Chimeric antigen receptor (CAR) modified T Cells in acute myeloid leukemia: limitations and expectations.

Acute myeloid leukemia (AML) is an aggressive hematologic malignancy with a poor prognosis despite the advent of novel therapies. Consequently, a major need exists for new therapeutic options, particularly for patients with relapsed/refractory (R/R) AML. In recent years, it has been possible to individualize the treatment of a subgroup of patients, particularly with the emergence of multiple targeted therapies. Nonetheless, a considerable number of patients remain without therapeutic options, and overall prognosis remains poor because of a high rate of disease relapse. In this sense, cellular therapies, especially chimeric antigen receptor (CAR)-T cell therapy, have dramatically shifted the therapeutic options for other hematologic malignancies, such as diffuse large B cell lymphoma and acute lymphoblastic leukemia. In contrast, effectively treating AML with CAR-based immunotherapy poses major biological and clinical challenges, most of them derived from the unmet need to identify target antigens with expression restricted to the AML blast without compromising the viability of the normal hematopoietic stem cell counterpart. Although those limitations have hampered CAR-T cell therapy translation to the clinic, there are several clinical trials where target antigens, such as CD123, CLL-1 or CD33 are being used to treat AML patients showing promising results. Moreover, there are continuing efforts to enhance the specificity and efficacy of CAR-T cell therapy in AML. These endeavors encompass the exploration of novel avenues, including the development of dual CAR-T cells and next-generation CAR-T cells, as well as the utilization of gene editing tools to mitigate off-tumor toxicities. In this review, we will summarize the ongoing clinical studies and the early clinical results reported with CAR-T cells in AML, as well as highlight CAR-T cell limitations and the most recent approaches to overcome these barriers. We will also discuss how and when CAR-T cells should be used in the context of AML.

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.

Corrigendum: Impact of disease burden and late loss of B cell aplasia on the risk of relapse after CD19 chimeric antigen receptor T Cell (Tisagenlecleucel) infusion in pediatric and young adult patients with relapse/refractory acute lymphoblastic leukemia: role of B-cell monitoring.

[This corrects the article DOI: 10.3389/fimmu.2023.1280580.].

Durable response after tisagenlecleucel in adults with relapsed/refractory follicular lymphoma: ELARA trial update.

ABSTRACT: Tisagenlecleucel is approved for adults with relapsed/refractory (r/r) follicular lymphoma (FL) in the third- or later-line setting. The primary analysis (median follow-up, 17 months) of the phase 2 ELARA trial reported high response rates and excellent safety profile in patients with extensively pretreated r/r FL. Here, we report longer-term efficacy, safety, pharmacokinetic, and exploratory biomarker analyses after median follow-up of 29 months (interquartile range, 22.2-37.7). As of 29 March 2022, 97 patients with r/r FL (grades 1-3A) received tisagenlecleucel infusion (0.6 × 108-6 × 108 chimeric antigen receptor-positive viable T cells). Bridging chemotherapy was allowed. Baseline clinical factors, tumor microenvironment, blood soluble factors, and circulating blood cells were correlated with clinical response. Cellular kinetics were assessed by quantitative polymerase chain reaction. Median progression-free survival (PFS), duration of response (DOR), and overall survival (OS) were not reached. Estimated 24-month PFS, DOR, and OS rates in all patients were 57.4% (95% confidence interval [CI], 46.2-67), 66.4% (95% CI, 54.3-76), and 87.7% (95% CI, 78.3-93.2), respectively. Complete response rate and overall response rate were 68.1% (95% CI, 57.7-77.3) and 86.2% (95% CI, 77.5-92.4), respectively. No new safety signals or treatment-related deaths were reported. Low levels of tumor-infiltrating LAG3+CD3+ exhausted T cells and higher baseline levels of naïve CD8+ T cells were associated with improved outcomes. Tisagenlecleucel continued to demonstrate highly durable efficacy and a favorable safety profile in this extended follow-up of 29 months in patients with r/r FL enrolled in ELARA. This trial was registered at www.clinicaltrials.gov as #NCT03568461.

ECP versus ruxolitinib in steroid-refractory acute GVHD - a retrospective study by the EBMT transplant complications working party.

Introduction: Extracorporal Photophoresis (ECP) is in clinical use for steroid-refractory and steroid-dependent acute GVHD (SR-aGVHD). Based on recent Phase-III study results, ruxolitinib has become the new standard of care for SR-aGVHD. Our aim was to collect comparative data between ruxolitinib and ECP in SR-aGVHD in order to improve the evidence base for clinical decision making. Methods: We asked EBMT centers if they were willing to participate in this study by completing a data form (Med-C) with detailed information on GVHD grading, -therapy, -dosing, -response and complications for each included patient. Results: 31 centers responded positively (14%) and we included all patients receiving alloSCT between 1/2017-7/2019 and treated with ECP or ruxolitinib for SR-aGVHD grades II-IV from these centers. We identified 53 and 40 patients with grades II-IV SR-aGVHD who were treated with ECP and ruxolitinib, respectively. We performed multivariate analyses adjusted on grading and type of SR-aGVHD (steroid dependent vs. refractory). At day+90 after initiation of treatment for SR-aGVHD we found no statistically significant differences in overall response. The odds ratio in the ruxolitinib group to achieve overall response vs. the ECP group was 1.13 (95% CI = [0.41; 3.22], p = 0.81). In line, we detected no statistically significant differences in overall survival, progression-free survival, non-relapse mortality and relapse incidence. Discussion: The clinical significance is limited by the retrospective study design and the current data can't replace prospective studies on ECP in SR-aGVHD. However, the present results contribute to the accumulating evidence on ECP as an effective treatment option in SR-aGVHD.

Targeting Hedgehog Signaling with Glasdegib in Patients with Refractory Sclerotic Chronic GVHD: A Report of Two Phase I/II Trials.

PURPOSE: Sclerotic chronic GVHD (scGVHD) is characterized by progressive skin fibrosis and frequent refractoriness to available therapies. Aberrant activation of Hedgehog signaling in dermal fibroblasts has been implicated in scGVHD. Here, we report the results of two phase I/II studies (NCT03415867, GETH-TC; NCT04111497, FHD) that evaluated glasdegib, a smoothened antagonist, as a novel therapeutic agent in refractory scGVHD. PATIENTS AND METHODS: Adult patients with active scGVHD after ≥1 (FHD) or ≥2 (GETH-TC) lines of therapy were enrolled. Primary endpoints were dose-limiting toxicity (DLT) and MTD in the GETH-TC trial, and safety and tolerability measures in the FHD trial. Glasdegib was administered once daily in 28-day cycles. Responses were scored per 2014 NIH cGVHD criteria. Correlative studies were performed to evaluate the role of fibroblast-independent immune mechanisms on clinical activity. RESULTS: Twenty (GETH-TC) and 15 (FHD) patients were recruited. Treatment-emergent grade (G) ≥2 adverse events (AE) in the GETH-TC trial included muscle cramps (85%), alopecia (50%), and dysgeusia (35%). Two patients experienced a DLT (G3 muscle cramps), and the MTD was established at 50 mg. G3 muscle cramps were the most frequently reported AE (33%) in the FHD trial. At 12-months, the skin/joint scGVHD overall response rate was 65% (all partial responses) in the GETH-TC trial and 47% (6 partial responses, 1 complete response) in the FHD cohort. No immune correlates of response were identified. CONCLUSIONS: Glasdegib demonstrated promising responses in patients with refractory scGVHD, but tolerability was limited by muscle cramping.

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.

Fractionated initial infusion and booster dose of ARI0002h, a humanised, BCMA-directed CAR T-cell therapy, for patients with relapsed or refractory multiple myeloma (CARTBCMA-HCB-01): a single-arm, multicentre, academic pilot study.

BACKGROUND: Chimeric antigen receptor (CAR) T-cell therapy is a promising option for patients with heavily treated multiple myeloma. Point-of-care manufacturing can increase the availability of these treatments worldwide. We aimed to assess the safety and activity of ARI0002h, a BCMA-targeted CAR T-cell therapy developed by academia, in patients with relapsed or refractory multiple myeloma. METHODS: CARTBCMA-HCB-01 is a single-arm, multicentre study done in five academic centres in Spain. Eligible patients had relapsed or refractory multiple myeloma and were aged 18-75 years; with an Eastern Cooperative Oncology Group performance status of 0-2; two or more previous lines of therapy including a proteasome inhibitor, an immunomodulatory agent, and an anti-CD38 antibody; refractoriness to the last line of therapy; and measurable disease according to the International Myeloma Working Group criteria. Patients received an initial fractionated infusion of 3 × 106 CAR T cells per kg bodyweight in three aliquots (0·3, 0·9, and 1·8 × 106 CAR-positive cells per kg intravenously on days 0, 3, and 7) and a non-fractionated booster dose of up to 3 × 106 CAR T cells per kg bodyweight, at least 100 days after the first infusion. The primary endpoints were overall response rate 100 days after first infusion and the proportion of patients developing cytokine-release syndrome or neurotoxic events in the first 30 days after receiving treatment. Here, we present an interim analysis of the ongoing trial; enrolment has ended. This study is registered with ClinicalTrials.gov, NCT04309981, and EudraCT, 2019-001472-11. FINDINGS: Between June 2, 2020, and Feb 24, 2021, 44 patients were assessed for eligibility, of whom 35 (80%) were enrolled. 30 (86%) of 35 patients received ARI0002h (median age 61 years [IQR 53-65], 12 [40%] were female, and 18 [60%] were male). At the planned interim analysis (cutoff date Oct 20, 2021), with a median follow-up of 12·1 months (IQR 9·1-13·5), overall response during the first 100 days from infusion was 100%, including 24 (80%) of 30 patients with a very good partial response or better (15 [50%] with complete response, nine [30%] with very good partial response, and six [20%] with partial response). Cytokine-release syndrome was observed in 24 (80%) of 30 patients (all grade 1-2). No cases of neurotoxic events were observed. Persistent grade 3-4 cytopenias were observed in 20 (67%) patients. Infections were reported in 20 (67%) patients. Three patients died: one because of progression, one because of a head injury, and one due to COVID-19. INTERPRETATION: ARI0002h administered in a fractioned manner with a booster dose after 3 months can provide deep and sustained responses in patients with relapsed or refractory multiple myeloma, with a low toxicity, especially in terms of neurological events, and with the possibility of a point-of-care approach. FUNDING: Instituto de Salud Carlos III (co-funded by the EU), Fundación La Caixa, and Fundació Bosch i Aymerich.

Monitoring of kinetics and exhaustion markers of circulating CAR-T cells as early predictive factors in patients with B-cell malignancies.

Purpose: CAR-T cell therapy has proven to be a disruptive treatment in the hematology field, however, less than 50% of patients maintain long-term response and early predictors of outcome are still inconsistently defined. Here, we aimed to optimize the detection of CD19 CAR-T cells in blood and to identify phenotypic features as early biomarkers associated with toxicity and outcomes. Experimental design: In this study, monitoring by flow cytometry and digital PCR (dPCR), and immunophenotypic characterization of circulating CAR-T cells from 48 patients treated with Tisa-cel or Axi-cel was performed. Results: Validation of the flow cytometry reagent for the detection of CAR-T cells in blood revealed CD19 protein conjugated with streptavidin as the optimal detection method. Kinetics of CAR-T cell expansion in blood confirmed median day of peak expansion at seven days post-infusion by both flow cytometry and digital PCR. Circulating CAR-T cells showed an activated, proliferative, and exhausted phenotype at the time of peak expansion. Patients with increased expansion showed more severe CRS and ICANs. Immunophenotypic characterization of CAR-T cells at the peak expansion identified the increased expression of co-inhibitory molecules PD1 and LAG3 and reduced levels of the cytotoxicity marker CD107a as predictors of a better long-term disease control. Conclusions: These data show the importance of CAR-T cells in vivo monitoring and identify the expression of PD1LAG3 and CD107a as early biomarkers of long-term disease control after CAR-T cell therapy.

Genetic deletion of HVEM in a leukemia B cell line promotes a preferential increase of PD-1- stem cell-like T cells over PD-1+ T cells curbing tumor progression.

Introduction: A high frequency of mutations affecting the gene encoding Herpes Virus Entry Mediator (HVEM, TNFRSF14) is a common clinical finding in a wide variety of human tumors, including those of hematological origin. Methods: We have addressed how HVEM expression on A20 leukemia cells influences tumor survival and its involvement in the modulation of the anti-tumor immune responses in a parental into F1 mouse tumor model of hybrid resistance by knocking-out HVEM expression. HVEM WT or HVEM KO leukemia cells were then injected intravenously into semiallogeneic F1 recipients and the extent of tumor dissemination was evaluated. Results: The loss of HVEM expression on A20 leukemia cells led to a significant increase of lymphoid and myeloid tumor cell infiltration curbing tumor progression. NK cells and to a lesser extent NKT cells and monocytes were the predominant innate populations contributing to the global increase of immune infiltrates in HVEM KO tumors compared to that present in HVEM KO tumors. In the overall increase of the adaptive T cell immune infiltrates, the stem cell-like PD-1- T cells progenitors and the effector T cell populations derived from them were more prominently present than terminally differentiated PD-1+ T cells. Conclusions: These results suggest that the PD-1- T cell subpopulation is likely to be a more relevant contributor to tumor rejection than the PD-1+ T cell subpopulation. These findings highlight the role of co-inhibitory signals delivered by HVEM upon engagement of BTLA on T cells and NK cells, placing HVEM/BTLA interaction in the spotlight as a novel immune checkpoint for the reinforcement of the anti-tumor responses in malignancies of hematopoietic origin.

Molecular Landscape and Validation of New Genomic Classification in 2668 Adult AML Patients: Real Life Data from the PETHEMA Registry.

Next-Generation Sequencing (NGS) implementation to perform accurate diagnosis in acute myeloid leukemia (AML) represents a major challenge for molecular laboratories in terms of specialization, standardization, costs and logistical support. In this context, the PETHEMA cooperative group has established the first nationwide diagnostic network of seven reference laboratories to provide standardized NGS studies for AML patients. Cross-validation (CV) rounds are regularly performed to ensure the quality of NGS studies and to keep updated clinically relevant genes recommended for NGS study. The molecular characterization of 2856 samples (1631 derived from the NGS-AML project; NCT03311815) with standardized NGS of consensus genes (ABL1, ASXL1, BRAF, CALR, CBL, CEBPA, CSF3R, DNMT3A, ETV6, EZH2, FLT3, GATA2, HRAS, IDH1, IDH2, JAK2, KIT, KRAS, MPL, NPM1, NRAS, PTPN11, RUNX1, SETBP1, SF3B1, SRSF2, TET2, TP53, U2AF1 and WT1) showed 97% of patients having at least one mutation. The mutational profile was highly variable according to moment of disease, age and sex, and several co-occurring and exclusion relations were detected. Molecular testing based on NGS allowed accurate diagnosis and reliable prognosis stratification of 954 AML patients according to new genomic classification proposed by Tazi et al. Novel molecular subgroups, such as mutated WT1 and mutations in at least two myelodysplasia-related genes, have been associated with an adverse prognosis in our cohort. In this way, the PETHEMA cooperative group efficiently provides an extensive molecular characterization for AML diagnosis and risk stratification, ensuring technical quality and equity in access to NGS studies.

A phase II, prospective, randomized, open-label study of defibrotide added to standard-of-care prophylaxis for the prevention of acute graft-versus-host disease after allogeneic hematopoietic cell transplantation.

Acute graft-versus-host disease (aGvHD) is a life-threatening complication typically occurring within 100 days after allogeneic hematopoietic cell transplantation (allo-HCT). This hypothesis-generating, phase II, prospective, open-label, randomized study (clinicaltrials gov. Identifier: NCT03339297) compared defibrotide added to standard-of-care (SOC) GvHD prophylaxis (defibrotide prophylaxis arm) versus SOC alone (SOC arm) to prevent aGvHD post-transplant. This study estimated incidences of aGvHD and was not statistically powered to assess differences among treatment arms. Patients were randomized 1:1 to defibrotide prophylaxis arm (n=79; median age 57 years; range, 2-69 years) or SOC arm (n=73; median age 56 years; range, 2-72 years). Patient demographics in the two arms were similar except for conditioning regimen type (myeloablative: defibrotide, 76% vs. SOC, 61%) and stem cell source for allo-HCT (bone marrow: defibrotide, 34% vs. SOC, 26%). In the intent-to-treat primary endpoint analysis, the cumulative incidence of grade B-D aGvHD at day 100 post-transplant was 38.4% in the defibrotide prophylaxis arm versus 47.1% in the SOC arm (difference: -8.8%, 90% confidence interval [CI]: -22.5 to 4.9). The difference noted at day 100 became more pronounced in a subgroup analysis of patients who received antithymocyte globulin (defibrotide: 30.4%, SOC: 47.6%; difference: -17.2%; 90% CI: -41.8 to 7.5). Overall survival rates at day 180 post-transplant were similar between arms, as were the rates of serious treatment-emergent adverse events (defibrotide: 42%, SOC: 44%). While the observed differences in endpoints between the two arms were not substantial, these results suggest defibrotide prophylaxis may add a benefit to currently available SOC to prevent aGvHD following allo-HCT without adding significant toxicities.

First-in-human study of JNJ-63709178, a CD123/CD3 targeting antibody, in relapsed/refractory acute myeloid leukemia.

This study aimed to identify a recommended phase II dose and evaluate the safety, tolerability, pharmacokinetics/pharmacodynamics, and preliminary clinical activity of JNJ-63709178, a CD123/CD3 dual-targeting antibody, in patients with relapsed or refractory acute myeloid leukemia. Intravenous (i.v.) and subcutaneous (s.c.) administration of JNJ-63709178 were evaluated. The i.v. infusions were administered once every 2 weeks (cohorts 1-5 [n = 17]) or twice weekly (cohorts 6-11 [n = 36]). A twice-weekly s.c. dosing regimen with step-up dosing was also studied (s.c. cohorts 1-2 [n = 9]). Treatment-emergent adverse events (TEAEs) greater than or equal to grade 3 were observed in 11 (65%) patients in cohorts 1-5 and 33 (92%) patients in cohorts 6-11. At the highest i.v. dose (4.8 µg/kg), 5 (71%) patients discontinued treatment due to TEAEs. For s.c. administration (n = 9), eight (89%) patients experienced TEAEs greater than or equal to grade 3 and injection site reactions (≤ grade 3) emerged in all patients. At 4.8 µg/kg (i.v. and s.c.), the mean maximum serum concentrations were 30.3 and 3.59 ng/ml, respectively. Increases in multiple cytokines were observed following i.v. and s.c. administrations, and step-up dosing strategies did not mitigate cytokine production or improve the safety profile and led to limited duration of treatment. Minimal clinical activity was observed across all cohorts. The i.v. and s.c. dosing of JNJ-63709178 was associated with suboptimal drug exposure, unfavorable safety profiles, limited clinical activity, and inability to identify a recommended phase II dose.

Impact of disease burden and late loss of B cell aplasia on the risk of relapse after CD19 chimeric antigen receptor T Cell (Tisagenlecleucel) infusion in pediatric and young adult patients with relapse/refractory acute lymphoblastic leukemia: role of B-cell monitoring.

Introduction: Loss of B-cell aplasia (BCA) is a well-known marker of functional loss of CD19 CAR-T. Most relapses and loss of BCA occur in the first months after CD19 CAR-T infusion. In addition, high tumor burden (HTB) has shown to have a strong impact on relapse, especially in CD19-negative. However, little is known about the impact of late loss of BCA or the relationship between BCA and pre-infusion tumor burden in patients infused with tisagenlecleucel for relapsed/refractory B-cell acute lymphoblastic leukemia. Therefore, the optimal management of patients with loss of BCA is yet to be defined. Methods: We conducted a Spanish, multicentre, retrospective study in patients infused with tisagenlecleucel after marketing authorization. A total of 73 consecutively treated patients were evaluated. Results: Prior to infusion, 39 patients had HTB (≥ 5% bone marrow blasts) whereas 34 had a low tumor burden (LTB) (<5% blasts). Complete remission was achieved in 90.4% of patients, of whom 59% relapsed. HTB was associated with inferior outcomes, with a 12-month EFS of 19.3% compared to 67.2% in patients with LTB (p<0.001) with a median follow-up of 13.5 months (95% CI 12.4 - 16.2). In the HTB subgroup relapses were mainly CD19-negative (72%) whereas in the LTB subgroup they were mainly CD19-positive (71%) (p=0.017). In the LTB group, all CD19-positive relapses were preceded by loss of BCA whereas only 57% (4/7) of HTB patients experienced CD19-positive relapse. We found a positive correlation between loss of BCA and CD19-positive relapse (R-squared: 74) which persisted beyond six months post-infusion. We also explored B-cell recovery over time using two different definitions of loss of BCA and found a few discrepancies. Interestingly, transient immature B-cell recovery followed by BCA was observed in two pediatric patients. In conclusion, HTB has an unfavorable impact on EFS and allo-SCT might be considered in all patients with HTB, regardless of BCA. In patients with LTB, loss of BCA preceded all CD19-positive relapses. CD19-positive relapse was also frequent in patients who lost BCA beyond six months post-infusion. Therefore, these patients are still at significant risk for relapse and close MRD monitoring and/or therapeutic interventions should be considered.

SF3B1, RUNX1 and TP53 Mutations Significantly Impact the Outcome of Patients With Lower-Risk Myelodysplastic Syndrome.

INTRODUCTION: Prognosis of patients with myelodysplastic syndrome (MDS), particularly the group with lower-risk disease (LR-MDS) is very heterogeneous. Several studies have described the prognostic value of recurrent somatic mutations in MDS including all risk categories. Recently, the incorporation of genomic data to clinical parameters defined the new Molecular International Prognostic Scoring System (IPSS-M). MATERIALS AND METHODS: In this study, we evaluated the impact of molecular profile in a series of 181 patients with LR-MDS and non-proliferative chronic myelomonocytic leukemia. RESULTS: Epigenetic regulators (TET2, ASXL1) and splicing (SF3B1) were the most recurrent mutated pathways. In univariate analysis, RUNX1 or TP53 mutations correlated with lower median overall survival (OS). In contrast, SF3B1 mutation was associated with prolonged median OS [95 months (95% IC, 32-157) vs. 33 months (95% CI, 19-46) in unmutated patients (P < 0.01)]. In a multivariate Cox regression model, RUNX1 mutations independently associated with shorter OS, while SF3B1 mutation retained its favorable impact on outcome (HR: 0.24, 95% CI, 0.1-0.5; P = 0.001). In addition, TP53 or RUNX1 mutations were identified as predictive covariates for the probability of leukemic progression (P < 0.001). CONCLUSION: Incorporation of molecular testing in LR-MDS identified a subset of patients with expected poorer outcome, either due to lower survival or probability of leukemic progression.

Comparison of outcomes for HLA-matched sibling and haplo-identical donors in Myelodysplastic syndromes: report from the chronic malignancies working party of EBMT.

Myelodysplastic syndromes (MDS) are the second common indication for an Allo-HCT. We compared the outcomes of 1414 matched sibling (MSD) with 415 haplo-identical donors (HD) transplanted with post-transplant cyclophosphamide (PTCy) as GVHD prophylaxis between 2014 and 2017. The median age at transplant with MSD was 58 and 61 years for HD. The median time to neutrophil engraftment was longer for HD being 20 vs 16 days for MSD (p < 0.001). Two-year overall survival (OS) and PFS (progression free survival) with MSD were significantly better at 58% compared with 50%, p ≤ 0.001, and 51% vs 47%, p = 0.029, with a HD. Relapse at 2 years was lower with a HD 23% than with MSD 29% (p = 0.016). Non relapse mortality (NRM) was higher with HD in the first 6 months post-transplant [HR 2.59 (1.5-4.48) p < 0.001] and was also higher at 2 years being 30% for HD and 20% for MSD, p ≤ 0.001. The incidence of acute GVHD grade II-IV and III-IV at 100 days was comparable for MSD and HD, however, chronic GVHD at 2 years was significantly higher with MSD being 44% vs 32% for HD (p < 0.001). After multivariable analysis, OS and primary graft failure were significantly worse for HD particularly before 6 months [HR 1.93(1.24-3.0)], and HR [3.5(1.5-8.1)]. The median age of HD 37 (IQR 30-47) years was significantly lower than sibling donors 56 (IQR 49-62 years) p < 0.001. However, there was no effect on NRM, relapse or PFS. This data set suggests that a MSD donor remains the preferred choice in MDS over a haplo donor. Transplants with haploidentical donors result in satisfactory long-term outcome, justifying it's use when no better donor is available.