bims-tremyl Biomed News
on Therapy resistance biology in myeloid leukemia
Issue of 2025–06–01
35 papers selected by
Paolo Gallipoli, Barts Cancer Institute, Queen Mary University of London



  1. Am J Hematol. 2025 May 30.
      According to the European LeukemiaNet (ELN) 2022 classification, acute myeloid leukemia (AML) patients with intermediate or adverse risk are offered allogeneic hematopoietic stem cell transplantation (allo-HSCT) in first remission. In this EBMT study, we included 1735 adult AML patients with ELN-2022 adverse-risk cytogenetics allografted between 2010 and 2022 in first remission (67% de novo AML, median age 56 years). Eleven non-overlapping adverse-risk cytogenetics groups were defined. The five most frequent were: Group 1 [n = 394; monosomy 17 or abn(17p); 2-year leukemia-free survival (LFS) 22%, and overall survival (OS) 25%]; Group 2 [n = 313; complex karyotype (CK) involving monosomy 5, monosomy 7, or del(5q) without monosomy 17 or abn(17p); LFS 27%, OS 37%]; Group 3 [n = 201; monosomy 5, monosomy 7, or del(5q) without CK and without monosomy 17 or abn(17p); LFS: 55%, OS: 63%]; Group 4 [n = 256; CK without monosomal karyotype (MK) or adverse additional cytogenetic abnormalities (ACA); LFS 50%, OS 61%]; Group 5 [n = 213; t(v, 11q23) without adverse ACA; LFS 50%, OS 59%]. In multivariable analysis, compared to CK without adverse ACA, LFS was negatively affected by monosomy 17 or 17p abnormalities, monosomy 5, 7, or del(5q) in the presence of CK, and t(8;16). In conclusion, this study revealed a very poor outcome of allografted AML patients with monosomy 17 or 17p abnormalities or CK involving monosomy 5, monosomy 7, and del5q. Outcomes were relatively favorable for most other ELN 2022 adverse categories, including CK with or without MK other than 5, 7, and 17, indicating that allo-HSCT can overcome their poor outcome.
    Keywords:  AML; ELN 2022 risk stratification; allogeneic hematopoietic stem cell transplantation (allo‐HSCT); complex karyotype; cytogenetic risk groups
    DOI:  https://doi.org/10.1002/ajh.27726
  2. Am J Hematol. 2025 May 29.
      CPX-351 has similar efficacy but more toxicity compared to venetoclax+hypomethylating agent therapy.
    Keywords:  mutations; myelodysplasia; survival; therapy‐related
    DOI:  https://doi.org/10.1002/ajh.27730
  3. Blood Adv. 2025 May 29. pii: bloodadvances.2024014916. [Epub ahead of print]
      Hematopoietic stem cells (HSC) rapidly expand during fetal development and after stress. Here, we identify BCLAF1 as a regulator of HSC repopulation activity with functions in expansion of fetal HSCs and hematopoietic reconstitution after stem cell transplantation. Using mice with hematopoietic-specific and inducible deletion of Bclaf1, we find that BCLAF1 promotes fetal HSC development but is dispensible for maintenance of adult HSCs at steady state. Loss of BCLAF1 in either fetal or adult HSCs significantly impairs their self-renewal and multi-lineage reconstitution activity after stem cell transplantation. Single-cell RNA sequencing of fetal hematopoietic progenitors reveals that loss of BCLAF1 reduces long-term HSCs and restrains expression of stress response genes. BCLAF1 associates with chromatin throughout the genome of fetal and adult hematopoietic cells, likely through indirect mechanisms, to regulate transcriptional programs. These results establish a novel function for the transcriptional regulator BCLAF1 in limiting stress responses in HSCs to preserve HSC development during embryogenesis and repopulation function after stem cell transplant.
    DOI:  https://doi.org/10.1182/bloodadvances.2024014916
  4. Leukemia. 2025 May 28.
      The European LeukemiaNet recently proposed specific Clinical Signs and Symptoms (CSSs) that may trigger cytoreduction in patients with polycythemia vera (PV) at low thrombotic risk (LR). To evaluate the impact of CSSs on the thrombotic risk of patients at LR, high risk by age only (HR-AGE) or by previous thrombosis (HR-THRO), we conducted a multicenter cooperative study (NCT06134102) involving 739 PV patients treated with first-line hydroxyurea. At hydroxyurea start, 443 patients had at least one CSS. In patients with and without CSSs, the incidence rate ratio of thrombosis was 2.2 and 0.7 per 100 patient-years, respectively (p < 0.001), and the thrombosis-free survival (TFS) adjusted for delayed entry at 5 years was 88.7% and 96.1% (p < 0.001). The best 5-years TFS was observed in LR and HR-AGE with no CSSs (LR, 100%; HR-AGE: 98.1%). LR, HR-AGE patients with CSSs and HR-THRO patients without CSSs had comparable TFS (89.2%, 92.1% and 88.8%, respectively). TFS of HR-THRO patients was 80.2%. In multivariate analysis including each CSS, inadequate hematocrit control (HR: 2.32, p < 0.001), relevant CVRFs (HR: 2.87, p = 0.006), progressive splenomegaly (HR: 4.02, p = 0.03) and previous thrombosis (HR: 3.76, p < 0.001) remained significantly associated with thrombotic risk. CSSs identify an increased thrombotic risk phenotype across all risk categories.
    DOI:  https://doi.org/10.1038/s41375-025-02646-y
  5. J Clin Invest. 2025 May 27. pii: e189266. [Epub ahead of print]
      Anemia is the primary clinical manifestation of myelodysplastic syndromes (MDS), but the molecular pathogenesis of ineffective erythropoiesis remains incompletely understood. Luspatercept, an activin receptor 2B (ACVRIIB-Fc) ligand trap, has been approved to treat anemia, however its molecular mechanism of action is unclear. We found that the ACVR2B, its ligand GDF11, and effector, SMAD2, are upregulated in MDS patient samples. GDF11 inhibited human erythropoiesis in vitro and caused anemia in zebrafish, effects that were abrogated by luspatercept. Upon GDF11 stimulation of human erythroid progenitors, SMAD2 binding occurred in the erythroid regulatory regions, including at GATA1 intron. Intronic SMAD2 binding led to skipping of exon 2 of GATA1, resulting in a shorter, hypomorphic isoform (GATA1s). CRISPR deletion of the SMAD2 binding intronic region decreased GATA1s production upon GDF11 stimulation. Expression of gata1s in a mouse model led to anemia, rescued by a murine ActRIIB-Fc (RAP-536). Finally, RNA-seq analysis of samples from the Phase 3 MEDALIST trial revealed that responders to Luspatercept had a higher proportion of GATA1s compared to non-responders. Moreover, the increase RBCs post-treatment was linked to a relative decrease in GATA1s isoform. Our study indicates that GDF11-mediated SMAD2 activation results in an increase in functionally impaired GATA1 isoforms, consequently contributing to anemia and influencing responses to Luspatercept in MDS.
    Keywords:  Cell biology; Hematology; Hematopoietic stem cells
    DOI:  https://doi.org/10.1172/JCI189266
  6. Br J Haematol. 2025 May 26.
      Real-world data (RWD) previously contributed to post-marketing regulatory decision-making, but are currently also considered as external controls to single-arm trials. The use of RWD control data may be compromised by methodological issues, urging validation of RWD control cohorts. Two external control cohorts of newly diagnosed acute myeloid leukaemia patients, one registered by the HARMONY Alliance (HA) and one by the Netherlands Cancer Registry (NCR), were compared to the control arm of the randomized HOVON-103 trial (H103 controls). All patients, aged >65 years with a WHO performance score of 0-2 (or missing), received standard induction chemotherapy. 1:1 propensity score calliper matching (PSM) was applied to improve comparability, and overall (OS) and relapse-free survival (RFS) were assessed. Fewer data elements were available in external cohorts compared to H103 controls, specifically in the NCR cohort. Baseline characteristics of the external cohorts differed from H103 controls; missing data were also more frequent and predominantly concerned WHO performance score. After PSM, HA patients demonstrated non-significantly different OS and RFS to H103 controls at 2 years (26 ± 4% vs. 31 ± 5%, p = 0.59; 24 ± 5% vs. 30 ± 6%, p = 0.52), while NCR patients had 12% lower OS (28 ± 4% vs. 40 ± 4%, p = 0.21). Validation of external control cohorts is needed before incorporating RWD control data into comparative analyses, as missing data, specifically comorbidities, and residual confounding may limit comparability.
    Keywords:  acute myeloid leukaemia; clinical trials; external control arm; external controls; non‐randomized studies; real‐world data
    DOI:  https://doi.org/10.1111/bjh.20185
  7. Eur J Haematol. 2025 May 29.
      Bone marrow (BM) vacuolization is a key morphological feature observed in VEXAS (Vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome. However, vacuolization alone is not specific to VEXAS, as it can also be seen in conditions such as myelodysplastic syndromes (MDS), acute myeloid leukemia (AML), metabolic disorders, and toxic exposures. VEXAS syndrome, a postzygotic mutation-driven autoinflammatory disease caused by somatic mutations in the UBA1 gene, leads to chronic immune activation, clonal expansion of hematopoietic cells, and systemic inflammation. UBA1 mutations result in protein misfolding, contributing to both hematologic and inflammatory abnormalities. In VEXAS syndrome, specific features of vacuolated progenitor cells suggest the diagnosis. These include a high number of vacuolated cells, increased vacuoles per cell, a predominance of vacuoles in early progenitors rather than later stages, and vacuolization in both myeloid and erythroid progenitors, with myeloid progenitors most affected. However, the absence or low frequency of vacuolated cells should not rule out the possibility of VEXAS, and UBA1 gene sequencing should still be considered, especially in patients with unexplained systemic inflammation, MDS, or associated with other hematologic disorders. These mutations may alter the BM microenvironment, promoting the survival and expansion of mutant clones, which drive disease progression. While there is no standard treatment for VEXAS, the condition provides a unique model for understanding how inflammation in the BM microenvironment contributes to clonal selection and hematologic malignancy development. Research into the genetic and molecular mechanisms behind BM vacuolization in VEXAS has improved the diagnostic approaches and enhanced our understanding of its impact on hematopoiesis. Ongoing studies into the interplay between vacuolization, clonal hematopoiesis, and immune dysregulation will be a key to developing effective therapies for this complex syndrome. We herein offer a comprehensive diagnostic approach to BM vacuolization linked to VEXAS syndrome, distinguishing it from vacuoles observed in other conditions. The analysis delves into the clinical and hematologic features, molecular pathways, and rapidly evolving diagnostic methods for VEXAS syndrome, emphasizing its impact on hematopoiesis from a hematologic perspective.
    Keywords:  UBA1 mutations; VEXAS syndrome; bone marrow vacuolization; clonal hematopoiesis; myelodysplastic syndromes
    DOI:  https://doi.org/10.1111/ejh.14441
  8. Eur J Haematol. 2025 May 28.
       INTRODUCTION: Myeloablative conditioning (MAC) for acute myeloid leukemia (AML) improves disease control by reducing relapse risk but is associated with higher non-relapse mortality (NRM). Reduced-intensity conditioning (RIC) aims to minimize toxicity but raises concerns about higher relapse rates. This study evaluates the impact of RIC versus MAC in AML patients under 65 years receiving GVHD prophylaxis with antithymocyte globulin, post-transplant cyclophosphamide, and cyclosporine.
    METHODS: We retrospectively analyzed 322 AML patients undergoing allogeneic HCT with uniform GVHD prophylaxis. Propensity score matching (PSM) was applied to adjust for baseline differences.
    RESULTS: In the matched cohort, 2-year overall survival (OS) did not differ significantly between RIC and MAC recipients (64.4% vs. 66.9%, p = 0.56). Relapse-free survival (RFS) at 2 years was 65.0% for MAC and 52.7% for RIC (p = 0.20). Two-year NRM was 19.4% for MAC and 19.1% for RIC (p = 0.84). Improved RFS was associated with non-high-risk DRI (HR: 0.39, p = 0.008), whereas conditioning intensity had no significant effect (HR: 0.98, p = 0.97). NRM was higher among patients with KPS < 90 (HR: 3.63, p = 0.01), with no significant impact observed from conditioning intensity (HR: 1.44, p = 0.43).
    CONCLUSION: In a relatively younger cohort, conditioning intensity did not significantly impact survival, and MAC was not associated with increased NRM.
    Keywords:  AML; GVHD prophylaxis; conditioning; myeloablative; reduced intensity; stem cell transplant
    DOI:  https://doi.org/10.1111/ejh.14438
  9. Nat Commun. 2025 May 27. 16(1): 4920
      The lack of curative therapies for acute myeloid leukaemia (AML) remains an ongoing challenge despite recent advances in the understanding of the molecular basis of the disease. Here we identify the WNK1-OXSR1/STK39 pathway as a previously uncharacterised dependency in AML. We show that genetic depletion and pharmacological inhibition of WNK1 or its downstream phosphorylation targets OXSR1 and STK39 strongly reduce cell proliferation and induce apoptosis in leukaemia cells in vitro and in vivo. Furthermore, we show that the WNK1-OXSR1/STK39 pathway controls mTORC1 signalling via regulating amino acid uptake through a mechanism involving the phosphorylation of amino acid transporters, such as SLC38A2. Our findings underscore an important role of the WNK1-OXSR1/STK39 pathway in regulating amino acid uptake and driving AML progression.
    DOI:  https://doi.org/10.1038/s41467-025-59969-8
  10. Cell Rep Med. 2025 May 16. pii: S2666-3791(25)00221-6. [Epub ahead of print] 102148
      Chimeric antigen receptor (CAR)-T therapy on acute myeloid leukemia (AML) is hindered by the absence of a suitable tumor-specific antigen. Here, we propose CD97 as a potential target for CAR-T therapy against AML based on its broader and higher expression on AML cells compared to normal hematopoietic stem and progenitor cells (HSPCs). To resolve the fratricide problem caused by CD97 expression on T cells, we knock out CD97 in CAR-T cells using CRISPR-Cas9. Our CD97KO CAR-T cells eliminate both AML cell lines and primary AML cells effectively while showing tolerable toxicity to HSPCs. Furthermore, we mutate the CD3ζ domain of the CAR and find that the optimized CD97 CAR-T cells exhibit persistent anti-tumor activity both in vitro and in multiple xenograft models. Mechanistically, transcriptional profiles reveal that the optimized CAR-T cells delay differentiation and resist exhaustion. Collectively, our study supports CD97 as a promising target for CAR-T therapy against AML.
    Keywords:  CD97; acute myeloid leukemia; chimeric antigen receptor; exhaustion; immunotherapy
    DOI:  https://doi.org/10.1016/j.xcrm.2025.102148
  11. Nat Commun. 2025 May 24. 16(1): 4833
      Ruxolitinib is a potent JAK1/JAK2 inhibitor, approved for the treatment of primary myelofibrosis (PMF) patients based on the concept of inhibition of oncogenic signaling. However, the effect of ruxolitinib on JAK2-V617F allelic burden is modest, suggesting that inhibition of JAK2-V617F signaling-driven clone expansion is not the main mechanism of action. We evaluate whether ruxolitinib mainly blocks the proliferation of the malignant clone or exerts its effects also by targeting non-malignant cells. Therefore, we develop two JAK2-V617F-driven myeloproliferative neoplasm (MPN) mouse models harboring ruxolitinib resistance mutations. Mice carrying ruxolitinib-resistant JAK2-V617F-driven MPN respond to ruxolitinib treatment similar to mice with ruxolitinib-sensitive JAK2-V617F MPN with respect to reduction of spleen size, leukocyte count and pro-inflammatory cytokines in the serum. Ruxolitinib reduces pro-inflammatory cytokines in both stromal cells and non-malignant hematopoietic cells. Using a rigorous ruxolitinib resistance mutation approach, we can prove that ruxolitinib acts independent of oncogenic JAK2-V617F signaling and reduces the main features of MPN disease such as spleen size and leukocyte counts. Our findings characterize the mechanism of action for ruxolitinib in MPN.
    DOI:  https://doi.org/10.1038/s41467-025-60019-6
  12. Blood. 2025 May 28. pii: blood.2024028215. [Epub ahead of print]
      Inotuzumab Ozogamicin (InO) is an antibody-calicheamicin conjugate with high efficacy in lymphoid malignancies. It targets the B-cell surface protein CD22, which is expressed in most B-ALL cases, albeit with variable intensity. However, factors governing CD22 expression and thus leukemia sensitivity to InO remain incompletely understood. Using multi-omic characterization of 196 human B-ALL samples, coupled with ex vivo InO sensitivity profiling, we show that early leukemia differentiation arrest at the Pre-pro-B stage is associated with resistance to InO. Screening 1,639 transcription factor genes prioritized Early B-cell Factor 1 (EBF1) as a key regulator of CD22 expression (false discovery rate=7.1×10-4). Comparing the ATAC-seq profiling results of the most InO-sensitive and -resistant cases (LC50 <10th vs. >90th percentile, n=18), the binding motif for EBF1 was strikingly enriched in regions with differential open chromatin status (P=8×10-174). CRISPR interference targeting EBF1 binding sites at the CD22 locus led to ~ 50-fold reduction in cell surface CD22 expression, and consequently ~ 22-fold increase in InO resistance in ALL cell lines. Interestingly, within BCR::ABL1 ALL, we observed intra-subtype heterogeneity linked to EBF1 transcriptional downregulation (P=1.1×10-15) and/or somatic alteration (P=0.004), which led to reduced CD22 expression (P=8.3×10-11) and ex vivo and in vivo resistance to InO. Collectively, these findings point to the direct impact of EBF1 on CD22 expression during B-cell development, which in turn contributes to inter-patient variability in InO response, even within the same subtype of B-ALL.
    DOI:  https://doi.org/10.1182/blood.2024028215
  13. Blood. 2025 May 28. pii: blood.2024027712. [Epub ahead of print]
      Acute megakaryoblastic leukemia driven by the RBM15-MKL1 fusion protein (RM-AMKL) is encoded by the recurrent t(1;22) translocation. Dysregulation of m6A modification affects RNA fate and is linked to oncogenesis. Because RBM15 is critical for bringing the m6A writer complex to specific RNAs, we hypothesized that RM disrupts m6A modification, altering RNA fate to drive leukemogenesis in RM-AMKL. Using a multi-omic approach, we show for the first time that RM retains the RNA-binding and m6A-modifying functions of RBM15 while also selectively regulating distinct mRNA targets including Frizzled genes in the WNT signaling pathway. Treating murine RM-AMKL cells with the METTL3 inhibitor STM3675, which decreases m6A deposition, induced apoptosis in vitro and prolonged survival in transplanted mice. Frizzled genes were upregulated by RM and downregulated upon METTL3 inhibition, implicating an m6A-dependent mechanism for their dysregulation. Direct Frizzled knockdown reduced RM-AMKL growth in vitro and in vivo, highlighting Wnt signaling as a key oncogenic driver. Elevated Wnt pathway and Frizzled expression in multiple forms of human AMKL underscores the relevance of our findings. Together, our results establish RM-specific m6A modifications and Wnt pathway activation as critical drivers of RM-AMKL, identifying these pathways as potential therapeutic targets.
    DOI:  https://doi.org/10.1182/blood.2024027712
  14. Bone Marrow Transplant. 2025 May 27.
      The use of post-transplant cyclophosphamide (PTCy) for graft-versus-host disease (GVHD) prophylaxis in severe aplastic anemia (SAA) remains understudied, particularly beyond haploidentical transplants. We analyzed outcomes of SAA patients who underwent stem cell transplantation (SCT) with PTCy from haploidentical donors (n = 209), HLA-matched sibling donors (MSD, n = 70), and unrelated donors (UD, n = 69) using EBMT data from 2010 to 2022. Median age was 22 years, and median time to transplantation was 8.6 months. For haploidentical, MSD, and UD cohorts, the 100-day cumulative incidence of grade II-IV acute GVHD was 19%, 11%, and 14% (p = 0.15), while grade III-IV was 6%, 3%, and 2% (p = 0.1). Two-year chronic and extensive chronic GVHD were 14%, 13%, and 14% (p = 0.1) and 5%, 6%, and 2% (p = 0.5), respectively. Non-relapse mortality at two years was 24% for haploidentical, 7% for MSD, and 10% for UD (p = 0.003). Two-year overall survival (OS) and GVHD- and relapse-free survival were 66% and 54% for haploidentical, 92% and 70% for MSD, and 81% and 66% for UD (p < 0.001, p = 0.06). In multivariable analysis, MSD and UD were associated with superior OS and GRFS compared to haploidentical. PTCy is safe and effective in SAA patients, though haploidentical SCT had higher NRM, leading to lower survival.
    DOI:  https://doi.org/10.1038/s41409-025-02633-y
  15. Commun Biol. 2025 May 26. 8(1): 808
      Mutations and gene rearrangements are crucial for the diagnosis and subtyping of acute myeloid leukemia (AML). However, the contribution of non-coding genetic variants, particularly those within cis-regulatory elements (CREs), to AML pathophysiology and heterogeneity remains poorly understood. In this study, we characterize the single-cell chromatin accessibility landscapes of 10 bone marrow samples from AML patients at diagnosis. Additionally, we develop eMut, an integrated computational pipeline for detecting, imputing, and functionally characterizing non-coding mutations in CREs at the single-cell level. Our analysis identifies 2878 potential somatic non-coding mutations, highlighting the extensive mutational heterogeneity in the non-coding genome of AML patients, with recurrent non-coding mutations displaying cell type-specific patterns. We show that mutated CREs are enriched with blood-related genetic variants, potentially linked to AML-associated genes, and harbor a higher abundance of functional CREs, suggesting their functional relevance in leukemogenesis. Importantly, we pinpoint candidate functional non-coding mutations that associate with alteration of target gene expression in AML. Collectively, our work provides a comprehensive resource of single-cell chromatin accessibility in AML and introduces an integrative approach to identify candidate functional non-coding mutations contributing to cellular heterogeneity in AML.
    DOI:  https://doi.org/10.1038/s42003-025-08257-8
  16. Ann Hematol. 2025 May 24.
      The present longitudinal study reports a unique patient followed over almost three decades who sequentially developed polycythemia vera, chronic myelomonocytic leukemia, and chronic myeloid leukemia. The patient received successive hydroxyurea, ruxolitinib, and a combination of ruxolitinib and nilotinib. The clonal architecture dynamic was reconstructed using targeted high throughput asymmetric capture sequencing, allowing detection and quantification of mutations in 43 myeloid genes and BCR::ABL1 fusion in multiple bone marrow or peripheral blood samples and in single cell-derived colonies obtained from bone marrow colony-forming cell assays. This analysis has uncovered an unexpected subclonal link between three myeloid malignancies, all stemming from a DNMT3A/TET2 double mutant clone. Over a period of more than 30 years, this clone underwent major telomere shortening. However, a striking sustained major molecular response of the terminal dominant clone carrying all driver mutations was achieved by combination therapy with nilotinib and ruxolitinib. The remaining clone driving both polycythemia and chronic myelomonocytic leukemia remained unaffected and evolved to myelofibrosis and proliferative CMML.
    Keywords:  Chronic myeloid leukemia; Chronic myelomonocytic leukemia; Co-occurrence; Dual targeting; Dual targeting myeloproliferative neoplasm; Polycythemia vera; Ruxolitinib; Telomere; Tyrosine kinase inhibitor; aCAP-Seq
    DOI:  https://doi.org/10.1007/s00277-025-06417-8
  17. Br J Haematol. 2025 May 26.
      Recent studies revealed that CEBPA with basic leucine zipper (bZIP) in-frame mutation (CEBPAbZIP-inf) is the bona fide entity with a favourable prognosis in acute myeloid leukaemia. However, the mechanism by which the bZIP signatures influence risk stratification remains unclear. We identified 141 patients with CEBPAbZIP-inf. Variant allele fraction (VAF) (cumulative incidence of relapse [CIR], VAFhigh vs. VAFlow, 74.0% vs. 27.0%, p < 0.001) and base change (≤ vs. >3 bases, 39.1% vs. 60.6%, p = 0.042) of bZIP mutations were associated with CIR. These two factors, along with the white blood cell count and measurable residual disease after first consolidation, could stratify patients into three risk subgroups (CIR, low vs. medium vs. high risk, 15.2% vs. 47.1% vs. 83.0%, p < 0.001). Compared with no transplantation, receiving a transplantation significantly decreased the relapse rates in medium-risk (transplantation vs. no transplantation, 11.6% vs. 49.7%, p = 0.009) and high-risk patients (5.6% vs. 84.1%, p < 0.001) but not low-risk (0% vs. 15.2%, p = 0.220). However, only high-risk patients could benefit from transplantation in terms of overall survival (100% vs. 59.7%, p = 0.003). Our study revealed the heterogeneity of CEBPAbZIP-inf patients and suggested a risk-adapted treatment modality. Transplantation is recommended for high-risk patients and consolidation chemotherapy is recommended for low-risk and medium-risk patients.
    Keywords:   CEBPA ; acute myeloid leukaemia; bZIP in‐frame mutation; post‐remission treatment; risk stratification
    DOI:  https://doi.org/10.1111/bjh.20164
  18. Blood Cancer Discov. 2025 May 28.
      The influence of genetic ancestry on genomics in T-cell Acute Lymphoblastic Leukemia (T-ALL) has not been fully explored. We examined the impact of genetic ancestry on multi-omic alterations, survival outcomes, and risk stratification. Among 1309 children and young adults with T-ALL treated on the Children's Oncology Group trial AALL0434, the prognostic value of five commonly altered T-ALL genes varied by ancestry-including NOTCH1, which was associated with superior overall survival for patients of European ancestry but non-prognostic among patients of African ancestry. Integrating genetic ancestry with published T-ALL risk classifiers, we identified that a X01 Penalized Cox Regression classifier stratified patients regardless of ancestry, whereas a European multi-gene classifier misclassified patients of certain ancestries. Overall, 80% of patients harbored a genomic alteration in at least one gene with differential prognostic impact in an ancestry-specific manner. These data demonstrate the importance of incorporating genetic ancestry into genomic risk classification.
    DOI:  https://doi.org/10.1158/2643-3230.BCD-25-0049
  19. Nat Commun. 2025 May 30. 16(1): 5048
      Severe immune aplastic anemia is a fatal disease due to the destruction of marrow hematopoietic cells by cytotoxic lymphocytes, serving as a paradigm for marrow failure syndromes and autoimmune diseases. To better understand its pathophysiology, we apply advanced single cell methodologies, including mass cytometry, single-cell RNA, and TCR/BCR sequencing, to patient samples from a clinical trial of immunosuppression and growth factor stimulation. We observe opposing changes in the abundance of myeloid cells and T cells, with T cell clonal expansion dominated by effector memory cells. Therapy reduces and suppresses cytotoxic T cells, but new T cell clones emerge hindering robust hematopoietic recovery. Enhanced cell-cell interactions including between hematopoietic cells and immune cells, in particular evolving IFNG and IFNGR, are noted in patients and are suppressed post-therapy. Hematologic recovery occurs with increases in the progenitor rather than stem cells. Genetic predispositions linked to immune activation genes enhances cytotoxic T cell activity and crosstalk with target cells.
    DOI:  https://doi.org/10.1038/s41467-025-60213-6
  20. Br J Haematol. 2025 May 25.
      Somatic mutations in UBA1 are linked to VEXAS syndrome, a late-onset inflammatory disorder with rheumatological and haematological features, primarily affecting elderly men. This study examines the epidemiology of VEXAS in the United Kingdom using genomic databases and patient cohorts to estimate prevalence, identify novel UBA1 variants and predict their pathogenicity. Analysing data from the UK Biobank, 100 000 Genomes Project and clinical diagnostic laboratories, we found that VEXAS prevalence in UK males over 50 is lower than in US-based cohorts. Notably, canonical (Met41) UBA1 mutations appear in ~1% of individuals with autoinflammatory disorders who have not been referred to haematology. However, among those investigated for myeloid malignancies, VEXAS is relatively common, with an estimated incidence of 1.51 per 100 000, or 171 new cases each year. We identified 47 UBA1 non-Met41 variants of uncertain significance, with several showing clonal dominance and clustering in functional domains, suggesting potential pathogenicity. Clinical presentation associated with non-Met41 variants often diverged from classical VEXAS features, underscoring the need for further studies. Our findings highlight the importance of broader screening for both canonical and non-canonical UBA1 mutations to improve understanding of VEXAS syndrome and its underlying mechanisms.
    Keywords:  MDS; UBA1; VEXAS
    DOI:  https://doi.org/10.1111/bjh.20176
  21. Clin Cancer Res. 2025 May 28.
      In December 2021, FDA approved abatacept (Orencia; Bristol Myers Squibb) in combination with a calcineurin inhibitor (CNI) and methotrexate (MTX) as the first drug for prophylaxis of acute graft versus host disease (aGVHD) in adults and pediatric patients 2 years and older undergoing hematopoietic stem cell transplantation (HSCT) from a matched or 1 allele-mismatched unrelated donor (URD). Study IM101311 included a randomized (1:1), double-blind evaluation of abatacept (N=73) versus placebo (N=69) +CNI+MTX as aGVHD prophylaxis in patients ≥6 years undergoing an 8/8 HLA-matched URD HSCT. Overall survival (OS) and Grade II-IV aGVHD free survival at Day 180 post-transplantation for abatacept versus placebo showed hazard ratio (HR) 0.33 (95% CI 0.12-0.93) and 0.54 (0.35-0.83), respectively. A second study, IM101841, was conducted using real-world data from Center for International Blood and Marrow Transplant Research (CIBMTR) registry for abatacept +CNI+MTX (N=54) versus CNI+MTX (N=162) in patients who underwent 7/8 mismatched URD HSCT. Day 180 OS was 98% (95% CI: 78, 100) with abatacept +CNI+MTX versus 75% (95% CI: 67, 82) with CNI+MTX. Serious adverse reactions included cytomegalovirus and Epstein-Barr Virus reactivation. An additional study in patients 2 to < 6 years was required as a condition of the approval.
    DOI:  https://doi.org/10.1158/1078-0432.CCR-25-0688
  22. Sci Adv. 2025 May 30. 11(22): eadq3052
      Understanding the regulation of N6-methyladenosine (m6A), the prominent internal modification in mRNA, fosters the development of potential therapeutic strategies for human cancers. While the m6A demethylases FTO and ALKBH5 are recognized for their crucial roles in various cancers, their impact on lymphoid leukemia remains uncertain. Using T cell acute lymphoblastic leukemia (T-ALL) as a model system, we identify FTO as a unique vulnerability in T cell leukemia. Knockout of FTO, but not ALKBH5, significantly suppresses leukemia initiation and progression. Mechanistic analysis reveals that FTO heightens ELK3 mRNA stability in an m6A-dependent manner. Elevated ELK3 in turn transcriptionally activates the expression of glycolytic genes. Pharmacological inhibition of FTO suppresses ELK3 expression, hampers glycolysis and manifests remarkable antileukemia efficacy. Our findings unravel the crucial role of FTO in T-ALL and highlight the FTO-ELK3 axis as a key nodule during leukemogenesis, thereby providing a fundamental basis to harness selective FTO antagonist for T-ALL therapeutics.
    DOI:  https://doi.org/10.1126/sciadv.adq3052
  23. Nature. 2025 May 28.
      Lentiviral vector (LV)-mediated ex vivo gene therapy for haematopoietic stem and progenitor cells (HSPCs) has delivered on the promise of a 'one-and-done' treatment for several genetic diseases1. However, ex vivo manipulation and patient conditioning before transplantation are major hurdles that could be overcome by an in vivo approach. Here we demonstrate that in vivo gene delivery to HSPCs after systemic LV administration is enabled by the substantial trafficking of these cells from the liver to the bone marrow in newborn mice. We improved gene-transfer efficiency using a phagocytosis-shielded LV, successfully reaching bona fide HSPCs capable of long-term multilineage output and engraftment after serial transplantation, as confirmed by clonal tracking. HSPC mobilization further increased gene transfer, extending the window of intervention, although permissiveness to LV transduction declined with age. We successfully tested this in vivo strategy in mouse models of adenosine deaminase deficiency, autosomal recessive osteopetrosis and Fanconi anaemia. Interestingly, in vivo gene transfer provided a selective advantage to corrected HSPCs in Fanconi anaemia, leading to near-complete haematopoietic reconstitution and prevention of bone marrow failure. Given that circulating HSPCs in humans are also most abundant shortly after birth, in vivo HSPC gene transfer holds strong translational potential across multiple diseases.
    DOI:  https://doi.org/10.1038/s41586-025-09070-3
  24. Leukemia. 2025 May 28.
      Whether adding anthracycline to intermediate- or high-dose cytarabine as consolidation is beneficial remains unclear in acute myeloid leukemia (AML). Eligible AML patients in first complete remission were randomly assigned (1:1) to receive either high-dose cytarabine with idarubicin (IA3 + 3) (idarubicin 10 mg/m2, d1-3 and cytarabine 2 g/m2, every 12 h, d1-3) or high-dose cytarabine (HDAC) (cytarabine 3 g/m2, every 12 h, d1-3) regimens as first consolidation. The primary endpoint was the rate of negative measurable residual disease (MRD-) after first consolidation. Between November 2018 and December 2021, 407 patients were assigned to IA3 + 3 (n = 204) or HDAC (n = 203) groups. MRD- after first consolidation for IA3 + 3 and HDAC groups was 65.2% (95%CI: 58.6-71.8%) and 53.2% (46.3-60.1%) (P = 0.009). The 3-year cumulative incidence of relapse was 22.6% (95%CI :16.8-29.0%) and 34.0% (27.1-41.1%) (P = 0.014), DFS was 68.4% (61.5-75.3%) and 52.9% (45.4-60.5%) (P = 0.003), OS was 75.5% (69.0-82.1%) and 69.6% (62.4-76.7%) (P = 0.18) and treatment-related mortality was 8.8% (5.2-13.6%) and 13.0% (8.5-18.5%) (P = 0.23) in two groups, respectively. Eighty-seven (43%) and 114 (56%) patients underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT), respectively (P = 0.006). IA3 + 3 regimen results in deeper remissions and reduces relapse compared to HDAC. This deeper remission improves DFS and translates into treatment advantage, with fewer patients undergoing allo-HSCT. (ClinicalTrials.gov, NCT03620955).
    DOI:  https://doi.org/10.1038/s41375-025-02655-x
  25. Exp Hematol. 2025 May 26. pii: S0301-472X(25)00108-0. [Epub ahead of print] 104817
      In addition to supplying oxygen and nutrients, blood vessels secrete paracrine molecules known as angiocrine factors to promote tissue homeostasis and repair. The bone marrow (BM) vasculature in long bones has differing properties between the diaphysis, metaphysis, and epiphysis in terms of its morphology, plasticity, perivascular cellular components, and angiocrine profiles. Blood vessel formation is linked with bone formation through paracrine interactions between endothelial cells (ECs) and osteolineage cells, so-called angiogenic-osteogenic coupling. ECs also play essential roles in maintenance of hematopoietic stem cells (HSCs) by forming vascular niches together with perivascular stromal cells. Recent studies highlight the heterogeneity of vascular niches at different bone regions, suggesting that HSCs are regulated by locally distinct mechanisms. Here, we provide an overview of the BM vasculature and discuss how the heterogeneous vasculature contributes to bone formation and HSC maintenance. TEASER ABSTRACT: The bone marrow (BM) vasculature in long bones has differing properties across different bone regions. Blood vessel formation is closely linked with bone formation, a process known as angiogenic-osteogenic coupling. The BM vasculature also supports hematopoietic stem cells (HSCs) by establishing vascular niches. Recent studies highlight regional heterogeneity of vascular niches at different bone regions, suggesting that HSCs are regulated by locally distinct mechanisms. This review outlines the BM vasculature and examine how its heterogeneity influences bone formation and HSC maintenance.
    Keywords:  Angiogenesis; angiogenic-osteogenic coupling; bone marrow vasculature; hematopoietic stem cells; stem cell niche
    DOI:  https://doi.org/10.1016/j.exphem.2025.104817
  26. Blood. 2025 May 28. pii: blood.2024027846. [Epub ahead of print]
      The integrity of the hematopoietic stem cell (HSC) pool depends on effective long-term self-renewal and the timely elimination of damaged or differentiation-prone HSCs. While the PERK branch of the unfolded protein response (UPR) has been shown to initiate pro-apoptotic signaling in response to ER stress in vitro, its role in regulating HSC fate in vivo remains incompletely understood. Here, we demonstrate that PERK is dispensable for steady-state hematopoiesis and HSC self-renewal under homeostatic conditions. However, under ER stress induced by disruption of ER-associated degradation (ERAD), via knockout of key components such as Sel1L or Hrd1, PERK becomes activated and drives HSC proliferation and depletion. Notably, deletion of PERK or expression of a kinase-dead PERK mutant significantly rescues the HSC defects caused by Sel1L or Hrd1 loss. Mechanistically, ERAD deficiency does not lead to increased HSC apoptosis or elevated reactive oxygen species (ROS), and PERK knockout has minimal impact on HSC apoptosis. Instead, PERK activation promotes aberrant mTOR signaling and HSC hyperproliferation, ultimately compromising self-renewal capacity. This PERK-driven elimination of stressed HSCs may function as a protective mechanism to maintain overall HSC pool integrity. Collectively, our findings reveal a previously unrecognized, proliferative, and apoptosis-independent role for PERK in regulating HSC fate under ER stress, highlighting a novel mechanism for preserving HSC homeostasis.
    DOI:  https://doi.org/10.1182/blood.2024027846
  27. Blood Adv. 2025 May 27. 9(10): 2570-2584
       ABSTRACT: Double-unit cord blood transplantation (dCBT) has been associated with high rates of progression-free survival (PFS) in adults with hematologic malignancies but also with relatively high rates of acute graft-versus-host disease (aGVHD). We conducted a single-arm, phase 2 clinical trial that investigated the addition of tocilizumab, an interleukin-6 receptor blocker, to cyclosporine-A (CSA) and mycophenolate mofetil (MMF) for aGVHD prophylaxis after intermediate-intensity dCBT. A total of 45 patients (median age, 47 years; range, 27-60 years; 80% acute leukemia; median hematopoietic cell transplant-comorbidity index, 2) were enrolled from March 2018 to March 2021. Transplant outcomes were compared with 39 previous CSA and MMF dCBT controls with similar inclusion criteria. Tocilizumab recipients had less pre-engraftment syndrome (38%; 95% confidence interval [CI], 24-52 vs 72%; 95% CI, 54-84; P < .001) but inferior day 45 neutrophil engraftment (93%; median, 25.5 days vs 97%; median, 22 days; P = .009]. The primary end point of day 100 grade 2 to 4 aGVHD was no different between groups (71%; 95% CI, 55-82 with tocilizumab vs 82%; 95% CI, 65-91; P = .11). However, there was a trend toward a lower day 100 incidence of stage 1 to 4 lower gastrointestinal aGVHD with tocilizumab (16%; 95% CI, 7-28 vs 33%; 95% CI, 19-48; P = .059). There were no significant differences in the 3-year incidences of relapse, transplant-related mortality, PFS, or overall survival between the groups. Tocilizumab recipients exhibited a distinct pattern of gut microbiome disruption. In summary, tocilizumab-based GVHD prophylaxis delayed neutrophil recovery without a significant reduction in aGVHD and had no survival benefit after dCBT. Investigation of alternative strategies to prevent severe aGVHD after dCBT is warranted. This trial was registered at www.clinicaltrials.gov as #NCT03434730.
    DOI:  https://doi.org/10.1182/bloodadvances.2024014177
  28. Nat Commun. 2025 May 27. 16(1): 4899
      The selection of genetically engineered immune or hematopoietic cells in vivo after gene editing remains a clinical problem and requires a method to spare on-target toxicity to normal cells. Here, we develop a base editing approach exploiting a naturally occurring CD33 single nucleotide polymorphism leading to removal of full-length CD33 surface expression on edited cells. CD33 editing in human and nonhuman primate hematopoietic stem and progenitor cells protects myeloid progeny from CD33-targeted therapeutics without affecting normal hematopoiesis in vivo, thus demonstrating potential for improved immunotherapies with reduced off-leukemia toxicity. For broader application to gene therapies, we demonstrate highly efficient (>70%) multiplexed adenine base editing of the CD33 and gamma globin genes, resulting in long-term persistence of dual gene-edited cells with HbF reactivation in nonhuman primates. Using the CD33 antibody-drug conjugate Gemtuzumab Ozogamicin, we show resistance of engrafted, multiplex edited human cells in vivo, and a 2-fold enrichment for edited cells in vitro. Together, our results highlight the potential of adenine base editors for improved immune and gene therapies.
    DOI:  https://doi.org/10.1038/s41467-025-59713-2
  29. Blood. 2025 May 30. pii: blood.2025028387. [Epub ahead of print]
      Relapsed/refractory T-cell acute lymphoblastic leukemia (ALL)/lymphoma (LBL) represent a significant unmet medical need. WU-CART-007 is a CD7-targeting, allogeneic, fratricide-resistant chimeric antigen receptor T cell product generated from healthy donor T cells. WU-CART-007 was evaluated in a phase 1/2 study with a 3+3 dose-escalation design followed by cohort expansion in relapsed/refractory T-ALL/LBL. Patients received one infusion of WU-CART-007 after standard or enhanced lymphodepleting chemotherapy. The primary objectives, to characterize safety and assess the composite complete remission rate, were met. Of 28 patients enrolled, 13 received the recommended phase 2 dose (RP2D) of 900 million cells of WU-CART-007 with enhanced lymphodepletion. The most common treatment-related adverse event was cytokine release syndrome (88.5%; 19.2% grade 3-4). Two grade 1 immune effector cell-associated neurotoxicity syndrome events (7.7%) and one grade 2 acute graft-vs-host disease event occurred (3.8%). One grade 2 immune effector cell associated HLH-like syndrome (IEC-HS) was observed. Among the 11 patients evaluable for response at the RP2D who received enhanced lymphodepleting chemotherapy, the overall response rate was 90.9% and composite complete remission rate was 72.7%. WU-CART-007 at the RP2D demonstrated a high response rate in patients with relapsed/refractory T-ALL/LBL and has the potential to provide a new treatment option. ClinicalTrials.gov registration: NCT04984356.
    DOI:  https://doi.org/10.1182/blood.2025028387
  30. Science. 2025 May 29. 388(6750): eadp2742
      Uncontrolled activation of the rat sarcoma (RAS)-extracellular signal-regulated kinase (ERK) pathway drives tumor growth, often because of oncogenic BRAF mutations. BRAF regulation, involving monomeric autoinhibition and activation by dimerization, has been intensely scrutinized, but mechanisms enabling oncogenic mutants to evade regulation remain unclear. By using cryo-electron microscopy, we solved the three-dimensional structures of the three oncogenic BRAF mutant classes, including the common V600E variant. These mutations disrupted wild-type BRAF's autoinhibited state, mediated by interactions between the cysteine-rich domain and kinase domain, thereby shifting the kinase domain into a preactivated conformation. This structural change likely results from helix αC displacement. PLX8394, a BRAF inhibitor that stabilizes helix αC in an inactive conformation, restored the autoinhibited conformation of oncogenic BRAF, explaining the properties of this class of compounds.
    DOI:  https://doi.org/10.1126/science.adp2742
  31. Cancer Metab. 2025 May 26. 13(1): 25
      Increasing emphasis has been placed on improving the physiological relevance of cell culture media with formulations such as Human Plasma-Like Medium (HPLM). Given that shifts in mitochondrial metabolism and nutrient use are emerging as anti-cancer targets, the present study sought to investigate the impact of culture media formulation on mitochondrial bioenergetics and cancer cell growth. To do this, we used acute myeloid leukemia (AML) cells and compared acute and chronic effects of HPLM versus different supraphysiological medias. The AML mitochondrial phenotype was largely unaffected by exposure to either physiological or supraphysiological medias, establishing that the key features of AML mitochondria remain phenotypically stable under diverse nutrient conditions and proliferation rates. Both acute and chronic culturing in HPLM slowed AML cell proliferation. However, merely identifying and supplementing single nutrients that were deficient in HPLM did not improve proliferation and was not sufficient to pinpoint actionable fuel preferences. Transferring cells back to native Iscove's Modified Dulbecco's Medium (IMDM) media immediately restored the proliferative phenotype, suggesting responsiveness to the entirety of the nutrient environment. Supraphysiological culture medias other than IMDM were all characterized by slower proliferation; however, none were associated with changes in cell viability, demonstrating that the native culture medium is optimal if the experimental aim is maximal growth. Despite Dulbecco's Modified Eagle Medium (DMEM) being similar in nutrient composition to IMDM and categorized as supraphysiological, both acute and chronic culturing in DMEM resulted in slower growth, akin to what was observed with HPLM. Altogether, independent of growth, AML mitochondria remain largely unperturbed by changes in the culture media, and rather than specific nutrients or physiological relevance, AML cell proliferation is influenced by the complete nutrient profile.
    DOI:  https://doi.org/10.1186/s40170-025-00395-1
  32. Lancet Haematol. 2025 Jun;pii: S2352-3026(25)00081-X. [Epub ahead of print]12(6): e414-e430
       BACKGROUND: The factor B inhibitor iptacopan improved 24-week outcomes in adult patients with paroxysmal nocturnal haemoglobinuria in the phase 3 APPLY-PNH and APPOINT-PNH trials; the trial extension periods assessed clinical activity and safety up to 48 weeks. Here, we report the final 48-week data from APPLY-PNH and APPOINT-PNH.
    METHODS: In both APPLY-PNH and APPOINT-PNH trials, patients were aged 18 years or older, with paroxysmal nocturnal haemoglobinuria (red and white blood cell population sizes ≥10%) and without laboratory evidence of bone marrow failure. In APPLY-PNH (an open-label, randomised, phase 3 trial conducted in 39 centres [38 hospitals, one outpatient research clinic] from 12 countries or regions), patients with haemoglobin concentration lower than 10 g/dL on anti-C5 treatment (stable eculizumab or ravulizumab regimen for ≥6 months) were randomly assigned (8:5) via interactive response technology to either receive oral iptacopan 200 mg twice daily (iptacopan group) or to continue their individual intravenous eculizumab or ravulizumab regimen for 24 weeks (anti-C5 group). Randomisation was stratified by type of anti-C5 and receipt of red blood cell (RBC) transfusions in the preceding 6 months. In APPOINT-PNH (an open-label, single-arm, phase 3 trial conducted in 12 hospitals from eight countries), complement inhibitor-naive patients with paroxysmal nocturnal haemoglobinuria and with haemoglobin concentration lower than 10 g/dL and lactate dehydrogenase (LDH) concentration higher than 1·5 times the upper limit of normal received iptacopan 200 mg twice daily for 24 weeks. Both trials had 24-week extension periods in which all patients received iptacopan monotherapy. Primary endpoints were the proportion of patients with an increase from baseline in haemoglobin concentration of 2 g/dL or higher (APPLY-PNH and APPOINT-PNH) and haemoglobin concentration 12 g/dL or higher (APPLY-PNH) between weeks 18 and 24, all in the absence of RBC transfusions between weeks 2 and 24; results for these primary endpoints have been reported previously. We report final activity and safety data at the completion of both trials (week 48). Prespecified endpoints at week 48 included percentage of patients with a haemoglobin increase from baseline of 2 g/dL or higher or haemoglobin 12 g/dL or higher (including post-transfusion data). Efficacy data were analysed per the intention-to-treat principle, and safety was analysed according to the treatment that patients received. APPLY-PNH and APPOINT-PNH are registered with ClinicalTrials.gov, NCT04558918 and NCT04820530, respectively.
    FINDINGS: In APPLY-PNH, between Jan 25, 2021, and April 8, 2022, 62 patients (43 [69%] female, 19 [31%] male; 48 [77%] White, 12 [19%] Asian, two [3%] Black) were randomly assigned to the iptacopan group and 35 patients (24 [69%] female, 11 [31%] male; 26 [74%] White, seven [20%] Asian, two [6%] Black) to the anti-C5 group; 61 (98%) and 34 (97%), respectively, entered the extension period. At trial completion (March 6, 2023), the median duration of iptacopan treatment was 337 days (IQR 168-338). In APPOINT-PNH, 40 patients were enrolled between July 19, 2021, and May 17, 2022, and received iptacopan (17 [43%] female, 23 [58%] male; 12 [30%] White, 27 [68%] Asian, one [3%] Black); all entered the extension period. At trial completion (April 18, 2023), the median duration of iptacopan treatment was 337 days (IQR 337-344). At week 48, irrespective of RBC transfusions, the number of patients who had an increase in haemoglobin concentration of 2 g/dL or higher was 51 (86%) of 59 in the APPLY-PNH iptacopan group, 21 (72%) of 29 in the APPLY-PNH anti-C5-to-iptacopan group, and 38 (97%) of 39 in APPOINT-PNH. The number of patients who had haemoglobin concentration of 12 g/dL or higher at week 48 was 40 (68%) of 59 in the APPLY-PNH iptacopan group, 17 (59%) of 29 in the APPLY-PNH anti-C5-to-iptacopan group, and 31 (79%) of 39 in APPOINT-PNH. There were no treatment discontinuations because of treatment-emergent adverse events or deaths. Across the 48-week trials, clinical breakthrough haemolysis occurred in seven (7%) of 96 iptacopan-treated patients in APPLY-PNH (including both groups) and two (5%) of 40 in APPOINT-PNH, but it was generally mild or moderate with no iptacopan discontinuation. Three major adverse vascular events occurred in APPLY-PNH by trial completion; all were considered unrelated to iptacopan. The most common treatment-emergent adverse event was COVID-19 in APPLY-PNH (iptacopan: 18/62 patients [29%]; anti-C5-to-iptacopan: 8/34 [24%]) and headache in APPOINT-PNH (12/40 [30%]). Severe and serious treatment-emergent adverse events were experienced by six (10%) and nine (15%) of 62 patients in the APPLY-PNH iptacopan group, respectively; in APPOINT-PNH, these were experienced by four (10%) and eight (20%) of 40 patients, respectively. The most common serious treatment-emergent adverse event was COVID-19, occurring in one (2%) of 62 patients in the APPLY-PNH iptacopan group and two (5%) of 40 patients in APPOINT-PNH. No severe treatment-emergent adverse events occurred in more than one patient.
    INTERPRETATION: Long-term data indicate durable haemolysis control with iptacopan in paroxysmal nocturnal haemoglobinuria, maintained normal or near-normal haemoglobin, and no new safety concerns. We believe that these data support iptacopan as a potential therapy option, suggesting that we are in a new treatment era for paroxysmal nocturnal haemoglobinuria.
    FUNDING: Novartis.
    DOI:  https://doi.org/10.1016/S2352-3026(25)00081-X
  33. Lancet Rheumatol. 2025 May 21. pii: S2665-9913(25)00034-7. [Epub ahead of print]
       BACKGROUND: Vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome is a recently described autoinflammatory disorder with little therapeutic evidence. We compared treatment outcomes of targeted therapies versus prednisolone alone in the largest UK cohort of patients with VEXAS syndrome to date.
    METHODS: In this retrospective cohort study, we analysed the outcomes of targeted therapies in patients with VEXAS syndrome in six tertiary referral centres across the UK between July 22, 2014, and Oct 19, 2024. The inclusion criteria were genetically confirmed VEXAS syndrome and receipt of at least one targeted therapy or prednisolone alone. Patients without clinical information at all timepoints after baseline were excluded. Data collection forms were used to record clinical and biochemical data at the following timepoints: time of diagnosis, initiation of treatment, and follow-up at 3 months, 6 months, and 12 months from the initiation of treatment (±28 days). Laboratory parameters, including C-reactive protein (CRP) and haemoglobin, and glucocorticoid doses were collected at each timepoint and compared between timepoints. Primary outcomes were complete response (ie, clinical remission, CRP ≤10 mg/L, and prednisolone ≤10 mg per day) and partial response (ie, clinical remission with ≥50% reductions in both CRP and glucocorticoid dose from baseline) to treatment. Treatment discontinuation and adverse events were documented for each treatment. Due to the high prevalence of cytopenias in VEXAS syndrome, these were only recorded as adverse events when necessitating treatment change. People with lived experience were not involved in the study.
    FINDINGS: We analysed 71 targeted therapies in 59 patients with genetically confirmed VEXAS syndrome. Of the 59 patients, 58 (98%) were male and one (2%) was female, with a mean age of 71 years (SD 8), and 27 (46%) had myelodysplastic syndrome. The treatments included tocilizumab (n=19), anakinra (n=13), azacitidine (n=13), baricitinib (n=11), and prednisolone only (n=10). At 6 months, in those who continued therapy, ten (91%) of 11 patients receiving azacitidine showed a response (three [27%] complete responses), as well as did seven (64%) of 11 receiving tocilizumab (four [36%] complete responses), three (100%) of three receiving anakinra (one [33%] complete response), and two (40%) of five receiving baricitinib (no complete responses). Although all patients who tolerated anakinra had a response, the discontinuation rate was high (eight [62%] of 13), mostly due to severe injection-site reactions (n=5). Patients were more likely to respond to azacitidine than to other therapies at 6 months (risk ratio 2·47, 95% CI 1·18-5·20; p=0·018). Absence of fever or thromboembolism at diagnosis was associated with better outcomes. By 6 months, median CRP concentrations had decreased in patients receiving tocilizumab (from 30 mg/L [IQR 13-45] to 4 mg/L [3-37]) or anakinra (from 18 mg/L [11-52] to 2 mg/L [1-28]), whereas azacitidine showed the greatest increase in haemoglobin (from mean concentration 104 g/L [SD 17·5] to 120 g/L [14·4]). 28 (39%) of 71 treatments were discontinued, most commonly due to serious adverse events (12 [17%]) and death (nine [13%]). Infections were most frequent with azacitidine (eight [62%] of 13) and tocilizumab (nine [47%] of 19).
    INTERPRETATION: In this UK cohort of patients with VEXAS syndrome, azacitidine and tocilizumab showed superior effectiveness compared with anakinra, baricitinib, and prednisolone only. Treatment selection should consider individual risk factors and tolerability. Prospective studies are needed to confirm optimal treatment strategies and develop standardised protocols.
    FUNDING: None.
    DOI:  https://doi.org/10.1016/S2665-9913(25)00034-7