Post-transplant Relapse Research Articles

Beneficial effects of cellular immunotherapy in the prevention and treatment of posttransplant hematologic relapse of myelodysplastic neoplasms.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only curative option for myelodysplastic syndrome (MDS). However, relapse remains the primary cause of transplantation failure. This single-center study aimed to evaluate factors influencing therapeutic interventions to prevent overt relapse of MDS and to identify treatment approaches that ensure optimal response and safety. We enrolled 149 patients with relapsed MDS who had undergone allo-HSCT between May 2009 and December 2017, among whom 87 patients had hematologic relapse (HemRel; marrow blasts ≥ 5%, blasts in peripheral blood or dysplasia fulfilling MDS diagnostic criteria) and 62 patients had pre-HemRel; pre-HemRel included imminent (n = 28; donor chimerism ≤ 95%), WT1-based molecular (n = 17; WT1 transcript > 250 copies/104ABL1), and cytogenetic (n = 17; recurrence of chromosomal aberrations) relapses. The estimated 4-year overall survival (OS) rate from the time of relapse was 44.1% among 62 pre-HemRel patients. However, the OS rate was significantly lower in 87 HemRel patients. In a multivariate analysis, preemptive use of cellular immunotherapy (cIMTx, either donor lymphocyte infusion, second allo-HSCT, or both) emerged as an independent factor in preventing HemRel and was more effective, particularly in the presence of other unfavorable factors, such as the absence of chronic graft-versus-host disease and a higher-risk group based on the MDS-transplantation prognostic scoring system. In HemRel, using cIMTx demonstrated a significantly superior OS rate compared to non-cIMTx modalities (25.8% vs. 6.1% vs. 0%, P < .001). In summary, cIMTx demonstrated superior outcomes in both pre-HemRel and HemRel groups, proving particularly advantageous in pre-HemRel cases with progression risk factors, while its benefits remained consistent in HemRel cases.

Measurable residual mutated IDH1 before allogeneic transplant for acute myeloid leukemia.

Measurable residual disease (MRD) in adults with acute myeloid leukemia (AML) in complete remission is an important prognostic marker, but detection methodology requires optimization. Persistence of mutated NPM1 or FLT3-ITD in the blood of adult patients with AML in first complete remission (CR1) prior to allogeneic hematopoietic cell transplant (alloHCT) associates with increased relapse and death after transplant. The prognostic implications of persistence of other common AML-associated mutations, such as IDH1, at this treatment landmark however remain incompletely defined. We performed testing for residual IDH1 variants (IDH1m) in pre-transplant CR1 blood of 148 adult patients undergoing alloHCT for IDH1-mutated AML at a CIBMTR reporting site between 2013 and 2019. No statistically significant post-transplant differences were observed between those testing IDH1m positive (n = 53, 36%) and negative pre-transplant (overall survival (OS): p = 0.4; relapse: p = 0.5). For patients with IDH1 mutated AML co-mutated with NPM1 and/or FLT3-ITD, only detection of persistent mutated NPM1 and/or FLT3-ITD was associated with significantly higher rates of relapse (p = 0.01). These data, from the largest study to date, do not support the detection of IDH1 mutation in CR1 blood prior to alloHCT as evidence of AML MRD for increased post-transplant relapse risk.

Quizartinib with donor lymphocyte infusion for post-transplant relapse of FLT3-ITD-positive acute myeloid leukemia.

FMS-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD)-positive acute myeloid leukemia (AML) has a poor prognosis, particularly with DNMT3A and NPM1 mutations. Quizartinib, a FLT3 inhibitor showing clinical benefit in FLT3-ITD-positive AML, has unclear safety and efficacy when combined with donor lymphocyte infusion (DLI). We report a case of FLT3-ITD-positive AML with DNMT3A and NPM1 mutations that relapsed after allogeneic hematopoietic stem cell transplantation (allo-HCT) and was treated with quizartinib and DLI. A 49-year-old man was diagnosed with AML. Target-sequencing analysis of the bone marrow revealed FLT3-ITD, DNMT3A R882, and NPM1 mutations. Although the patient achieved complete remission (CR) through induction therapy and received allo-HCT, he relapsed on day 71. Quizartinib was initiated on day 79, and the patient achieved CR with incomplete recovery on day 106. He did not desire a second allo-HCT and continued quizartinib in combination with DLI, which was started on day 156 and administered eight times every 2 to 3months. The patient achieved hematological CR on day 163 and remained in molecular CR 3years after allo-HCT without adverse effects. Quizartinib combined with DLI may be a feasible treatment for early relapse of FLT3-ITD-positive AML after allo-HCT, even with concurrent DNMT3A and NPM1 mutations.

Managing post-transplant relapse in FLT3-mutated AML with gilteritinib

Managing post-transplant relapse in FLT3-mutated AML with gilteritinib

Tracking Rare Single Donor and Recipient Immune and Leukemia Cells after Allogeneic Hematopoietic Cell Transplantation Using Mitochondrial DNA Mutations.

Combined tracking of clonal evolution and chimeric cell phenotypes could enable detection of the key cellular populations associated with response following therapy, including after allogeneic hematopoietic stem cell transplantation (HSCT). We demonstrate that mitochondrial DNA (mtDNA) mutations coevolve with somatic nuclear DNA mutations at relapse post-HSCT and provide a sensitive means to monitor these cellular populations. Furthermore, detection of mtDNA mutations via single-cell assay for transposase-accessible chromatin with select antigen profiling by sequencing (ASAP-seq) simultaneously determines not only donor and recipient cells but also their phenotype at frequencies of 0.1% to 1%. Finally, integration of mtDNA mutations, surface markers, and chromatin accessibility profiles enables the phenotypic resolution of leukemic populations from normal immune cells, thereby providing fresh insights into residual donor-derived engraftment and short-term clonal evolution following therapy for post-transplant leukemia relapse. As throughput evolves, we envision future development of single-cell sequencing-based post-transplant monitoring as a powerful approach for guiding clinical decision-making. Significance: mtDNA mutations enable single-cell tracking of leukemic clonal evolution and donor-recipient origin following allogeneic HSCT. This provides unprecedented insight into chimeric cellular phenotypes of early immune reconstitution, incipient relapse, and quality of donor engraftment with immediate translational potential for future clinical post-transplant monitoring and decision-making.

WT1 Expression Is Associated with Poor Overall Survival after Azacytidine and DLI in a Cohort of Adult AML and MDS Patients.

Introduction: Post-transplant relapse of acute myeloid leukemia and myelodysplastic syndrome faces restricted effective salvage regimens. We retrospectively analyzed the use of Azacitidine-donor lymphocyte infusion (AZA/DLI) in this setting. Furthermore, data on bone marrow Wilms tumor gene 1 (WT1) expression were collected. Methods: A Cox proportional hazards model, an outcome-oriented approach for the lowest smoothed plot of the martingale residuals, was performed for the cut-point determination of the respective WT1 expression levels. Finally, a Cox proportional hazards model investigated the association of overall survival (OS) with predictors. Results: An overall response of 41.4% with a median duration of 11.9 months for stable disease and 19.5 months for complete response (CR) patients was achieved. The disease risk index (DRI) high-/very high-risk patients had a shorter OS of 4.4 months than intermediate-risk patients, with 14.5 months, p = 0.007. At transplant, WT1-overexpressing patients (>150 copies) had a shorter median OS of 5.3 months than low-WT1-expressing ones, with 13.5 months, p = 0.024. Furthermore, patients with ≤1000 WT1 copies at relapse had a significantly longer OS with 15.3 months than patients overexpressing WT1, with 4.4 months, p = 0.0002. Conclusions: DRI and WT1 expression associate significantly with OS after AZA/DLI. Hence, WT1 may represent an MRD marker, especially in CR patients at high risk.

AML-106 From Clonal Evolution to Posttransplant Relapse—Case Report of Secondary Acute Myeloid Leukemia

AML-106 From Clonal Evolution to Posttransplant Relapse—Case Report of Secondary Acute Myeloid Leukemia

From Clonal Evolution to Post-transplant Relapse—Case Report of Secondary Acute Myeloid Leukemia

From Clonal Evolution to Post-transplant Relapse—Case Report of Secondary Acute Myeloid Leukemia

WT1 gene mutations impact post-transplant relapse in myelodysplastic syndrome with excess blasts 2 patients.

Wilms tumor 1 (WT1) gene mutations are infrequent in myelodysplastic syndrome (MDS), but MDS with WT1 mutations (WT1mut) is considered high risk for acute myeloid leukemia (AML) transformation. The influence of WT1 mutations in patients with MDS after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is unclear. We performed a retrospective analysis of 136 MDS with excess blasts 2 (MDS-EB2) patients with available WT1 status who underwent their first allo-HSCT between 2017 and 2022 in our center. There were 20 (20/136, 15%) cases in the WT1mut group and 116 (116/136, 85%) cases in the WT1 wild-type (WT1wt) group. WT1mut patients had a higher 2-year cumulative incidence of relapse (CIR) than WT1wt cases (26.2% vs. 9.4%, p = 0.037) after allo-HSCT. Multivariate analysis of relapse showed that WT1 mutations (HR, 6.0; p = 0.002), TP53 mutations (HR, 4.2; p = 0.021), and ≥ 5% blasts in bone marrow (BM) at transplantation (HR, 6.6; p = 0.004) were independent risk factors for relapse. Patients were stratified into three groups according to the risk factors. Two-year CIR differed significantly in high-, intermediate-, and low-risk groups (31.8%, 11.6%, and 0%, respectively). Hence, WT1 mutations may be related to post-transplant relapse in patients with MDS-EB2, which warrants further study.

Exploring Pattern of Relapse in Pediatric Patients with Acute Lymphocytic Leukemia and Acute Myeloid Leukemia Undergoing Stem Cell Transplant Using Machine Learning Methods.

Background. Leukemic relapse remains the primary cause of treatment failure and death after allogeneic hematopoietic stem cell transplant. Changes in post-transplant donor chimerism have been identified as a predictor of relapse. A better predictive model of relapse incorporating donor chimerism has the potential to improve leukemia-free survival by allowing earlier initiation of post-transplant treatment on individual patients. We explored the use of machine learning, a suite of analytical methods focusing on pattern recognition, to improve post-transplant relapse prediction. Methods. Using a cohort of 63 pediatric patients with acute lymphocytic leukemia (ALL) and 46 patients with acute myeloid leukemia (AML) who underwent stem cell transplant at a single institution, we built predictive models of leukemic relapse with both pre-transplant and post-transplant patient variables (specifically lineage-specific chimerism) using the random forest classifier. Local Interpretable Model-Agnostic Explanations, an interpretable machine learning tool was used to confirm our random forest classification result. Results. Our analysis showed that a random forest model using these hyperparameter values achieved 85% accuracy, 85% sensitivity, 89% specificity for ALL, while for AML 81% accuracy, 75% sensitivity, and 100% specificity at predicting relapses within 24 months post-HSCT in cross validation. The Local Interpretable Model-Agnostic Explanations tool was able to confirm many variables that the random forest classifier identified as important for the relapse prediction. Conclusions. Machine learning methods can reveal the interaction of different risk factors of post-transplant leukemic relapse and robust predictions can be obtained even with a modest clinical dataset. The random forest classifier distinguished different important predictive factors between ALL and AML in our relapse models, consistent with previous knowledge, lending increased confidence to adopting machine learning prediction to clinical management.

A Tailored Virtual Program for Alcohol Use Disorder Treatment Among Liver Transplant Candidates and Recipients Is Feasible and Associated With Lower Post-Transplant Relapse.

Alcohol-associated liver disease (ALD) is a leading indication for liver transplant (LT) in the United States. Rates of early liver transplant (ELT) with less than 6 months of sobriety have increased substantially. Patients who receive ELT commonly have alcohol-associated hepatitis (AH) and are often too ill to complete an intensive outpatient program (IOP) for alcohol use disorder (AUD) prior to LT. ELT recipients feel alienated from traditional IOPs. We implemented Total Recovery-LT, a tailored virtual outpatient IOP specific for patients under evaluation or waitlisted for LT who were too ill to attend community-based alcohol treatment programs. The 12-week program consisted of weekly group and individual counseling delivered by a master's level Certified Addiction Counselor trained in the basics of LT.Treatment consisted of 12-Step Facilitation, Motivational Interviewing, and Cognitive Behavioral Therapy. We report on program design, implementation, feasibility and early outcomes. From March 2021 to September 2022, 42 patients (36% female, 23 in LT evaluation, 19 post-transplant) enrolled across five cohorts with 76% (32/42) completing the program. Alcohol relapse was more common among noncompleters versus those who completed the program (8/10, 80%vs. 7/32, 22%, p = 0.002). History of trauma or post-traumatic stress symptoms were associated with lower likelihood of completion. Patients' desire for continued engagement after completion led to the creation of a monthly alumni group. Our integrated IOP model for patients with high-risk AUD in LT evaluation or post-transplant is well-received by patients and could be considered a model for LT programs.

Post-Transplant Maintenance Therapy in Acute Myeloid Leukemia.

Allogeneic hematopoietic cell transplantation (allo-HCT) is potentially curative for patients with acute myeloid leukemia (AML). However, the post-transplant relapse rate ranges from 40 to 70%, particularly with reduced intensity conditioning, and remains a major cause of treatment failure for these patients due to the limited efficacy of salvage therapy options. Strategies to mitigate this risk are urgently needed. In the past few years, the basic framework of post-transplant maintenance has been shaped by several clinical trials investigating targeted therapy, chemotherapy, and immunomodulatory therapies. Although the practice of post-transplant maintenance in AML has become more common, there remain challenges regarding the feasibility and efficacy of this strategy. Here, we review major developments in post-transplant maintenance in AML, along with ongoing and future planned studies in this area, outlining the limitations of available data and our future goals.

WT1-guided pre-emptive therapy after allogeneic hematopoietic stem cell transplantation in patients with acute myeloid leukemia.

Measurable residual disease (MRD)-guided pre-emptive therapies are now widely used to prevent post-transplant hematological relapse in patients with acute myeloid leukemia (AML). This single-center retrospective study aimed to clarify the significance of pre-emptive treatment based on Wilms' tumor gene-1 mRNA (WT1) monitoring for MRD in patients with AML who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT). Patients with AML who received chemotherapy for hematological relapse or WT1 increase after allo-HSCT were eligible for inclusion. From January 2017 to June 2022, 30 patients with a median age of 57 (16-70) years were included and stratified into two groups: 10 with WT1 increase and 20 with hematological relapse. The median times from HCT to WT1 increase or hematological relapse were 309days (range: 48-985) or 242days (range: 67-1116), respectively. Less intensive chemotherapy using azacitidine or cytarabine was selected for all patients with WT1 increase and 12 (60%) with hematological relapse. The 1-year overall survival and event-free survival rates for WT1 increase and hematological relapse were 70% vs. 44% (P = 0.024) and 70% vs. 29% (P = 0.029), respectively. These real-world data suggest that WT1-guided pre-emptive therapy may be superior to therapy after hematological relapse in patients with AML who have undergone allo-HSCT.

Low-dose decitabine plus venetoclax as post-transplant maintenance for high-risk myeloid malignancies.

Relapse remains a major cause of treatment failure following allogeneic stem cell transplantation (allo-SCT) for patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). We retrospectively investigated low-dose decitabine and venetoclax (DEC/VEN) as post-transplant maintenance in 26 older patients with AML and MDS. The cumulative incidence of day 100 gIII-IV acute graft versus host disease (GVHD) and 1-year moderate-severe chronic GVHD was 5% and 26%, respectively. One patient relapsed 14 m after transplant. The 1-year non-relapse mortality and survival were 11% and 84%, respectively. DEC/VEN is a safe and potentially effective strategy to reduce the risk of post-transplant relapse.

Abstract CT143: IFN-γ and donor leukocyte infusion to treat relapsed myeloblastic malignancies after allogeneic hematopoietic stem cell transplantation

Abstract Introduction: Allogeneic stem cell transplantation (alloSCT) can provide a cure for myeloid malignancies partially through the graft-vs-leukemia effect (GVL), wherein donor-derived alloreactive T cells attack recipient leukemia cells. Preclinical data strongly suggested IFN-γ is crucial for effective GVL against myeloblastic leukemia. IFN-γ receptor gene-deficient myeloblastic leukemia were resistant to GVL in mouse models (Matte-Martone, Shlomchik JCI 2017). IFN-γ upregulated HLA expression in relapsed myeloblasts in vitro (Christopher NEJM 2018, Toffalori Nat Med 2019). We hypothesized that IFN-γ would sensitize myeloblasts to alloreactive T cells and promote GVL. Here, we present the results of a phase 1 study to evaluate the safety of IFN-γ combined with donor leukocyte infusions (DLI) for relapsed myeloblastic malignancies post-transplant (NCT04628338). Methods: HLA-matched donor alloSCT recipients with relapsed acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) and no active graft-versus-host disease (GVHD) were eligible. Patients self-administered 100mcg IFN-γ (Actimmune, Horizon Therapeutics) three times a week for 4 weeks (cohort 1) or 1 week (cohort 2), followed by DLI and concurrent IFN-γ for a total of 12 weeks. Flow cytometry-based surface HLA expression and single-cell RNAseq (scRNAseq) were analyzed using bone marrow (BM) collected before and after IFN-γ. Results: Seven patients with high-risk diseases (2 MDS and 5 AML) were enrolled. There were no serious adverse events during IFN-γ monotherapy. After DLI, 5 patients developed grade I-II GVHD along with immune effector cell-associated neurotoxicity syndrome (grade 1 or 2; n=2) and idiopathic pneumonia syndrome (IPS; n=1). All immune-mediated toxicities, including IPS, resolved with corticosteroids. 4 out of 6 DLI recipients achieved minimal residual disease negative complete remissions and full donor hematopoietic cell reconstitution. The median overall survival was 579 days (range, 97-906) in responders. Myeloid blasts upregulated HLA-DR after IFN-γ, and enrichment of recipient malignant hematopoietic stem cells expressing CIITA was observed in post-IFN-γ BM by scRNAseq. Conclusions: This first in human use of IFN-γ to treat post-transplant relapse was safe, with a promising efficacy signal when combined with DLI. Correlative studies support our hypothesis that in vivo IFN-γ activates myeloblasts, manifest by HLA-DR upregulation and CIITA induction. We plan to design a phase 2 trial to formally test the efficacy of this novel immunotherapeutic approach to boost GVL in alloSCT. Citation Format: Sawa Ito, Emily Geramita, Kedwin Ventura, Biswas Neupane, Shruti Bhise, Scott N. Furlan, Warren D. Shromchik. IFN-γ and donor leukocyte infusion to treat relapsed myeloblastic malignancies after allogeneic hematopoietic stem cell transplantation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT143.

Donor Lymphocyte Infusion in the Treatment of Post-Transplant Relapse of Acute Myeloid Leukemias and Myelodysplastic Syndromes Significantly Improves Overall Survival: A French-Italian Experience of 134 Patients.

Disease relapse after allogeneic stem cell transplantation (allo-SCT) is the main challenge for curing acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). We investigated the overall survival (OS) after allo-SCT relapse according to different therapeutic approaches. We analyzed 134 patients who relapsed after allo-SCT performed between 2015 and 2021 at Saint-Antoine University Hospital, Paris and Spedali Civili di Brescia, Brescia. Of these, 103 (77%) were treated, comprising 69/103 (67%) who received therapy in overt relapse and 34/103 (33%) who were treated in a pre-emptive manner when molecular/cytogenetics recurrence or mixed chimerism occurred. The treatment was donor lymphocyte infusion (DLI)-based for 40/103 (39%) patients. The 1-, 2-, and 5-year OS of patients treated with DLI (n = 40) was 67%, 34%, and 34%, respectively, for those treated preventively (n = 20) and 43%, 20%, and 20%, respectively, for those treated in overt relapse (n = 20) (p < 0.01). The 1-, 2-, and 5-year OS of patients treated without DLI (n = 63) was 54%, 40%, and 26%, respectively, for those treated preventively (n = 14) and 17%, 5%, and 0%, respectively, for those treated in overt relapse (n = 49) (p < 0.01). Relapse treatment with a pre-emptive strategy was associated with improved outcomes, particularly when DLI was employed.

Abstract 3855: Kinetics of neoantigen-specific T cells in post-transplant relapse

Abstract Introduction: Graft-versus-leukemia effect (GVL) underpins the curative mechanism of allogeneic stem cell transplantation (alloSCT) for acute leukemias. Donor-derived T cells can recognize various antigens, including human leukocyte antigen (HLA), minor-histocompatibility antigens (miHA), over-expressed antigens, or neoantigens derived from somatic mutations of leukemia. However, the role of neoantigens has not been fully investigated in GVL. Here, we aimed to predict neoantigens and identify neoantigen-reactive T cells using samples after alloSCT. Materials: Leukemia blasts were purified from relapsed samples. Recipient saliva or T cells from pre-transplant peripheral blood (PB) were used as a recipient germline control, while donor monocyte or CD34 cells were used as donor controls. DNA/RNA isolated from these specimens were analyzed for whole exome sequencing (WES) paired with RNAseq. Somatic mutations were called using blasts and recipient germline controls by mutect and mpileup and annotation with SnpEff. Somatic mutations with variant allele frequency &amp;gt;20% were screened for neoantigen prediction bound to recipient HLA (IC50 &amp;lt; 500nM) by pVAC-seq. We also genotyped 73 SNPs associated with publicly known miHAs. Serial PB were stained for HLA-A*02:01 tetramers loaded with neoantigens or CMVpp65. T cells were stimulated with neoantigens for 10 days and tested for cytokine production in responses to target or control peptides. Results: We screened neoantigens in 8 patients relapsing after alloSCT (7 acute myeloid leukemia and 1 acute lymphoblastic leukemia) and their donors (4 matched siblings, 1 matched unrelated, 3 haploidentical). In 7 subjects, WES/RNAseq showed an average of 273 somatic mutations per patient (range 108- 609). In one subject, targeted next-generation sequencing was used to detect 2 somatic mutations. Among these mutations, seven out of eight subjects (87.5%) had potential neoantigen candidates, with a median number of 9 antigens per subject. In contrast, only 2 subjects (25%) had potential miHA. UPN8, a responder to donor lymphocyte infusion (DLI), showed dominant CMVpp65-specific T cells at the time of relapse and emergence of TP53- (neoantigen) or HA-2- (miHA) specific T cells after relapse. HA-2-specific T cells upregulated PD-1 expression at the time of graft-versus-host disease (GVHD), indicating activation of these miHA-specific T cells during GVHD. In two subjects (UPN3 and UPN8) who achieved long-term remission after DLI, CD8 T cells specific to neoantigens were detectable by IFN-γ/CD107a production in reaction to mutant peptides (SDE2.pK123X or TP53.pR248W) from post-relapse samples. Discussion: Our study showed the feasibility of in-silico neoantigens prediction and neoantigen-specific T-cell detection from a subject who developed relapse after alloSCT. Further investigation is needed to test if neoepitope burden and miHA disparity could correlate with transplant outcomes. Citation Format: Biswas Neupane, Jui-En Ray Lee, Kedwin Ventura, Kayla Parr, Kevin Quann, Sawa Ito. Kinetics of neoantigen-specific T cells in post-transplant relapse [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3855.

Transplant versus no transplant in myelodysplastic syndrome and acute myeloid leukemia with TP53 mutation; a referral center experience.

A remarkably high rate of post-transplant relapse in patients with TP53-mutated myelodysplastic syndrome/acute myeloid leukemia (MDS/AML) calls to question the utility of allogeneic stem cell transplant (HSCT). We, therefore, performed a retrospective analysis to compare the outcomes between HSCT (N = 38) versus non-HSCT (N = 45) approaches. Patients in the HSCT cohort were younger (median age 63 vs. 72) while patients in the non-HSCT cohort more commonly had complex karyotype with chromosome 17 aberrancy and 5q deletion (p < .01). A total of 69 TP53 variants including 64 pathogenic variants, and 5 variants of undetermined significance were detected. Nine patients (4 in HSCT and 5 in non-HSCT) had multi-hit TP53 variants. After induction: 57.9% versus 56.6% in the HSCT versus non-HSCT cohort achieved morphologic complete remission. Median time to HSCT was 6 months and median follow-up was 15.1 months for HSCT and 5.7 months for non-HSCT. Median disease-free survival (DFS) and overall survival (OS) were 11.7 and 15.9 months for HSCT, and 4.1 and 5.7 months for non-HSCT cohorts, respectively. Non-relapse mortality at 12 months was 22% versus 44% for HSCT versus non-HSCT. In the HSCT cohort, the rate of grade II-IV acute and chronic graft-versus-host disease (GVHD) was 55% and 18%, respectively. None of the patients from the non-HSCT cohort were alive while four patients from the HSCT cohort were alive, in remission, and without GVHD (GRFS) at the time of abstraction. Better treatment strategies for patients with TP53-mutated MDS/AML remain an area of unmet clinical need.

Transplantation of hematopoietic progenitors in myelofibrosis.

The objective of this work is to generate recommendations on the management of allogeneic stem cell transplantation (allo-SCT) in primary myelofibrosis (PMF). A comprehensive systematic review of articles published between 1999 and 2015 (January) was used as a source of scientific evidence. The recommendations were produced through a Delphi process involving a panel of 23 experts appointed by the European LeukemiaNet and the European Blood and Marrow Transplantation Group. Key questions included patient selection, donor selection, pre-transplant management, conditioning regimen, post-transplant management, prevention, and management of post-transplant relapse. Patients with intermediate-2 or high-risk disease and age < 70 years should be considered candidates for allo-SCT. Patients with intermediate-risk 1 disease and age < 65 years should be considered candidates if they have refractory transfusion-dependent anemia, or a peripheral blood (PB) blast percentage > 2%, or adverse cytogenetics. Splenectomy before transplantation must be decided on a case-by-case basis. Patients with intermediate-2 or high-risk disease who lack a human leukocyte antigen (HLA)-matched sibling or unrelated donor should be enrolled in a protocol that uses HLA non-identical donors. PB was considered the most appropriate source of hematopoietic stem cells for transplants from HLA-matched unrelated donors and siblings. The optimal intensity of the conditioning regimen has yet to be defined. Strategies such as discontinuation of immunosuppressive drugs, infusion of donor lymphocytes, or both were considered adequate to prevent clinical relapse. In conclusion, we provide consensus-based recommendations aimed at optimizing allo-SCT in PMF. Unmet clinical needs were highlighted.

A288 ALCOHOL RELAPSE AND ADVERSE OUTCOMES IN EARLY VERSUS ROUTINE LIVER TRANSPLANT FOR ALCOHOL-ASSOCIATED LIVER DISEASE IN THE PROVINCE OF BRITISH COLUMBIA

Abstract Background Liver transplant is a life-saving treatment for patients with alcohol-associated liver disease (ALD) resulting in decompensated cirrhosis or severe alcoholic hepatitis, significantly reducing mortality compared to supportive treatment. Despite its previous wide acceptance, there is a lack of strong evidence to justify a 6-month abstinence period. In 2019, BC Transplant policies were updated to allow liver transplant within 6-months of alcohol use in carefully selected patients with limited life expectancy and favorable multidisciplinary psychosocial assessment. Aims This study aims to assess alcohol relapse rates and adverse outcomes in patients who received an early liver transplant for ALD. Methods A retrospective chart review was performed on all adult patients who underwent liver transplant in the province of British Columbia between January 1, 2020, and December 31, 2022. Follow up data was extracted until May 31, 2023. Patients were included if they had alcohol documented as a contributing factor to their liver disease prior to transplant. Early transplant was defined as alcohol abstinence of 179-days or less and routine transplant as 180-days or more. Alcohol use and time to alcohol use were determined by patient history, random biochemical testing, and health-care utilization for an alcohol-associated complication. Graft dysfunction or rejection resulting in a change in therapeutic management, noncompliance determined by clinician documentation, rehospitalization, and death were recorded as adverse events. Results 278 patients underwent liver transplant during the study period. 81 patients were classified as alcohol-related, and 15 received early transplant. The mean follow-up period was 20.5 months. Early transplant recipients were more likely to be younger (median 45 vs. 58 years, p = 0.003) and have a higher MELD score at the time of transplant (median 37 vs. 17, p ampersand:003C 0.001). There was no significant difference in post-transplant alcohol relapse (13 vs. 15%, hazard ratio = 0.78, 95% CI [0.17, 3.55], p = 0.74). Graft dysfunction was increased in patients who received early transplant (53 vs. 25%, relative risk = 2.17, 95% CI [1.15, 4.10]). There was no significant difference between rates of noncompliance (0 vs. 9%), rehospitalization (53 vs. 56%), or death (0 vs. 2%). Conclusions Alcohol relapse is similar between early and routine liver transplant. Graft dysfunction is increased in early transplant, although other adverse events including medication noncompliance, rehospitalization, and death are not significant different. These results are favorable for the continued use of early liver transplant for ALD, providing an effective treatment for ALD and significantly reducing mortality in patients with a limited life expectancy. Funding Agencies None