Allogeneic hematopoietic cell transplantation for myelofibrosis aged 70 years or older: a study from the German Registry for Stem Cell Transplantation.

BACKGROUND: Current consensus recommends hematopoietic cell transplantation (HCT) for patients with myelofibrosis with intermediate or high-risk disease and age of less than 70 years. However, a higher chronological age should not be prohibitive for the eligibility decision in general, acknowledging that current life expectancy for the general population aged 70 years is ∼15 years, and current numbers of patients transplanted at 70 years or older is steadily increasing. OBJECTIVE: The following study aimed to evaluate characteristics and outcomes of HCT in 115 myelofibrosis patients aged 70 years or older. STUDY DESIGN: This is a retrospective multicenter study, using the German Registry for Stem Cell Transplantation and Cellular Therapy (DRST). Adult myelofibrosis patients were included who received HCT up until 2021. Patients with secondary leukemia were excluded. Main endpoints were HCT demographics over time and outcomes after HCT (including overall survival, relapse incidence, non-relapse mortality, and graft-versus-host disease/relapse-free survival). RESULTS: Numbers of HCT increased over the past decade, with a significant spike since 2019. Comorbidity status of transplanted patients improved over time, while reduced intensity conditioning was the preferred HCT platform especially in most recent years. The 3-year overall survival was 55% (95% confidence interval, 44-65%). The 1-year cumulative incidence of relapse was 7% (95% CI, 3-13%) and the 1-year cumulative incidence of non-relapse mortality was 22% (95% CI, 14-31%). The 3-year graft-versus-host disease and relapse-free survival was 37% (95% CI, 27-47%). Driver mutation genotype (in particular non-CALR/MPL genotype) appeared to be the only variable that was significantly and independently associated with better survival in multivariable analysis, whereas neither comorbidity index nor dose intensity of pre-transplant conditioning appeared to influence outcome. CONCLUSION: This study demonstrated feasibility of curative treatment with HCT for myelofibrosis aged 70 or older, with significant increases in HCT numbers and improved fitness of the elderly over recent years.

Hematopoietic stem cell transplantation for DLBCL: a report from the European Society for Blood and Marrow Transplantation on more than 40,000 patients over 32 years.

Autologous(auto-) and allogeneic(allo-) hematopoietic stem cell transplantation (HSCT) are key treatments for relapsed/refractory diffuse large B-cell lymphoma (DLBCL), although their roles are challenged by CAR-T-cells and other immunotherapies. We examined the transplantation trends and outcomes for DLBCL patients undergoing auto-/allo-HSCT between 1990 and 2021 reported to EBMT. Over this period, 41,148 patients underwent auto-HSCT, peaking at 1911 cases in 2016, while allo-HSCT saw a maximum of 294 cases in 2018. The recent decline in transplants corresponds to increased CAR-T treatments (1117 cases in 2021). Median age for auto-HSCT rose from 42 (1990-1994) to 58 years (2015-2021), with peripheral blood becoming the primary stem cell source post-1994. Allo-HSCT median age increased from 36 (1990-1994) to 54 (2015-2021) years, with mobilized blood as the primary source post-1998 and reduced intensity conditioning post-2000. Unrelated and mismatched allo-HSCT accounted for 50% and 19% of allo-HSCT in 2015-2021. Three-year overall survival (OS) after auto-HSCT improved from 56% (1990-1994) to 70% (2015-2021), p < 0.001, with a decrease in relapse incidence (RI) from 49% to 38%, while non-relapse mortality (NRM) remained unchanged (4%). After allo-HSCT, 3-year-OS increased from 33% (1990-1999) to 46% (2015-2021) (p < 0.001); 3-year RI remained at 39% and 1-year-NRM decreased to 19% (p < 0.001). Our data reflect advancements over 32 years and >40,000 transplants, providing insights for evaluating emerging DLBCL therapies.

Clinical Practice Recommendations for Hematopoietic Cell Transplantation and Cellular Therapies in Follicular Lymphoma: A Collaborative Effort on Behalf of the American Society for Transplantation and Cellular Therapy and the European Society for Blood and Marrow Transplantation.

Follicular lymphoma (FL) is the most common indolent B-cell non-Hodgkin lymphoma (NHL), accounting for nearly one-third of all NHL. The therapeutic landscape for patients with FL has significantly expanded over the past decade, but the disease continues to be considered incurable. Hematopoietic cell transplantation (HCT) is potentially curative in some cases. Recently, the emergence of chimeric antigen receptor T-cell therapy (CAR-T) for patients with relapsed/refractory (R/R) FL has yielded impressive response rates and long-term remissions, but definitive statement on the curative potential of CAR-T is currently not possible due to limited patient numbers and relatively short follow up. A consensus on the contemporary role, optimal timing, and sequencing of HCT (autologous or allogeneic) and cellular therapies in FL is needed. As a result, the American Society of Transplantation and Cellular Therapy (ASTCT) Committee on Practice Guidelines endorsed this effort to formulate consensus recommendations to address this unmet need. The RAND-modified Delphi method was used to generate 15 consensus statements/recommendations. These clinical practice recommendations will help guide clinicians managing patients with FL. Of note, the use of bispecific antibodies in R/R FL was not in the scope of this project.

Microbiological risk factors, ICU survival, and 1-year survival in hematological patients with pneumonia requiring invasive mechanical ventilation.

PURPOSE: To identify pathogenic microorganisms and microbiological risk factors causing high morbidity and mortality in immunocompromised patients requiring invasive mechanical ventilation due to pneumonia. METHODS: A retrospective single-center study was performed at the intensive care unit (ICU) of the Department of Internal Medicine at Heidelberg University Hospital (Germany) including 246 consecutive patients with hematological malignancies requiring invasive mechanical ventilation due to pneumonia from 08/2004 to 07/2016. Microbiological and radiological data were collected and statistically analyzed for risk factors for ICU and 1-year mortality. RESULTS: ICU and 1-year mortality were 63.0% (155/246) and 81.0% (196/242), respectively. Pneumonia causing pathogens were identified in 143 (58.1%) patients, multimicrobial infections were present in 51 (20.7%) patients. Fungal, bacterial and viral pathogens were detected in 89 (36.2%), 55 (22.4%) and 41 (16.7%) patients, respectively. Human herpesviruses were concomitantly reactivated in 85 (34.6%) patients. As significant microbiological risk factors for ICU mortality probable invasive Aspergillus disease with positive serum-Galactomannan (odds ratio 3.1 (1.2-8.0), p = 0.021,) and pulmonary Cytomegalovirus reactivation at intubation (odds ratio 5.3 (1.1-26.8), p = 0.043,) were identified. 1-year mortality was not significantly associated with type of infection. Of interest, 19 patients had infections with various respiratory viruses and Aspergillus spp. superinfections and experienced high ICU and 1-year mortality of 78.9% (15/19) and 89.5% (17/19), respectively. CONCLUSIONS: Patients with hematological malignancies requiring invasive mechanical ventilation due to pneumonia showed high ICU and 1-year mortality. Pulmonary Aspergillosis and pulmonary reactivation of Cytomegalovirus at intubation were significantly associated with negative outcome.

How risky is a second allogeneic stem cell transplantation?

There is no consensus on second allogeneic stem cell transplantation (alloSCT) indications in patients with hematologic malignancies relapsing after a first alloSCT. In historic publications, a very high non-relapse mortality (NRM) has been described, arguing against performing a second alloSCT. We analysed the outcome of 3356 second alloSCTs performed 2011-21 following a hematologic malignancy relapse. Outcomes at two years after second alloSCT were: NRM 22%, relapse incidence 50%, overall survival 38%, and progression-free survival 28%. Key risk factors for increased NRM were: older age, low performance score, high disease-risk-index, early relapse after the first alloSCT, unrelated/haploidentical donor, and GVHD before second alloSCT. Any type of GVHD after first alloSCT was also important risk factor for acute GVHD and chronic GVHD after second alloSCT. There was a preferential use of a different donor (80%) at second alloSCT from first alloSCT. However, in multivariate analysis, the use of the same alloSCT donor for second alloSCT vs. a different donor was not associated with any of the survival or GVHD endpoints. We show considerably improved outcome as compared to historic reports. These current data support a wider use of second alloSCT and provide risk factors for NRM that need to be considered.

Continuously improving outcome over time after second allogeneic stem cell transplantation in relapsed acute myeloid leukemia: an EBMT registry analysis of 1540 patients.

Second allogeneic stem cell transplantation (alloSCT2) is among the most effective treatments for acute myeloid leukemia (AML) relapse after first alloSCT (alloSCT1). Long-term EBMT registry data were used to provide large scale, up-to-date outcome results and to identify factors for improved outcome. Among 1540 recipients of alloSCT2, increasing age, better disease control and performance status before alloSCT2, more use of alternative donors and higher conditioning intensity represented important trends over time. Between the first (2000-2004) and last (2015-2019) period, two-year overall and leukemia-free survival (OS/LFS) increased considerably (OS: 22.5-35%, LFS: 14.5-24.5%). Cumulative relapse incidence (RI) decreased from 64% to 50.7%, whereas graft-versus-host disease and non-relapse mortality (NRM) remained unchanged. In multivariable analysis, later period of alloSCT2 was associated with improved OS/LFS (HR = 0.47/0.53) and reduced RI (HR = 0.44). Beyond, remission duration, disease stage and patient performance score were factors for OS, LFS, RI, and NRM. Myeloablative conditioning for alloSCT2 decreased RI without increasing NRM, leading to improved OS/LFS. Haploidentical or unrelated donors and older age were associated with higher NRM and inferior OS. In summary, outcome after alloSCT2 has continuously improved over the last two decades despite increasing patient age. The identified factors provide clues for the optimized implementation of alloSCT2.

The immunoglobulin superfamily ligand B7H6 subjects T cell responses to NK cell surveillance.

Understanding the mechanisms that regulate T cell immunity is critical for the development of effective therapies for diseases associated with T cell dysfunction, including autoimmune diseases, chronic infections, and cancer. Co-inhibitory "checkpoint molecules," such as programmed cell death protein-1, balance excessive or prolonged immune activation by T cell-intrinsic signaling. Here, by screening for mediators of natural killer (NK) cell recognition on T cells, we identified the immunoglobulin superfamily ligand B7H6 to be highly expressed by activated T cells, including patient-infused CD19-targeting chimeric antigen receptor (CAR) T cells. Unlike other checkpoint molecules, B7H6 mediated NKp30-dependent recognition and subsequent cytolysis of activated T cells by NK cells. B7H6+ T cells were prevalent in the tissue and blood of several diseases, and their abundance in tumor tissue positively correlated with clinical response in a cohort of patients with immune checkpoint inhibitor-treated esophageal cancer. In humanized mouse models, NK cell surveillance via B7H6 limited the persistence and antitumor activity of CAR T cells, and its genetic deletion enhanced T cell proliferation and persistence. Together, we provide evidence of B7H6 protein expression by activated T cells and suggest the B7H6-NKp30 axis as a therapeutically actionable NK cell-dependent immune checkpoint that regulates human T cell function.

Treatment of chronic COVID-19 with convalescent/postvaccination plasma in patients with hematologic malignancies.

Immunocompromised patients are at high risk to fail clearance of SARS-CoV-2. Prolonged COVID-19 constitutes a health risk and a management problem as cancer treatments often have to be disrupted. As SARS-CoV-2 evolves, new variants of concern have emerged that evade available monoclonal antibodies. Moreover, antiviral therapy promotes SARS-CoV-2 escape mutations, particularly in immunocompromised patients. These patients frequently suffer from prolonged infection. No successful treatment has been established for persistent COVID-19 infection. Here, we report on a series of 21 immunocompromised patients with COVID-19-most of them hematologic malignancies-treated with plasma obtained from recently convalescent or vaccinated donors or a combination thereof. Repeated dosing of SARS-CoV-2-antibody-containing plasma could clear SARS-CoV-2 infection in 16 out of 21 immunocompromised patients even if COVID-19-specific treatments failed to induce sustained viral clearance or to improve clinical course of SARS-CoV-2 infection. Ten patients were major responders defined as an increase delta(d)Ct of > = 5 after the first administration of convalescent and/or vaccinated plasma (C/VP). On average, SARS-CoV-2 PCR Ct values increased from a median value of 22.55 (IQR = 19.10-24.25) to a median value of 29.57 (IQR = 27.55-34.63; p = <.0001) in the major response subgroup. Furthermore, when treated a second time with C/VP, even 4 out of 5 of the initial nonresponders showed an increase in Ct-values from a median value of 23.13 (IQR = 17.75-28.05) to a median value of 32.79 (IQR = 31.75-33.75; p = .013). Our results suggest that C/VP could be a feasible treatment of COVID-19 infection in patients with hematologic malignancies who did not respond to antiviral treatment.

Donor KIR genotype based outcome prediction after allogeneic stem cell transplantation: no land in sight.

Optimizing natural killer (NK) cell alloreactivity could further improve outcome after allogeneic hematopoietic cell transplantation (alloHCT). The donor's Killer-cell Immunoglobulin-like Receptor (KIR) genotype may provide important information in this regard. In the past decade, different models have been proposed aiming at maximizing NK cell activation by activating KIR-ligand interactions or minimizing inhibitory KIR-ligand interactions. Alternative classifications intended predicting outcome after alloHCT by donor KIR-haplotypes. In the present study, we aimed at validating proposed models and exploring more classification approaches. To this end, we analyzed samples stored at the Collaborative Biobank from HLA-compatible unrelated stem cell donors who had donated for patients with acute myeloid leukemia (AML) or myelodysplastic neoplasm (MDS) and whose outcome data had been reported to EBMT or CIBMTR. The donor KIR genotype was determined by high resolution amplicon-based next generation sequencing. We analyzed data from 5,017 transplants. The median patient age at alloHCT was 56 years. Patients were transplanted for AML between 2013 and 2018. Donor-recipient pairs were matched for HLA-A, -B, -C, -DRB1, and -DQB1 (79%) or had single HLA mismatches. Myeloablative conditioning was given to 56% of patients. Fifty-two percent of patients received anti-thymocyte-globulin-based graft-versus-host disease prophylaxis, 32% calcineurin-inhibitor-based prophylaxis, and 7% post-transplant cyclophosphamide-based prophylaxis. We tested several previously reported classifications in multivariable regression analyses but could not confirm outcome associations. Exploratory analyses in 1,939 patients (39%) who were transplanted from donors with homozygous centromeric (cen) or telomeric (tel) A or B motifs, showed that the donor cen B/B-tel A/A diplotype was associated with a trend to better event-free survival (HR 0.84, p=.08) and reduced risk of non-relapse mortality (NRM) (HR 0.65, p=.01). When we further dissected the contribution of B subtypes, we found that only the cen B01/B01-telA/A diplotype was associated with a reduced risk of relapse (HR 0.40, p=.04) while all subtype combinations contributed to a reduced risk of NRM. This exploratory finding has to be validated in an independent data set. In summary, the existing body of evidence is not (yet) consistent enough to recommend use of donor KIR genotype information for donor selection in routine clinical practice.

Acalabrutinib, venetoclax, and obinutuzumab in relapsed/refractory CLL: final efficacy and ctDNA analysis of the CLL2-BAAG trial.

ABSTRACT: The phase 2 CLL2-BAAG trial tested the measurable residual disease (MRD)-guided triple combination of acalabrutinib, venetoclax, and obinutuzumab after optional bendamustine debulking in 45 patients with relapsed/refractory chronic lymphocytic leukemia (CLL). MRD was measured by flow cytometry (FCM; undetectable MRD <10-4) in peripheral blood (PB) and circulating tumor DNA (ctDNA) using digital droplet polymerase chain reaction of variable-diversity-joining (VDJ) rearrangements and CLL-related mutations in plasma. The median number of previous treatments was 1 (range, 1-4); 18 patients (40%) had received a Bruton tyrosine kinase inhibitor (BTKi) and/or venetoclax before inclusion, 14 of 44 (31.8%) had TP53 aberrations, and 34 (75.6%) had unmutated immunoglobulin heavy-chain variable region genes. With a median observation time of 36.3 months and all patients off-treatment for a median of 21.9 months, uMRD <10-4 in PB was achieved in 42 of the 45 patients (93.3%) at any time point, including 17 of 18 (94.4%) previously exposed to venetoclax/BTKi and 13 of 14 (92.9%) with TP53 aberrations. The estimated 3-year progression-free and overall survival rates were 85.0% and 93.8%, respectively. Overall, 585 paired FCM/ctDNA samples were analyzed and 18 MRD recurrences (5 with and 13 without clinical progression) occurred after the end of treatment. Twelve samples were first detected by ctDNA, 3 by FCM, and 3 synchronously. In conclusion, time-limited MRD-guided acalabrutinib, venetoclax, and obinutuzumab achieved deep remissions in almost all patients with relapsed/refractory CLL. The addition of ctDNA-based analyses to FCM MRD assessment seems to improve early detection of relapses. This trial was registered at www.clinicaltrials.gov as #NCT03787264.

Reduced intensity versus myeloablative conditioning for MDS: long-term results of an EBMT phase III study (RICMAC).

Short-term outcome of myeloablative (MAC) and reduced intensity (RIC) conditioning in the prospective randomized international EBMT RICMAC study in patients with myelodyplastic syndrome (MDS) was comparable but longer follow up is lacking. Patients with MDS aged 18-65 years were randomized to receive MAC (N = 64) with busulfan/cyclophosphamide or RIC (n = 65) with busulfan/fludarabine followed by stem cell transplantation -(HCT) from HLA matched or mismatched donor. After a median follow-up of 6.2 (0.4-12.5) years, 10-year OS and RFS were 54.0% and 43.9% for RIC and 44.4% and 44.2% for MAC (p = 0.15 and p = 0.78), respectively. Since the first report, 6 patients died on NRM, 4 after RIC, and 2 after MAC. Similarly, 8 patients relapsed (4 in each arm), increasing the number of relapsed patients to 28. The second HCT was performed in 18 pts, 8 in the MAC, and 10 in the RIC arm. In a multivariate analysis, ECOG status and chemotherapy prior to HCT were independent risk factors for OS and RFS, ECOG and low cytogenetic risk for NRM and chemotherapy prior to HCT for RI. Patients with low cytogenetic risk had better OS [p = 0.002], RFS [p = 0.02], and NRM (p = 0.015) after RIC as compared to MAC.

Evaluation of all-cause mortality and cardiovascular safety in patients receiving chimeric antigen receptor T cell therapy: a prospective cohort study.

Background: Assessment of cardiovascular risk is critical for patients with cancer. Previous retrospective studies suggest potential cardiotoxicity of CAR T cell therapies. We aimed to prospectively assess cardiotoxicity and the predictive value of cardiac biomarkers and classical risk factors (age, cardiac function, diabetes, arterial hypertension, smoking) for cardiac events and all-cause mortality (ACM). Methods: In this prospective cohort study, all patients treated with CAR T cell constructs (axi-cel, tisa-cel, brexu-cel, ide-cel, or the 3rd generation CAR HD-CAR-1) from Oct 1, 2018, to Sept 30, 2022 at the University Hospital Heidelberg were included. Surveillance included cardiac assessment with biomarkers (high-sensitive Troponin T (hs-cTnT), N-terminal brain natriuretic peptide (NT-proBNP)), 12-lead-ECG, and 2D echocardiography. ACM was defined as the primary study endpoint, while cardiotoxicity, defined by clinical syndromes of heart failure or decline in ejection fraction, served as a secondary endpoint. Findings: Overall, 137 patients (median age 60, range 20-83, IQR 16), were included in the study. 46 patients died during the follow up period (median 0.75 years, range 0.02-4.33, IQR 0.89) 57 month, with a median survival of 0.57 years (range 0.03-2.38 years, IQR 0.79). A septal wall thickness above 11 mm (HR 2.48, 95%-CI = 1.10-5.67, p = 0.029) was associated with an increased risk of ACM, with a trend seen for reduced left ventricular ejection fraction prior to therapy (LVEF <40%; HR 9.17, 95%-CI = 1.30-183.11, p = 0.051). Secondary endpoint was reached by 93 patients while no baseline parameter was able to predict an elevated risk. However, hs-cTnT change from baseline of 50% or more during the first 14 days after CAR infusion predicted ACM (HR 3.81, 95%-CI = 1.58-9.45; p = 0.003). None of the baseline characteristics was able to predict the incidence of cardiac events. Interpretation: Reduced pre-lymphodepletion ejection fraction and early post-infusion biomarker kinetics may be associated with increased ACM and cardiotoxicity events. These findings may help to identify patients who could benefit from intensified cardio-oncological surveillance. Funding: The German Center for Cardiovascular Research, German Research Foundation, and the Federal Ministry of Education and Research.

PTCy versus ATG as graft-versus-host disease prophylaxis in mismatched unrelated stem cell transplantation.

There is an increased risk of GVHD and of non-relapse mortality (NRM) after allogeneic stem cell transplantations (alloSCT) when mismatched unrelated donors (MMUD) are used. In Europe, it is standard practice to use rabbit anti-thymocyte globulin (rATG) to reduce the high NRM and GVHD risks after MMUD alloSCT. As an alternative to rATG, post-transplantation Cyclophosphamide (PTCy) is in increasing clinical use. It is currently impossible to give general recommendations regarding preference for one method over another since comparative evidence from larger data sets is lacking. To improve the evidence base, we analyzed the outcome of rATG vs. PTCy prophylaxis in adult patients with hematologic malignancies undergoing first peripheral blood alloSCT from MMUD (9/10 antigen match) between Jan 2018 and June 2021 in the database of the European Society for Blood and Marrow Transplantation (EBMT). We performed multivariate analyses using the Cox proportional-hazards regression model. We included 2123 patients in the final analyses (PTCy, n = 583; rATG, n = 1540). p values and hazard ratios (HR) presented here are multivariate outcomes. Two years after alloSCT we found a lower NRM in the PTCy group of 18% vs. 24.9% in the rATG group; p = 0.028, HR 0.74. Overall survival in the PTCy cohort was higher with 65.7% vs. 55.7% in the rATG cohort; p < 0.001, HR 0.77. Progression-free survival was also better in the PTCy patients with 59.1% vs. 48.8% when using rATG; p = 0.001, 0.78. The incidences of chronic GVHD and acute GVHD were not significantly different between the groups. We found significantly lower NRM as well as higher survival in recipients of peripheral blood alloSCTs from MMUD receiving PTCy as compared to rATG. The results of the current analysis suggest an added value of PTCy as GVHD prophylaxis in MMUD alloSCT.

Improvements in Posttransplant Outcomes Over Two Decades in Older Patients with Acute Myeloid Leukemia in the EBMT ALWP Study.

PURPOSE: Acute myeloid leukemia (AML) is a disease of older patients. Progress in allogeneic hematopoietic cell transplantation (allo-HCT) allowed the delivery of allo-HCT to older patients. We assessed changes over time in transplant characteristics and outcomes in patients with AML ages 65 years and above. PATIENTS AND METHODS: We identified 7,215 patients with AML (median age 68 years, range 65-80) allografted between 2000 and 2021 in first complete remission (CR1; 64%), second or subsequent remission (CR2+; 14%), or active disease (22%). RESULTS: Median follow-up was 40 months. The 3-year cumulative relapse incidence (RI) gradually and significantly decreased from 37% to 31%, then to 30% (P = 0.001) over the three time periods (2000-2009; 2010-2014; 2015-2021), whereas nonrelapse mortality (NRM) decreased from 31% and 31% to 27% (P = 0.003). The 3-year leukemia-free survival (LFS) and overall survival (OS) gradually and significantly improved from 32% to 38%, and then to 44% (P = 0.001) and from 37% to 42%, and then to 49% (P = 0.001), respectively. In multivariate analysis, significant improvement in the RI, LFS, and OS were noted after 2015, whereas NRM was not significantly affected. This improvement was observed regardless of disease status at transplant. CONCLUSIONS: In older patients with AML, we observed an impressive improvement over time in posttransplant outcomes, mostly attributed to decreased RI rather than decreased NRM, and regardless of disease status at transplant. These large-scale, real-world data can serve as a benchmark for future studies in this setting and indicate that the opportunity for transplant for the elderly should be mandatory and no longer an option.

Allogeneic hematopoietic stem-cell transplantation for patients with Richter transformation: a retrospective study on behalf of the Chronic Malignancies Working Party of the EBMT.

Management of Richter transformation (RT) is particularly challenging, with survival estimates <1 year. We report on outcomes of 66 RT patients undergoing allogeneic-HCT (allo-HCT) between 2008 and 2018 registered with the EBMT. Median age at allo-HCT was 56.2 years (interquartile range (IQR), 51.3-63.1). Median time from RT to allo-HCT was 6.9 months (IQR, 4.9-11) and 28 (42.4%) were in complete remission (CR). The majority underwent reduced intensity conditioning (66.2%) using peripheral blood derived stem cells. Eighteen (27.3%) patients had a matched sibling donor, 24 (36.4%) a matched unrelated donor and the remaining were mismatched. Median follow-up was 6.6 years; 1- and 3- year overall and progression free survival (PFS) (95% CI) was 65% (54-77) and 39% (27-51) and 53% (41-65) and 29% (18-40), respectively. Patients in CR at time of allo-HCT had significantly better 3-year PFS (39% vs. 21%, p = 0.032). Cumulative incidences of grade II-IV acute graft versus host disease (GVHD) at day +100 was 41% (95% CI 29-53) and chronic GVHD at 3 years was 53% (95% CI 41-65). High rates of non-relapse mortality (NRM) were observed; 38% (95% CI, 26-50) at 3 years. Although potentially curative, approaches to reduce considerable NRM and chronic GVHD rates are required.

Allogeneic hematopoietic cell transplantation for older patients with AML with active disease. A study from the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation (EBMT).

Older adults with acute myeloid leukemia (AML) refractory to initial or reinduction chemotherapy have a dismal prognosis if they do not undergo hematopoietic stem-cell transplantation (HCT). However, data assessing HCT outcomes from different donors are scarce. We evaluated results from a retrospective analysis on patients aged ≥70 years, with AML not in remission who received an allogeneic HCT from HLA-matched sibling donor (MSD), HLA-10/10 matched unrelated donor (MUD), or T-cell replete haploidentical (Haplo) donor, from 2010 to 2021, reported to the ALWP-EBMT database. A total of 360 patients (median age 72 years, range 70-79) were included in the analysis. Median follow-up for the entire population was 35.5 months. Donors were MSD (n = 58), 10/10 HLA-MUD (n = 228), and Haplo (n = 74). A total of 213 (59.2%) patients were primary induction failures, while 147 (40.8%) were in first or subsequent relapse. Graft source was peripheral blood in 92% of the patients. Patients transplanted from Haplo donors more frequently received marrow grafts (p < 0.01) and presented the combination female donor to male recipient (p < 0.01). The overall 2-year rates of overall survival (OS) and leukemia-free survival (LFS) were: 62.4% (95% CI 47.2-74.3) and 47.6% (95% CI 33.1-60.8) for MSD, 43% (95% CI 35.8-49.9), and 37.5% (95% CI 30.7-44.4) for MUD, and 25.9% (95% CI 15.8-37.2), and 26.5% (95% CI 16.3-37.8) for recipients of Haplo transplants. The 2-year cumulative incidence of relapse (RI) was slightly lower for Haplo recipients at 29.6% (95% CI 19-40.9), for MUD it was 30.2% (95% CI 23.9-36.7), and for MSD 34.9% (95% CI 22-48.2); counterbalanced by a higher incidence of non-relapse mortality (NRM) of 43.9% (95% CI 31.6-55.6) for Haplo recipients, 32.2% (95% CI 26-33.1) for MUD and 17.5% (95% CI 8.4-29.3) for MSD. Graft-versus-host disease (GVHD-free, relapse-free survival (GRFS) was 35.3% (95% CI 22.3-48.5) for MSD, 29.6% (95% CI 23.2-36.2) for MUD, and 19.2% (95% CI 10.7-29.6) for Haplo patients. In the multivariate model, compared to the referent group of MSD recipients, the risk of NRM was higher among patients transplanted from Haplo donors ([hazard ratio] HR 5.1, 95% CI 2.23-11.61, p < 0.001) and MUD (HR 3.21, 95% CI 1.48-0.6.94, p = 0.003). Furthermore, both Haplo and MUD were associated with inferior OS, (HR 3.6, 95% CI 1.98-0.6.56, p < 0.001, and HR 2.3, 95% CI 1.37-0.3.88, p = 0.002, respectively), and LFS (HR 2.24, 95% CI 1.31-0.3.84, p = 0.003, and HR 1.64, 95% CI 1.04-0.2.60, p = 0.034, respectively). Patients transplanted from Haplo donors were also associated with worse GFRS (HR 1.72, 95% CI 1.07-2.77, p:0.025) compared with MSD patients. Older adult AML patients with active disease transplanted from MSD experienced prolonged OS and LFS compared to 10/10 MUD and Haplo due to lower NRM. Prospective clinical trials are warranted.

Treosulfan compared to busulfan in allogeneic haematopoietic stem cell transplantation for myelofibrosis: a registry-based study from the Chronic Malignancies Working Party of the EBMT.

We aimed to compare outcomes following treosulfan (TREO) or busulfan (BU) conditioning in a large cohort of myelofibrosis (MF) patients from the EBMT registry. A total of 530 patients were included; 73 received TREO and 457 BU (BU ≤ 6.4 mg/kg in 134, considered RIC, BU > 6.4 mg/kg in 323 considered higher dose (HD)). Groups were compared using adjusted Cox models. Cumulative incidences of engraftment and acute GVHD were similar across the 3 groups. The TREO group had significantly better OS than BU-HD (HR:0.61, 95% CI: 0.39-0.93) and a trend towards better OS over BU-RIC (HR: 0.66, 95% CI: 0.41-1.05). Moreover, the TREO cohort had a significantly better Progression-Free-Survival (PFS) than both the BU-HD (HR: 0.57, 95% CI: 0.38-0.84) and BU-RIC (HR: 0.60, 95% CI: 0.39-0.91) cohorts, which had similar PFS estimates. Non-relapse mortality (NRM) was reduced in the TREO and BU-RIC cohorts (HR: 0.44, 95% CI: 0.24-0.80 TREO vs BU-HD; HR: 0.54, 95% CI: 0.28-1.04 TREO vs BU-RIC). Of note, relapse risk did not significantly differ across the three groups. In summary, within the limits of a registry-based study, TREO conditioning may improve PFS in MF HSCT and have lower NRM than BU-HD with a similar relapse risk to BU-RIC. Prospective studies are needed to confirm these findings.

Impact of comorbidities and body mass index on the outcomes of allogeneic hematopoietic cell transplantation in myelofibrosis: A study on behalf of the Chronic Malignancies Working Party of EBMT.

Investigating the evaluation of eligibility for transplant in myelofibrosis (MF): The role of HCT-CI and BMI. HCT-CI emerges as a key prognostic factor, while BMI shows limited impact. This study expands insights for better clinical decision-making in MF allo-HCT.