Risk Stratification in Older Intensively Treated Patients With AML.

PURPOSE: AML is a genetically heterogeneous disease, particularly in older patients. In patients older than 60 years, survival rates are variable after the most important curative approach, intensive chemotherapy followed by allogeneic hematopoietic cell transplantation (allo-HCT). Thus, there is an urgent need in clinical practice for a prognostic model to identify older patients with AML who benefit from curative treatment. METHODS: We studied 1,910 intensively treated patients older than 60 years with AML and high-risk myelodysplastic syndrome (HR-MDS) from two cohorts (NCRI-AML18 and HOVON-SAKK). The median patient age was 67 years. Using a random survival forest, clinical, molecular, and cytogenetic variables were evaluated in an AML development cohort (n = 1,204) for association with overall survival (OS). Relative weights of selected variables determined the prognostic model, which was validated in AML (n = 491) and HR-MDS cohorts (n = 215). RESULTS: The complete cohort had a high frequency of poor-risk features, including 2022 European LeukemiaNet adverse-risk (57.3%), mutated TP53 (14.4%), and myelodysplasia-related genetic features (65.1%). Nine variables were used to construct four groups with highly distinct 4-year OS in the (1) AML development, (2) AML validation, and (3) HR-MDS test cohorts ([1] favorable: 54% ± 4%, intermediate: 38% ± 2%, poor: 21% ± 2%, very poor: 4% ± 1%; [2] 54% ± 9%, 43% ± 4%, 27% ± 4%, 4% ± 3%; and [3] 54% ± 10%, 33% ± 6%, 14% ± 5%, 0% ± 3%, respectively). This new AML60+ classification improves current prognostic classifications. Importantly, patients within the AML60+ intermediate- and very poor-risk group significantly benefited from allo-HCT, whereas the poor-risk patients showed an indication, albeit nonsignificant, for improved outcome after allo-HCT. CONCLUSION: The new AML60+ classification provides prognostic information for intensively treated patients 60 years and older with AML and HR-MDS and identifies patients who benefit from intensive chemotherapy and allo-HCT.

Higher survival following transplantation with a mismatched unrelated donor with posttransplant cyclophosphamide-based graft-versus-host disease prophylaxis than with double unit umbilical cord blood in patients with acute myeloid leukemia in first complete remission: A study from the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation.

The best donor option for acute myeloid leukemia (AML) patients lacking an HLA-matched donor has remained intensively debated. We herein report the results of a large retrospective registry study comparing hematopoietic cell transplantation (HCT) outcomes between double-unit umbilical cord blood transplantation (dCBT, n = 209) versus 9/10 HLA-matched unrelated donor (UD) with posttransplant cyclophosphamide (PTCy)-based graft-versus-host disease (GVHD) prophylaxis (UD 9/10, n = 270) in patients with AML in first complete remission (CR1). Inclusion criteria consisted of adult patient, AML in CR1 at transplantation, either peripheral blood stem cells (PBSC) from UD 9/10 with PTCy as GVHD prophylaxis or dCBT without PTCy, transplantation between 2013 and 2021, and no in vivo T-cell depletion. The 180-day cumulative incidence of grade II-IV acute GVHD was 29% in UD 9/10 versus 44% in dCBT recipients (p = .001). After adjustment for covariates, dCBT recipients had a higher non-relapse mortality (HR = 2.35, 95% CI: 1.23-4.48; p = .01), comparable relapse incidence (HR = 1.12, 95% CI: 0.67-1.86; p = .66), lower leukemia-free survival (HR = 1.5, 95% CI: 1.01-2.23; p = .047), and lower overall survival (HR = 1.66, 95% CI: 1.08-2.55; p = .02) compared with patients receiving UD 9/10 HCT. In summary, our results suggest that transplantation outcomes are better with UD 9/10 with PTCy-based GVHD prophylaxis than with dCBT for AML patients in CR1. These data might support the use of UD 9/10 with PTCy-based GVHD prophylaxis over dCBT in AML patients lacking an HLA-matched donor.

Externally Controlled Studies Using Real-World Data in Patients With Hematological Cancers: A Systematic Review.

Importance: The use of real-world data (RWD) external control arms in prospective studies is increasing. The advantages, including the immediate availability of a control population, must be balanced with the requirements of meeting evidentiary standards. Objective: To address the question of whether and to what extent the methods of RWD studies compare to standard methods used in randomized clinical trials. Evidence Review: A systematic search across 4 electronic databases and Google Scholar was conducted from January 1, 2000, to October 23, 2023. Studies were included in the systematic review if they compared an intervention arm in a clinical trial to an RWD control arm in patients with hematological cancers and if they were published between 2000 and 2023. Findings: Thirty-two prospective intervention studies incorporating external control data from RWD sources of patients with hematological cancers were identified. A total of 4306 patients from intervention arms and 10 594 from RWD control arms were included across all studies. Only 2 studies (6%) included prospectively collected RWD. The complete trial inclusion criteria were applied to the RWD cohort in 7 studies (22%). Four studies (13%) published the statistical analysis plan and prespecified use of RWD. A total of 23 studies (72%) applied matching algorithms for trial and RWD cohorts, including matching for demographic, disease, and/or therapy-related characteristics. The end point criteria were the same as the trial in 8 studies (25%). In contrast, 12 studies (38%) used different end points, and 12 (38%) did not provide an end point definition for the RWD. Twelve studies (38%) had a median follow-up difference of less than a year between arms. Eight studies (25%) reported toxic effect data for the trial arm, of which 5 studies reported toxic effect data for the RWD arm. Conclusions and Relevance: In this systematic review, limitations were observed in the application of clinical trial eligibility criteria to RWD, statistical rigor and application of matching methods, the definition of end points, follow-up, and reporting of adverse events, which may challenge the conclusions reported in studies using RWD.

Allogeneic stem cell transplantation in de novo core-binding factor acute myeloid leukemia in first complete remission: data from the EBMT.

Core-binding factor acute myeloid leukemia (CBF-AML) represents 12-15% of all AML cases. Although CBF positivity infers a survival advantage, overall survival (OS) remains dismal. Treatment is with cytarabine/anthracycline-based chemotherapy induction followed by high-dose cytarabine (HiDAC) consolidation. Allogeneic hematopoietic stem cell transplantation (allo-SCT) is reserved for relapse or for patients having not achieved MRD-negativity at high risk for relapse. The role of SCT in first complete remission (CR1) remains controversial and is considered in high risk conditions. In this retrospective, multi-national, European Society for Blood and Marrow Transplantation (EBMT)-based study, we identified 1901 patients with de novo CBF-AML who received an allo-SCT or autologous transplantation (ASCT) in CR1. 65.5% harbored t(8;21) and 34.4% inv(16). In this group, the majority (77%) were treated with allo-SCT in CR1. In multivariate analysis, treatment with allo-SCT was an independent and significant, negative predictor of NRM and OS (HR 4.26, p < 0.0001 and HR 1.67, p = 0.003) and among patients treated with allo-SCT, those treated with MSD had the best outcomes, comparable to those treated with ASCT. There was no interaction between the type of transplant and MRD status at time of SCT. In both, MRD-negative and MRD-positive groups, NRM was worse in the allo-SCT group (MRD-: 12.9% vs 5.2%, p = 0.007; MRD+: 10.6% vs 0%, p = 0.004). We therefore demonstrated that consolidation in CR1 with allo-SCT results in worse outcomes than ASCT. Whether consolidation with ASCT yields better outcomes than chemotherapy alone or chemotherapy in combination with Gemtuzumab Ozogamicin is yet to be investigated.

Prognostic impact of number of induction courses to attain complete remission in patients with acute myeloid leukemia transplanted with either a matched sibling or human leucocyte antigen 10/10 or 9/10 unrelated donor: An Acute Leukemia Working Party European Society for Blood and Marrow Transplantation study.

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.

Younger unrelated donors may be preferable over HLA match in the PTCy era: a study from the ALWP of the EBMT.

ABSTRACT: There is a paucity of information on how to select the most appropriate unrelated donor (UD) in hematopoietic stem cell transplantation (HSCT) using posttransplant cyclophosphamide (PTCy). We retrospectively analyzed the characteristics of 10/10 matched UDs (MUDs) and 9/10 mismatched UDs (MMUDs) that may affect transplant outcomes in patients with acute myeloid leukemia (AML) in first or second complete remission (CR1 or CR2). The primary end point was leukemia-free survival (LFS). Overall, 1011 patients were included with a median age of 54 years (range, 18-77). Donors had a median age of 29 years (range, 18-64); 304 (30%) were females, of which 150 (15% of the whole group) were donors to male recipients, and 621 (61%) were MUDs; 522 (52%) had negative cytomegalovirus (CMV-neg) serostatus, of which 189 (19%) were used for CMV-neg recipients. Donor age older than 30 years had a negative impact on relapse (hazard ratio [HR], 1.38; 95% confidence interval [CI], 1.06-1.8), LFS (HR, 1.4; 95% CI, 1.12-1.74), overall survival (HR 1.45; 95% CI, 1.14-1.85) and graft-versus-host disease (GVHD) free, relapse-free survival (HR, 1.29; 95% CI, 1.07-1.56). In addition, CMV-neg donors for CMV-neg recipients were associated with improved LFS (HR, 0.74; 95% CI, 0.55-0.99). The use of MMUD and female donors for male recipients did not significantly impact any transplant outcomes. For patients undergoing HSCT from a UD with PTCy for AML, donor age <30 years significantly improves survival. In this context, donor age might be prioritized over HLA match considerations. In addition, CMV-neg donors are preferable for CMV-neg recipients. However, further research is needed to validate and refine these recommendations.

Benefits and risks of clofarabine in adult acute lymphoblastic leukemia investigated in depth by multi-state modeling.

BACKGROUND: We recently reported results of the prospective, open-label HOVON-100 trial in 334 adult patients with acute lymphoblastic leukemia (ALL) randomized to first-line treatment with or without clofarabine (CLO). No improvement of event-free survival (EFS) was observed, while a higher proportion of patients receiving CLO obtained minimal residual disease (MRD) negativity. AIM: In order to investigate the effects of CLO in more depth, two multi-state models were developed to identify why CLO did not show a long-term survival benefit despite more MRD-negativity. METHODS: The first model evaluated the effect of CLO on going off-protocol (not due to refractory disease/relapse, completion or death) as a proxy of severe treatment-related toxicity, while the second model evaluated the effect of CLO on obtaining MRD negativity. The subsequent impact of these intermediate events on death or relapsed/refractory disease was assessed in both models. RESULTS: Overall, patients receiving CLO went off-protocol more frequently than control patients (35/168 [21%] vs. 18/166 [11%], p = 0.019; HR 2.00 [1.13-3.52], p = 0.02), especially during maintenance (13/44 [30%] vs. 6/56 [11%]; HR 2.85 [95%CI 1.08-7.50], p = 0.035). Going off-protocol was, however, not associated with more relapse or death. Patients in the CLO arm showed a trend towards an increased rate of MRD-negativity compared with control patients (HR MRD-negativity: 1.35 [0.95-1.91], p = 0.10), which did not translate into a significant survival benefit. CONCLUSION: We conclude that the intermediate states, i.e., going off-protocol and MRD-negativity, were affected by adding CLO, but these transitions were not associated with subsequent survival estimates, suggesting relatively modest antileukemic activity in ALL.

Bayesian interim analysis for prospective randomized studies: reanalysis of the acute myeloid leukemia HOVON 132 clinical trial.

Randomized controlled trials (RCTs) are the gold standard to establish the benefit-risk ratio of novel drugs. However, the evaluation of mature results often takes many years. We hypothesized that the addition of Bayesian inference methods at interim analysis time points might accelerate and enforce the knowledge that such trials may generate. In order to test that hypothesis, we retrospectively applied a Bayesian approach to the HOVON 132 trial, in which 800 newly diagnosed AML patients aged 18 to 65 years were randomly assigned to a "7 + 3" induction with or without lenalidomide. Five years after the first patient was recruited, the trial was negative for its primary endpoint with no difference in event-free survival (EFS) between experimental and control groups (hazard ratio [HR] 0.99, p = 0.96) in the final conventional analysis. We retrospectively simulated interim analyses after the inclusion of 150, 300, 450, and 600 patients using a Bayesian methodology to detect early lack of efficacy signals. The HR for EFS comparing the lenalidomide arm with the control treatment arm was 1.21 (95% CI 0.81-1.69), 1.05 (95% CI 0.86-1.30), 1.00 (95% CI 0.84-1.19), and 1.02 (95% CI 0.87-1.19) at interim analysis 1, 2, 3 and 4, respectively. Complete remission rates were lower in the lenalidomide arm, and early deaths more frequent. A Bayesian approach identified that the probability of a clinically relevant benefit for EFS (HR < 0.76, as assumed in the statistical analysis plan) was very low at the first interim analysis (1.2%, 0.6%, 0.4%, and 0.1%, respectively). Similar observations were made for low probabilities of any benefit regarding CR. Therefore, Bayesian analysis significantly adds to conventional methods applied for interim analysis and may thereby accelerate the performance and completion of phase III trials.

Complex karyotype but not other cytogenetic abnormalities is associated with worse posttransplant survival of patients with nucleophosmin 1-mutated acute myeloid leukemia: A study from the European Society for Blood and Marrow Transplantation Acute Leukemia Working Party.

In the 2022 European LeukemiaNet classification, patients with nucleophosmin 1 (NPM1)-mutated acute myeloid leukemia (AML) were classified in the adverse-risk category in the presence of high-risk cytogenetics (CG). Nonetheless, the impact of various CG aberrations on posttransplant outcomes remains to be unraveled. This registry study analyzed adult patients with NPM1-mutated de novo AML who underwent their first allogeneic hematopoietic cell transplantation in the first complete remission from 2005 to 2021. A total of 3275 patients were identified, 2782 had normal karyotype, 493 had chromosomal aberrations including 160 with adverse-risk CG, 72 patients had complex karyotype (CK), and 66 monosomal karyotype (MK). Overall, 2377 (73%) patients had FLT3-ITD. On univariate analysis, only FLT3-ITD, minimal/measurable residual disease (MRD) positivity and CK, but not abnormal CG, affected posttransplant outcomes. On multivariable analysis, CK was associated with lower overall survival (OS) (hazard ratio [HR] 1.72, p = .009). In the subgroup of 493 patients with aberrant CG, the 2-year leukemia-free survival (LFS) and OS were around 61% and 68%, respectively. On multivariable analysis for this subgroup, CK and MRD positivity were associated with increased risk of relapse (HR 1.7, p = .025; and 1.99, p = .003 respectively) and worse LFS (HR 1.62, p = .018; and 1.64, p = .011 respectively) while FLT3-ITD, MK, or other CG abnormalities had no significant effect. Importantly, CK negatively affected OS (HR 1.91, p = .002). In the first complete remission transplant setting, CK was found as the only cytogenetic risk factor for worse outcomes in NPM1-mutated AML. Nevertheless, even for this subgroup, a significant proportion of patients can achieve long-term posttransplant survival.

Cord blood transplantation for AML: Comparable LFS in patients with de novo versus secondary AML in CR1, an ALWP/EBMT study.

We investigated whether secondary versus de novo acute myeloid leukaemia (AML) would be associated with poor outcomes in adult acute AML patients in first complete remission (CR1) receiving unrelated cord blood transplantation (CBT). This is a retrospective study from the acute leukaemia working party of the European Society for Blood and Marrow Transplantation. Inclusion criteria included adult at first allogeneic haematopoietic cell transplantation between 2000 and 2021, unrelated single or double unit CBT, AML in CR1, no ex vivo T-cell depletion and no post-transplant cyclophosphamide. The primary end-point of the study was leukaemia-free survival (LFS). A total of 879 patients with de novo (n = 696) or secondary (n = 183) AML met the inclusion criteria. In multivariable analyses, sAML patients had non-significantly different LFS (HR = 0.98, p = 0.86), overall survival (HR = 1.07, p = 0.58), relapse incidence (HR = 0.74, p = 0.09) and non-relapse mortality (HR = 1.26, p = 0.13) than those with de novo AML. Our results demonstrate non-significantly different LFS following CBT in adult patients with secondary versus de novo AML.

Validation of the transplant conditioning intensity (TCI) index for allogeneic hematopoietic cell transplantation.

The intensity of the conditioning regimen given before allogeneic hematopoietic cell transplantation (allo-HCT) can vary substantially. To confirm the ability of the recently developed transplant conditioning intensity (TCI) score to stratify the preparative regimens of allo-HCT, we used an independent and contemporary patient cohort of 4060 transplant recipients with acute myeloid leukemia meeting inclusion criteria from the discovery study (allo-HCT in first complete remission, matched donor), but who were allografted in a more recent period (2018-2021) and were one decade older (55-75 years, median 63.4 years), we assigned them to a TCI category (low n = 1934, 48%; intermediate n = 1948, 48%, high n = 178, 4%) according to the calculated TCI score ([1-2], [2.5-3.5], [4-6], respectively), and examined the validity of the TCI category in predicting early non-relapse mortality (NRM), 2-year NRM and relapse (REL). In the unadjusted comparison, the TCI index provided a significant risk stratification for d100 and d180 NRM, NRM and REL risk. In the multivariate analysis adjusted for significant variables, there was an independent association of TCI with early NRM, NRM and REL. In summary, we confirm in contemporary treated patients that TCI reflects the conditioning regimen related morbidity and anti-leukemic efficacy satisfactorily and across other established prognostic factors.

Attitudes of healthcare professionals and drug regulators about progression-free survival as endpoint in the advanced cancer setting.

PURPOSE: To describe the attitudes of healthcare professionals and drug regulators about progression-free survival (PFS) as efficacy endpoint in clinical trials with patients with advanced cancer and to explore to what extent these attitudes influence the willingness to trade between PFS and toxicity. METHODS: Cross-sectional survey with regulators from the European Medicines Agency (EMA), and healthcare professionals (HCP) from the "Stichting Hemato-Oncologie voor Volwassenen Nederland" (HOVON) collaborative group and the European Organisation for Research and Treatment of Cancer (EORTC). Attitudes towards PFS were elicited using 5-point Likert items. The respondents' willingness to trade between PFS and grade 3 or 4 (G34) toxicity was assessed using the threshold technique and quantified in terms of their maximum acceptable risk (MAR). RESULTS: Responses were collected from 287 HCPs and 64 regulators with mainly clinical expertise. Attitudes towards PFS were often spread out in both groups and related to beliefs about PFS being a likely surrogate for clinical benefit, being an intrinsic benefit to be distinguished from OS, or on the importance given to OS. Being a regulator or holding stronger beliefs about PFS being a likely surrogate or an intrinsic benefit were associated with a higher MAR. Presence of a supportive trend in OS was stated as important but was not associated with MAR. There was agreement on the need to address bias in the adjudication of PFS and the need for improving communication to patients about meaning, strengths, and limitations of improvements in PFS. CONCLUSION: Attitudes towards PFS were spread out and were associated with individual differences in the willingness to trade between toxicity and PFS. There was agreement on the need to address bias in the adjudication of PFS and improving communication to patients.

Therapeutic Drug Monitoring of Kinase Inhibitors in Oncology.

Although kinase inhibitors (KI) frequently portray large interpatient variability, a 'one size fits all' regimen is still often used. In the meantime, relationships between exposure-response and exposure-toxicity have been established for several KIs, so this regimen could lead to unnecessary toxicity and suboptimal efficacy. Dose adjustments based on measured systemic pharmacokinetic levels-i.e., therapeutic drug monitoring (TDM)-could therefore improve treatment efficacy and reduce the incidence of toxicities. Therefore, the aim of this comprehensive review is to give an overview of the available evidence for TDM for the 77 FDA/EMA kinase inhibitors currently approved (as of July 1st, 2023) used in hematology and oncology. We elaborate on exposure-response and exposure-toxicity relationships for these kinase inhibitors and provide practical recommendations for TDM and discuss corresponding pharmacokinetic targets when possible.

Etoposide plus cytarabine versus cyclophosphamide or melphalan in busulfan-based preparative regimens for autologous stem cell transplantation in adults with acute myeloid leukemia in first complete remission: a study from the Acute Leukemia Working Party of the EBMT.

We retrospectively compared the impact of the conditioning regimen in adult patients with acute myeloid leukemia (AML) in first complete remission (CR1) that received high-dose myeloablative chemotherapy followed by autologous stem cell transplantation (ASCT) from 2010 to 2021 with either high-dose cytarabine, etoposide and busulfan (BEA), busulfan with cyclophosphamide (BUCY) or busulfan and high-dose melphalan (BUMEL) registered in the EBMT database. Overall 1560 patients underwent ASCT, of which 156, 1143 and 261 received BEA, BUCY and BUMEL, respectively. Compared to BUCY and BUMEL, BEA patients were younger (p < 0.001) and less frequently had NPM1 mutations (p = 0.03). Transplant outcomes at 5 years with BEA, BUCY and BUMEL were: cumulative incidence of relapse 41.8%, 46.6% and 51.6%; non-relapse mortality (NRM) 1.5%, 5.2% and 7.3%; probability of leukemia-free survival (LFS) 56.7%, 48.2% and 41.1%; and overall survival (OS) 71.3%, 62.3% and 56%, respectively. In multivariable analysis the BEA regimen showed significant improvement in OS compared to BUCY (hazard ratio [HR] 0.65; 95% CI, 0.42-0.83; p = 0.048) and BUMEL (HR 0.59; 95% CI, 0.37-0.94; p = 0.029). In conclusion, high-dose myeloablative combination chemotherapy with BEA offered improved outcomes compared to classical BUCY or BUMEL in patients with AML in CR1 undergoing ASCT.

Allogeneic Hematopoietic Cell Transplantation Improves Outcome in Myelodysplastic Syndrome Across High-Risk Genetic Subgroups: Genetic Analysis of the Blood and Marrow Transplant Clinical Trials Network 1102 Study.

PURPOSE: Allogeneic hematopoietic cell transplantation (HCT) in patients with myelodysplastic syndrome (MDS) improves overall survival (OS). We evaluated the impact of MDS genetics on the benefit of HCT in a biological assignment (donor v no donor) study. METHODS: We performed targeted sequencing in 309 patients age 50-75 years with International Prognostic Scoring System (IPSS) intermediate-2 or high-risk MDS, enrolled in the Blood and Marrow Transplant Clinical Trials Network 1102 study and assessed the association of gene mutations with OS. Patients with TP53 mutations were classified as TP53multihit if two alleles were altered (via point mutation, deletion, or copy-neutral loss of heterozygosity). RESULTS: The distribution of gene mutations was similar in the donor and no donor arms, with TP53 (28% v 29%; P = .89), ASXL1 (23% v 29%; P = .37), and SRSF2 (16% v 16%; P = .99) being most common. OS in patients with a TP53 mutation was worse compared with patients without TP53 mutation (21% ± 5% [SE] v 52% ± 4% at 3 years; P < .001). Among those with a TP53 mutation, OS was similar between TP53single versus TP53multihit (22% ± 8% v 20% ± 6% at 3 years; P = .31). Considering HCT as a time-dependent covariate, patients with a TP53 mutation who underwent HCT had improved OS compared with non-HCT treatment (OS at 3 years: 23% ± 7% v 11% ± 7%; P = .04), associated with a hazard ratio of 3.89; 95% CI, 1.87 to 8.12; P < .001 after adjustment for covariates. OS among patients with molecular IPSS (IPSS-M) very high risk without a TP53 mutation was significantly improved if they had a donor (68% ± 10% v 0% ± 12% at 3 years; P = .001). CONCLUSION: HCT improved OS compared with non-HCT treatment in patients with TP53 mutations irrespective of TP53 allelic status. Patients with IPSS-M very high risk without a TP53 mutation had favorable outcomes when a donor was available.

Improved Posttransplant Outcomes in Recent Years for AML Patients with FLT3-ITD and Wild-type NPM1: A Report from the EBMT Acute Leukemia Working Party.

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.

Allogeneic Stem Cell Transplantation in Patients >40 Years of Age With Acute Lymphoblastic Leukemia: Reduced Intensity Versus Myeloablative Conditioning.

BACKGROUND: The outcome in older patients with acute lymphoblastic leukemia (ALL) remains unsatisfactory due to high relapse and nonrelapse mortality (NRM) rates. Allogeneic stem cell transplantation (alloHSCT) as postremission therapy has an important role in reducing relapse rate, albeit its application is limited in older adult patients due to alloHSCT-related morbidity and mortality. Reduced-intensity conditioning (RIC) alloHSCT has been developed as a less toxic conditioning regimen, but comparative studies with myeloablative conditioning (MAC) are limited in patients with ALL. METHODS: In this retrospective study, RIC-alloHSCT (n = 111) was compared with MAC-alloHSCT (n = 77) in patients aged 41 to 65 y with ALL in first complete remission. MAC was predominantly applied by combining high-dose total body irradiation and cyclophosphamide, whereas RIC mainly consisted of fludarabine and 2 Gy total body irradiation. RESULTS: Unadjusted overall survival was 54% (95% confidence interval [CI], 42%-65%) at 5 y in MAC recipients compared with 39% (95% CI, 29%-49%) in RIC recipients. Overall survival and relapse-free survival were not significantly associated with type of conditioning after adjusted for the covariates age, leukemia risk status at diagnosis, donor type, and donor and recipient gender combination. NRM was significantly lower after RIC (subdistribution hazard ratio: 0.41, 95% CI, 0.22-0.78; P = 0.006), whereas relapse was significantly higher (subdistribution hazard ratio: 3.04, 95% CI, 1.71-5.40; P < 0.001). CONCLUSIONS: Collectively, RIC-alloHSCT has resulted in less NRM, but it was also found to be associated with a significantly higher relapse rate. These results suggest that MAC-alloHSCT may provide a more effective type of consolidation therapy for the reduction of relapse and that RIC-alloHSCT may be restricted to patients at higher risk for NRM.

Prediction of Nonrelapse Mortality in Patients With Acute Myeloid Leukemia and Acute Lymphoblastic Leukemia Receiving Allogeneic Stem Cell Transplantation With Posttransplantation Cyclophosphamide-based Graft Versus Host Disease Prophylaxis.

Graft versus host disease (GVHD) prophylaxis with posttransplantation cyclophosphamide (PTCY) has been established to reduce severe GVHD, and thereby potentially reducing nonrelapse mortality (NRM) after allogeneic stem cell transplantation (alloSCT). We evaluated the predictive capacity of established NRM-risk scores in patients receiving PTCY-based GVHD prophylaxis, and subsequently developed and validated a novel PTCY-specific NRM-risk model. Adult patients (n = 1861) with AML or ALL in first complete remission who received alloSCT with PTCY-based GVHD prophylaxis were included. The PTCY-risk score was developed using multivariable Fine and Gray regression, selecting parameters from the hematopoietic cell transplantation-comorbidity index (HCT-CI) and European Group for Blood and Marrow Transplantation (EBMT) score with a subdistribution hazard ratio (SHR) of ≥1.2 for 2-year NRM in the training set (70% split), which was validated in the test set (30%). The performance of the EBMT score, HCT-CI, and integrated EBMT score was relatively poor for discriminating 2-year NRM (c-statistic 51.7%, 56.6%, and 59.2%, respectively). The PTCY-risk score included 10 variables which were collapsed in 3 risk groups estimating 2-year NRM of 11% ± 2%, 19% ± 2%, and 36% ± 3% (training set, c-statistic 64%), and 11% ± 2%, 18% ± 3%, and 31% ± 5% (test set, c-statistic 63%), which also translated into different overall survival. Collectively, we developed an NRM-risk score for acute leukemia patients receiving PTCY that better predicted 2-year NRM compared with existing models, which might be applicable to the specific toxicities of high-dose cyclophosphamide.

Comorbidities in transplant recipients with acute myeloid leukemia receiving low-intensity conditioning regimens: an ALWP EBMT study.

Older age and a high burden of comorbidities often drive the selection of low-intensity conditioning regimens in allogeneic hematopoietic stem cell transplantation recipients. However, the impact of comorbidities in the low-intensity conditioning setting is unclear. We sought to determine the contribution of individual comorbidities and their cumulative burden on the risk of nonrelapse mortality (NRM) among patients receiving low-intensity regimens. In a retrospective analysis of adults (≥18 years) who underwent transplantation for acute myeloid leukemia in the first complete remission between 2008 and 2018, we studied recipients of low-intensity regimens as defined by the transplantation conditioning intensity (TCI) scale. Multivariable Cox models were constructed to study associations of comorbidities with NRM. Comorbidities identified as putative risk factors in the low-TCI setting were included in combined multivariable regression models assessed for overall survival, NRM, and relapse. A total of 1663 patients with a median age of 61 years received low-TCI regimens. Cardiac comorbidity (including arrhythmia/valvular disease) and psychiatric disease were associated with increased NRM risk (hazard ratio [HR], 1.54; 95% confidence interval [CI], 1.13-2.09 and HR, 1.69; 95% CI, 1.02-2.82, respectively). Moderate pulmonary dysfunction, though prevalent, was not associated with increased NRM. In a combined model, cardiac, psychiatric, renal, and inflammatory bowel diseases were independently associated with adverse transplantation outcomes. These findings may inform patient and regimen selection and reinforce the need for further investigation of cardioprotective transplantation approaches.