bims-tremyl Biomed News
on Therapy resistance biology in myeloid leukemia
Issue of 2026–10–18
24 papers selected by
Paolo Gallipoli, Barts Cancer Institute, Queen Mary University of London



  1. Blood. 2026 Oct 13. pii: blood.2025030377. [Epub ahead of print]
      Phosphatase Mg2+/Mn2+ dependent 1D protein (PPM1D) is a serine threonine phosphatase known to regulate oncogenic pathways. PPM1D mutations are enriched in therapy-related MDS and AML, but the role of PPM1D in myeloproliferative neoplasms (MPN) remains largely unexplored. By sequencing 519 MPN patients, we detected activating PPM1D mutations in 3.1% of them. Importantly, PPM1D was overexpressed in hematopoietic stem and progenitor cells (HSPCs) in most PPM1D wild-type (WT) MPN cases. To elucidate the impact of PPM1D mutations on MPN HSPCs, we generated isogenic JAK2V617F+/PPM1D-WT and JAK2V617F+/PPM1D mutant (MUT) induced pluripotent stem cell (iPSC) lines from a MPN patient. Single-cell RNA-sequencing (scRNA-seq) of iPSC derived HSPCs revealed altered TP53, DNA damage response and cell cycle regulation. scRNA-seq analysis of primary PPM1D-MUT MPN patient mononuclear cells (MNCs) further confirmed upregulation of MYC, mTORC1, OXPHOS, JAK/STAT, and NF-κB pathways and corresponding genes in HSCs. The allosteric PPM1D inhibitor (PPM1Di) GSK2830371 preferentially inhibited colony formation in myelofibrosis (MF) samples. Combination treatment of GSK2830371 with low dose inhibition of HDM2, a negative regulator of p53, significantly improved targeting of JAK2V617F+ HSPCs, while sparing normal HSPCs. Single-cell mutational and protein analysis of a clonally complex MF patient sample treated with this combination strategy revealed reduced mutated clones and increased WT clones by >4-fold. Dual PPM1D and HDM2 targeting also significantly decreased leukemic burden in a xenograft MPN model. These findings support PPM1D as a critical MPN HSPCs regulator and support dual PPM1D/HDM2 inhibition as a treatment strategy for MF patients.
    DOI:  https://doi.org/10.1182/blood.2025030377
  2. Leukemia. 2026 Oct 13.
      Acute myeloid leukemia (AML) cells are highly dependent on mitochondrial activity for survival, with this metabolic reliance driven in part by BCL-2, which is therapeutically targeted by venetoclax-based therapies. The regulation of mitochondrial dynamics in leukemic cells is therefore essential for maintaining mitochondrial homeostasis. However, the mechanisms that enable selective degradation of damaged mitochondria (mitophagy) are still poorly understood in AML. In this study, we sought to elucidate the role of PTEN-induced putative kinase 1 (PINK1), a key sensor of mitochondrial stress, in regulating mitophagy in leukemic cells. Our results identified PINK1 as a central modulator of mitophagy. Genetic depletion of PINK1 reduced both basal and stress-induced mitophagy, leading to mitochondria accumulation and functional impairment. Additionally, we discovered that PINK1 stabilization during mitochondrial stress is regulated by Prohibitin 2 (PHB2), and that depletion or inhibition of PHB2 mirrored the biological effects of PINK1 loss. Notably, both genetic depletion of PINK1 or PHB2, as well as pharmacological inhibition of PHB2, significantly increased AML cell sensitivity to venetoclax both in vitro and in vivo. Together, these findings highlight the potential of targeting the PHB2/PINK1 signalling pathway to improve the efficacy of venetoclax-based therapies in AML by disrupting the mitophagy process.
    DOI:  https://doi.org/10.1038/s41375-026-03160-5
  3. Blood Adv. 2026 Oct 14. pii: bloodadvances.2026021650. [Epub ahead of print]
       BACKGROUND: Myelofibrosis (MF) is a myeloid bone marrow malignancy with a progressive clinical course marked by disease-related symptoms, splenomegaly, cytopenias, thrombosis/hemorrhage, and a risk for blast phase transformation. Treatment recommendations are based on the burden of symptoms, prognosis of the disease, and benefits/risks of each treatment modality.
    METHODS: ASH formed a multidisciplinary guideline panel that included specialists in myelofibrosis and hematopoietic cell transplantation, as well 2 patient representatives and was balanced to minimize potential bias from conflicts of interest. The Mayo Clinic Evidence-based Practice Center supported the guideline development process, including updating or performing systematic evidence reviews (up to January 31, 2025). The panel prioritized clinical questions and outcomes according to their importance for patients and clinicians. The panel used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, including GRADE Evidence-to-Decision frameworks, to assess evidence and make recommendations, which were subject to public comment.
    RESULTS: The panel agreed on 10 recommendations regarding prognostic testing, indications for interferon and JAK inhibitor therapy, management of MF-associated anemia, timing of transplantation, anti-platelet therapy, and iron chelation.
    CONCLUSIONS: Key recommendations of these guidelines include suggestions for extended molecular genetic testing; use of JAK-inhibition in symptomatic, lower risk MF patients; therapeutic strategies for patients with MF-anemia and JAK-inhibitor induced anemia; and considerations regarding hematopoietic cell transplantation including timing of referral and optimization prior to the procedure. Key future research agendas were identified for all recommendations.
    DOI:  https://doi.org/10.1182/bloodadvances.2026021650
  4. Blood. 2026 Oct 13. pii: blood.2026034923. [Epub ahead of print]
      Germline DDX41 variants are a recognized cause of adult myelodysplastic neoplasms (MDS), characterized by distinct biological features and favorable prognosis. The independent effect of DDX41 status on outcomes after allogeneic transplantation, the role of conditioning intensity, and treatment-related toxicity risk remain unresolved. To address this gap, we analyzed 1,514 patients with MDS undergoing transplantation prior to routine DDX41 testing alongside a wild-type comparator, providing an unbiased benchmark for this molecular subgroup. Forty-nine patients (3.2%) carried pathogenic/likely pathogenic (P/LP) germline DDX41 variants; 19 (39%) had an additional somatic DDX41 mutation, most commonly p.R525H. P/LP DDX41 cases were older (median 63 vs 59 years) and showed lower IPSS-M risk with absent TP53 mutations (0% vs 21%). In terms of outcome, 2-year relapse incidence was significantly lower in P/LP DDX41 (17% vs 34%, p=0.01). In multivariable analysis, the presence of a DDX41 P/LP variant independently associated with lower risk of relapse (hazard ratio 0.43, 95% CI 0.21-0.88; p=0.02), concentrated in the reduced-intensity/nonmyeloablative stratum. Adjusted models showed significantly improved disease-free survival (DFS) for P/LP DDX41 (hazard ratio 0.62, 95% CI 0.41-0.95; p=0.03) and no significant association with non-relapse mortality (NRM) or graft-versus-host disease (GVHD). In summary, these findings identify DDX41-associated MDS as a transplant subgroup with superior DFS regardless of conditioning intensity driven by reduced relapse risk and lack of excess NRM and GVHD supporting incorporation of germline DDX41 status into transplant planning.
    DOI:  https://doi.org/10.1182/blood.2026034923
  5. Blood. 2026 Oct 16. pii: blood.2026033409. [Epub ahead of print]
      RAS mutations are recurrent in acute myeloid leukemia (AML); yet, their genomic and clinical landscape remain poorly characterized. We analyzed centralized molecular profiling data in 8,553 patients with newly diagnosed AML. Of these, 1,775 (21%) harbored RAS mutations: NRAS in 1,103 (13%), KRAS in 445 (5%), and both in 227 (3%). RAS mutations primarily clustered in P-loop hotspots (G12/G13, 70%), with NRAS showing higher Q61 mutation prevalence (24% vs. 9%) and KRAS showing additional K117/A146 hotspots. Multiple RAS mutations occurred in 23% of patients. Convergent evolution of RAS signaling mutations emerged as a key feature of RASmut AML. RTK/RAS pathway mutations were non-uniformly enriched: PTPN11, KIT and FLT3-TKD mutations were positively associated, CBL mutations showed no association, and FLT3-ITD mutations were negatively associated. The prognostic impact of RAS mutations was dependent on the genomic background and treatment. In multivariate analyses in intensively treated patients, NRAS mutations showed opposing associations with overall survival (OS): adverse in patients with AML, myelodysplasia-related (HR=1.32, p=0.036) and favorable in those with NPM1 (HR=0.61, p=0.036) or FLT3-ITD (HR=0.63, p=0.048) mutations, among others. KRAS mutations predicted inferior OS (HR=1.41; p=0.003). In patients treated with non-intensive, venetoclax-based regimens, RAS mutations were associated with markedly inferior OS in patients with NPM1 (HR=2.98, p=0.007) or IDH1/2 mutations (HR=4.06, p<0.001). These data inform risk stratification and development of RAS-targeting strategies in AML.
    DOI:  https://doi.org/10.1182/blood.2026033409
  6. Leuk Res. 2026 Oct 13. pii: S0145-2126(26)00187-6. [Epub ahead of print]171 108343
      Megakaryocytes (Mks) are haematopoietic cells responsible for platelet production. They arise from haematopoietic stem cells (HSCs) through a differentiation process known as megakaryopoiesis, which is classically viewed as occurring in a stepwise manner. However, recent studies have challenged this model, suggesting an alternative direct differentiation route producing functionally distinct Mk subtypes. Understanding this process is important, as dysregulation can lead to the development of diseases such as paediatric acute megakaryoblastic leukaemia (AMKL). This is a rare subtype of acute myeloid leukaemia (AML) that has a significantly worse prognosis compared to other AML subtypes. Accurate classification of AML increasingly relies on an integrated genetic and immunophenotypic diagnostic pathway. The poor prognosis of AML is largely driven by the presence of therapy-resistant leukaemia stem cells (LSCs). Furthermore, LSCs are often resistant to targeted therapies like the BCL-2 inhibitor venetoclax, yet they show a distinct dependency on other proteins within the same apoptosis pathway, notably BCL-XL. Therefore, this review aims to summarise current knowledge on normal megakaryopoiesis and explore how its dysregulation contributes to LSC emergence in paediatric AMKL, while also highlighting the therapeutic implications of both BCL-XL dependency and emerging subtype-specific therapies.
    Keywords:  Acute megakaryocytic leukaemia; Leukaemia stem cells; Megakaryocytes; Megakaryopoiesis
    DOI:  https://doi.org/10.1016/j.leukres.2026.108343
  7. bioRxiv. 2026 Sep 29. pii: 2026.09.28.755049. [Epub ahead of print]
      TNFα is the primary age-related cytokine responsible for hyperreactive platelet formation. In mouse models, increased TNFα induced abnormal megakaryocyte development and platelet activity. Here, we extend these findings to demonstrate that TNFα drives this thrombotic phenotype through expansion of the hematopoietic stem and progenitor cell (HSPCs) compartment. Using HSPC-specific TNFα receptor labeling and single cell RNA sequencing, we found that TNFα receptors are absent from megakaryocytes and their progenitors (MkPs) indicating that TNFα does not directly act on these cells. Chronic TNFα exposure expanded HSPCs in the bone marrow and extramedullary tissues - and these expanded HSPCs retained functional repopulation capacity. Using species-specificity TNFα receptor activation, we further demonstrate that TNFαR1 signaling is sufficient to induce platelet hyperreactivity independent of HSPC expansion. Unlike emergency hematopoiesis, chronic TNFα promoted megakaryopoiesis through the canonical hematopoietic hierarchy as demonstrated by lineage-tracing studies. Mechanistically, chronic TNFα induced a distinct transcriptional program in single cell RNA sequencing of HSPCs and megakaryocytes. Together, these findings establish that chronic TNFα promotes hyperreactive platelet formation not through direct effects on megakaryocytes or MkPs but by expanding and transcriptionally reprogramming HSPCs, thereby imprinting a TNFα dependent program that persists through megakaryopoiesis and ultimately produces hyperreactive platelets.
    Key Points: Chronic TNFα exposure drives HSC expansion and myeloid biasing of progenitors.TNFα regulates platelet hyperreactivity by signaling through HSPCs, not Mks.
    DOI:  https://doi.org/10.64898/2026.09.28.755049
  8. Leukemia. 2026 Oct 16.
      Chronic myeloid leukemia (CML) is driven by the constitutively active BCR::ABL1 kinase, which promotes uncontrolled cell proliferation. Although protein-tyrosine kinase inhibitors (TKIs) have revolutionized CML treatment, resistance remains a significant barrier to curative therapy, particularly due to BCR::ABL1 mutations and the persistence of leukemia stem cells (LSCs). New treatment strategies that directly inhibit BCR::ABL1 protein expression are needed to achieve more effective therapy. Using a high-content antibody microarray and bioinformatics analyses, we investigated differences in the proteome and phosphorylation landscape of Imatinib (IM)-resistant cells and identified highly activated members of the eukaryotic translation initiation complex (eIF4F), particularly eIF4G1, a core component of eIF4F. These eIF4F complex members are highly expressed and activated in CD34+ CML stem/progenitor cells and in IM-resistant cells. Genetic inhibition of eIF4G1 or pharmacological targeting with the small-molecule inhibitor SBI-756 diminished eIF4F complex assembly, reduced overall translation initiation, reduced BCR::ABL1 expression and key downstream targets, impaired the survival of nonresponder stem/progenitor cells, including BCR::ABL1-T315I mutant cells, and sensitized them to TKIs, with strong synergistic effects in vitro and in a PDX model. These findings underscore the potential of eIF4F complex inhibition as a new therapeutic strategy to overcome TKI resistance in CML and other BCR::ABL1+ malignancies.
    DOI:  https://doi.org/10.1038/s41375-026-03157-0
  9. EClinicalMedicine. 2026 Oct;100 104238
       Background: Clonal haematopoiesis is a precursor of myeloid neoplasia and common in older adults, Precursor risk stratification is critical to early cancer detection, guiding surveillance and prevention efforts to high-risk populations. Existing clonal haematopoiesis risk scores use molecular features to estimate risk of myeloid neoplasia, but only around 1% of adults with detectable clonal haematopoiesis are at high risk of myeloid neoplasia transformation. Moreover, sequencing based molecular diagnostics are expensive with limited global availability highlighting the need for pre-sequencing strategies which identify populations enriched for individuals with high-risk clonal haematopoiesis.
    Methods: We used blood count parameters, age, and sex as input features to and develop a multi-class machine learning model that pre-classifies individuals based on their probability of having high-risk clonal haematopoiesis or developing future myeloid neoplasia. Stratified splitting was used to divide 461,576 eligible UK Biobank participants (recruited October 1, 2006 to March 13, 2010) into a training cohort for model derivation (n = 369,260) and a test cohort for internal validation (n = 92,316). Ground truth output class assignments were defined based on documented progression to incident myeloid neoplasia and presence of clonal haematopoiesis with high-risk features defined using molecular parameters of the clonal haematopoiesis risk score. Individuals were labelled positive if they had high-risk clonal haematopoiesis and progressed to myeloid neoplasia, negative if they lacked clonal haematopoiesis with high-risk features, and equivocal if they had higher risk features but had no documented incident myeloid neoplasia event. We then compared model predictions against ground truth labels for validation in the UKB test cohort as well as in independent clinical and population cohorts from Dana-Farber Cancer Institute Hematologic Malignancy Data Repository (HMDR; n = 2233; March 26, 2010, to June 5, 2024) and the All of US database (n = 14,674; May 31, 2017 to October 1, 2023), respectively.
    Findings: The resulting pre-sequencing risk model (PRISM) categorises all cases of high-risk clonal haematopoiesis as positive and pre-classifies 40% (2158 of 5383) of low-risk clonal haematopoiesis and 55% (47,894 of 86,429) of clonal haematopoiesis-negative cases as negative. Validation of PRISM revealed an area under the curve of 0.89 (95% CI 0.85-0.93) in the UK Biobank test cohort, 0.74 (0.61-0.84) in HMDR, and 0.87 (0.77-0.96) in All of US. Negative predictive values for negative class assignments were 0.993 (95% CI 0.992-0.993) in the UKB test cohort, 0.968 (0.943-0.981) in HMDR, and 0.998 (0.997-0.999) in All of US.
    Interpretation: PRISM positive class assignment defines a population most enriched for high-risk clonal haematopoiesis, while negative class predictions, mark individuals without high-risk clonal haematopoiesis. PRISM therefore provides a framework for reproducibly assigning blood count-based risk thresholds to prioritise clonal haematopoiesis screening in populations at risk for myeloid neoplasia.
    Funding: Damon Runyon Cancer Research Foundation, Edward P Evans Foundation for MDS, and the National Heart Lung and Blood Institute.
    Keywords:  Blood counts; Clonal haematopoiesis; High-risk clonal haematopoiesis; Myeloid neoplasia; PRISM; Pre-sequencing risk model
    DOI:  https://doi.org/10.1016/j.eclinm.2026.104238
  10. Blood. 2026 Oct 13. pii: blood.2026034288. [Epub ahead of print]
      Hematopoietic stem cell transplantation is limited not only by donor cell number and recipient conditioning, but also by loss of stem-cell fitness during collection and processing. Hematopoietic stem and progenitor cells normally reside in a physiologically hypoxic marrow environment, yet routine ex vivo handling exposes them to ambient oxygen outside this niche. Although ambient oxygen exposure during ex vivo handling impairs hematopoietic stem cell (HSC) function, the metabolic basis for this effect remains incompletely defined. Using hypoxic handling as a physiologic reference, we examined whether functionally relevant consequences of ambient oxygen exposure remain modifiable in human CD34+ cells during ex vivo handling. Quantitative LC-MS profiling revealed that ambient oxygen exposure rapidly increased intracellular amino acids, including branched-chain amino acids, together with activation of nutrient-sensing pathways. This metabolic shift was associated with increased mTORC1 signaling, attenuation of lysosomal programs, and impaired primary and secondary engraftment. Complementary single-cell analyses supported a coordinated transition toward nutrient-activated states under ambient oxygen, whereas hypoxia preserved relative metabolic restraint. Transient restriction of essential amino acids or branched-chain amino acids during ex vivo handling restored lysosomal programs and improved engraftment of normoxia-handled human CD34+ cells. Pharmacologic LAT1 inhibition similarly improved engraftment. Together, these findings identify disruption of amino acid homeostasis as a previously underappreciated consequence of ambient oxygen exposure during routine ex vivo handling and demonstrate that a functionally relevant component of this injury remains modifiable after exposure to improve human HSPC engraftment.
    DOI:  https://doi.org/10.1182/blood.2026034288
  11. EMBO J. 2026 Oct 14.
      Fusion oncoproteins drive aggressive leukemias by mediating aberrant gene expression within specialized biomolecular condensates that contain various biomolecules. While RNA is known to influence condensate properties, the RNA constituents of fusion protein-containing onco-condensates remain poorly defined. Here, we use bicon-seq (biotinylated-isoxazole-mediated precipitation of condensome and RNA sequencing) to globally profile condensate-associated RNAs from cellular samples. Using experimental perturbation of cytoplasmic RNA-containing condensates, we demonstrated that bicon-seq accurately quantifies changes in RNA solubility, that correlate with published RNA enrichment in these structures. In leukemia cells driven by the NUP98::KDM5A fusion oncoprotein, bicon-seq revealed highly conserved long non-coding RNAs (lncRNAs) that are associated with NUP98::KDM5A onco-condensates. Among them, the lncRNA Gas5 was highly expressed and essential for the proliferation of AML cells. Mechanistically, Gas5 co-localized with NUP98::KDM5A in condensates and modulated NUP98::KDM5A chromatin binding and the expression dynamics of differentiation/apoptosis-associated genes in AML cells. Together, our results introduce a novel approach to systematically profile condensate-associated RNAs and identify the lncRNA Gas5 as a critical regulator of NUP98::KDM5A-driven transcription in AML cells.
    DOI:  https://doi.org/10.1038/s44318-026-00926-6
  12. Clin Lymphoma Myeloma Leuk. 2026 Sep 25. pii: S2152-2650(26)03981-9. [Epub ahead of print]
      The treatment paradigm for fit, younger adults with acute myeloid leukemia (AML) is evolving toward the frontline use of lower-intensity, better-tolerated therapies that more effectively target disease biology. For over 45 years, intensive chemotherapy (IC) has endured as the cornerstone of induction therapy for fit AML patients. Clinical outcomes have slowly improved during this time; however, long-term survival remains suboptimal, and IC-related toxicity is significant. For older AML patients, clinical outcomes have been transformed by the introduction of hypomethylating agents in combination with venetoclax (HMA-Ven) because of its potent anti-leukemic activity and improved tolerability. The success of HMA-Ven highlights the importance of rationally designed therapies that exploit leukemia dependencies while minimizing systemic toxicity. We outline the development of IC and HMA-Ven while also describing the first studies to directly compare these distinct modalities in younger patients. We explore growing evidence that guides the use of lower-intensity therapy in younger AML patients who would traditionally receive IC but may achieve favorable outcomes using HMA-Ven. When considering the use of HMA-Ven in younger patients, we highlight several important issues including the need for improved patient selection for HMA-Ven, optimal implementation of HMA-Ven in patients planned for allogeneic stem cell transplant (HCT), evaluation of post-HCT outcomes following induction using HMA-Ven, utilization of measurable residual disease (MRD) during treatment with HMA-Ven, and the prospect of triple combinations incorporating novel targeted agents.
    Keywords:  Azacitidine; Decitabine; Hypomethylating agent; Induction chemotherapy; Venetoclax
    DOI:  https://doi.org/10.1016/j.clml.2026.09.016
  13. Nat Commun. 2026 09 12. pii: 10765. [Epub ahead of print]17(1):
      Somatic mutations in the de novo methyltransferase DNMT3A and cytosine demethylase TET2 are common in age-related clonal hematopoiesis and hematopoietic neoplasms. TET2 mutations, unlike DNMT3A mutations, increase sensitivity to PARP inhibitors (PARPi). We find that TET2 loss, but not DNMT3A loss, alters DNA replication fork progression upon treatment with PARPi Olaparib, resulting in longer DNA replication tracts and increased DNA breaks. This reveals a new link between abnormal fork elongation and PARPi sensitivity in TET2-deficient cells. The elongated forks of TET2-deficient cells contain PRIMPOL-dependent single-stranded (ss)-DNA gaps. This phenotype is dependent on the catalytic activity of TET2 and is mitigated by TET1/3 depletion. Furthermore, TET2 loss causes an imbalance in cytosine methylation and an increase in 5hmU modifications. These modifications are processed by SMUG1, creating abasic sites, detectable via a modified DNA fiber method. A CRISPR screen identified the base excision repair nuclease APE1 as linked to increased PARPi sensitivity in TET2-deficient cells. We propose that abasic sites, skipped by PRIMPOL repriming, lead to ssDNA gaps that are converted into DNA breaks by APE1, increasing PARPi toxicity. Finally, we identify TET2 mutations as an unrecognized predictor of PARPi response in bone marrow samples from patients with myeloid malignancies.
    DOI:  https://doi.org/10.1038/s41467-026-77587-w
  14. Cancer Res Commun. 2026 Oct 12.
      NAMPT, a key enzyme in NAD biosynthesis, is a potential therapeutic target in cancer. Acute myeloid leukemia (AML) is among cancer types exhibiting high NAMPT dependence, and elevated NAMPT activity is implicated in venetoclax resistance. Thus, pharmacological NAMPT inhibitors (NAMPTi) have been developed as a promising therapeutic approach in some cancers. However, our current knowledge of in vivo factors that determine NAMPTi therapeutic efficacy is incomplete. Here, using mouse models we found that NAMPTi efficacy against AML is limited by dietary nicotinic acid (NA). Specifically, NA and nicotinic acid riboside (NAR), an NA-derived metabolite, promoted NAD biosynthesis independent of NAMPT and rescued AML cells from NAMPTi-mediated toxicity in vitro. Importantly, in AML xenograft models, dietary NA restriction, which selectively reduces circulating NAR levels, enhanced antitumor efficacy of NAMPTi and prolonged animal survival. Although the combination treatment caused transient hematological toxicity, peripheral blood cell counts largely recovered after treatment. Our findings highlight systemic NAD precursor metabolism, including NAR, as a determinant of responses to NAMPT-targeted therapies. We conclude that NA restriction may improve the therapeutic efficacy of NAMPT inhibitors in AML.
    DOI:  https://doi.org/10.1158/2767-9764.CRC-26-0274
  15. Cell Stem Cell. 2026 Oct 13. pii: S1934-5909(26)00347-4. [Epub ahead of print]
      Mapping how genetic perturbations influence cell fate is key to understanding human development and disease. Here, we developed a massively parallel single-cell CRISPR (scCRISPR) screening platform in primary human hematopoietic stem and progenitor cells (HSPCs), profiling 322 regulators across 172,382 single-perturbed cells. The resulting multi-layered regulatory framework captured known associations and enabled functional annotation of regulator-phenotype relationships. Specifically, our atlas revealed that regulators acted within perturbation clusters to govern distinct gene programs that shaped cell fate. As proof of concept, we illustrated several examples. SMYD3 emerged as a negative regulator of long-term regenerative capacity. Analysis of lineage output further identified KMT5B, TRIM24, SETD7, and NSD3 as regulators associated with lineage-biased outputs. Finally, integration with clinical datasets identified PRDM10 as a candidate dependency in acute myeloid leukemia (AML). This work establishes a scalable functional genomics platform in a primary human stem cell system.
    Keywords:  acute myeloid leukemia; epigenetic regulation; functional genomics; hematopoietic differentiation; hematopoietic stem and progenitor cells; human hematopoiesis; lineage output; single-cell CRISPR screening
    DOI:  https://doi.org/10.1016/j.stem.2026.09.005
  16. Hemasphere. 2026 Oct;10(10): e70498
      Hypomethylating agents (HMAs) combined with Venetoclax have reshaped the therapeutic landscape of acute myeloid leukemia (AML), yet the biological determinants of response remain unclear. We integrated clinical and genomic profiling in 132 newly diagnosed or relapsed/refractory AML patients treated with HMA-Venetoclax and performed single-cell RNA sequencing and T cell receptor (TCR) profiling in 10 newly diagnosed cases to define cellular and immune correlates of response. Response rates and survival aligned with published data. DNA Sequencing confirmed the favorable impact of IDH2 and the poor prognosis of TP53 mutations. scRNA-seq and TCR analysis showed that responders exhibited expansion of cytotoxic CD8+ T cells, increased TCR clonal diversity, and activation of antigen-presentation pathways. Nonresponders displayed baseline inflammatory signaling, impaired myeloid maturation, and a suppressive microenvironment enriched in IDO1+ dendritic cells. Resistant AMLs showed stem-like dedifferentiation and sustained EMT. LAG-3 expression marked dysfunctional T cell states and emerged as a potential biomarker and therapeutic target.
    DOI:  https://doi.org/10.1002/hem3.70498
  17. Blood Rev. 2026 Oct 01. pii: S0268-960X(26)00075-5. [Epub ahead of print] 101436
      BCR::ABL1 tyrosine kinase inhibitors (TKIs) have transformed the treatment landscape of chronic-phase chronic myeloid leukemia, normalizing life expectancy for most patients. However, potential ABL1 kinase domain mutation-driven treatment resistance and intolerance are perennial clinical challenges. For frontline therapy, generically available first-generation BCR::ABL1 TKI imatinib is a rational and cost-effective approach to optimize survival. Second-line options are more likely to elicit deep molecular responses and treatment-free remission. However, achievement of these milestones has not been associated with improved overall survival as compared with imatinib. The "gatekeeper" T315I ABL1 kinase domain mutation confers resistance to imatinib and all second-generation TKIs. For patients with this mutation and/or resistance or intolerance to prior TKIs, third-generation ponatinib, first-in-class specifically targeting the Abl myristoyl pocket inhibitor asciminib, or (upon regulatory approval) potentially olverembatinib may be appropriate alternatives. Considerable finesse is warranted to tailor a range of efficacious and well-tolerated therapies to the individual needs of patients.
    Keywords:  BCR::ABL1; Chronic myeloid leukemia; Efficacy; Safety; Tyrosine kinase inhibitors
    DOI:  https://doi.org/10.1016/j.blre.2026.101436
  18. Haematologica. 2026 Oct 15.
      CAR NK cell therapy is expected to be developed to treat acute myeloid leukemia (AML). C-type lectin-like molecule 1 (CLL-1) is a candidate target. However, AML cells with minimal CLL-1 expression (CLL-1dim) may not be eliminated by CAR NK cells. Here we demonstrate that cord blood (CB)-derived NK cells transduced with a novel high-affinity CAR that recognizes CLL-1 can eliminate CLL-1dim AML cells. A newly established anti- CLL-1 monoclonal antibody (mAb) designated as 2-23 exhibits a higher affinity for CLL- 1 than the widely used anti-CLL-1 mAb M26. CB-derived NK cells transduced with a CAR derived from 2-23, but not M26, killed CLL-1dim AML cells in vitro. Additionally, treatment with 2-23 CAR NK cells, but not M26 CAR NK cells, significantly enhanced the survival of the mice transplanted with CLL-1dim AML cells in vivo. Furthermore, in AML patient-derived xenograft models, the 2-23 CAR NK cells expanded robustly, persisted, and eradicated AML cells.
    DOI:  https://doi.org/10.3324/haematol.2026.301327
  19. bioRxiv. 2026 Sep 29. pii: 2026.09.28.755094. [Epub ahead of print]
      Stem cell factor (SCF) from Leptin Receptor-expressing (LepR + ) mesenchymal stromal cells and endothelial cells is required for hematopoietic stem and progenitor cell maintenance in bone marrow. Consistent with this, Scf is highly expressed by LepR + cells and at lower levels by endothelial cells in bone marrow. However, endothelial cells outside the bone marrow produce circulating SCF, raising the question of whether the SCF that promotes stem and progenitor cell maintenance is produced inside or outside bone marrow. We found that Scf deletion in spleen and liver endothelial cells reduces SCF levels in the blood without affecting stem or progenitor numbers in the bone marrow. Moreover, deletion of Scf from mesenchymal cells in the long bones, but not vertebrae, of Prx1 Cre ; Scf fl/fl mice depletes stem and progenitor cells in long bones but not vertebrae. SCF thus acts locally within the bones in which it is made to promote stem and progenitor cell maintenance.
    Key Points: Scf deletion in endothelial cells outside of BM reduces SCF levels in blood without affecting stem or progenitor cell frequencies in BM Scf deletion from mesenchymal cells in long bones, but not vertebrae, depletes stem and progenitor cells in long bones but not vertebrae.
    DOI:  https://doi.org/10.64898/2026.09.28.755094
  20. J Clin Oncol. 2026 Oct 13. JCO2600992
    VERIFY Investigators
       PURPOSE: Polycythemia vera (PV) is a myeloproliferative neoplasm characterized by erythrocytosis. Rusfertide is a subcutaneous, injectable, hepcidin mimetic peptide that suppresses erythrocytosis. The phase III VERIFY trial evaluated the efficacy and safety of rusfertide in phlebotomy-dependent patients with PV and poorly controlled hematocrit.
    METHODS: In VERIFY Part 1a (32 weeks), patients requiring frequent phlebotomy were randomly assigned (1:1, double-blind) to receive rusfertide or placebo with or without cytoreductive therapy. The primary efficacy end point was clinical response (absence of phlebotomy eligibility; weeks 20-32). Key secondary end points (baseline to week 32) included mean number of phlebotomies, proportion of patients who maintained hematocrit <45%, and mean change from baseline in patient-reported outcomes (Patient-Reported Outcomes Measurement Information System [PROMIS] Fatigue Short Form 8a [SF-8a] T score and Myelofibrosis Symptom Assessment Form [MFSAF] Total Symptom Score-7 items [TSS7]).
    RESULTS: Patients (N = 293) were randomly assigned to rusfertide (n = 147) or placebo (n = 146). Significantly more patients (n = 113, 77%) achieved a clinical response with rusfertide versus placebo (n = 48; 33%; P < .0001). Compared with placebo, rusfertide reduced mean ± standard deviation number of phlebotomies (0.5 ± 1.2 v 1.8 ± 1.5; P < .0001) and was superior in maintaining hematocrit <45% (n = 92 [63%] v n = 21 [14%]; P < .0001). Rusfertide led to a significant improvement in the PROMIS Fatigue SF-8a T-score and MFSAF TSS7 versus placebo (P = .0252 and .0240, respectively). Injection site reactions, anemia, and fatigue were the most common adverse events. No deaths were reported.
    CONCLUSION: Rusfertide significantly improved hematocrit control, reduced the need for phlebotomy, and improved patient-reported symptoms versus placebo in phlebotomy-dependent patients with PV who were also receiving standard-of-care therapy.
    DOI:  https://doi.org/10.1200/JCO-26-00992
  21. Transplant Cell Ther. 2026 Oct 16. pii: S2666-6367(26)00807-9. [Epub ahead of print]
    GETH-TC
       BACKGROUND: Cardiac events after allogeneic hematopoietic cell transplantation (allo-HCT) are associated with increased non-relapse mortality (NRM) and inferior survival. The CARE-BMT score predicts cardiovascular events after hematopoietic cell transplantation but does not incorporate post-transplant cyclophosphamide (PTCy). We aimed to externally validate the original CARE-BMT score and a modified version incorporating standard-dose PTCy exposure in patients with acute myeloid leukemia (AML) undergoing allo-HCT.
    METHODS: We conducted a retrospective multicenter study including 809 adults with AML who underwent first allo-HCT across 11 Spanish transplant centers. The original and modified CARE-BMT scores were retrospectively applied. The primary endpoint was the cumulative incidence of post-transplant cardiac events, with relapse and death considered competing risks.
    RESULTS: Sixty patients developed a cardiac event, corresponding to a cumulative incidence of 6.9% (95% CI, 5.2-8.8). Cardiac events were associated with inferior 3-year overall survival (50.1% vs 62.5%; P = 0.001) and higher 3-year NRM (21.3% vs 6.2%; P = 0.001). Using the original CARE-BMT score, patients were classified as intermediate-risk (n = 246) or high-risk (n = 563), with no low-risk patients identified. Cardiac event incidence was higher in the high-risk group (8.6% vs 3.0%; HR, 2.89; P = 0.005). The modified CARE-BMT score classified patients as low-risk (n = 85), intermediate-risk (n = 558), or high-risk (n = 166), with progressively increasing cardiac event incidence (2.4%, 6.1%, and 11.8%, respectively; P = 0.011). High-risk patients had a significantly greater risk of cardiac events than low-risk patients (HR, 5.37; P = 0.024).
    CONCLUSIONS: In this AML allo-HCT cohort, cardiac events occurred in approximately 7% of patients and were associated with worse survival and increased NRM. Incorporating standard-dose PTCy improved risk stratification, supporting inclusion of transplant-specific variables in cardiovascular risk prediction after allo-HCT.
    Keywords:  Acute myeloid leukemia; CARE-BMT; allogeneic hematopoietic cell transplantation; cardio-oncology; cardiotoxicity; post-transplant cyclophosphamide
    DOI:  https://doi.org/10.1016/j.jtct.2026.10.018