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Introduction: For the majority of patients with acute myeloid leukemia (AML) an allogeneic stem cell transplant (SCT) in first complete remission (CR) is preferred. However, whether the number of courses required to achieve CR has a prognostic impact is unclear. It is unknown which factors remain important in patients requiring more than one course of induction to attain remission., Methods: This Acute Leukaemia Working Party study from the European Society for Blood and Marrow Transplantation identified adults who received an allograft in first CR from either a fully matched sibling or 10/10 or 9/10 human leucocyte antigen (HLA)-matched unrelated donor (HLA-A, HLA-B, HLA-C, HLA-DR, or HLA-DQ). Univariate and multivariate analyses were undertaken to identify the prognostic impact of one or two courses of induction to attain CR., Results: A total of 4995 patients were included with 3839 (77%) patients attaining a CR following one course of induction chemotherapy (IND1), and 1116 patients requiring two courses (IND2) to attain CR. IND2 as compared to IND1 was a poor prognostic factor in a univariate analysis and remained so in a multivariate Cox model, resulting in an increased hazard ratio of relapse (1.38; 95% confidence interval [CI], 1.16-1.64; p = .0003) and of death (1.27; 95% CI, 1.09-1.47; p = .002). Adverse prognostic factors in a multivariate analysis of the outcomes of patients requiring IND2 included age, FLT3-ITD, adverse cytogenetics, and performance status. Pretransplant measurable residual disease retained a prognostic impact regardless of IND1 or IND2., Conclusion: Initial response to chemotherapy as determined by number of courses to attain CR, retained prognostic relevance even following SCT in CR., (© 2024 The Authors. Cancer published by Wiley Periodicals LLC on behalf of American Cancer Society.)

Allogeneic hematopoietic cell transplantation (allo-HCT) is recommended for core-binding factor mutated (CBF) AML patients achieving second complete remission (CR2). However, approximately 20% of patients may relapse after transplant and donor preference remains unclear. We compared in this EBMT global multicenter registry-based analysis the allo-HCT outcomes using either haploidentical (Haplo), matched siblings donors (MSD), or 10/10 matched unrelated donors (MUD). Data from 865 de novo adult CBF AML patients in CR2 receiving allo-HCT in 227 EBMT centers from 2010 to 2022 were analyzed, in which 329 MSD, 374 MUD, and 162 Haplo-HCTs were included. For the entire cohort, 503 (58%) patients were inv(16)/CBFB-MYH11 and 362 patients (42%) were t(8;21)/RUNX1-RUNX1T1 AML. On multivariate analysis, Haplo-HCT was associated with a lower Relapse Incidence (RI) compared to either MSD (hazard ratio [HR] = 0.56, 95% CI 0.32-0.97; p < .05) or MUD (HR = 0.57, 95% CI: 0.33-0.99, p < .05). No significant difference was observed among the 3 types of donors on LFS, OS and GRFS. CBF-AML with t(8;21) was associated with both higher RI (HR = 1.79, 95% CI 1.3-2.47; p < .01) and higher NRM (HR = 1.58, 95% CI 1.1-2.27; p < .01) than CBF-AML with inv(16), which led to worse LFS, OS and GRFS. To conclude, for CBF-AML patients in CR2, Haplo-HCTs were associated with a lower RI compared to MSD and MUD allo-HCTs. There was no difference on LFS, OS or GRFS. CBF AML patients with inv(16) had a better progonosis than those with t(8;21) after allo-HCT in CR2., (© 2024 Wiley Periodicals LLC.)

A randomized study (acronym: MC-FludT.14/L Trial II) demonstrated that fludarabine plus treosulfan (30 g/m²) was an effective and well tolerated conditioning regimen for allogeneic hematopoietic cell transplantation (allo-HCT) in older patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). To further evaluate this regimen, all 252 study patients aged 50 to 70 years were compared with similar patients, who underwent allo-HCT after fludarabine/melphalan (140 mg/m²) (FluMel) or busulfan (12.8 mg/kg)/cyclophosphamide (120 mg/kg) (BuCy) regimens and whose data was provided by the European Society for Blood and Marrow Transplantation registry. In 1:1 propensity-score matched-paired analysis (PSA) of AML patients, there was no difference in 2-year-relapse-incidence after FluTreo compared with either FluMel (n = 110, p = 0.28) or BuCy (n = 78, p = 0.98). However, 2-year-non-relapse-mortality (NRM) was lower compared with FluMel (p = 0.019) and BuCy (p < 0.001). Consequently, 2-year-overall-survival (OS) after FluTreo was higher compared with FluMel (p = 0.04) and BuCy (p < 0.001). For MDS patients, no endpoint differences between FluTreo and FluMel (n = 30) were evident, whereas 2-year-OS after FluTreo was higher compared with BuCy (n = 25, p = 0.01) due to lower 2-year-NRM. Multivariate sensitivity analysis confirmed all significant results of PSA. Consequently, FluTreo (30 g/m²) seems to retain efficacy compared with FluMel and BuCy, but is better tolerated by older patients., (© 2024. The Author(s).)

Therapy-related myeloid neoplasms (t-MN), either myelodysplastic neoplasms (t-MDS) or acute myeloid leukemias (t-AML), have a poor prognosis and allogeneic haematopoietic cell transplantation (allo-HCT) represents the only curative option. In this multicenter, registry-based study, we analyzed outcomes of 378 patients undergoing first allo-HCT between 2006-2017 for t-MN arising secondary to lymphoma treatment. Median age was 58 years at allo-HCT; 222 (59%) had a diagnosis of t-MDS and 156 (41%) of t-AML, respectively. At the time of allo-HCT, 46% of t-MN cases were reported as in complete remission (CR) and 15% of lymphomas were recorded as not in remission. A reduced intensity conditioning regimen was used in 70% of cases. For the entire cohort, 5-year OS, and t-MN PFS, relapse incidence and NRM were 32%, 28%, 35% and 37%, respectively. In multivariable analysis, undergoing allo-HCT with t-MN not in CR and older age were associated with significantly worse OS, PFS and NRM. At 5 years post allo-HCT, the relapse incidence of lymphoma was low at 3%, while the rate of secondary malignancies was 8%. This analysis shows the curative potential of allo-HCT for patients with t-MN arising secondary to lymphoma treatment in approximately a third of patients., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Allogeneic hematopoietic cell transplantation (allo-HCT) remains the best consolidation strategy for acute myeloid leukemia (AML) with complex karyotype (CK). However, CK is a heterogenous and highly diverse entity. Numerical abnormalities have been associated with a controversial prognosis and AML with only multiple numerical abnormalities known as pure hyperdiploid karyotype (HDK) may have a distinct prognosis after allo-HCT compared to non-pure HDK CK AML. A total of 236 patients were identified within the EBMT registry as having HDK comprising 95 pure (pHDK) and 141 with other cytogenetic abnormalities (HDK+). The 2-year probability of leukemia-free survival (LFS) was 50% for pHDK and 31% for HDK+ (p = 0.003). The 2-year probability of overall survival (OS) was 57% for pHDK and 36% for HDK+ (p = 0.007). The 2-year cumulative incidence of relapse (RI) was 22% for pHDK and 44% for HDK+ (p = 0.001). The 2-year probability of graft-versus-host disease (GvHD)-free and relapse-free survival (GRFS) was 36% for pHDK and 21% for HDK+ (p = 0.01). On multivariate analysis, pHDK remained associated with significantly better LFS, OS and GRFS and lower RI (all p-values <0.004). pHDK AML constitutes probably a distinct cytogenetic entity from HDK+ or other non-hyperdiploid CK AML with better outcomes after allo-HCT., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

Total body irradiation (TBI) at myeloablative doses is superior to chemotherapy-based regimens in young patients with acute lymphoblastic leukemia (ALL) undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, in elderly and unfit patients, in whom reduced-intensity conditioning (RIC) regimens are preferred, whether a TBI-based or a chemotherapy-based approach is better is unexplored. Thiotepa can be used as part of ALL conditioning regimens. The current study aimed to compare transplantation outcomes after RIC with TBI-based or thiotepa-based regimens in patients with ALL. The study cohort comprised patients aged ≥40 years undergoing allo-HSCT for ALL in first complete remission between 2000 and 2020 who received an RIC regimen containing either TBI (4 to 6 Gy) or thiotepa. We identified a total of 265 patients, including 117 who received a TBI-based RIC regimen and 148 who received a thiotepa-based RIC regimen. Univariate analysis revealed no significant differences in the following transplantation outcomes for TBI versus thiotepa: relapse, 23% versus 28% (P = .24); nonrelapse mortality, 20% versus 26% (P = .61); leukemia-free survival, 57% versus 46% (P = .12); overall survival, 67% versus 56% (P = .18); graft-versus-host disease (GVHD]/relapse-free survival, 45% versus 38% (P = .21); grade II-IV acute GVHD, 30% in both groups (P = .84); grade III-IV acute GVHD, 9% versus 10% (P = .89). The sole exception was the incidence of chronic GVHD, which was higher in the recipients of TBI-based regimens (43% versus 29%; P = .03). However, multivariate analysis revealed no differences in transplantation outcomes between the 2 groups. In patients aged ≥40 years receiving RIC, use of a thiotepa-based regimen may represent a valid alternative to TBI-based regimens, as no differences were observed in the main transplantation outcomes., (Copyright © 2023 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Purpose: Allogeneic hematopoietic cell transplantation (allo-HCT) is recommended in first complete remission (CR1) in patients with acute myeloid leukemia (AML) harboring FMS-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD). We assessed changes over time in transplant characteristics and outcomes in patients with AML age 60 years and younger with a FLT3-ITD., Experimental Design: We identified 1,827 adult patients with AML (median age 49 years, range 18-60) with FLT3-ITD and intermediate karyotype, allografted between 2012 and 2021 in CR1., Results: NPM1 was mutated in 72% of patients. We compared changes over time in 688 patients transplanted between 2012 and 2016, and 1,139 patients transplanted between 2017 and 2021. For patients with wild-type NPM1, the 2-year leukemia-free survival (LFS) and overall survival (OS) significantly improved over time from 54% to 64% (HR = 0.67; P = 0.011) and from 63% to 71% (HR = 0.66; P = 0.021), respectively. Allo-HCT in recent years significantly reduced the cumulative incidence of relapse (CIR). For patients with NPM1 mutation, no significant changes over time were noted., Conclusions: In patients with AML with FLT3-ITD and wild-type NPM1, we noticed a significant decrease over time in the CIR and improvement of LFS and OS, likely reflecting the efficacy of FLT-3 inhibitors, including when used as posttransplant maintenance, in this high-risk setting. On the contrary, no significant change over time was noticed in outcomes of patients harboring a FLT3 and NPM1 mutation., (©2023 American Association for Cancer Research.)

Background: Allogeneic hematopoietic cell transplantation (allo-HCT) is the only cure for acute myeloid leukemia (AML) in second complete remission (CR2). Patients lacking a matched sibling donor (MSD) receive transplants from matched unrelated donors (MUDs), mismatched unrelated donors (MMUDs), haploidentical (haplo) donors, or cord blood., Methods: This is a retrospective, registry-based European Society for Blood and Marrow Transplantation study that investigates changes in patient- and transplant-related characteristics and posttransplant outcomes over time., Results: We identified 3955 adult patients (46.7% female; median age, 52 years [range, 18-78 years]) with AML in CR2 first transplanted between 2005 and 2019 from a MUD 10/10 (61.4%), MMUD 9/10 (21.9%), or haplo donor (16.7%) and followed for 3.7 years. A total of 725 patients were transplanted between 2005 and 2009, 1600 between 2010 and 2014, and 1630 between 2015 and 2019. Over the three time periods, there was a significant increase in patient age (from 48.7 to 53.5 years; p < .001), use of a haplo donor (from 4.6% to 26.4%; p < .001), and use of posttransplant cyclophosphamide (from 0.4% to 29%; p < .001). There was a significant decrease in total body irradiation and in vivo T-cell depletion. In multivariate analysis, transplants performed more recently had better outcomes. Leukemia-free survival (hazard ratio [HR], 0.79; p = .002) and overall survival (HR, 0.73; p < .001) increased over time. Similarly, nonrelapse mortality (HR, 0.64; p < .001) decreased over time. We also observed better graft-vs-host disease (GVHD) rates (acute GVHD II-IV: HR, 0.78; p = .03; GVHD-free, relapse-free survival: HR, 0.69; p < .001)., Conclusions: Even in the absence of an MSD, outcomes of allo-HCT in CR2 for AML have significantly improved over time, with most favorable outcomes achieved with a MUD., (© 2023 American Cancer Society.)

Allogeneic hematopoietic cell transplantation is a potentially curative treatment in high-risk acute lymphoblastic leukemia (ALL). Conditioning regimens based on ≥12 Gray total body irradiation (TBI) represent the current standard in patients ≤45 years, whereas elderly patients frequently receive intermediate intensity conditioning (IIC) to reduce toxicity. To evaluate the role of TBI as a backbone of IIC in ALL, a retrospective, registry-based study included patients >45 years transplanted from matched donors in first complete remission, who had received either fludarabine/TBI 8 Gy (FluTBI8, n = 262), or the most popular, irradiation-free alternative fludarabine/busulfan, comprising busulfan 6.4 mg/kg (FluBu6.4, n = 188) or 9.6 mg/kg (FluBu9.6, n = 51). At two years, overall survival (OS) was 68.5%, 57%, and 62.2%, leukemia-free survival (LFS) was 58%, 42.7%, and 45%, relapse incidence (RI) was 27.2%, 40%, and 30.9%, and non-relapse-mortality (NRM) was 23.1%, 20.7%, and 26.8% for patients receiving FluTBI8Gy, FluBu6.4, and FluBu9.6, respectively. In multivariate analysis, the risk of NRM, acute and chronic graft-versus-host disease was not influenced by conditioning. However, RI was higher after FluBu6.4 (hazard ratio [HR] [95% CI]: 1.85 [1.16-2.95]), and LFS was lower after both FluBu6.4 (HR: 1.56 [1.09-2.23]) and FluBu9.6 (HR: 1.63 [1.02-2.58]) as compared to FluTBI8. Although only resulting in a non-significant advantage in OS, this observation indicates a stronger anti-leukemic efficacy of TBI-based intermediate intensity conditioning., (© 2023. The Author(s).)

We previously analyzed trends in incidence and factors associated with lethal complications in ALL/AML/CML patients (causes of deaths; COD-1 study). The objective of this study was the analysis of incidence and specific causes of death after HCT, with focus on infectious deaths in two time periods, 1980-2001 (cohort-1) and 2002-2015 (cohort-2). All patients with HCT for lymphoma, plasma cell disorders, chronic leukemia (except CML), myelodysplastic/myeloproliferative disorders, registered in the EBMT-ProMISe-database were included (n = 232,618) (COD-2 study). Results were compared to those in the ALL/AML/CML COD-1 study. Mortality from bacterial, viral, fungal, and parasitic infections decreased in very early, early and intermediate phases. In the late phase, mortality from bacterial infections increased, while mortality from fungal, viral, or unknown infectious etiology did not change. This pattern was similar for allo- and auto-HCT in COD-1 and COD-2 studies, with a distinct and constant lower incidence of all types of infections at all phases, after auto-HCT. In conclusion, infections were the main cause of death before day +100, followed by relapse. Mortality from infectious deaths significantly decreased, except late phase. Post-transplant mortality has significantly decreased in all phases, from all causes after auto-HCT; it has decreased in all phases after allo-HCT except late phase., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

We compared transplants (HSCT) from matched related siblings (MSD) with those from matched 10/10 and mismatched 9/10 unrelated (UD) and T-replete haploidentical (Haplo) donors in acute myeloid leukemia (AML) in first complete remission (CR1) achieved after two inductions, a known poor prognostic factor. One thousand two hundred and ninety-five patients were included: MSD (n = 428), UD 10/10 (n = 554), UD 9/10 (n = 135), and Haplo (n = 178). Acute GVHD II-IV was higher in all groups compared to MSD. Extensive chronic (c) GVHD was significantly higher in UD 9/10 (HR = 2.52; 95% CI 1.55-4.11, p = 0.0002) and UD 10/10 (HR = 1.48; 95% CI 1.03-2.13, p = 0.036) and cGVHD all grades were higher in UD 9/10 vs MSD (HR = 1.77; 95% CI 1.26-2.49, p = 0.0009). Non-relapse mortality was higher in all groups compared to MSD. Relapse incidence, leukemia-free, and overall survival did not differ significantly between donor types. Finally, GVHD-free relapse-free survival was lower in HSCT from UD 9/10 (HR = 1.56, 95% CI 1.20-2.03, p = 0.0009) but not in those from UD 10/10 (HR = 1.13, p = 0.22) and Haplo donors (HR = 1.12, p = 0.43) compared to MSD. In conclusion, in AML patients undergoing HSCT in CR1 achieved after two induction courses 10/10 UD and Haplo but not 9/10 UD donors are comparable alternatives to MSD., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

Pre-transplant detectable measurable residual disease (MRD) is still associated with high risk of relapse and poor outcomes in acute myeloid leukemia (AML). We aimed at evaluating the impact of disease burden on prediction of relapse and survival in patients receiving allogeneic hematopoietic cell transplantation (allo-HCT) in first remission (CR1). We identified a total of 3202 adult AML patients, of these 1776 patients were in CR1 and MRD positive and 1426 patients were primary refractory at time of transplant. After a median follow-up of 24.4 months, non-relapse mortality and relapse rate were significantly higher in the primary refractory group compared to the CR1 MRD positive group (Hazards Ratio (HR) = 1.82 (95% CI: 1.47-2.24) p < 0.001 and HR = 1.54 (95% CI: 1.34-1.77), p < 0.001), respectively. Leukemia-free survival (LFS) and overall survival (OS) were significantly worse in the primary refractory group (HR = 1.61 (95% CI: 1.44-1.81), p < 0.001 and HR = 1.71 (95% CI: 1.51-1.94), p < 0.001, respectively). Our real-life data suggest that patients in CR1 and MRD positive at time of transplant could still be salvaged by allo-HCT with a 2-year OS of 63%, if negative MRD cannot be obtained and their outcomes are significantly better than patients transplanted with active disease., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

Pre-transplant measurable residual disease (MRD) predicts relapse and outcome of allogeneic haematopoietic cell transplantation (allo-HCT). The impact of MRD on the outcomes of post-transplant cyclophosphamide (PTCy)-based allo-HCT from a matched unrelated donor (UD) is unknown. This study assessed the impact of MRD in acute myeloid leukaemia (AML) in the first complete remission (CR1). A total of 272 patients (MRD negative [MRD-], n = 165; MRD positive [MRD+], n = 107) with a median follow-up of 19 (range: 16-24) months were studied. The incidence of grades II-IV and grades III-IV acute GVHD at day 180 was 25.2% and 25% (p = 0.99), and 10.6% and 6.8% (p = 0.29), respectively, and 2-year chronic GVHD was 35% and 30.4% (p = 0.96) in MRD+ and MRD- cohorts, respectively. In multivariate analysis, MRD+ status was associated with a higher incidence of relapse (RI) (hazard ratio [HR] = 2.56, 95% CI: 1.39-4.72), lower leukaemia-free survival (LFS) (HR = 2.04, 95% CI: 1.23-3.39), overall survival (OS) (HR = 1.83, 95% CI: 1.04-3.25) and GVHD-free, relapse-free survival (GRFS) (HR = 1.69, 95% CI: 1.10-2.58). MRD status did not have a significant impact on non-relapse mortality (NRM), or acute or chronic GVHD risk. Among patients with AML undergoing UD allo-HCT with PTCy, pre-transplant MRD+ status predicted a higher relapse rate, lower LFS, OS and GRFS., (© 2023 British Society for Haematology and John Wiley & Sons Ltd.)

Post-transplant cyclophosphamide (PTCy) is being increasingly used as graft-versus-host disease (GVHD) prophylaxis post allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with acute myeloid leukemia (AML) transplanted in first complete remission (CR1). However, results may differ in patients transplanted in CR2. We retrospectively evaluated transplant outcomes of adult AML patients transplanted between 2010-2019 from 9-10/10 human leukocyte antigen (HLA)-matched unrelated donor (UD) in CR2. In total, 127 patients were included (median age 45.5 years, 54% male). Median follow-up was 19.2 months. Conditioning was myeloablative (MAC) in 50.4% and the graft source was peripheral blood in 93.7% of the transplants. Incidence of acute (a)GVHD II-IV and III-IV was 26.2% and 9.2%. Two-year total and extensive chronic (c)GVHD were 34.3% and 13.8 %, respectively. Two-year non-relapse mortality (NRM), relapse incidence (RI), leukemia-free survival (LFS), overall survival (OS), and GVHD-free, relapse-free survival (GRFS) were 17.2%, 21.1%, 61.7, %, 65.2%, and 49.3%, respectively. Time from diagnosis to transplant (>18 months) was a favorable prognostic factor for RI, LFS, OS, and GRFS while favorable risk cytogenetics was a positive prognostic factor for OS. The patient's age was a poor prognostic factor for NRM and cGVHD. Finally, the female-to-male combination and reduced intensity conditioning (RIC) were poor and favorable prognostic factors for cGVHD, respectively. We conclude that PTCy is an effective method for GVHD prophylaxis in AML patients undergoing allo-HCT in CR2 from UD., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

Allogeneic hematopoietic cell transplantation (allo-HCT) with reduced intensity conditioning (RIC) is an option for elderly patients with acute lymphoblastic leukemia (ALL). We retrospectively compared results of RIC-allo-HCT from either a matched sibling donor (MSD, n = 209) or matched unrelated donor (MUD, n = 209) with autologous (auto, n = 142) HCT for patients aged 55 years or more treated in first complete remission (CR1) between 2000 and 2018. The probabilities of leukemia-free survival (LFS) at 5 years were 34% for RIC-allo-HCT versus 39% for auto-HCT (p = 0.11) while overall survival (OS) rates were 42% versus 45% (p = 0.23), respectively. The incidence of relapse (RI) and non-relapse mortality (NRM) was 41% versus 51% (p = 0.22) and 25% versus 10% (p = 0.001), respectively. In a multivariate model, using auto-HCT as reference, the risk of NRM was increased for MSD-HCT (Hazard ratio [HR] = 2.1, p = 0.02) and MUD-HCT (HR = 3.08, p < 0.001), which for MUD-HCT translated into a decreased chance of LFS (HR = 1.55, p = 0.01) and OS (HR = 1.62, p = 0.008). No significant associations were found with respect to the risk of relapse. We conclude that for patients with ALL in CR1, aged above 55 years, auto-HCT may be considered a transplant option alternative to RIC-allo-HCT, although its value requires verification in prospective trials., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

Cyclophosphamide is frequently substituted with fludarabine (Flu) in conditioning regimens before allogeneic hematopoietic cell transplantation (allo-HCT). We aimed to compare retrospectively, total body irradiation (12 Gy) plus Flu (FluTBI12) versus busulfan (Bu) plus Flu (FB4) as a myeloablative conditioning before allo-HCT in patients with acute myeloid leukemia (AML). Out of 3203 patients who met the inclusion criteria, 109 patients treated with FluTBI12 and 213 treated with FB4 were included in a final matched-pair analysis. In both groups, median patient age was 41 years, first or second complete remission (CR1/CR2) proportion was 78%/22%, allo-HCT from an unrelated donor was performed in 78% of patients. The probabilities of leukemia-free survival and overall survival at 2 years in FluTBI12 and FB4 groups were 65% vs. 60% (p = 0.64) and 70% vs. 72% (p = 0.87), respectively. The cumulative incidence of relapse was 19% vs. 29% (p = 0.11), while non-relapse mortality was 16% vs. 11%, respectively (p = 0.13). There were no statistical differences in both acute and chronic graft-versus-host disease (GVHD) incidence. The probability of GVHD-free, relapse-free survival (GRFS) was 49% for both groups. FluTBI12 and FB4 are comparable myeloablative regimens before allo-HCT in AML patients transplanted in CR1 and CR2., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

Introduction: Allogeneic hematopoietic stem-cell transplantation (allo-HSCT) remains the best curative option for high-risk myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Unfortunately, it is still associated with a significant risk of relapse due to mechanisms of escape from the control of alloreactive T cells. Repetitive adjuvant donor lymphocyte infusion (DLI), termed prophylactic DLI (proDLI), as an effective strategy in preventing relapse is still debated., Methods: We performed a retrospective multicenter study to evaluate the efficacy of proDLI in allografted AML and MDS. We identified 56 patients treated with proDLI (DLI planned in full chimeras without any sign of disease relapse) and matched them to 167 patients in control group, (DLI performed for mixed chimerism or positive minimal residual disease) based on similar age, initial disease, cytogenetic prognosis, and conditioning intensity., Results: In univariate analysis, the incidence of severe aGVHD at 100 days and incidence of all grades of chronic GVHD 1 year after allo-HSCT were similar in the two groups. We also observed a trend of higher 3-year RI (52.61% [95% confidence interval 25.99-79.23]) in the proDLI group versus the control group (29.31% [20.28-38.34], p = 0.067). However, 3-year overall survival (p = 0.892), progression-free survival (p = 0.239), and nonrelapse mortality (p = 0.343) were similar between the two groups. In multivariate analysis, the only factor influencing overall and progression-free survival was anti-thymocyte globulin administration during the conditioning regimen., Conclusion: The proDLI strategy had an acceptable toxicity profile but did not improve patient outcomes compared to the pre-emptive strategy., (© 2023 S. Karger AG, Basel.)

Splenomegaly is a hallmark of myelofibrosis, a debilitating haematological malignancy for which the only curative option is allogeneic haematopoietic cell transplantation (HCT). Considerable splenic enlargement might be associated with a higher risk of delayed engraftment and graft failure, increased non-relapse mortality, and worse overall survival after HCT as compared with patients without significantly enlarged splenomegaly. Currently, there are no standardised guidelines to assist transplantation physicians in deciding optimal management of splenomegaly before HCT. Therefore, the aim of this Position Paper is to offer a shared position statement on this issue. An international group of haematologists, transplantation physicians, gastroenterologists, surgeons, radiotherapists, and radiologists with experience in the treatment of myelofibrosis contributed to this Position Paper. The key issues addressed by this group included the assessment, prevalence, and clinical significance of splenomegaly, and the need for a therapeutic intervention before HCT for the control of splenomegaly. Specific scenarios, including splanchnic vein thrombosis and COVID-19, are also discussed. All patients with myelofibrosis must have their spleen size assessed before allogeneic HCT. Myelofibrosis patients with splenomegaly measuring 5 cm and larger, particularly when exceeding 15 cm below the left costal margin, or with splenomegaly-related symptoms, could benefit from treatment with the aim of reducing the spleen size before HCT. In the absence of, or loss of, response, patients with increasing spleen size should be evaluated for second-line options, depending on availability, patient fitness, and centre experience. Splanchnic vein thrombosis is not an absolute contraindication for HCT, but a multidisciplinary approach is warranted. Finally, prevention and treatment of COVID-19 should adhere to standard recommendations for immunocompromised patients., Competing Interests: Declaration of interests CH received grants from Novartis and Constellation Pharmaceutical; consulting fees from Keros, Galecto, AOP, and Roche; payment for presentations from Novartis, Celgene, CTI BioPharma, AbbVie, Jansen, Constellation Pharmaceuticals, Galecto, CTI BioPharma, Roche, Geron, Promedior, AbbVie, and AOP Pharma; support for attending meetings from Novartis; participated on advisory boards for Galecto and Keros; and held leadership or fiduciary roles in European Hematology Association, British Society for Haematology, Myeloproliferative Neoplasms Voice, and Blood Cancer UK. NK received research grants from Novartis; consulting fees from Novartis; payments or honoraria for lectures, presentations, speakers bureaus, manuscript writing, or educational events from Novartis and Neovii; support for attending meetings and travel from Neovii; participated on a data safety monitoring board or advisory board for Hovon and Novartis; and held leadership or fiduciary roles in other boards, societies, committees or advocacy groups, paid or unpaid, for the European Society for Blood and Marrow Transplantation, German Society for Stem Cell Transplantation and Cellular Therapy, and the German Registry for Stem Cell Transplantation. RM received funding from Celgene, Incyte, AbbVie, Samus, Genotech, Promedior, CTI, Constellation, Mays Cancer Center, and P30 Cancer Center; support grants from National Cancer Institute (grant number CA054174); and consulting fees from Novartis, Sierra Onc, LaJolla, Pharma, and Constellation. NPe received support from the National Institutes of Health, National Cancer Institute (award number P30 CA016672); grants from Affymetrix, US Department of Defence, and SagerStrong foundation; royalties from Karger Publishers; consulting fees from Pacylex Pharmaceuticals, ImmunoGen, Bristol-Myers Squibb, Blueprint Medicines, Clearview Healthcare Partners, Astellas Pharma US, and Protagonist Therapeutics; honoraria from Incyte, Novartis, LFB Biotechnologies, Stemline Therapeutics, Celgene, AbbVie, MustangBio, Roche Diagnostics, Blueprint Medicines, DAVA Oncology, Springer Science + Business Media, Aptitude Health, and CareDx; support for attending meetings from Stemline Therapeutics, Celgene, MustangBio, DAVA oncology, AbbVie; participated on a data safety monitoring board and advisory board for ASCO Leukemia Advisory Panel; held leadership or fiduciary role in other boards, societies, committees or advocacy groups, paid or unpaid for by American Society of Hematology Communications Committee, Dan's House of Hope, and HemOnc Times/Oncology Times; and received equipment, materials, drugs, medical writing support, gifts, or other services from Novartis, Stemline Therapeutics, Samus Therapeutics, AbbVie, CEllectis, Affymetrix, Daiichi Sankyo, and Plexxikon. UP received research funding from Bayer, Novartis, AbbVie, and Incyte. AMV participated in advisory boards for Novartis; and provided consulting services for Novartis. IY-A received honoraria from Novartis. All other authors declare no competing interests., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Different doses of treosulfan plus fludarabine have shown advantage over reduced intensity regimens. However, data comparing higher doses of treosulfan to myeloablative busulfan are limited. Thus, we compared outcomes between FT14 (fludarabine 150/160 mg/m 2 and treosulfan 42 g/m 2 , or FT14) over FB4 (fludarabine 150/160 mg/m 2 and busulfan 12.8 mg/kg). We retrospectively studied patients from European Society for Blood and Marrow Transplantation registry: a) adults diagnosed with acute myeloid leukemia (AML), b) recipients of first allogeneic hematopoietic stem cell transplantation (HSCT) from unrelated or sibling donor (2010-2020), c) HSCT at first or second complete remission, d) conditioning with FT14 or FB4. FT14 recipients (n = 678) were older, with higher rates of secondary AML, unrelated donors, peripheral blood grafts, and adverse cytogenetics, but lower percentage of female donor to male recipient compared to FB4 (n = 2025). Analysis was stratified on age. In patients aged < 55 years, FT14 was associated with higher relapse incidence (RI) and lower Leukemia-Free Survival (LFS). In patients aged≥55 years, acute GVHD CI was higher in FB4, without significant differences in other outcomes. Although FT14 has been used for higher-risk HSCT patients, our large real-world multicenter study suggests that FB4 is associated with better outcomes compared to FT14 in younger patients., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

Trends in outcome of transplantation (HSCT) in secondary acute myeloid leukemia (sAML) are limited. We evaluated results of HSCT in 4224 patients with sAML in complete remission; 1337 were transplanted in 2000-2010 and 2887 in 2011-2020. Median age was 54 (range, 18-74) and 59 (range, 18-78) years, respectively (p < 0.0001). Donors were MSD in 65% vs. 37%, 10/10 UD in 27% vs. 50%, and 9/10 UD in 8% vs. 13%, respectively (p < 0.0001). Conditioning was myeloablative in 46% and 38%, respectively. Two-year non-relapse mortality (NRM) was lower in patients transplanted in 2011-2020 vs. those transplanted in 2000-2010, 18% vs. 21% (hazard ratio (HR) = 0.82, 95% CI: 0.68-0.9; p = 0.04) and modified GVHD-free, relapse-free survival (GRFS) (HR = 0.9, 95% CI: 0.81-0.99; p = 0.04) was better in patients transplanted in the 2011-2020 vs. those transplanted in 2000-2010. Two-year relapse incidence (RI) was similar between the 2 groups with 32% vs. 31%, (HR = 1.05, 95% CI: 0.9-1.22; p = 0.55). Likewise, leukemia-free survival (LFS) (HR = 0.95, 95% CI: 0.84-1.07; p = 0.38) and overall survival (OS) (HR = 0.93, 95% CI: 0.82-1.05; p = 0.26) were not significantly different between the two periods. In conclusion, Incidence of NRM has been significantly reduced and GRFS significantly increased in HSCT for sAML in the last 2 decades., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

Measurable residual disease (MRD) assessment before allogeneic hematopoietic cell transplantation (HCT) may help physicians to identify a subgroup of patients at high risk of relapse for de novo acute myeloid leukemia (AML) but its relevance among patients affected by secondary AML (sAML) is still unknown. We assessed the impact of MRD among 318 adult patients with sAML who received an allogeneic HCT in first complete remission. At the time of HCT, a total of 208 (65%) patients achieved MRD negativity, while 110 (35%) had positive MRD. 2-year overall survival (OS) was 58.8 % (95% CI 52.2-64.9) with leukemia-free survival (LFS) of 50.0 % (95% CI 43.7-56.1), relapse incidence of 34.2% (95% CI 28.4-40.1) and non-relapse mortality (NRM) of 23.3 % (95% CI 19-27.7) for the entire cohort. In multivariate analysis, HCT recipients with KPS ≥ 90 experienced less disease recurrence (HR 0.61, 95% CI 0.4-0.94) with better LFS (HR 0.63, 95% CI 0.44-0.89) and OS (HR 0.58, 95% CI 0.39-0.86). There were no differences in major clinical endpoints between patients with MRD-positive and MRD-negative status at the time of HCT. Pre-transplantation assessment of MRD was not informative on post-HCT outcomes in this retrospective registry-based analysis among patients affected by sAML., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

The optimal conditioning regimen prior haploidentical stem cell transplantation (Haplo-SCT) with post transplantation cyclophosphamide (PT-Cy) for acute myeloid leukemia (AML) remains unknown. A non-myeloablative conditioning (NMAC) regimen (cyclophosphamide + fludarabine + TBI 2 Gy [CyFluTBI]) is a safe approach, but relapse incidence remains high in this setting. Alternatively, a reduced intensity conditioning (RIC) regimen combining thiotepa and reduced-dose busulfan with fludarabine (TBF) may decrease AML relapse. However, an excess of toxicity may counterbalance this potential benefit. We retrospectively compared CyFluTBI vs. TBF in CR AML patients who underwent Haplo-SCT with PT-Cy, in two different populations based on age. We analyzed 490 patients. In patients aged <60 years (n = 203), we observed a higher RI (HR = 3.59, 95% CI = 1.75-7.37, p < 0.01), lower LFS (HR = 1.98, 95% CI = 1.22-3.22, p < 0.01) and lower OS (HR = 1.73, 95% CI = 1.04-2.88, p = 0.04) in the CyFluTBI group, without significant difference in NRM. In older patients (n = 287), we observed that conditioning regimen did not significantly influence LFS (HR = 0.90, 95% CI = 0.56-1.44, p = 0.65), OS (HR = 0.81, 95% CI = 0.49-1.32, p = 0.39) and RI (HR = 1.78, 95% CI = 0.90-3.50, p = 0.10), but showed that CyFluTBI was associated with a significantly lower risk of NRM (HR = 0.48, 95% CI = 0.25-0.92, p = 0.03). Thus, younger patients seem to benefit from conditioning intensification from CyFluTBI to TBF regimens prior PT-Cy Haplo-SCT for CR AML, while older ones do not., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

Background: There are currently few data on the outcome of acute myeloid leukemia (AML) in adolescents after allogeneic HSCT. The aim of this study is to describe the outcome and its specific risk factors for children, adolescents and young adults after a first allogeneic HSCT for AML., Methods: In this retrospective study, we compared the outcome of AML patients receiving a first allogeneic HSCT between 2005 and 2017 according to their age at transplantation's time: children (< 15 years, n = 564), adolescent and post-adolescent (APA) patients (15-25 years, n = 647) and young adults (26-40 years; n = 1434)., Results: With a median follow-up of 4.37 years (min-max 0.18-14.73 years), the probability of 2-year overall survival (OS) was 71.4% in children, 61.1% in APA patients and 62.9% in young adults (p = 0.0009 for intergroup difference). Both relapse and non-relapse mortality (NRM) Cumulative Incidence (CI) estimated at 2 years were different between the age groups (30.8% for children, 35.2% for APA patients and 29.4% for young adults-p = 0.0254, and 7.0% for children, 10.6% for APA patients and 14.2% for young adults, p < 0.0001; respectively). Whilst there was no difference between the three groups for grade I to IV acute GVHD CI at 3 months, the chronic GVHD CI at 2 years was higher in APA patients and young adults (31.4% and 36.4%, respectively) in comparison to the children (17.5%) (p < 0.0001). In multivariable analysis, factors associated with death were AML cytogenetics (HR1.73 [1.29-2.32] for intermediate risk 1, HR 1.50 [1.13-2.01] for intermediate risk 2, HR 2.22 [1.70-2.89] for high cytogenetics risk compared to low risk), use of TBI ≥ 8 Grays (HR 1.33 [1.09-1.61]), disease status at transplant (HR 1.40 [1.10-1.78] for second Complete Remission (CR), HR 2.26 [1.02-4.98] for third CR and HR 3.07 [2.44-3.85] for active disease, compared to first CR), graft source (HR 1.26 [1.05-1.50] for Peripheral Blood Stem Cells compared to Bone Marrow) and donor age (HR 1.01 (1-1.02] by increase of 1 year)., Conclusion: Age is an independent risk factor for NRM and extensive chronic GVHD. This study suggests that APA patients with AML could be beneficially treated with a chemotherapy-based MAC regimen and bone marrow as a stem cells source., (© 2021. The Author(s).)

Limited data is available on factors impacting the outcomes of second hematopoietic cell transplantation (HCT2) in patients with secondary acute myeloid leukemia (sAML). This study aimed to assess HCT2 outcome for sAML comparing reduced-intensity (RIC) to myeloablative (MAC) conditioning. Two hundred and fifteen patients were included: RIC (n = 134), MAC (n = 81). The median follow-up was 41.1 (95% CI: 26.7-69.3) and 28.5 (95% CI: 23.9-75.4) months, respectively. At two years, the relapse incidence (RI) was 58.3% versus 51.1% in RIC and MAC, respectively. The 2-year leukemia free survival (LFS) was 26.6% versus 26%, and the graft-versus-host disease (GVHD)-free, relapse-free survival (GRFS) was 16.4% versus 12.1%, while OS was 31.4% and 39.7%, for RIC and MAC respectively. MVA showed a significantly lower RI [hazard ratio (HR) = 0.46 (95% CI, 0.26-0.8, p = 0.006)] and improved LFS [HR = 0.62 (95% CI, 0.39-0.98, p = 0.042)] with MAC versus RIC. The choice of conditioning regimen did not impact non-relapse mortality [HR = 1.14 (95% CI, 0.52-2.5, p = 0.74)], overall survival (OS) [HR = 0.72 (95% CI, 0.44-1.17, p = 0.18)] or GRFS [HR = 0.89 (95% CI, 0.59-1.36, p = 0.6)]. In conclusion, MAC was associated with a lower RI and superior LFS. These results support the use of MAC for eligible patients with sAML who are being considered for HCT2., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

We performed a registry study on therapy-related myeloid neoplasm (t-MN), both therapy-related myelodysplastic syndrome (t-MDS) and acute myeloid leukemia (t-AML) following treatment for breast cancer who underwent a first allogeneic hematopoietic cell transplant (allo-HCT). Of 252 identified female patients (median age 57 years), 77% were transplanted for t-AML and 23% for t-MDS, with a median time from breast cancer diagnosis to the diagnosis of tMN and subsequent allo-HCT of 3.7 and 4.6 years, respectively. At transplant, 191 patients were in remission for breast cancer, while 4 were not (57 missing). T-MN was in a complete remission at the time of transplant in 67% of patients. 2-year overall survival, relapse free-survival, relapse incidence and non-relapse mortality were 50%, 45%, 33%, and 22%, respectively. Multivariable analysis revealed that if the t-MN was not in CR pre-transplant, this was associated with lower OS, RFS, and a higher relapse incidence. Seventeen cases of breast cancer recurrence were recorded after a median of 2.4 years post-transplant, and relapse of primary breast cancer accounted for 7% of deaths. This study indicates that allo-HCT for t-MN following treatment for breast cancer shows encouraging transplant outcomes. The incidence of breast cancer relapse post-transplant remains a cause for concern., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

Relapse is a major cause of treatment failure after allogeneic hematopoietic cell transplantation (allo-HCT) in myeloid malignancies. Additional strategies have been devised to further maximize the immunologic effect of allo-HCT, notably through maintenance therapy with hypomethylating agents such as 5-azacytidine (AZA). We conducted a single-center retrospective study to investigate the efficacy of AZA after allo-HCT for high-risk myeloid malignancies. All patients transplanted between Jan 2014 and Sept 2019 for high-risk acute myeloid leukemia (n = 123), myelodysplastic syndrome (n = 51), or chronic myelomonocytic leukemia (n = 11) were included. Patients who died, relapsed, or developed grade ≥ 2 acute graft-versus-host disease before day + 60 were excluded, as well as those who were eligible for anti-FMS-like tyrosine kinase 3 maintenance. Of the 185 included patients, 65 received AZA while 120 did not. Median age at transplant was 59 years; 51.9% of patients were males. The median follow-up was 24 months for both groups. Regarding main patient characteristics and transplantation modalities, the two groups were comparable. In multivariate analyses, there were no significant differences between the two groups in terms of 2-year cumulative incidence of relapse (HR = 1.19; 95% confidence interval (CI) 0.67-2.12; p = 0.55), overall survival (HR = 0.62; 95%CI 0.35-1.12; p = 0.12) and event-free survival (HR = 0.97; 95%CI 0.60-1.58; p = 0.91) rates. In conclusion, single-agent AZA does not appear to be an optimal drug for preventing post-transplant relapse in patients with high-risk myeloid malignancies. This study highlights the need for prospective studies of alternative therapies or combination approaches in the post-transplant setting., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

There are no data indicating whether the number of induction courses needed to achieve first complete remission (CR1) is of prognostic significance in Haploidentical transplantation (HaploSCT). We compared transplantation outcomes of adults with AML that underwent HaploSCT in CR1, achieved following one or two induction courses. A total of 635 patients were included: 469 (74%) with 1 and 166 (26%) with two induction chemotherapy courses. A total of 429 (91.5%) and 151 (91%) patients had de novo AML and 40 (8.5%) and 15 (9%) had secondary AML (p = 0.84). Engraftment rates were 97.2 and 97.6%. Day 180 incidence of acute GVHD II-IV and III-IV was similar in both induction groups (31.1 and 34.8%, and 10 and 10.6 %), as was 2-4 year total and extensive chronic GVHD (33.7 and 36.5 %, and 12.2 and 12.1%), respectively. Two-year relapse incidence (RI) was higher while leukemia-free survival (LFS), overall survival (OS) and GVHD-free, relapse-free survival (GRFS) were inferior for patients achieving CR1 with 2 vs 1 course and were 29.1% vs 15.1%, 88 (p = 0.001), 56.2% vs 66.9% (p = 0.03), 58.8% vs 72.2% (p = 0.044) and 44% vs 55.6% (p = 0.013), respectively. Non-relapse mortality (NRM) did not differ, 18% vs 14.6% 90 (p = 0.25). These results were confirmed by multivariate analysis., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

FMS-like tyrosine kinase 3 internal tandem duplication (FLT3-ITD) mutational status is a pivotal prognosticator in acute myeloid leukemia (AML) patients and significantly increases the risk of disease relapse. However, it remains unclear whether in FLT3-ITD patients referred for allogeneic stem cell transplantation (allo-SCT), baseline cytogenetics significantly impacts clinical outcome. Using the European Society of Blood and Marrow Transplantation registry, we performed a retrospective analysis of 1631 FLT3-ITD AML patients who underwent allo-SCT with the aim of determining the influence of cytogenetic risk category on patient outcomes. Median patient age was 49 years and median follow-up duration was 36 months. Two-year leukemia-free survival (LFS) and incidence of relapse were 54% and 31.6%, respectively. Non-relapse mortality was experienced by 14.4% with a 2-year overall survival (OS) of 60.1%. On multivariate analysis, LFS was significantly lower in patients with intermediate and adverse risk cytogenetics compared with those with favorable risk cytogenetics, (hazard ratio [HR] = 1.48, 95% confidence interval [CI], 1.06-2.06; p = .02), and (HR = 01.65, 95% CI, 1.13-2.40; p = .009), respectively. OS was significantly lower in patients with adverse risk cytogenetics compared with patients with favorable risk cytogenetics (HR = 1.74, 95% CI, 1.16-2.61; p = .008) with a trend toward lower OS in patients with intermediate risk cytogenetics compared to those with favorable risk cytogenetics (HR = 1.43, 95% CI, 1.00-2.05; p = .052). In addition, adverse risk patients and intermediate risk patients experienced higher relapse rates compared with favorable risk patients (HR = 1.83, 95% CI, 1.13-2.94; p = .013 and HR = 1.82, 95% CI, 1.19-2.77; p = .005). Overall, cytogenetic studies aid in refinement of risk stratification in transplanted FLT3-ITD AML patients., (© 2022 Wiley Periodicals LLC.)

Allogeneic hematopoietic cell transplantation (allo-HCT) is the only curative treatment for patients with myeloid/lymphoid neoplasm (MLN) with FGFR1 rearrangement, but data on overall results are limited. We report on the largest series of patients (n = 22) with FGFR1-rearranged MLN undergoing allo-HCT. Distribution according to cytogenetic subtype was: t(8;13) in 11 cases, t(8;22) in 7 cases, t(6;8) in 2 cases, and other (n = 2). Over a third of patients displayed a chronic myeloproliferative (MPN) phenotype, another third showed MPN features with concomitant lymphoma or acute leukemia, and the remaining ones presented as acute leukemia. After a median follow-up of 4.1 years from transplant, the estimated 5-year survival rate, progression-free survival, non-relapse mortality and relapse incidence was 74%, 63%, 14% and 23%, respectively. Causes of death were relapse/progression (n = 4), graft-versus-host disease (n = 2) and organ toxicity (n = 1). Six patients experienced disease relapse at a median of 6.1 months (range: 2.3-119.6). Two of them achieved complete remission with ponatinib or pemigatinib and were alive at 34.5 and 37 months from relapse, respectively. These data highlight the significant curative potential of allo-HCT in this aggressive disease. Maintenance with tyrosine kinase inhibitors may be a promising approach, at least in cases with detectable residual disease after transplant., (© 2021. The Author(s), under exclusive licence to Springer Nature Limited.)

Measurable residual disease (MRD) prior to hematopoietic cell transplant (HCT) for acute myeloid leukemia (AML) in first complete morphological remission (CR1) is an independent predictor of outcome, but few studies address CR2. This analysis by the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation registry assessed HCT outcomes by declared MRD status in a cohort of 1042 adult patients with AML CR2 at HCT. Patients were transplanted 2006-2016 from human leukocyte antigen (HLA) matched siblings (n = 719) or HLA 10/10 matched unrelated donors (n = 293). Conditioning was myeloablative (n = 610) or reduced-intensity (n = 432) and 566 patients (54%) had in-vivo T cell depletion. At HCT, 749 patients (72%) were MRD negative (MRD NEG) and 293 (28%) were MRD positive (MRD POS). Time from diagnosis to HCT was longer in MRD NEG than MRD POS patients (18 vs. 16 months (P < 0.001). Two-year relapse rates were 24% (95% CI, 21-28) and 40% (95% CI, 34-46) in MRD NEG and MRD POS groups (P < 0.001), respectively. Leukemia-free survival (LFS) was 57% (53-61) and 46% (40-52%), respectively (P = 0.001), but there was no difference in terms of overall survival. Prognostic factors for relapse and LFS were MRD NEG status, good risk cytogenetics, and longer time from diagnosis to HCT. In-vivo T cell depletion predicted relapse.

We compared transplant outcomes of 708 acute myeloid leukemia (AML) patients receiving haploidentical allogeneic hematopoietic-cell transplantation using thiotepa/busulfan/fludarabine (TBF) conditioning with posttransplant cyclophosphamide (ptCy), to 2083 patients receiving matched unrelated donor (MUD) transplantation using fludarabine/busulfan (FB) conditioning and in vivo T-cell depletion. For intermediate cytogenetic risk AML transplanted in first complete remission (CR1), multivariate analysis revealed that haplo-TBF significantly increased nonrelapse mortality (NRM) (HR 2.1; p = 0.0006) but did not affect relapse incidence (RI), leukemia-free survival (LFS), overall survival (OS), or graft-versus-host disease-free, relapse-free survival (GRFS). For high cytogenetic risk AML transplanted in CR1, haplo-TBF significantly increased NRM (HR = 2.7; p = 0.02), decreased RI (HR = 0.45; p = 0.03) but had no influence on LFS, OS, or GRFS. For AML transplanted in CR2, haplo-TBF significantly increased NRM (HR = 2.36; p = 0.008), decreased RI (HR = 0.38; p = 0.005), but had no influence on LFS, OS, or GRFS. Finally, for AML patients transplanted with active disease, haplo-TBF had no influence on transplant outcomes. In conclusion, compared to MUD-FB, haplo-TBF increased NRM, reduced RI in high-risk AML in CR, resulting in similar LFS, OS, and GRFS. These results comparing two different approaches support the use of a haploidentical family donor for high-risk AML patients lacking a matched sibling donor.

The indication for performing an allogeneic hematopoietic stem cell transplantation (allo-HCT) in patients with isolated trisomy 8 AML in first complete remission (CR) is still debated. Here, we compared outcomes of such patients given either allo-HCT or autologous (auto)-HCT. Inclusion criteria consisted of adult patients with de novo AML, isolated trisomy 8, first HCT between 2000 and 2018, CR1 at transplantation, and either auto-HCT or allo-HCT with a HLA-identical sibling donor (MSD) or a 10/10 HLA-matched unrelated donor (UD 10/10). A total of 401 patients met the inclusion criteria. They underwent an auto-HCT (n = 81), allo-HCT with a MSD (n = 186) or allo-HCT with a 10/10 UD (n = 134). At 3 years, relapse incidence, nonrelapse mortality and leukemia-free survival (LFS) were 59%, 5%, and 37%, respectively, in auto-HCT recipients; 31% (P < 0.001), 14% (P = 0.04), and 55% (P = 0.033), respectively, in MSD recipients and 29% (P < 0.001), 13% (P = 0.15), and 59% (P = 0.03), respectively, in UD 10/10 recipients. In multivariate analysis, in comparison to auto-HCT, MSD and UD 10/10 were associated with a lower risk of relapse (HR = 0.47, P < 0.001 and HR = 0.40, P < 0.001, respectively) translating to better LFS (HR = 0.69, P = 0.04 and HR = 0.60, P = 0.03, respectively). There was also a similar trend for overall survival (HR = 0.73, P = 0.12 and HR = 0.65, P = 0.08).

A multistage model instructed by a large dataset (knowledge bank [KB] algorithm) has recently been developed to improve outcome predictions and tailor therapeutic decisions, including hematopoietic stem cell transplantation (HSCT) in acute myeloid leukemia (AML). We assessed the performance of the KB in guiding HSCT decisions in first complete remission (CR1) in 656 AML patients younger than 60 years from the ALFA-0702 trial (NCT00932412). KB predictions of overall survival (OS) were superior to those of European LeukemiaNet (ELN) 2017 risk stratification (C-index, 68.9 vs 63.0). Among patients reaching CR1, HSCT in CR1, as a time-dependent covariate, was detrimental in those with favorable ELN 2017 risk and those with negative NPM1 minimal residual disease (MRD; interaction tests, P = .01 and P = .02, respectively). Using KB simulations of survival at 5 years in a scenario without HSCT in CR1 (KB score), we identified, in a similar time-dependent analysis, a significant interaction between KB score and HSCT, with HSCT in CR1 being detrimental only in patients with a good prognosis based on KB simulations (KB score ≥40; interaction test, P = .01). We could finally integrate ELN 2017, NPM1 MRD, and KB scores to sort 545 CR1 patients into 278 (51.0%) HSCT candidates and 267 (49.0%) chemotherapy-only candidates. In both time-dependent and 6-month landmark analyses, HSCT significantly improved OS in HSCT candidates, whereas it significantly shortened OS in chemotherapy-only candidates. Integrating KB predictions with ELN 2017 and MRD may thus represent a promising approach to optimize HSCT timing in younger AML patients., (© 2021 by The American Society of Hematology.)

Results from registry studies suggest that harnessing Natural Killer (NK) cell reactivity mediated through Killer cell Immunoglobulin-like Receptors (KIR) could reduce the risk of relapse after allogeneic Hematopoietic Cell Transplantation (HCT). Several competing models have been developed to classify donors as KIR-advantageous or disadvantageous. Basically, these models differ by grouping donors based on distinct KIR-KIR-ligand combinations or by haplotype motif assignment. This study aimed to validate different models for unrelated donor selection for patients with Myelodysplatic Syndromes (MDS) or secondary Acute Myeloid Leukemia (sAML). In a joint retrospective study of the European Society for Blood and Marrow Transplantation (EBMT) and the Center for International Blood and Marrow Transplant Research (CIBMTR) registry data from 1704 patients with secondary AML or MDS were analysed. The cohort consisted mainly of older patients (median age 61 years) with high risk disease who had received chemotherapy-based reduced intensity conditioning and anti-thymocyte globulin prior to allogeneic HCT from well-matched unrelated stem cell donors. The impact of the predictors on Overall Survival (OS) and relapse incidence was tested in Cox regression models adjusted for patient age, a modified disease risk index, performance status, donor age, HLA-match, sex-match, CMV-match, conditioning intensity, type of T-cell depletion and graft type. KIR genes were typed using high-resolution amplicon-based next generation sequencing. In univariable and multivariable analyses none of the models predicted OS and the risk of relapse consistently. Our results do not support the hypothesis that optimizing NK-mediated alloreactivity is possible by KIR-genotype informed selection of HLA-matched unrelated donors. However, in the context of allogeneic transplantation, NK-cell biology is complex and only partly understood. KIR-genes are highly diverse and current assignment of haplotype motifs based on the presence or absence of selected KIR genes is over-simplistic. As a consequence, further research is highly warranted and should integrate cutting edge knowledge on KIR genetics, and NK-cell biology into future studies focused on homogeneous groups of patients and treatment modalities., Competing Interests: The DKMS Life Science Laboratory (VL, CM, AS) implemented the KIR genotyping as part of the upfront genotyping profile for volunteers enrolled into the DKMS and offers KIR genotyping also for external customers. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Schetelig, Baldauf, Koster, Kuxhausen, Heidenreich, de Wreede, Spellman, van Gelder, Bruno, Onida, Lange, Massalski, Potter, Ljungman, Schaap, Hayden, Lee, Kröger, Hsu, Schmidt, Yakoub-Agha and Robin.)

Karyotypic analysis at time of diagnosis has an important value in determining initial response to treatment, remission duration and overall survival (OS) in acute myeloid leukemia (AML). Less is known about its value before allogeneic hematopoietic cell transplantation (allo-HCT) in patients transplanted with active disease, either relapsed or primary refractory (Rel-Ref) AML. We explored the impact of cytogenetic risk (stratification according to MRC-UK) in 2089 patients with either Ref (n = 972) or Rel AML (n = 1117) transplanted during the period 2000-2017. Overall, 154 patients had a favorable risk, 1283 had an intermediate risk and 652 had an adverse cytogenetic risk. Median follow-up was 49 months. Compared to the favorable risk group, intermediate and adverse risk patients were associated with worse leukemia-free survival and OS and also with a higher incidence of relapse. In a subgroup analysis of patients in the intermediate risk group harboring Fms-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD), this remained an important prognostic factor, being associated with worse outcomes. When analyzing patients according to the intensity of the conditioning regimen, no differences were observed for the main transplant outcomes. In conclusion, in patients diagnosed with AML and transplanted with active disease, karyotype remains an important prognostic factor, allowing splitting patients into different risk groups according to their cytogenetics. Similarly, FLT3-ITD mutation also remains a negative prognostic factor in this population., (© 2020 Wiley Periodicals LLC.)

Microtransplantation (MT) is based on injection of HLA-mismatched G-CSF mobilized hematopoietic stem cells, in combination with chemotherapy but without use of conditioning regimen nor immunosuppressive drugs. As a result, a transient microchimerism is induced without engraftment. Its efficacy relies both on host immune system stimulation (recipient versus tumor) and on a graft versus tumor effect. Data are scarce and concern mostly Asian patients with acute myeloid leukemia (AML) and high risk myelodysplastic syndrome (HR-MDS). In comparison to conventional treatment without MT, higher complete remission rates and longer disease free survival and overall survival have been reported. Safety seems acceptable. The most frequent adverse event is non-severe cytokine release syndrome. Risk of GVHD remains very low. Here, we summarize the published data and detail the practical aspects of the procedure. Current data are not strong enough to provide recommendations on indications. Nevertheless, it seems reasonable to propose MT to patients with AML or HR-MDS, regardless of age, presenting an indication for allogeneic stem cell transplantation but ineligible for it. MT is still under investigation and rather be proposed within clinical trials., (Copyright © 2020 Société Française du Cancer. Published by Elsevier Masson SAS. All rights reserved.)

Induction chemotherapy (7 + 3 regimen) remains the gold standard for patients with acute myeloid leukemia (AML) but is responsible for gut damage leading to several complications such as bloodstream infection (BSI). We aimed to investigate the impact of induction chemotherapy on the intestinal barrier of patients with AML and in wild-type mice. Next, we assessed the potential benefit of strengthening the mucosal barrier in transgenic mice releasing a recombinant protein able to reinforce the mucus layer (Tg222). In patients, we observed a decrease of plasma citrulline, which is a marker of the functional enterocyte mass, of short-chain fatty acids and of fecal bacterial load, except for Escherichia coli and Enterococcus spp., which became dominant. Both the α and β-diversities of fecal microbiota decreased. In wild-type mice, citrulline levels decreased under chemotherapy along with an increase of E. coli and Enterococcus spp load associated with concomitant histologic impairment. By comparison with wild-type mice, Tg222 mice, 3 days after completing chemotherapy, had higher citrulline levels, a faster healing epithelium, and preserved α-diversity of their intestinal microbiota. This was associated with reduced bacterial translocations. Our results highlight the intestinal damage and the dysbiosis induced by the 7 + 3 regimen. As a proof of concept, our transgenic model suggests that strengthening the intestinal barrier is a promising approach to limit BSI and improve AML patients' outcome.

Allogeneic stem cell transplantation (allo-SCT) represents the most beneficial treatment for patients with active relapsed/refractory (R/R) hematologic malignancies. Recently, sequential regimens combining debulking chemotherapy followed by reduced-intensity conditioning (RIC) have shown encouraging results for these patients. In this retrospective study, we report the extended results of a sequential regimen of clofarabine, cytosine arabinoside, and RIC in 131 adults with active R/R myeloid disease at transplant. Conditioning consisted of clofarabine (30 mg/m 2 /day) and cytosine arabinoside (1 g/m 2 /day) for 5 days, followed, after a rest of 3 days, by an RIC combining cyclophosphamide (60 mg/kg) for 1 day, iv busulfan (3.2 mg/kg/day) for 2 days, and anti-thymocyte globulin (2.5 mg/kg/day) for 2 days. Between 2007 and 2016, 131 patients (males n = 75, median age: 52.6 years) were identified from the SFGM-TC registry. There were 111 acute myeloid leukemia (AML) patients and 20 cases with myelodysplastic or myeloproliferative syndrome. Status at transplant was known for all but 4 patients and was primary refractory (n = 81) and 1st or 2nd relapse (n = 46). All patients received allo-SCT from a matched donor (sibling n = 64, unrelated n = 67). Engraftment was observed in 105/122 (86%) evaluable cases and 63% of the patients achieved complete remission (CR) after transplant. The 1-year overall survival, disease-free survival, relapse incidence, non-relapse mortality, and graft-versus-host disease-free/relapse-free survival were 39.2%, 28.1%, 41.0%, 30.8%, and 22.2%, respectively. This study confirms that this sequential clofarabine-based regimen provides a high CR rate in this critical population, although relapse remains a matter of concern.

Core binding factor acute myeloid leukemia (AML) comprises two subtypes with distinct cytogenetic abnormalities of either t(8;21)(q22;q22) or inv(16)(p13q22)/t(16;16)(p13;q22). Since long-term response to chemotherapy in these leukemias is relatively good, allogeneic hematopoietic stem cell transplantation is considered in patients who relapse and achieve second complete remission. To evaluate the outcomes of allogeneic transplantation in this indication, we studied 631 patients reported to the European Society for Blood and Marrow Transplantation Registry between the years 2000 and 2014. Leukemia-free survival probabilities at two and five years were 59.1% and 54.1%, while overall survival probabilities were 65% and 58.2%, respectively. The incidence of relapse and risk of non-relapse mortality at the same time points were 19.8% and 22.5% for relapse and 20.9% and 23.3% for non-relapse mortality, respectively. The most important adverse factors influencing leukemia-free and overall survival were: leukemia with t(8;21), presence of three or more additional chromosomal abnormalities, and Karnofsky performance score <80. Relapse risk was increased in t(8;21) leukemia and associated with additional cytogenetic abnormalities as well as reduced intensity conditioning. Measurable residual disease in molecular evaluation before transplantation was associated with increased risk of relapse and inferior leukemia-free survival., (Copyright© 2020 Ferrata Storti Foundation.)

Measurable residual disease (MRD) status pre-allogeneic hematopoietic cell transplantation (allo-HCT) has been shown to predict transplant outcomes. We investigated the effect of Anti-Thymocyte Globulin (ATG) on acute myelogenous leukemia (AML) relapse by pretransplant MRD status. AML patients undergoing allo-HCT in first complete remission from either a matched sibling or unrelated donor during the 2006-2017 period were selected. Outcomes of 1509 patients (MRD + , n = 426) were studied. ATG was used in 561 (52%) and 239 (58%) patients within the MRD - and MRD + cohorts, respectively. In MRD - patients, ATG did not affect relapse incidence (RI) (HR = 0.80, p = 0.17), but was associated with reduced incidence of grade II-IV acute GVHD, grade II-IV and chronic GVHD, reduced nonrelapse mortality (HR = 0.66, p = 0.05), improved leukemia-free survival (HR = 0.74, p = 0.02), overall survival (HR = 0.69, p = 0.01), and GVHD-relapse free survival (HR = 0.62, p < 0.01). In MRD + patients, ATG was associated with a lower incidence of chronic GVHD (total, HR 0.56 p = 0.03; extensive, HR 0.40 P = 0.01), without an impact on other allo-HCT outcome parameters, including RI(HR = 1.02, p = 0.92). The use of ATG was associated with reduced risk for GVHD. ATG did not increase RI, even in high-risk AML patients who were MRD + before allo-HCT.

Allogeneic hematopoietic stem cell transplantation is the only potentially curative therapy for acute myeloid leukemia. In the absence of an HLA-matched related or unrelated donor (MRD or MUD), the best alternative donor source remains controversial. Umbilical cord blood and haploidentical donors offer a shorter delay from indication to transplantation. This retrospective multicentre study of a French registry compares overall survival in the 18 months following registration in the absence of a MRD between four types of donors. Between 2012 and 2016, 1302 patients were transplanted using MUD (control, n = 803), mismatched MUD (n = 219), umbilical cord blood (n = 153) and haploidentical (n = 127) donors. Multivariate analyses were conducted for overall survival after registration, after transplant, and transplant-related mortality. After adjustment for variables, the type of donor did not influence any of the three end points. Our results confirmed the significant negative impact of longer time between registration and transplant: HR = 1.04 [1.02-1.06] (p < 0.0001). This indicates a positive correlation between better survival and shorter registration-to-transplantation wait time. In the absence of a sibling donor, the alternative stem cell source does not impact early survival in acute myeloid leukemia patients. The minimization of registration-to-transplantation time should be considered when weighing the alternative donor options.

Following chemotherapy, secondary acute myeloid leukemia (sAML), occurring after antecedent hematologic diseases, previous chemotherapy or radiation, has an inferior prognosis compared with de novo AML. To define the outcome of sAML in the context of allogeneic stem cell transplantation (alloSCT), a retrospective, registry-based comparison was performed, including 11,439 patients with de novo and 1325 with sAML. Among transplants in first complete remission (CR1) (n = 8,600), the 3-year cumulative incidence of relapse (RI) and non-relapse mortality (NRM) was 28.5% and 16.4% for de novo, and 35% and 23.4% for sAML. Three-year overall survival (OS), leukemia-free survival (LFS) and Graft-versus-Host Disease/relapse-free survival (GRFS) was 60.8%, 55.1%, and 38.6% for de novo, and 46.7%, 41.6%, and 28.4% for sAML, respectively. In multivariate analysis, sAML was associated with a lower OS (HR = 1.33 [95% CI = 1.21-1.48]; p < 10 -5 ), LFS (HR = 1.32 [95% CI = 1.19-1.45]; p < 10 -5 ) and GRFS (HR = 1.2 [95% CI = 1.1-1.31]; p < 10 -4 ) and higher NRM (HR = 1.37 [95% CI = 1.17-1.59]; p < 10 -4 ) and RI (HR = 1.27 [95% CI = 1.12-1.44]; p < 10 -3 ). Results of the Cox model were confirmed in a matched-pair analysis. In contrast, results did not differ between de novo and sAML after alloSCT in induction failure or relapse. Hence, this analysis identified sAML as an independent risk factor for outcome after alloSCT in CR1.

Monosomy 7 or deletion 7q (-7/7q-) is the most frequent adverse cytogenetic features reported in acute myeloid leukemia (AML), and is a common indication for allogeneic stem cell transplantation (SCT). Nevertheless, -7/7q- occurs frequently with other high-risk cytogenetic abnormalities such as complex karyotype (CK), monosomal karyotype (MK), monosomy 5 or deletion 5q (-5/5q-), 17p abnormalities (abn(17p)) or inversion of chromosome 3 (inv(3)), the presence of which may influence the outcomes after SCT. A total of 1109 patients were allocated to this study. Two-year probability of leukemia-free survival (LFS) and overall survival (OS) were 30% and 36%, respectively. Two-year probability of non-relapse mortality (NRM) was 20%. We defined five different cytogenetic subgroups: the "-7/7q- ± CK group- designated group1," the "MK group-designated group 2," the "-5/5q- group- designated group 3," the "abn(17p) group- designated group 4" and the "inv(3) group- designated group 5." The 2-year probability of LFS in first remission was 48% for group 1, 36.4% for group 2, 28.4% for group 3, 19.1% for group 4 and 17.3% for group 5, respectively (P < .001). Multivariate analysis confirmed those significant differences across groups. Note, SCT in -7/7q- AML provides durable responses in one third of the patients. The presence of -7/7q- with or without CK in the absence of MK, abn(17p) or inv(3) is associated with a better survival after SCT. On the contrary, addition of MK, -5/5q-, abn(17p) or inv(3) identifies a sub-group of patients with poor prognosis even after SCT., (© 2019 Wiley Periodicals, Inc.)

Deletion 5q or monosomy 5 (-5/5q-) in acute myeloid leukemia (AML) is a common high-risk feature that is referred to allogeneic stem cell transplantation. However, -5/5q- is frequently associated with other high-risk cytogenetic aberrations such as complex karyotype, monosomal karyotype, monosomy 7 (-7), or 17p abnormalities (abn (17p)), the significance of which is unknown. In order to address this question, we studied adult patients with AML harboring -5/5q- having their first allogeneic transplantation between 2000 and 2015. Five hundred and one patients with -5/5q- have been analyzed. Three hundred and thirty-eight patients (67%) were in first remission and 142 (28%) had an active disease at time of allogeneic transplantation. The 2-year probabilities of overall survival and leukemia-free survival were 27% and 20%, respectively. The 2-year probability of treatment-related mortality was 20%. We identified four different cytogenetic groups according to additional abnormalities with prognostic impact: -5/5q- without complex karyotype, monosomal karyotype or abn(17p), -5/5q- within a complex karyotype, -5/5q- within a monosomal karyotype and the combination of -5/5q- with abn(17p). In multivariate analysis, factors associated with worse overall survival and leukemia-free survival across the four groups were active disease, age, monosomal karyotype, and abn(17p). The presence of -5/5q- without monosomal karyotype or abn(17p) was associated with a significantly better survival rate while -5/5q- in conjunction with monosomal karyotype or abn(17p) translated into a worse outcome. The patients harboring the combination of -5/5q- with abn(17p) showed very limited benefit from allogeneic transplantation., (Copyright© 2020 Ferrata Storti Foundation.)

Allogeneic hematopoietic cell transplant (HCT) is a curative therapy for patients with secondary acute myeloid leukemia (sAML), though the impact of conditioning regimens on HCT outcomes for patients with antecedent lymphoid malignancy is largely unknown. This multicenter, retrospective registry study of the ALWP of the EBMT assessed HCT outcomes in this population. In all, 549 patients ≥18 years with sAML following an antecedent lymphoid malignancy treated with first allograft between 2000-2016 were included. Myeloablative (MAC) and reduced intensity conditioning (RIC) was given in 258 (47%) and 291 (53%), respectively. At 2 years, leukemia-free survival (LFS) was 31.7% (95% CI, 27.5-35.9), overall survival (OS) was 37.4% (95% CI, 33-41.8), nonrelapse mortality (NRM) was 28.9% (95% CI, 25-33), and GVHD-free, relapse-free survival (GRFS) was 22.8% (95% CI, 19-26.6). In multivariate analysis, patients receiving RIC regimens had lower risk of NRM (HR: 0.58, CI: 0.40-0.83, p = 0.003), and improved LFS (HR: 0.67, CI: 0.52-0.85, p = 0.001). Patients with prior autologous HCT had inferior LFS (HR: 1.30, CI: 1.01-1.67, p = 0.01). This study demonstrates that sAML patients following prior lymphoid malignancy treated with RIC regimens have a lower risk of NRM and improved LFS, OS, and GFRS. Other variables associated with inferior outcomes include older age, active disease, adverse cytogenetics, and prior auto-HCT.

Allogeneic haemopoietic cell transplant (allo-HCT) may be curative in acute myeloid leukaemia (AML) in second complete remission (CR2) but the impact of reduced intensity (RIC) versus myeloablative conditioning (MAC) is uncertain. The Acute Leukaemia Working Party of the European Society for Blood and Bone Marrow Transplantation Registry studied an AML CR2 cohort characterised by age ≥ 18 years, first allo-HCT 2007-2016, available cytogenetic profile at diagnosis, donors who were matched family, volunteer unrelated with HLA antigen match 10/10 or 9/10 or haplo-identical. The 1879 eligible patients included 1010 (54%) MAC allo-HCT recipients. In patients <50 years (y), two year outcomes for MAC vs RIC allo-HCT were equivalent with leukaemia-free survival (LFS) 54% for each, overall survival (OS), 61% vs 62%, non-relapse mortality (NRM) 18% vs 15% and graft versus host disease relapse-free survival (GRFS) 38% vs 42%. In patients ≥50 y, 2 y outcomes for MAC vs RIC allo-HCT were equivalent for LFS 52% vs 49%, OS 58% vs 55% and GRFS 42.4% vs 36%. However, NRM was significantly inferior after MAC allo-HCT, 27% vs 19% (P = 0.01) despite worse cGVHD after RIC-allo (32% vs 39%). These data support the need for ongoing prospective study of conditioning intensity and GVHD mitigation in AML.

Thirty patients, with high-risk acute myeloid leukemia (AML, n = 20) or myelodysplastic syndrome (MDS, n = 10), were enrolled in a phase II trial entailing prophylactic post-transplant azacitidine (AZA) plus escalated doses of donor lymphocyte infusion (DLI). The median number of AZA cycles was 5 (1-12) with 10 patients (33%) completing the 12 projected cycles. DLI were performed in 17 patients: 5 received one DLI, 2 received 2 DLI and 8 received 3 infusions. AZA was well tolerated, but discontinued in 20 patients primarily due to graft-versus-host disease (GvHD) and relapse. The cumulative incidence (CI) of grade 1-3 acute GvHD was 31.5% and the chronic GvHD CI was 53% at 2 years. At a median follow-up of 49 months (27-63), 18 patients are alive. The overall and disease-free survivals are 65.5% (CI 95% = 48.2-82.8) at 2 years. Cause of death was mainly relapse for 9 patients. The median time to relapse was 7 months (2.5-58) and the cumulative incidence of relapse at 2 years was 27.6% (CI 95% = 12.8-44.6). These results confirm that AZA is well tolerated as a prophylactic treatment to reduce the risk of post-transplantation relapse and compared favorably to those of patients who receive no post-transplant maintenance.

Myelodysplastic syndromes (MDS), myeloproliferative neoplasms (MPN) and chronic myelomonocytic leukaemia (CMML) can progress to secondary acute myeloid leukaemia (sAML). We compared the outcome of 4214 sAML patients who received allogeneic haematopoietic stem cell transplantation (allo-HSCT) from an unrelated (62%) or human leucocyte antigen (HLA)-identical sibling donor (38%) according the underlying disease: MDS (n = 3541), CMML (n = 251) or MPN (n = 422). After a median follow up of 46·5 months, the estimated 3-year progression-free (PFS) and overall survival (OS) for the entire group was 36% (34-37%) and 41% (40-43%), respectively. The cumulative incidence of relapse and non-relapse mortality (NRM) was 37% (35-39%) and 27% (26-29%), respectively. In a multivariable analysis for OS, besides age (P < 0·001), unrelated donor (P = 0·011), cytomegalovirus ± constellation (P = 0·007), Karnofsky index ≤ 80 (P < 0·001), remission status (P < 0·001), peripheral blood as stem cell source (P = 0·009), sAML from MPN (P = 0·003) remained a significant factor in comparison to sAML from MDS, while worse outcome of sAML from CMML did not reach statistical significance (P = 0·06). This large registry study demonstrates a major impact of the underlying disease on outcome of sAML after allo-HSCT., (© 2019 British Society for Haematology and John Wiley & Sons Ltd.)

We previously reported in a French prospective randomized study that transplantation of 2 unrelated cord blood (UCB) units instead of 1 unit does not decrease the risk of transplantation failure but may enhance alloreactivity. Here we evaluated the influence of pretransplantation minimal residual disease (MRD) on leukemia relapse and survival after single- versus double-UCB transplantation (UCBT). Among 137 children and young adults who underwent UCBT in this randomized study, 115 had available data on MRD assessment done immediately before initiation of the pretransplantation conditioning regimen. MRD was considered positive at a level of ≥10 -4 , which was the case of 43 out of 115 patients. Overall, the mean 3-year survival probability was 69.1 ± 4.4%, and it was not significantly influenced by the MRD level: 70.7 ± 5.4% in MRD-negative (<10 -4 ) patients (n = 72), 71.1 ± 9.4% in MRD-positive patients with 10 -4 ≤ MRD <10 -3 (n = 26) and 58.8 ± 11.9% in MRD-positive patients with ≥10 -3 (n = 17). In the MRD-positive group, the mean risk of relapse was significantly lower in the double-UCBT arm compared with the single-UCBT arm (10.5 ± 7.2% versus 41.7 ± 10.4%; P = .025) leading to a higher mean 3-year survival rate (82.6 ± 9.3% versus 53.6 ± 10.3%; P = .031). This difference was observed only in patients who had not received antithymocyte globulin during their conditioning regimen. In the MRD-negative group, there was no differencebetween the single- and the double-UCBT arms. We conclude that even in cases of positive pretransplantation MRD, UCBT in children and young adults with acute leukemia yields a high cure rate, and that a double-unit strategy may enhance the graft-versus-leukemia effect and survival in these patients., (Copyright © 2018 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)