ALL at Princess Margaret Hospital, Toronto, between 2010 and 2021. Outcomes assessed included overall survival (OS), graft-versus-host disease and relapse-free survival (GRFS), cumulative incidences of relapse (CIR), and nonrelapse mortality (NRM). ResultsThe median follow-up was 36 months. Thirty-one participants (26.5%) received blinatumomab. Blinatumomab group had higher proportions of individuals with high disease risk index, primary induction failure and was more likely to receive dual T cell depletion with antithymocyte globulin and post-transplant cyclophosphamide. Two-year OS, GRFS, NRM, and CIR in the blinatumomab and nonblinatumomab groups were, respectively: 65.4% versus 45.6% (P = .05), 42.2% versus 17.3% (P = .01), 3.2% versus 43.0% (P = .007) and 34.4% versus 14.4% (P = .02). Blinatumomab was associated with a lower incidence of day-100 grade 2 to 4 and grade 3 to 4 acute graft-versus-host disease (aGVHD): 27.5% versus 56.7% (P = .009), and 10.9% versus 34.7% (P = .04), respectively. Multivariate analysis confirmed the association between pretransplant blinatumomab and improved OS and NRM. ConclusionsPretransplant blinatumomab is associated with improved OS and lower risk of NRM in B cell ALL patients undergoing allogeneic HCT, likely reflecting lower burden of treatment-related toxicity in this population. Larger prospective trials are warranted to validate our findings.

Projected Impact of Omidubicel-onlv on Racial/Ethnic Disparities in Allogeneic Hematopoietic Cell Transplantation (Allo-HCT) Outcomes in Hematologic Malignancies.

In a phaseIII clinical trial (NCT02730299), omidubicel-onlv, a nicotinamide-modified allogeneic hematopoietic progenitor cell therapy, showed rapid hematopoietic and immune recovery compared with standard umbilical cord blood (UCB) transplant across all racial/ethnic groups. A decision-tree model was used to project the effect of omidubicel-onlv availability on addressing health disparities in allogeneic hematopoietic cell transplantation (allo-HCT) access and outcomes for patients with hematologic malignancies. The model used a hypothetical population of 10,000 allo-HCT-eligible US adults, for whom matched related donors were not available. Patients received matched or mismatched unrelated donor, haploidentical, UCB transplant, or no transplant. Scenarios with omidubicel-onlv use of 0% (status quo), 10%, 15%, 20%, and 30% were modeled on the basis of proportional reductions in other allo-HCT sources or no transplant by racial/ethnic group. Increased omidubicel-onlv use was associated with a higher proportion of patients undergoing allo-HCT, decreased time to allo-HCT, decreased 1-year non-relapse mortality, and increased 1-year overall survival, particularly among racial minorities. In the scenario modeling 20% omidubicel-onlv use, the proportion of Black patients receiving allo-HCT increased by 129%; increases were also observed in Asian (64%), Hispanic (45%), and other (42%) patient groups. Modeled time to allo-HCT improved among transplanted patients (23%) from 11.4weeks to 8.8weeks. One-year OS in the overall population increased by 3%, with improvements ranging from 3% for White patients to 5% for Black patients. This study demonstrates that broad access to omidubicel-onlv could increase access to allo-HCT and improve outcomes for patients, with the greatest benefits seen among racial/ethnic minority groups.