The treatment of relapsed/refractory acute myeloid leukemia (AML) is associated with a dismal prognosis. The allogeneic hematopoietic cell transplantation (allo-HCT) is frequently performed as salvage therapy. Reduced intensity conditioning protocols have been developed with the aim of reducing the leukemia burden without increasing their toxicity. We compared the reduced intensity conditioning FM140 (fludarabine, 150 mg/m2; melphalan 140 mg/m2) with FBM110 (fludarabine 150 mg/m2; BCNU, also known as carmustine, 300-400 mg/m2; and melphalan 110 mg/m2). From the European Bone Marrow Transplantation (EBMT) Acute Leukemia Working Party registry, we identified 293 adult patients (FM140, n = 118 and FBM110, n = 175) with AML with relapsed/refractory disease prior to allo-HCT. There were some differences such as age (FM140 = 59.5 years vs. FBM110 = 65.1 years, p < 0.001) and graft-versus-host disease (GvHD) prophylaxis based on in vivo T-cell depletion (TCD, FM140 = 39% vs. FBM110 = 75%, p < 0.001). No differences were observed between FM140- and FBM110-treated patients regarding overall survival (OS) (2-year OS: 39.3% vs. 45.7%, p = 0.58), progression-free survival (PFS) (2-year PFS: 36.1% vs. 37.3%, p = 0.69), non-relapse mortality (NRM) (2-year NRM: 15.3% vs. 25.7%, p = 0.10) and relapse incidence (RI) (2-year RI: 48.6% vs. 37.0%, p = 0.7). In conclusion, despite differences in age and GvHD prophylaxis, AML patients with active disease undergoing allo-HCT after FBM110 conditioning showed similar outcomes compared to FM140.

• MeSH
• Leukemia, Myeloid, Acute * therapy   mortality   MeSH
• Adult MeSH
• Transplantation, Homologous methods   MeSH
• Carmustine therapeutic use   administration & dosage   MeSH
• Middle Aged MeSH
• Humans MeSH
• Melphalan * therapeutic use   administration & dosage   MeSH
• Transplantation Conditioning methods   MeSH
• Antineoplastic Combined Chemotherapy Protocols therapeutic use   MeSH
• Recurrence MeSH
• Registries * MeSH
• Aged MeSH
• Hematopoietic Stem Cell Transplantation * methods   MeSH
• Vidarabine * analogs & derivatives   therapeutic use   administration & dosage   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Multicenter Study MeSH
• Comparative Study MeSH

AIMS: Allogeneic haematopoietic stem cell transplantation (allo-HSCT) is a vital treatment for various paediatric malignant and nonmalignant diseases. The conditioning treatment before allo-HSCT is crucial for successful engraftment. Treosulfan, a cytotoxic prodrug, has gained popularity due to its lower toxicity compared to traditional alkylating agents used for conditioning treatment. METHODS: We investigated the relationship between pharmacokinetics and pharmacodynamics of treosulfan in paediatric patients, in a substudy pooling from 2 multicentre phase 2 clinical trials. A total of 83 children with malignant and nonmalignant diseases received treosulfan-based conditioning. Treosulfan exposure and its relationship with clinical outcomes, including survival, graft failure and graft-vs.-host disease, were investigated. RESULTS: Our findings reveal no significant association between treosulfan exposure and the key clinical outcomes or toxicity (P-values between .22 and .99), if the dosing is based on the approved product information. CONCLUSION: These findings suggest that treosulfan exposure after standardized body surface area-based dosing is appropriate in paediatric allo-HSCT.

• MeSH
• Antineoplastic Agents, Alkylating * adverse effects   administration & dosage   therapeutic use   pharmacokinetics   MeSH
• Busulfan * analogs & derivatives   administration & dosage   adverse effects   pharmacokinetics   MeSH
• Child MeSH
• Transplantation, Homologous * adverse effects   MeSH
• Infant MeSH
• Humans MeSH
• Adolescent MeSH
• Graft vs Host Disease * prevention & control   MeSH
• Child, Preschool MeSH
• Transplantation Conditioning * methods   adverse effects   MeSH
• Hematopoietic Stem Cell Transplantation * adverse effects   MeSH
• Treatment Outcome MeSH
• Check Tag
• Child MeSH
• Infant MeSH
• Humans MeSH
• Adolescent MeSH
• Male MeSH
• Child, Preschool MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Clinical Trial, Phase II MeSH
• Multicenter Study MeSH

Hematopoietic stem cell transplantation (HSCT) is a life-saving procedure to treat hematopoietic disorders. Current bone marrow conditioning protocols create space for healthy donor stem cells by employing irradiation and/or chemotherapy, but carry severe toxicities, resulting in significant morbidity, mortality and substantial long-term complications. To develop a low-toxicity solution, we generated a bi-specific T-cell engager (BTCE) that targets CD117, an abundantly expressed receptor on hematopoietic stem and progenitor cells (HSPC) and leukemia-initiating cells (LICs). We show that the CD117×CD3 BTCE efficiently depletes in vitro and in vivo HSPCs and LICs. The CD117×CD3 BTCE was not toxic and facilitates highly efficient engraftment of human allogenic donor CD34+cells in humanized mice, thereby restoring hematopoiesis in vivo in both normal and leukemia-bearing humanized mice. We demonstrate here that a potent CD117×CD3 BTCE enables rapid HSCT in both benign and malignant conditions.

• MeSH
• Hematopoietic Stem Cells immunology   metabolism   MeSH
• Immunotherapy * methods   MeSH
• Leukemia * therapy   immunology   MeSH
• Humans MeSH
• Mice MeSH
• Transplantation Conditioning * methods   MeSH
• Proto-Oncogene Proteins c-kit immunology   metabolism   MeSH
• Hematopoietic Stem Cell Transplantation * methods   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

The superiority of total body irradiation (TBI)-based vs chemotherapy conditioning for allogeneic hematopoietic stem cell transplantation (allo-HSCT) in children with acute lymphoblastic leukemia (ALL) has been established in the international, prospective phase-3 FORUM study, randomizing 417 patients aged 4-18 years in complete remission (CR), who received allo-HSCT from HLA-matched sibling or unrelated donors. Because of the unavailability of TBI in some regions and to accommodate individual contraindications, this study reports the prespecified comparison of outcomes of patients receiving busulfan (BU)- or treosulfan (TREO)-based regimens from 2013 to 2018. Overall, 180 and 128 patients received BU/thiotepa (THIO)/fludarabine (FLU) or TREO/THIO/FLU, respectively. Data were analyzed as of February 2023, with a median follow-up of 4.2 years (range, 0.3-9.1). 3-year overall survival was 0.71 (BU, 95% confidence interval [0.64-0.77]) and 0.72 (TREO, [0.63-0.79]) and 3-year event-free survival was 0.60 (BU, [0.53-0.67]) and 0.55 (TREO, [0.46-0.63]). The 3-year cumulative incidence of relapse (BU, 0.31 [0.25-0.38]; TREO, 0.36 [0.27-0.44]); and nonrelapse mortality (BU, 0.08 [0.05-0.13]; TREO, 0.09 [0.05-0.15]) were comparable. One case of fatal veno-occlusive disease occurred in each group. No significant differences in acute and chronic graft-versus-host disease (GVHD) or 3-year GVHD-free and relapse-free survival (BU, 0.48 [0.41-0.55]; TREO, 0.45 [0.37-0.54]) were recorded. Outcomes for patients in first and second CR were similar irrespective of the regimen. In conclusion, BU/THIO/FLU or TREO/THIO/FLU regimens can be an alternative to TBI for patients with ALL aged >4 years with contraindications or lack of access to TBI. This trial was registered at www.ClinicalTrials.gov as #NCT01949129.

• MeSH
• Precursor Cell Lymphoblastic Leukemia-Lymphoma * therapy   mortality   MeSH
• Busulfan * analogs & derivatives   therapeutic use   MeSH
• Child MeSH
• Transplantation, Homologous MeSH
• Humans MeSH
• Adolescent MeSH
• Graft vs Host Disease * etiology   MeSH
• Child, Preschool MeSH
• Transplantation Conditioning * methods   MeSH
• Hematopoietic Stem Cell Transplantation * adverse effects   MeSH
• Vidarabine analogs & derivatives   therapeutic use   administration & dosage   MeSH
• Treatment Outcome MeSH
• Check Tag
• Child MeSH
• Humans MeSH
• Adolescent MeSH
• Male MeSH
• Child, Preschool MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Multicenter Study MeSH
• Randomized Controlled Trial MeSH
• Comparative Study MeSH

We retrospectively analyzed the impact of conditioning intensity on transplant outcomes according to their cytogenetic/molecular risk in a cohort of 1823 patients with acute myeloid leukemia (AML) and intermediate- or adverse-risk cytogenetics in first complete remission (CR1). These patients received their first hematopoietic stem cell transplantation (HSCT) using post-transplant cyclophosphamide (PTCy). The intermediate-risk cytogenetic group included 1386 (76%) patients, and 608 (34%) had mutated FLT3-ITD. Myeloablative conditioning was used in 930 patients (51%), while 1130 (62%) received an intensified conditioning (score ≥2.5) based on the transplant conditioning intensity (TCI) score. Conditioning intensity using the myeloablative/reduced intensity stratification did not impact transplant outcomes across the entire cohort. However, a higher TCI score was associated with a lower risk of relapse, with no effect on survival. In specific cytogenetic risk groups, a higher TCI score did not influence outcomes in the adverse-risk group. In the intermediate-risk group, the impact varied with FLT3-ITD status. Patients with FLT3-ITD mutation who received a higher TCI showed a beneficial effect on relapse, leukemia-free survival (LFS), and overall survival. Conversely, in FLT3-ITD wild-type patients, more intense conditioning had a detrimental effect on graft-versus-host disease-free, and relapse-free survival with no effect on other outcomes. In conclusion, for AML patients in CR1 undergoing HSCT with PTCy, it is crucial to consider cytogenetic risk and molecular status when selecting the conditioning regimen. Intensive conditioning should be considered for patients with intermediate-risk cytogenetics and mutated FLT3-ITD but should probably be avoided for those with wild-type FLT3-ITD.

• MeSH
• Leukemia, Myeloid, Acute * therapy   genetics   mortality   MeSH
• Cyclophosphamide * therapeutic use   administration & dosage   pharmacology   MeSH
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Transplantation Conditioning * methods   MeSH
• Retrospective Studies MeSH
• Risk Factors MeSH
• Aged MeSH
• Hematopoietic Stem Cell Transplantation * methods   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH

BACKGROUND: The rate of immune reconstitution after allogeneic hematopoietic stem cell transplantation (allo-HSCT) plays the principal role in the development of serious post-transplant complications. However, the post-transplantation course has a significant impact on shaping the immune system of the recipient, per se, thus representing risk factors for subsequent unfavorable outcomes. The predictive power of an interferon gamma (IFNγ) release assay (IGRA) on graft-versus-host disease (GVHD) or hematological relapse in recipients of allo-HSCT treated with post-transplantation cyclophosphamide and the impact of these complications on the restoration of cellular immune responsiveness was evaluated. STUDY DESIGN: A prospective observational study in which 62 adult patients with myeloid hematological malignancies who underwent allo-HSCT with a myeloablative conditioning regimen combined with post-transplantation cyclophosphamide were enrolled. Clinical data were collected and the IGRA was performed before commencement of the conditioning regimen and for 12 months post-allo-HSCT. Multivariate Cox regression and logistic regression models with backward stepwise analyses were used to calculate the predictive values for acute or chronic GVHD, or hematological relapse. RESULTS: Pre-transplantation and early post-transplantation IGRA values and other selected covariables (age, diagnosis, relapse risk, conditioning type, pre-T lymphocyte count, and donor sex), enabled prediction of the 12-month incidence of chronic GVHD with positive and negative predictive values of 75 % and 88 %, respectively. However, the IGRA did not improve the predictive value for acute GVHD or hematological relapse. Patients with myelodysplastic syndrome (MDS) had a significantly lower pre-transplant IGRA value (p = 0.021) and a delayed IFNγ response in IGRA, post-HSCT, than patients with acute myeloid leukemia (AML) (p = 0.015 and p = 0.0063 for 3 and 4 months post-HSCT, respectively). CONCLUSIONS: The IGRA can be used to monitor the recovery of total cellular immunity, post-HSCT and it has shown potential for use in personalized post-transplantation care. In the multivariate backward stepwise logistic regression model, pre-and early post-transplantation IGRA values showed potential for predicting chronic GVHD. Patients with MDS had a significantly lower pre-transplantation IGRA value and delayed IFNγ response in IGRA, post-HSCT, than patients with AML.

• MeSH
• Chronic Disease MeSH
• Cyclophosphamide * therapeutic use   MeSH
• Adult MeSH
• Hematologic Neoplasms therapy   MeSH
• Transplantation, Homologous MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Myeloablative Agonists therapeutic use   MeSH
• Graft vs Host Disease * diagnosis   prevention & control   etiology   MeSH
• Transplantation Conditioning * methods   MeSH
• Prospective Studies MeSH
• Aged MeSH
• Interferon-gamma Release Tests MeSH
• Hematopoietic Stem Cell Transplantation * adverse effects   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Observational Study MeSH

The optimal conditioning for patients with higher risk MDS receiving potentially curative allogeneic haematopoietic stem cell transplant(allo-HCT) remains to be defined. This is particularly the case for patients with excess of blasts at time of allo-HCT. Sequential (Seq) conditioning, whereby chemotherapy is followed rapidly by transplant conditioning, offers an opportunity to decrease disease burden, potentially improving outcomes allo-HCT outcomes. Herein we present the only analysis comparing Seq to myeloablative (MAC) and reduced intensity conditioning (RIC) specifically focussed on MDS patients with excess of blasts at allo-HCT. 303 patients were identified in the EBMT registry, receiving RIC (n = 158), Seq (n = 105), and MAC (n = 40). Median follow-up was 67.2 months and median age at allo-HCT was 59.5 years (IQR 53.5-65.6). For the entire cohort, 3 y overall survival (OS) was 50% (95% CI 45-56%) and relapse free survival (RFS) 45% (95% CI 40-51%). No significant differences in OS (log-rank p = 0.13) and RFS (log-rank p = 0.18) were observed between conditioning protocols. On multivariable analysis, lower performance status, worse IPSS-R cytogenetics, sibling donor (compared to 8/8 MUD) and ≥20% blasts at allo-HCT were associated with worse outcomes. In conclusion, the Seq protocol did little to influence the outcome in this high-risk group of patients, with outcomes mostly determined by baseline disease risk and patient characteristics such as performance status.

• MeSH
• Chronic Disease MeSH
• Transplantation, Homologous methods   MeSH
• Middle Aged MeSH
• Humans MeSH
• Neoplasm Recurrence, Local MeSH
• Myelodysplastic Syndromes * therapy   MeSH
• Graft vs Host Disease * etiology   MeSH
• Transplantation Conditioning methods   MeSH
• Retrospective Studies MeSH
• Aged MeSH
• Hematopoietic Stem Cell Transplantation * methods   MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Aged MeSH
• Publication type
• Journal Article MeSH

Optimal conditioning prior to allogeneic hematopoietic stem cell transplantation for children with non-malignant diseases is subject of ongoing research. This prospective, randomized, phase 2 trial compared safety and efficacy of busulfan with treosulfan based preparative regimens. Children with non-malignant diseases received fludarabine and either intravenous (IV) busulfan (4.8 to 3.2 mg/kg/day) or IV treosulfan (10, 12, or 14 g/m2/day). Thiotepa administration (2 × 5 mg/kg) was at the investigator's discretion. Primary endpoint was freedom from transplantation (treatment)-related mortality (freedom from TRM), defined as death between Days -7 and +100. Overall, 101 patients (busulfan 50, treosulfan 51) with at least 12 months follow-up were analyzed. Freedom from TRM was 90.0% (95% CI: 78.2%, 96.7%) after busulfan and 100.0% (95% CI: 93.0%, 100.0%) after treosulfan. Secondary outcomes (transplantation-related mortality [12.0% versus 3.9%]) and overall survival (88.0% versus 96.1%) favored treosulfan. Graft failure was more common after treosulfan (n = 11), than after busulfan (n = 2) while all patients were rescued by second procedures except one busulfan patient. CTCAE Grade III adverse events were similar in both groups. This study confirmed treosulfan to be an excellent alternative to busulfan and can be safely used for conditioning treatment in children with non-malignant disease.

• MeSH
• Busulfan therapeutic use   MeSH
• Child MeSH
• Humans MeSH
• Graft vs Host Disease * etiology   MeSH
• Transplantation Conditioning methods   MeSH
• Prospective Studies MeSH
• Hematopoietic Stem Cell Transplantation * methods   MeSH
• Vidarabine therapeutic use   MeSH
• Check Tag
• Child MeSH
• Humans MeSH
• Publication type
• Journal Article MeSH
• Clinical Trial, Phase II MeSH
• Research Support, Non-U.S. Gov't MeSH
• Randomized Controlled Trial MeSH

It has been reported in prospective randomized trials that antithymocyte globulin (ATG)-based graft-versus-host disease (GVHD) prophylaxis has benefits in the setting of allogeneic hematopoietic stem cell transplantation (allo-HSCT) with unrelated donors (UDs). However, the optimal GVHD prophylaxis strategy has been challenged recently by the increasing use of posttransplant cyclophosphamide (PTCY). We report from the European Society for Blood and Marrow Transplantation registry the outcomes of 960 patients with myelodysplastic neoplasms who underwent allo-HSCT from UD with PTCY or ATG as GVHD prophylaxis. The primary outcomes were overall survival (OS) and progression-free survival (PFS). The disease characteristics were similar in both groups. Day 28 neutrophil engraftment was significantly better with ATG (93% vs 85%). Over a median follow-up of 4.4 years, the 5-year OS was 58% with PTCY, and 49% in the ATG group. The 5-year PFS was higher for PTCY at 53% vs 44% for ATG. Grade 2 to 4 acute GVHD incidence was lower when PTCY was used (23%), whereas there was no difference in the incidence of chronic GVHD at 5 years. Multivariable analyses confirmed better OS and PFS with PTCY with a hazard ratio (HR) for ATG of 1.32 (1-1.74) and a better PFS for PTCY with a HR for ATG of 1.33. This study suggests that GVHD prophylaxis using PTCY instead of ATG in this setting remains a valid option. Further prospective randomized studies would be essential to confirm these results.

• MeSH
• Antilymphocyte Serum * therapeutic use   MeSH
• Cyclophosphamide * therapeutic use   MeSH
• Adult MeSH
• Transplantation, Homologous MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Myelodysplastic Syndromes * therapy   mortality   MeSH
• Graft vs Host Disease * prevention & control   etiology   MeSH
• Unrelated Donors * MeSH
• Transplantation Conditioning methods   MeSH
• Aged MeSH
• Hematopoietic Stem Cell Transplantation * methods   adverse effects   MeSH
• Treatment Outcome MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH

We compared transplantation (HSCT) outcomes in AML patients undergoing HSCT with post-transplant cyclophosphamide (PTCy) in first complete remission from 1065 young (<35 years) haploidentical (Haplo) donors (yHaplo) vs. 147 old (≥35 years) mismatched unrelated donors (oMMUD) (first comparison) and from 271 young (<35 years) MMUD (yMMUD) vs. 1315 old (≥35 years) Haplo donors (oHaplo) (second comparison). Acute graft-versus-host disease (aGVHD) grades II-IV were significantly lower in the yHaplo vs. oMMUD group (HR = 0.62, p = 0.007). There were no significant differences in chronic GVHD, non-relapse mortality (NRM), relapse incidence, leukemia-free survival, overall survival, and GVHD-free and relapse-free survival. As for the second comparison, more patients in the oHaplo group had de novo AML, 86.6% vs. 81.9% in the yMMUD group (p = 0.044), while myeloablative conditioning was used more frequently in the yMMUD group, 53.3% vs. 46.8% in the oHaplo group (p = 0.049). aGVHD grades II-IV and NRM were significantly lower in the yMMUD vs. oHaplo group (HR = 0.69, p = 0.013 and HR = 0.60, p = 0.022). All other transplant outcomes did not differ. In conclusion, HSCT from young alternative donors (<35 years) results in a lower incidence of grades II-IV aGVHD. In addition, NRM is lower in HSCT from yMMUD compared to HSCT from oHaplo.

• MeSH
• Leukemia, Myeloid, Acute * therapy   mortality   MeSH
• Cyclophosphamide * therapeutic use   MeSH
• Child MeSH
• Adult MeSH
• Transplantation, Haploidentical methods   MeSH
• Transplantation, Homologous methods   MeSH
• Remission Induction MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Graft vs Host Disease MeSH
• Unrelated Donors * MeSH
• Disease-Free Survival MeSH
• Transplantation Conditioning methods   MeSH
• Hematopoietic Stem Cell Transplantation * methods   MeSH
• Age Factors MeSH
• Check Tag
• Child MeSH
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Comparative Study MeSH
• Geographicals
• Europe MeSH