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.

Effects of Total Body Irradiation on Hematopoietic Cell Transplantation Outcomes in Pediatric Acute Myeloid Leukemia with Prior Central Nervous System Involvement

The 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. We analyzed a publicly available dataset derived from the Center for 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. The 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 (CR) between 2008 and 2016, who provided consent for research. Patients with mismatched related donor transplants and noncalcineurin 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. The Cox regression model and Fine-Grey methods were employed to delineate the effects of TBI and CNS disease on key HCT outcomes. The study cohort comprised 550 pediatric AML patients, of which 25% (n = 136) were AML-CNS(+). CNS involvement was more prevalent in patients aged 0 to 3 years, patients who were in the second CR, and those with a mismatched unrelated donor or umbilical cord blood. AML-CNS(+) patients demonstrated a lower relapse rate (hazard ratio: 0.50, 95% confidence interval: 0.33 to 0.76) compared to AML-CNS(-) patients, with comparable disease-free survival (DFS) and overall survival (OS) (P = .10 and 0.20, respectively) in the two cohorts. The entire TBI-treated cohort showed an association with increased risks of grade 2 to 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 nonrelapse mortality and a trend of higher grade 3 to 4 acute GVHD. In 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.

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.

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.

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.

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

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 Pretransplant Respiratory Virus Detection on Posttransplant Outcomes in Children Undergoing Hematopoietic Cell Transplantation.

Pretransplant respiratory virus (RV) infections have been associated with negative transplant outcomes in adult hematopoietic cell transplantation (HCT) recipients. In the era of HCT delay because of high-risk RVs, we examined the impact of pretransplant RV detection on transplant outcomes in pediatric HCT recipients. This retrospective cohort study included pediatric myeloablative allogeneic HCT recipients from 2010 to 2019. All patients were screened for RV at least once within 90 days before HCT using reverse transcriptase polymerase chain reaction (PCR), regardless of symptoms. Posttransplant outcomes included days alive and out of hospital and progression to lower respiratory tract infection (LRTI). Among 310 patients, 134 had an RV detected in the 90 days before HCT. In univariable analysis, transplant factors including younger age, total body irradiation, umbilical cord blood transplantation, lymphocyte count <100/mm3, HCT comorbidity index score ≥3, and viral factors including symptomatic infection, human rhinovirus as a virus type, and symptomatic pretransplant upper respiratory tract infection were associated with fewer days alive and out of hospital. In multivariable analysis, transplant factors remained significant, but not viral factors. There was a higher incidence of progression to posttransplant LRTI with the same pretransplant RV if the last positive PCR before HCT was ≤30 days compared with >30 days (P = .007). In the setting of recommending HCT delay for high-risk RVs, symptomatic upper respiratory tract infection, including human rhinovirus 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.

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

This 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.

Optimized BEAC conditioning regimen improves clinical outcomes of autologous hematopoietic stem cell transplantation in non-Hodgkin lymphomas

The conditioning regimen is an important part of autologous hematopoietic stem cell transplantation (ASCT). We explored the efficacy and safety of an optimized BEAC (adjusted-dose, intermediate-dose cytarabine and reduced-dose cyclophosphamide, AD-BEAC) conditioning regimen for non-Hodgkin lymphoma (NHL). A total of 141 NHL patients received AD-BEAC or a standard-dose BEAC (SD-BEAC) conditioning regimen from January 2007 to December 2017, and 104 patients were included in the study after 1:1 propensity matching. The 5-year overall survival (OS) and progression free survival (PFS) rates were significantly higher with AD-BEAC than with SD-BEAC (82.7% vs. 67.3%, P = 0.039; 76.9% vs. 57.7%, P = 0.039). Transplant-related mortality (TRM) was 3.8% in both the AD-BEAC and SD-BEAC groups. The AD-BEAC group had lower incidence of oral ulcers and cardiotoxicity than the SD-BEAC group. An optimized BEAC conditioning regimen is an effective conditioning regimen for ASCT in NHL with acceptable toxicity, that is more effective and safer than a standard BEAC conditioning regimen.

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.

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.

Disease Status and Interval between Hematopoietic Cell Transplantations Predict Outcome of Pediatric Patients Who Undergo Subsequent Transplantation for Relapsed Hematologic Malignancy

Patients with hematologic malignancies who relapse after allogeneic hematopoietic cell transplantation (HCT) have a poor prognosis. Although proceeding to subsequent HCT can provide potential for long-term survival, there are limited data to guide which patients are most likely to benefit and which HCT strategies are best in this heavily pretreated population. The goals of this study were to describe the clinical outcomes of subsequent HCT in pediatric patients with relapsed hematologic malignancies in a cohort enriched for haploidentical donors, and to evaluate the associations of patient-, disease-, and treatment-related factors with survival. We retrospectively evaluated patients who underwent a subsequent HCT for management of post-HCT relapse at a single institution between 2000 and 2021. Among 106 patients who underwent a second allogeneic HCT, the 1-year event-free survival (EFS) was 34% and 1-year overall survival (OS) was 46%, with a 5-year EFS of 26% and 5-year OS of 31%. Only disease-related factors were associated with outcome after second HCT-specifically, the interval between HCTs and the presence or absence of active disease at the time of HCT. In this cohort, patient- and treatment-related factors were not associated with differences in EFS or OS. Patients undergoing a third or fourth HCT (n = 13) had comparable survival outcomes to those undergoing a second HCT. Our experience highlights that a subsequent HCT has curative potential for a subset of patients who relapse after HCT, including those who undergo a subsequent HCT from a haploidentical donor. Although relapse and treatment-related toxicities remain major challenges, our study indicates that achieving complete remission prior to subsequent HCTs has the potential to further improve outcomes.

The Role of Autologous Hematopoietic Stem Cell Transplantation in the Therapy of Systemic AL Amyloidosis

Aim. To assess the outcomes of autologous hematopoietic stem cell transplantation (auto-HSCT) in systemic AL Amyloidosis patients treated at the R.M. Gorbacheva Scientific Research Institute of Pediatric Oncology, Hematology and Transplantation.&#x0D; Materials &amp; Methods. In the period from 2005 to 2022, auto-HSCT was performed in 33 patients with systemic AL Amyloidosis. In 7 of them, auto-HSCT was not preceded by the induction therapy “upfront”. From 2012 all patients received induction therapy prior to transplantation. The median age of patients was 54 years (range 38–68 years); among them there were 17 women and 16 men.&#x0D; Results. The 3-year follow-up period showed hematological response rate of 76 % (95% confidence interval [95% CI] 50–90 %), heart response rate of 27 % (95% CI 6–55 %), renal response rate of 76 % (95% CI 41–93 %), and hepatic response rate of 26 % (95% CI 8–50 %). The 5-year overall (OS) and progression-free (PFS) survivals were 71 % (95% CI 49–85 %) and 53 % (95% CI 32–71 %), respectively. The OS parameters in the group with delayed auto-HSCT, i.e., after induction therapy, were better than in the “upfront” group: 82 % (95% CI 60–93 %) vs. 43 % (95% CI 10–73 %) (p = 0.03). The OS parameters were affected by health status (p = 0.03), reduced left ventricular ejection fraction &lt; 60 % (p = 0.006), stage of heart disease (p = 0.016), and stage III kidney disease (p = 0.007). The PFS parameters depended on ECOG performance status (p = 0.004) and stage of heart disease (p = 0.041).&#x0D; Conclusion. The presented data confirm the results of the studies emphasizing the importance of induction therapy prior to auto-HSCT in the treatment of systemic AL Amyloidosis. More stringent parameters of renal function, left ventricular ejection fraction, and ECOG performance status can be used as criteria for auto-HSCT eligibility. Reduced melphalan doses, as conditioning regimen, can be administered to patients with pronounced comorbidity.

Decitabine-containing conditioning improved outcomes for children with higher-risk myelodysplastic syndrome undergoing allogeneic hematopoietic stem cell transplantation.

Myelodysplastic syndrome (MDS) is a rare clonal hematopoietic disorder in children. The risk stratification system and treatment strategy for adults are unfit for children. The role of hypomethylating agents (HMAs) in higher-risk childhood MDS has not been identified. This study aimed to investigate the outcomes of hematopoietic stem cell transplantation (HSCT) in children with higher-risk MDS at one single center. A retrospective study was conducted in children with higher-risk MDS undergoing HSCT between September 2019 and March 2023 at Blood Diseases Hospital CAMS. The clinical characteristics and transplantation information were reviewed and analyzed. A total of 27 patients were analyzed, including 11 with MDS with excess blasts (MDS-EB), 14 with MDS-EB in transformation (MDS-EBt) or acute myeloid leukemia with myelodysplasia-related changes (AML-MRC), and 2 with therapy-related MDS/AML (t-MDS/AML). Eight patients harbored monosomy 7. Before transplantation, induction therapy was administered to 25 patients, and 19 of them achieved bone marrow blasts <5% before HSCT. The stem cell source was unmanipulated-related bone marrow or peripheral blood stem cells for nineteen patients and unrelated cord blood for eight. All patients received decitabine-containing and Bu/Cy-based myeloablative conditioning; 26 patients achieved initial engraftment. The cumulative incidences of grade II-IV and grade III-IV acute graft-versus-host disease (GvHD) at 100 days were 65.4% and 42.3%, respectively. The incidence of cGvHD was 38.5%. The median follow-up was 26 (range 4-49) months after transplantation. By the end of follow-up, two patients died of complications and two died of disease progression. The probability of 3-year overall survival (OS) was 84.8% (95%CI, 71.1 to 98.5%). In summary, decitabine-containing myeloablative conditioning resulted in excellent outcomes for children with higher-risk MDS undergoing allogeneic HSCT.

The effect of center experience on allogeneic hematopoietic cell transplantation outcomes in acute myeloid leukemia.

This study aimed to address the prognostic impact of center experience based on the data of 7821 adults with acute myeloid leukemia who underwent allogeneic hematopoietic cell transplantation (HCT) from 2010 to 2019 in Japan, where medical care was provided within a uniform healthcare system. Center experience was defined based on the number of allogeneic HCTs performed for any indication during the study period, by which centers were divided into low-, intermediate-, and high-volume centers. After adjusting for known confounding factors, the risk of overall mortality was lowest for the high-volume centers and highest for the low-volume centers, with the difference between the center categories attributed primarily to the risk of relapse. Patients transplanted at high-volume centers had higher risks of acute and chronic graft-versus-host diseases but without an increased risk of non-relapse mortality (NRM). These findings reveal the presence of a center effect in allogeneic HCT conducted during the past decade in Japan, highlighting the difference in relapse based on center experience. The weaker effect on NRM compared with that on relapse suggests that the transplantation care quality is becoming equalized across the country.