Accelerated DNA replication fork speed due to loss of R-loops in myelodysplastic syndromes with SF3B1 mutation.

Myelodysplastic syndromes (MDS) with mutated SF3B1 gene present features including a favourable outcome distinct from MDS with mutations in other splicing factor genes SRSF2 or U2AF1. Molecular bases of these divergences are poorly understood. Here we find that SF3B1-mutated MDS show reduced R-loop formation predominating in gene bodies associated with intron retention reduction, not found in U2AF1- or SRSF2-mutated MDS. Compared to erythroblasts from SRSF2- or U2AF1-mutated patients, SF3B1-mutated erythroblasts exhibit augmented DNA synthesis, accelerated replication forks, and single-stranded DNA exposure upon differentiation. Importantly, histone deacetylase inhibition using vorinostat restores R-loop formation, slows down DNA replication forks and improves SF3B1-mutated erythroblast differentiation. In conclusion, loss of R-loops with associated DNA replication stress represents a hallmark of SF3B1-mutated MDS ineffective erythropoiesis, which could be used as a therapeutic target.

Pracinostat combined with azacitidine in newly diagnosed adult acute myeloid leukemia (AML) patients unfit for standard induction chemotherapy: PRIMULA phase III study.

Non-intensive therapies such as the hypomethylating agent (HMA) azacitidine (AZA) have been used in patients with AML ineligible for intensive induction chemotherapy (IC) or stem cell transplant due to advanced age, comorbidities, and/or risk factors. However, response rates and survival remain dismal. Pre-clinical studies indicate the epigenetic combination of HMAs and HDAC inhibitors induce re-expression of silenced genes synergistically. The activity of pracinostat, an oral pan-HDAC inhibitor, has been shown in xenograft tumor models of AML and promising efficacy was seen in a Phase 2 study. This Phase 3 study (NCT03151408) evaluated the efficacy/safety of pracinostat administered with AZA in adult patients with newly diagnosed AML ineligible to receive IC. Patients were randomized to either pracinostat plus AZA or placebo/AZA and stratified by cytogenetic risk and ECOG status. As planned, an interim analysis was performed when 232/390 events (deaths) occurred. A total of 406 patients were randomized (203/group) at the time of the analysis. Median overall survival was 9.95 months for both treatment groups (p=0.8275). There was no significant difference between treatments in secondary efficacy endpoints, reflecting a lack of clinical response. This study did not show a benefit of adding pracinostat to AZA in elderly patients unfit for IC.

Phase to phase: Navigating drug combinations with hypomethylating agents in higher-risk MDS trials for optimal outcomes.

Recent developments in high-risk Myelodysplastic Neoplasms (HR MDS) treatment are confronted with challenges in study design due to evolving drug combinations with Hypomethylating Agents (HMAs). The shift from the International Prognostic Scoring System (IPSS) to its molecular revision (IPSS-M) has notably influenced research and clinical practice. Introducing concepts like the MDS/AML overlap complicate classifications and including chronic myelomonocytic leukemia (CMML) in MDS studies introduces another layer of complexity. The International Consortium for MDS emphasizes aligning HR MDS criteria with the 2022 ELN criteria for AML. Differences in advancements between AML and MDS treatments and hematological toxicity in HR MDS underline the importance of detailed trial designs. Effective therapeutic strategies require accurate reporting of adverse events, highlighting the need for clarity in criteria like the Common Terminology Criteria for Adverse Events (CTCAE). We provide an overview on negative clinical trials in HR MDS, analyze possible reasons and explore possibilities to optimize future clinical trials in this challenging patient population.

MDS/CMML from resource-limited region: Characteristics and comparison to tertiary reference European center.

INTRODUCTION: Myelodysplastic Syndromes (MDS) and Chronic Myelomonocytic Leukemia (CMML) are clonal myeloid malignancies, characterized by bone marrow failure leading to cytopenias (and possible myeloproliferation for CMML) and a high propensity to evolve to Acute Myeloid Leukemia (AML). OBJECTIVE AND METHODS: The aim of our retrospective study was to evaluate the clinical and hematological features; the prevalence of MDS subtypes, R-IPSS, and the outcome of 106 Armenian MDS/CMML patients diagnosed over the 2008-2020 period in a single Armenian Hematology center and compare them to French MDS patients included in the GFM registry. RESULTS: Median age in the Armenian cohort was 64 years (range 19-84) and 55% were males. The main MDS subtypes were MDS-MLD (29.2%) and MDS-SLD (27.3%), the least frequent was del 5q (0.9%). By comparison, a higher prevalence of MDS-MLD, MDS-EB2, and MDS-RS was found in the French cohort. Armenian patients' cohort generally had poor access to standard MDS treatment and 42.3% of the patients were transfusion dependent. Overall survival, however, did not significantly differ between Armenian and French cohorts. CONCLUSION: Our study stresses issues regarding epidemiology, access to diagnosis, difficulties of risk stratification, and access to treatment.

Chronic Myelomonocytic Leukemia Patients With Lysozyme Nephropathy and Renal Infiltration Display Markers of Severe Disease.

Introduction: Chronic myelomonocytic leukemia (CMML) is a hematologic disorder that is an overlap syndrome between myelodysplastic syndromes and myeloproliferative neoplasms, and can be associated with autoimmune and inflammatory diseases. This study aimed to describe kidney involvement in patients with CMML, their treatments, and outcomes. Methods: We conducted a French and American multicenter retrospective study in 15 centers, identifying patients with CMML with acute kidney injury (AKI), chronic kidney disease (CKD), and urine abnormalities. Results: Sixteen patients (males, n = 14; median age 76.5 years [71.9-83]) developed a kidney disease 6 months [1.6-25.6] after the diagnosis of CMML. At the time of kidney disease diagnosis, median urinary protein-to-creatinine ratio was 2 g/g [1.25-3.4], and median serum creatinine was 2.26 mg/dl [1.46-2.68]. Fourteen patients (87.5%) underwent a kidney biopsy, and the 2 main pathological findings were lysozyme nephropathy (56%) and renal infiltration by the CMML (37.5%). Ten patients received a new treatment following the CMML-associated kidney injury. Among patients with monitored kidney function, and after a median follow-up of 15 months [9.9-34.9], 4 patients had CKD stage 3, 4 had CKD stage 4, 1 had an end-stage kidney disease. In our patient series, 2 patients evolved to an acute myeloid leukemia (AML), and 5 died. Compared with 116 CMML controls, patients who had a kidney involvement had a higher monocyte count (P < 0.001), had more CMML-1 (P = 0.005), were more susceptible to develop an AML (P = 0.02), and were more eligible to receive a specific hematologic treatment, with hydroxyurea, or hypomethylating agents (P < 0.001), but no survival difference was seen between the 2 groups (P = 0.6978). Conclusion: In this cohort of patients with CMML with a kidney injury, the 2 most frequent renal complications were lysozyme-induced nephropathy and renal infiltration by the CMML. Kidney involvement should be closely monitored in patients with CMML.

[Treating high-risk myelodysplastic syndromes]. / Traitement des syndromes myélodysplasiques de haut risque.

Myelodysplastic syndromes (MDS) are clonal stem cell diseases that primarily affect the elderly. They are classified into low- and high-risk MDS according to prognostic scoring systems. In high-risk patients, treatment should aim to modify the course of the disease by preventing progression to acute myeloid leukemia, and thus improve survival. Stem cell transplantation remains the only curative treatment when possible, but this concerns a small minority of patients. Treatment is mainly based on hypomethylating agents (HMA). Our understanding of the biology of MDS has led to the development of drugs targeting key cellular processes such as apoptosis or post-translational modifications of proteins, the microenvironment and genetic mutations. Currently, new drugs are mainly tested in combination with HMAs in several clinical trials and, although none has yet obtained marketing authorization, many molecules seem promising.

CPX-351 in higher risk myelodysplastic syndrome and chronic myelomonocytic leukaemia: a multicentre, single-arm, phase 2 study.

BACKGROUND: CPX-351, an encapsulated form of cytarabine and daunorubicin, has shown greater efficacy than the classic 3 + 7 treatment administration in secondary acute myeloid leukaemia. Given that higher-risk myelodysplastic syndrome and chronic myelomonocytic leukaemia share similarities with secondary acute myeloid leukaemia, we aimed to investigate the safety and efficacy of CPX-351 in this context. METHODS: This investigator-initiated two-cohort phase 2 trial was conducted by the Groupe Francophone des Myélodysplasies, with 12 participating centres in France. It comprised cohort A (reported here and completed), which included patients in first-line treatment, and cohort B, which was stopped for lack of inclusion (ie, not enough patients met the inclusion criteria), for patients with hypomethylating agent failure that is not reported here. Cohort A enrolled patients with newly diagnosed higher-risk myelodysplastic syndrome or chronic myelomonocytic leukaemia (aged 18-70 years old) with an Eastern Cooperative Oncology Group performance status of 0-1. Intravenous CPX-351 (100 mg/m2 cytarabine and 44 mg/m2 daunorubicin) was given on days 1, 3, and 5, with a second induction cycle given (same daily dose on days 1 and 3) if at least a partial response was not reached. Patients who responded could receive up to four monthly consolidation cycles (same daily dose on day 1) or allogeneic haematopoietic stem-cell transplantation (HSCT). Overall response rate after one or two induction courses according to European LeukemiaNet 2017 acute myeloid leukaemia was the primary endpoint after CPX-351 induction, whether patients received one or two induction cycles. Safety was assessed in all patients enrolled (in cohort A). This trial is registered with ClinicalTrials.gov, NCT04273802. FINDINGS: Between April 29, 2020, and Feb 10, 2021, 21 (68%) male and ten (32%) female patients were enrolled. 27 (87%) of 31 patients responded (95% CI 70-96). 16 (52%) of the 31 patients received at least one consolidation cycle. 30 (97%) of the 31 patients included were initially considered eligible for allogeneic HSCT and 29 (94%) of the 31 patients had the procedure. Median follow-up was 16·1 months (IQR 8·3-18·1). The most common grade 3-4 adverse events were pulmonary (eight [26%] of 31 patients) and cardiovascular (six [19%] of 31 patients). There were 14 serious adverse events (mainly hospitalisation for infection [n=5] and only one was treatment-related) and no treatment-related death. INTERPRETATION: CPX-351 appears to be active and safe in patients with higher-risk myelodysplastic syndrome and chronic myelomonocytic leukaemia, allowing bridging to allogenic HSCT in most patients. FUNDING: Jazz Pharmaceuticals.

UBTF tandem duplications define a distinct subtype of adult de novo acute myeloid leukemia.

Tandem duplications (TDs) of the UBTF gene have been recently described as a recurrent alteration in pediatric acute myeloid leukemia (AML). Here, by screening 1946 newly diagnosed adult AML, we found that UBTF-TDs occur in about 3% of patients aged 18-60 years, in a mutually exclusive pattern with other known AML subtype-defining alterations. The characteristics of 59 adults with UBTF-TD AML included young age (median 37 years), low bone marrow (BM) blast infiltration (median 25%), and high rates of WT1 mutations (61%), FLT3-ITDs (51%) and trisomy 8 (29%). BM morphology frequently demonstrates dysmyelopoiesis albeit modulated by the co-occurrence of FLT3-ITD. UBTF-TD patients have lower complete remission (CR) rates (57% after 1 course and 76% after 2 courses of intensive chemotherapy [ICT]) than UBTF-wild-type patients. In patients enrolled in the ALFA-0702 study (n = 614 patients including 21 with UBTF-TD AML), the 3-year disease-free survival (DFS) and overall survival of UBTF-TD patients were 42.9% (95%CI: 23.4-78.5%) and 57.1% (95%CI: 39.5-82.8%) and did not significantly differ from those of ELN 2022 intermediate/adverse risk patients. Finally, the study of paired diagnosis and relapsed/refractory AML samples suggests that WT1-mutated clones are frequently selected under ICT. This study supports the recognition of UBTF-TD AML as a new AML entity in adults.

Allogeneic transplantation in acute myelogenous leukemia: a comprehensive single institution's experience.

Debates on the role and timing of allogeneic hemtopoietic stem cell transplantation (HSCT) in acute myelogenous leukemia (AML) have persisted for decades. Time to transplant introduces an immortal time and current treatment algorithm mainly relies on the European LeukemiaNet disease risk classification. Previous studies are also limited to age groups, remission status and other ill-defined parameters. We studied all patients at diagnosis irrespective of age and comorbidities to estimate the cumulative incidence and potential benefit or disadvantage of HSCT in a single center. As a time-dependent covariate, HSCT improved overall survival in intermediate- and poor-risk patients (hazard ratio =0.51; P=0.004). In goodrisk patients only eight were transplanted in first complete remission. Overall, the 4-year cumulative incidence of HSCT was only 21.9% but was higher (52.1%) for patients in the first age quartile (16-57 years old) and 26.4% in older patients (57-70 years old) (P<0.001). It was negligible in patients older than 70 years reflecting our own transplant policy but also barriers to transplantation (comorbidities and remission status). However, HSCT patients need to survive, be considered eligible both by the referring and the HSCT physicians and have a suitable donor to get transplantation. We, thus, comprehensively analyzed the complete decision-making and outcome of all our AML patients from diagnosis to last followup to decipher how patient allocation and therapy inform the value of HSCT. The role of HSCT in AML is shifting with broad access to different donors including haploidentical ones. Thus, it may (or may not) lead to increased numbers of allogeneic HSCT in AML in adults.

Real-World Validation of Molecular International Prognostic Scoring System for Myelodysplastic Syndromes.

PURPOSE: Myelodysplastic syndromes (MDS) are heterogeneous myeloid neoplasms in which a risk-adapted treatment strategy is needed. Recently, a new clinical-molecular prognostic model, the Molecular International Prognostic Scoring System (IPSS-M) was proposed to improve the prediction of clinical outcome of the currently available tool (Revised International Prognostic Scoring System [IPSS-R]). We aimed to provide an extensive validation of IPSS-M. METHODS: A total of 2,876 patients with primary MDS from the GenoMed4All consortium were retrospectively analyzed. RESULTS: IPSS-M improved prognostic discrimination across all clinical end points with respect to IPSS-R (concordance was 0.81 v 0.74 for overall survival and 0.89 v 0.76 for leukemia-free survival, respectively). This was true even in those patients without detectable gene mutations. Compared with the IPSS-R based stratification, the IPSS-M risk group changed in 46% of patients (23.6% and 22.4% of subjects were upstaged and downstaged, respectively).In patients treated with hematopoietic stem cell transplantation (HSCT), IPSS-M significantly improved the prediction of the risk of disease relapse and the probability of post-transplantation survival versus IPSS-R (concordance was 0.76 v 0.60 for overall survival and 0.89 v 0.70 for probability of relapse, respectively). In high-risk patients treated with hypomethylating agents (HMA), IPSS-M failed to stratify individual probability of response; response duration and probability of survival were inversely related to IPSS-M risk.Finally, we tested the accuracy in predicting IPSS-M when molecular information was missed and we defined a minimum set of 15 relevant genes associated with high performance of the score. CONCLUSION: IPSS-M improves MDS prognostication and might result in a more effective selection of candidates to HSCT. Additional factors other than gene mutations can be involved in determining HMA sensitivity. The definition of a minimum set of relevant genes may facilitate the clinical implementation of the score.

Clonal hematopoiesis driven by chromosome 1q/MDM4 trisomy defines a canonical route toward leukemia in Fanconi anemia.

Fanconi anemia (FA) patients experience chromosome instability, yielding hematopoietic stem/progenitor cell (HSPC) exhaustion and predisposition to poor-prognosis myeloid leukemia. Based on a longitudinal cohort of 335 patients, we performed clinical, genomic, and functional studies in 62 patients with clonal evolution. We found a unique pattern of somatic structural variants and mutations that shares features of BRCA-related cancers, the FA-hallmark being unbalanced, microhomology-mediated translocations driving copy-number alterations. Half the patients developed chromosome 1q gain, driving clonal hematopoiesis through MDM4 trisomy downmodulating p53 signaling later followed by secondary acute myeloid lukemia genomic alterations. Functionally, MDM4 triplication conferred greater fitness to murine and human primary FA HSPCs, rescued inflammation-mediated bone marrow failure, and drove clonal dominance in FA mouse models, while targeting MDM4 impaired leukemia cells in vitro and in vivo. Our results identify a linear route toward secondary leukemogenesis whereby early MDM4-driven downregulation of basal p53 activation plays a pivotal role, opening monitoring and therapeutic prospects.

Myelodysplastic Syndrome associated TET2 mutations affect NK cell function and genome methylation.

Myelodysplastic syndromes (MDS) are clonal hematopoietic disorders, representing high risk of progression to acute myeloid leukaemia, and frequently associated to somatic mutations, notably in the epigenetic regulator TET2. Natural Killer (NK) cells play a role in the anti-leukemic immune response via their cytolytic activity. Here we show that patients with MDS clones harbouring mutations in the TET2 gene are characterised by phenotypic defects in their circulating NK cells. Remarkably, NK cells and MDS clones from the same patient share the TET2 genotype, and the NK cells are characterised by increased methylation of genomic DNA and reduced expression of Killer Immunoglobulin-like receptors (KIR), perforin, and TNF-α. In vitro inhibition of TET2 in NK cells of healthy donors reduces their cytotoxicity, supporting its critical role in NK cell function. Conversely, NK cells from patients treated with azacytidine (#NCT02985190; https://clinicaltrials.gov/ ) show increased KIR and cytolytic protein expression, and IFN-γ production. Altogether, our findings show that, in addition to their oncogenic consequences in the myeloid cell subsets, TET2 mutations contribute to repressing NK-cell function in MDS patients.

Consensus proposal for revised International Working Group 2023 response criteria for higher-risk myelodysplastic syndromes.

Myelodysplastic syndromes/myelodysplastic neoplasms (MDS) are associated with variable clinical presentations and outcomes. The initial response criteria developed by the International Working Group (IWG) in 2000 have been used in clinical practice, clinical trials, regulatory reviews, and drug labels. Although the IWG criteria were revised in 2006 and 2018 (the latter focusing on lower-risk disease), limitations persist in their application to higher-risk MDS (HR-MDS) and their ability to fully capture the clinical benefits of novel investigational drugs or serve as valid surrogates for longer-term clinical end points (eg, overall survival). Further, issues related to the ambiguity and practicality of some criteria lead to variability in interpretation and interobserver inconsistency in reporting results from the same sets of data. Thus, we convened an international panel of 36 MDS experts and used an established modified Delphi process to develop consensus recommendations for updated response criteria that would be more reflective of patient-centered and clinically relevant outcomes in HR-MDS. Among others, the IWG 2023 criteria include changes in the hemoglobin threshold for complete remission (CR), the introduction of CR with limited count recovery and CR with partial hematologic recovery as provisional response criteria, the elimination of marrow CR, and specific recommendations for the standardization of time-to-event end points and the derivation and reporting of responses. The updated criteria should lead to a better correlation between patient-centered outcomes and clinical trial results in an era of multiple emerging new agents with novel mechanisms of action.