Early Therapeutic Drug Monitoring Optimizes Teicoplanin Use in Febrile Neutropenic Patients with Hematological Malignancies.

INTRODUCTION: A target trough concentration (Cmin) of teicoplanin ≥ 15-20 mg/L between the fourth and sixth day has been suggested for severe infections or management of febrile neutropenia (FN). Owing to no reports discussing the impact of early target attainment on treatment outcomes, this study aimed to evaluate the dose-Cmin relationship and clinical outcome and estimate the optimal early target Cmin for FN in patients with hematological malignancies. METHODS: This single-center, prospective study enrolled patients with hematological malignancies who were treated with teicoplanin either as an empirical antibiotic for FN or as targeted treatment for Gram-positive bacteria. Blood samples were collected on day three (48 h) post-loading doses, day 5 (96 h), and day 8 (when applicable) and determined by ultrahigh-pressure liquid chromatography-triple quadruple mass spectrometry. A total of 117 samples from 47 patients with FN (27 men, 20 women) were consecutively analyzed. A two-tailed α value of 0.05 was considered statistically significant. RESULTS: The mean Cmin values at 48 h, 96 h, and on day 8 were 23.4, 21.4, and 27.8 mg/L, respectively. The patients achieving Cmin ≥ 20 mg/L at 48 h had a higher likelihood of treatment success. The areas under the receiver operating characteristic curves were 0.71 for clinical efficacy and the cutoff value of Cmin at 48 h was 18.85 mg/L (95% confidence interval 0.55-0.87; P = 0.018). CONCLUSIONS: The Cmin of teicoplanin after completion of loading doses could predict the treatment response, with a target concentration ≥ 18.85 mg/L.

Stellae-123 gene expression signature improved risk stratification in taiwanese acute myeloid leukemia patients.

The European Leukemia Net recommendations provide valuable guidance in treatment decisions of patients with acute myeloid leukemia (AML). However, the genetic complexity and heterogeneity of AML are not fully covered, notwithstanding that gene expression analysis is crucial in the risk stratification of AML. The Stellae-123 score, an AI-based model that captures gene expression patterns, has demonstrated robust survival predictions in AML patients across four western-population cohorts. This study aims to evaluate the applicability of Stellae-123 in a Taiwanese cohort. The Stellae-123 model was applied to 304 de novo AML patients diagnosed and treated at the National Taiwan University Hospital. We find that the pretrained (BeatAML-based) model achieved c-indexes of 0.631 and 0.632 for the prediction of overall survival (OS) and relapse-free survival (RFS), respectively. Model retraining within our cohort further improve the cross-validated c-indexes to 0.667 and 0.667 for OS and RFS prediction, respectively. Multivariable analysis identify both pretrained and retrained models as independent prognostic biomarkers. We further show that incorporating age, Stellae-123, and ELN classification remarkably improves risk stratification, revealing c-indices of 0.73 and 0.728 for OS and RFS, respectively. In summary, the Stellae-123 gene expression signature is a valuable prognostic tool for AML patients and model retraining can improve the accuracy and applicability of the model in different populations.

Association of JAK2V617F allele burden and clinical correlates in polycythemia vera: a systematic review and meta-analysis.

Janus kinase 2 (JAK2) V617F mutation is present in most patients with polycythemia vera (PV). One persistently puzzling aspect unresolved is the association between JAK2V617F allele burden (also known as variant allele frequency) and the relevant clinical characteristics. Numerous studies have reported associations between allele burden and both hematologic and clinical features. While there are strong indications linking high allele burden in PV patients with symptoms and clinical characteristics, not all associations are definitive, and disparate and contradictory findings have been reported. Hence, this study aimed to synthesize existing data from the literature to better understand the association between JAK2V617F allele burden and relevant clinical correlates. Out of the 1,851 studies identified, 39 studies provided evidence related to the association between JAK2V617F allele burden and clinical correlates, and 21 studies were included in meta-analyses. Meta-analyses of correlation demonstrated that leucocyte and erythrocyte counts were significantly and positively correlated with JAK2V617F allele burden, whereas platelet count was not. Meta-analyses of standardized mean difference demonstrated that leucocyte and hematocrit were significantly higher in patients with higher JAK2V617F allele burden, whereas platelet count was significantly lower. Meta-analyses of odds ratio demonstrated that patients who had higher JAK2V617F allele burden had a significantly greater odds ratio for developing pruritus, splenomegaly, thrombosis, myelofibrosis, and acute myeloid leukemia. Our study integrates data from approximately 5,462 patients, contributing insights into the association between JAK2V617F allele burden and various hematological parameters, symptomatic manifestations, and complications. However, varied methods of data presentation and statistical analyses prevented the execution of high-quality meta-analyses.

CEBPA mutations in acute myeloid leukemia: implications in risk stratification and treatment.

Mutations in CCAAT enhancer binding protein α (CEBPA) occur in approximately 10% of patients with de novo acute myeloid leukemia (AML). Emerging evidence supports that in-frame mutations in the basic leucine zipper domain of CEBPA (CEBPAbZIP-inf) confer a survival benefit, and CEBPAbZIP-inf replaced CEBPA double mutations (CEBPAdm) as a unique entity in the 2022 World Health Organization (WHO-2022) classification and International Consensus Classification (ICC). However, challenges remain in daily clinical practice since more than 30% patients with CEBPAbZIP-inf die of AML despite intensive treatment. This review aims to provide a comprehensive summary of the heterogeneities observed in AML with CEBPAdm and CEBPAbZIP-inf, and will discuss the prognostic implications of concurrent mutations and novel mechanistic targets that may inform future drug development. The ultimate goal is to optimize clinical management and to provide precision medicine for this category of patients.

Comparison of the 2022 world health organization classification and international consensus classification in myelodysplastic syndromes/neoplasms.

In 2022, two novel classification systems for myelodysplastic syndromes/neoplasms (MDS) have been proposed: the International Consensus Classification (ICC) and the 2022 World Health Organization (WHO-2022) classification. These two contemporary systems exhibit numerous shared features but also diverge significantly in terminology and the definition of new entities. Thus, we retrospectively validated the ICC and WHO-2022 classification and found that both systems promoted efficient segregation of this heterogeneous disease. After examining the distinction between the two systems, we showed that a peripheral blood blast percentage ≥ 5% indicates adverse survival. Identifying MDS/acute myeloid leukemia with MDS-related gene mutations or cytogenetic abnormalities helps differentiate survival outcomes. In MDS, not otherwise specified patients, those diagnosed with hypoplastic MDS and single lineage dysplasia displayed a trend of superior survival compared to other low-risk MDS patients. Furthermore, the impact of bone marrow fibrosis on survival was less pronounced within the ICC framework. Allogeneic transplantation appears to improve outcomes for patients diagnosed with MDS with excess blasts in the ICC. Therefore, we proposed an integrated system that may lead to the accurate diagnosis and advancement of future research for MDS. Prospective studies are warranted to validate this refined classification.

Kinome expression profiling improves risk stratification and therapeutic targeting in myelodysplastic syndromes.

The human kinome, which comprises over five hundred kinases, plays a critical role in regulating numerous essential cellular functions. Although the dysregulation of kinases has been observed in various human cancers, the characterization and clinical implications of kinase expressions in myelodysplastic syndrome (MDS) have not been systematically investigated. In this study, we evaluated the kinome expression profiles of 341 adult patients with primary MDS and identified seven kinases (PTK7, KIT, MAST4, NTRK1, PAK6, CAMK1D, and PRKCZ) whose expression levels were highly predictive of compromised patient survival. We then constructed the KInase Stratification Score (KISS) by combining the weighted expressions of the seven kinases, and validated its prognostic significance in two external MDS cohorts. A higher KISS was associated with older age, higher peripheral blood and marrow blast percentages, higher Revised International Prognostic Scoring System (IPSS-R) risks, complex karyotype, and mutations in several adverse-risk genes in MDS, such as ASXL1, EZH2, NPM1, RUNX1, STAG2, and TP53. Multivariate analysis confirmed that a higher KISS was an independent unfavorable risk factor in MDS. Mechanistically, the KISS-high patients were enriched for genesets associated with hematopoietic and leukemic stem cell signatures. By investigating the Genomics of Drug Sensitivity in Cancer (GDSC) database, we identified axitinib and taselisib as candidate compounds that could potentially target the KISS-high myeloblasts. Altogether, our findings suggest that KISS holds the potential to improve the current prognostic scheme of MDS and inform novel therapeutic opportunities.

Dysregulated immune and metabolic pathways are associated with poor survival in adult acute myeloid leukemia with CEBPA bZIP in-frame mutations.

Acute myeloid leukemia (AML) with CEBPA bZIP in-frame mutations (CEBPAbZIP-inf) is classified within the favorable-risk group by the 2022 European LeukemiaNet (ELN-2022). However, heterogeneous clinical outcomes are still observed in these patients. In this study, we aimed to investigate the mutation profiles and transcriptomic patterns associated with poor outcomes in patients with CEBPAbZIP-inf. One hundred and thirteen CEBPAbZIP-inf patients were identified in a cohort of 887 AML patients homogeneously treated with intensive chemotherapy. Concurrent WT1 or DNMT3A mutations significantly predicted worse survival in AML patients with CEBPAbZIP-inf. RNA-sequencing analysis revealed an enrichment of interferon (IFN) signaling and metabolic pathways in those with a shorter event-free survival (EFS). CEBPAbZIP-inf patients with a shorter EFS had higher expression of IFN-stimulated genes (IRF2, IRF5, OAS2, and IFI35). Genes in mitochondrial complexes I (NDUFA12 and NDUFB6) and V (ATP5PB and ATP5IF1) were overexpressed and were associated with poorer survival, and the results were independently validated in the TARGET AML cohort. In conclusion, concurrent WT1 or DNMT3A mutations and a dysregulated immune and metabolic state were correlated with poor survival in patients with CEBPAbZIP-inf, and upfront allogeneic transplantation may be indicated for better long-term disease control.

Sabatolimab plus hypomethylating agents in previously untreated patients with higher-risk myelodysplastic syndromes (STIMULUS-MDS1): a randomised, double-blind, placebo-controlled, phase 2 trial.

BACKGROUND: Sabatolimab is an immunotherapy targeting T-cell immunoglobulin domain and mucin domain-3 (TIM-3), an immuno-myeloid regulator expressed on immune cells and leukaemic stem cells. In this trial, we compared the efficacy and safety of sabatolimab plus hypomethylating agent with placebo plus hypomethylating agents in previously untreated patients with higher-risk myelodysplastic syndromes. METHODS: STIMULUS-MDS1 was a multicentre, randomised, double-blind, placebo-controlled, phase 2 study done at 54 investigational sites in 17 countries. Adult patients (aged ≥18 years) with intermediate-risk, high-risk, and very high-risk myelodysplastic syndromes (according to Revised International Prognostic Scoring System criteria) who had not received previous treatment were included. Patients were randomly assigned (1:1) to intravenous sabatolimab (400 mg on day 8 and 22) or placebo plus a hypomethylating agent (intravenous decitabine 20 mg/m2 on day 1-5 or intravenous or subcutaneous azacitidine 75 mg/m2 on day 1-7 or day 1-5 and day 8 and 9) every 28 days until treatment discontinuation. The two primary endpoints were complete response rate and progression-free survival, assessed in the full analysis set, which included all randomly assigned patients. Complete response was analysed, as prespecified, 7 months after the last patient was randomly assigned. All other analyses presented, including progression-free survival, were done at the final data cutoff prespecified via a protocol amendment on Sept 2, 2021. Safety was assessed in in all patients who received at least one dose of study treatment. This study is registered with ClinicalTrials.gov, NCT03946670, and is ongoing. FINDINGS: Between July 29, 2019, and Aug 10, 2020, 127 patients were randomly assigned to sabatolimab plus a hypomethylating agent group (sabatolimab group; n=65) or placebo plus a hypomethylating agent (placebo group; n=62). The median age of participants was 73 years (IQR 69-77), of whom 86 (68%) of 127 patients were male and 77 (61%) were White. The primary endpoints were not met. Complete response (cutoff date of March 10, 2021) was achieved in 14 (22%; 95% CI 12·3-33·5) of 65 patients in the sabatolimab group vs 11 (18%; 9·2-29·5) of 62 patients in the placebo group (p=0·77). At the cutoff date of the final analysis (March 1, 2022), median follow-up for progression-free survival was 17·8 months (IQR 16·6-19·4) in the sabatolimab group and 19·2 months (17·7-22·3) in the placebo group, and the median progression-free survival was 11·1 months (95% CI 7·6-17·6) in the sabatolimab group vs 8·5 months (6·9-11·3) in the placebo group (hazard ratio 0·75 [95% CI 0·48-1·17]; p=0·1022). The most common adverse events of any grade were neutropenia (35 [56%] of 62 patients in the sabatolimab group vs 43 [68%] of 63 patients in the placebo group), thrombocytopenia (30 [48%] vs 32 [51%]), constipation (29 [47%] vs 24 [38%]), diarrhoea (27 [44%] vs 14 [22%]), anaemia (22 [35%] vs 34 [54%]), febrile neutropenia (22 [35%] vs 15 [24%]), and leukopenia (15 [24%] vs 20 [32%]). One patient developed a serious potential treatment-related immune-mediated adverse event in the sabatolimab group. There was one treatment-related death in the sabatolimab group due to pneumonitis. INTERPRETATION: The addition of sabatolimab to hypomethylating agents in this study did not result in a significant improvement in complete response rates or progression-free survival. Sabatolimab had a manageable safety in most patients with higher-risk myelodysplastic syndromes. A randomised phase 3 trial is ongoing to assess the potential benefit of sabatolimab plus azacitidine on overall survival in this setting. FUNDING: Novartis Pharmaceuticals.

Study Protocol of a Randomized Controlled Clinical Trial to Evaluate the Efficacy and Safety of Ropeginterferon Alfa-2b in COVID-19 Patients with Comorbidities.

INTRODUCTION: Ropeginterferon alfa-2b represents a new-generation PEGylated interferon. It is approved for the treatment of polycythemia vera and shows promising anti-SARS-CoV-2 activities. OBJECTIVE: This clinical study aims to evaluate the efficacy and safety of ropeginterferon alfa-2b in patients with coronavirus disease 2019 (COVID-19) and comorbidities. METHODS: The randomized controlled study is designed to enroll adult patients with COVID-19 infection and comorbidities. Patients are non-responders to anti-SARS-CoV-2 drugs or not suitable to receive them. Comorbidities include hematologic cancer, solid tumor, and well-controlled autoimmune disease. Non-responders to anti-SARS-CoV-2 drugs are defined as having received treatment but have a Ct value < 30 at 14 days after symptom onset. Patients are randomized in a 1:1 ratio to receive ropeginterferon alfa-2b at 250 µg plus standard of care (SOC) or SOC alone. SARS-CoV-2 antigen test will be conducted at day 15 and day 29 visits to determine whether to administer additional ropeginterferon alfa-2b doses. Patients who are positive on the antigen test on days 15 and 29 will receive the second and third doses of ropeginterferon alfa-2b at 350 µg and 500 µg, respectively. Patients with a negative antigen test but a Ct value < 30 by reverse transcription polymerase chain reaction (RT-PCR) at days 15 and 29 are also administered the second (350 µg) and third (500 µg) doses. Patients at high risk of COVID-19 rebound/relapse, e.g., immunocompromised patients, will be given additional ropeginterferon alfa-2b doses even if the Ct is ≥ 30. Approximately 60 patients will be enrolled. PLANNED OUTCOMES: The primary outcome is to compare the time from randomization to the achievement of Ct value ≥ 30 by RT-PCR between ropeginterferon alfa-2b and control groups. Our previous studies have shown safety and promising anti-SARS-CoV-2 activities in patients with moderate or severe COVID-19. This study will provide valuable data in patients with COVID-19 and comorbidities, for whom safe and effective treatment is urgently needed. TRIAL REGISTRATION NUMBER: This trial is registered at ClinicalTrials.gov (Identifier NCT05808322).

Anti-leukemia effects of omipalisib in acute myeloid leukemia: inhibition of PI3K/AKT/mTOR signaling and suppression of mitochondrial biogenesis.

Omipalisib (GSK2126458), a potent dual PI3K/mTOR inhibitor, is reported to exhibit anti-tumor effect in several kinds of cancers. More than 50% of acute myeloid leukemia (AML) patients display a hyperactivation of PI3K/AKT/mTOR signaling. We investigated the anti-proliferative effect of omipalisib in AML cell lines with varied genetic backgrounds. The OCI-AML3 and THP-1 cell lines had a significant response to omipalisib, with IC50 values of 17.45 nM and 8.93 nM, respectively. We integrated transcriptomic profile and metabolomic analyses, and followed by gene set enrichment analysis (GSEA) and metabolite enrichment analysis. Our findings showed that in addition to inhibiting PI3K/AKT/mTOR signaling and inducing cell cycle arrest at the G0/G1 phase, omipalisib also suppressed mitochondrial respiration and biogenesis. Furthermore, omipalisib downregulated several genes associated with serine, glycine, threonine, and glutathione metabolism, and decreased their protein and glutathione levels. In vivo experiments revealed that omipalisib significantly inhibited tumor growth and prolonged mouse survival without weight loss. Gedatolisib and dactolisib, another two PI3K/mTOR inhibitors, exerted similar effects without affecting mitochondria biogenesis. These results highlight the multifaceted anti-leukemic effect of omipalisib, revealing its potential as a novel therapeutic agent in AML treatment.

Management of classical Philadelphia chromosome-negative myeloproliferative neoplasms in Asia: consensus of the Asian Myeloid Working Group.

Myeloproliferative neoplasms (MPN) are a heterogeneous group of clonal hematopoietic stem cell disorders characterized clinically by the proliferation of one or more hematopoietic lineage(s). The classical Philadelphia-chromosome (Ph)-negative MPNs include polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF). The Asian Myeloid Working Group (AMWG) comprises representatives from fifteen Asian centers experienced in the management of MPN. This consensus from the AMWG aims to review the current evidence in the risk stratification and treatment of Ph-negative MPN, to identify management gaps for future improvement, and to offer pragmatic approaches for treatment commensurate with different levels of resources, drug availabilities and reimbursement policies in its constituent regions. The management of MPN should be patient-specific and based on accurate diagnostic and prognostic tools. In patients with PV, ET and early/prefibrotic PMF, symptoms and risk stratification will guide the need for early cytoreduction. In younger patients requiring cytoreduction and in those experiencing resistance or intolerance to hydroxyurea, recombinant interferon-α preparations (pegylated interferon-α 2A or ropeginterferon-α 2b) should be considered. In myelofibrosis, continuous risk assessment and symptom burden assessment are essential in guiding treatment selection. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) in MF should always be based on accurate risk stratification for disease-risk and post-HSCT outcome. Management of classical Ph-negative MPN entails accurate diagnosis, cytogenetic and molecular evaluation, risk stratification, and treatment strategies that are outcome-oriented (curative, disease modification, improvement of quality-of-life).

Validation of the molecular international prognostic scoring system in patients with myelodysplastic syndromes defined by international consensus classification.

Myelodysplastic syndromes (MDS) have varied prognoses and require a risk-adapted treatment strategy for treatment optimization. Recently, a molecular prognostic model (Molecular International Prognostic Scoring System [IPSS-M]) that combines clinical parameters, cytogenetic abnormalities, and mutation topography was proposed. This study validated the IPSS-M in 649 patients with primary MDS (based on the 2022 International Consensus Classification [ICC]) and compared its prognostic power to those of the IPSS and revised IPSS (IPSS-R). Overall, 42.5% of the patients were reclassified and 29.3% were up-staged from the IPSS-R. After the reclassification, 16.9% of the patients may receive different treatment strategies. The IPSS-M had greater discriminative potential than the IPSS-R and IPSS. Patients with high, or very high-risk IPSS-M might benefit from allogeneic hematopoietic stem cell transplantation. IPSS-M, age, ferritin level, and the 2022 ICC categorization predicted outcomes independently. After analyzing demographic and genetic features, complementary genetic analyses, including KMT2A-PTD, were suggested for accurate IPSS-M categorization of patients with ASXL1, TET2, STAG2, RUNX1, SF3B1, SRSF2, DNMT3A, U2AF1, and BCOR mutations and those classified as MDS, not otherwise specified with single lineage dysplasia/multi-lineage dysplasia based on the 2022 ICC. This study confirmed that the IPSS-M can better risk-stratified MDS patients for optimized therapeutic decision-making.

TP53 status and impact on AML prognosis within the ELN 2022 risk classification.

This study reports the following: (1) frequency of TP53 comutation within each component of the European LeukemiaNet 2022 acute myeloid leukemia risk classification, (2) relevance of TP53 mutated variant allelic fraction <10%, (3) prognostic impact of -7, -5/del(5q), -17/abn(17p), complex karyotype/monosomal karyotype, or myelodysplasia-related gene mutations with/without mutated TP53.

Evaluation of the clinical significance of global mRNA alternative splicing in patients with acute myeloid leukemia.

Aberrant alternative splicing (AS) is involved in leukemogenesis. This study explored the clinical impact of alterations in global AS patterns in 341 patients with acute myeloid leukemia (AML) newly diagnosed at the National Taiwan University Hospital and validated it using The Cancer Genome Atlas (TCGA) cohort. While studying normal cord blood CD34+ /CD38- cells, we found that AML cells exhibited significantly different global splicing patterns. AML with mutated TP53 had a particularly high degree of genome-wide aberrations in the splicing patterns. Aberrance in the global splicing pattern was an independent unfavorable prognostic factor affecting the overall survival of patients with AML receiving standard intensive chemotherapy. The integration of global splicing patterns into the 2022 European LeukemiaNet risk classification could stratify AML patients into four groups with distinct prognoses in both our experimental and TCGA cohorts. We further identified four genes with AS alterations that harbored prognostic significance in both of these cohorts. Moreover, these survival-associated AS events are involved in several important cellular processes that might be associated with poor response to intensive chemotherapy. In summary, our study demonstrated the clinical and biological implications of differential global splicing patterns in AML patients. Further studies with larger prospective cohorts are required to confirm these findings.

Validation of the prognostic significance of the 2022 European LeukemiaNet risk stratification system in intensive chemotherapy treated aged 18 to 65 years patients with de novo acute myeloid leukemia.

The European LeukemiaNet (ELN) recently proposed a revised recommendation for the diagnosis and management of acute myeloid leukemia (AML) in adults, recognized as ELN-2022. However, validation in a large real-world cohort remains lacking. In this study, we aimed to validate the prognostic relevance of the ELN-2022 in a cohort of 809 de novo, non-M3, younger (ages 18-65 years) AML patients receiving standard chemotherapy. The risk categories of 106 (13.1%) patients were reclassified from that determined using ELN-2017 to that determined using ELN-2022. The ELN-2022 effectively helped distinguish patients as favorable, intermediate, and adverse risk groups in terms of remission rates and survival. Among patients who achieved first complete remission (CR1), allogeneic transplantation was beneficial for those in the intermediate risk group, but not for those in the favorable or adverse risk groups. We further refined the ELN-2022 system by re-categorizing AML patients with t(8;21)(q22;q22.1)/RUNX1::RUNX1T1 with KIThigh , JAK2 or FLT3-ITDhigh mutations into the intermediate risk subset, AML patients with t(7;11)(p15;p15)/NUP98::HOXA9 and AML patients with co-mutated DNMT3A and FLT3-ITD into the adverse risk subsets, and AML patients with complex or monosomal karyotypes, inv (3)(q21.3q26.2) or t(3;3)(q21.3;q26.2)/GATA2,MECOM(EVI1) or TP53 mutation into the very adverse risk subset. The refined ELN-2022 system performed effectively to distinguish patients as favorable, intermediate, adverse, and very adverse risk groups. In conclusion, the ELN-2022 helped distinguish younger, intensively treated patients into three groups with distinct outcomes; the proposed refinement of ELN-2022 may further improve risk stratification among AML patients. Prospective validation of the new predictive model is necessary.

A three-gene leukaemic stem cell signature score is robustly prognostic in chronic myelomonocytic leukaemia.

Leukaemic stem cell (LSC) gene expression has recently been linked to prognosis in patients with acute myeloid leukaemia (17-gene LSC score, LSC-17) and myelodysplastic syndromes. Although chronic myelomonocytic leukaemia (CMML) is regarded as a stem cell disorder, the clinical and biological impact of LSCs on CMML patients remains elusive. Making use of multiple independent validation cohorts, we here describe a concise three-gene expression signature (LSC-3, derived from the LSC-17 score) as an independent and robust prognostic factor for leukaemia-free and overall survival in CMML. We propose that LSC-3 could be used to supplement existing risk stratification systems, to improve prognostic performance and guide management decisions.

Oxidized Mitochondrial DNA Engages TLR9 to Activate the NLRP3 Inflammasome in Myelodysplastic Syndromes.

Myelodysplastic Syndromes (MDSs) are bone marrow (BM) failure malignancies characterized by constitutive innate immune activation, including NLRP3 inflammasome driven pyroptotic cell death. We recently reported that the danger-associated molecular pattern (DAMP) oxidized mitochondrial DNA (ox-mtDNA) is diagnostically increased in MDS plasma although the functional consequences remain poorly defined. We hypothesized that ox-mtDNA is released into the cytosol, upon NLRP3 inflammasome pyroptotic lysis, where it propagates and further enhances the inflammatory cell death feed-forward loop onto healthy tissues. This activation can be mediated via ox-mtDNA engagement of Toll-like receptor 9 (TLR9), an endosomal DNA sensing pattern recognition receptor known to prime and activate the inflammasome propagating the IFN-induced inflammatory response in neighboring healthy hematopoietic stem and progenitor cells (HSPCs), which presents a potentially targetable axis for the reduction in inflammasome activation in MDS. We found that extracellular ox-mtDNA activates the TLR9-MyD88-inflammasome pathway, demonstrated by increased lysosome formation, IRF7 translocation, and interferon-stimulated gene (ISG) production. Extracellular ox-mtDNA also induces TLR9 redistribution in MDS HSPCs to the cell surface. The effects on NLRP3 inflammasome activation were validated by blocking TLR9 activation via chemical inhibition and CRISPR knockout, demonstrating that TLR9 was necessary for ox-mtDNA-mediated inflammasome activation. Conversely, lentiviral overexpression of TLR9 sensitized cells to ox-mtDNA. Lastly, inhibiting TLR9 restored hematopoietic colony formation in MDS BM. We conclude that MDS HSPCs are primed for inflammasome activation via ox-mtDNA released by pyroptotic cells. Blocking the TLR9/ox-mtDNA axis may prove to be a novel therapeutic strategy for MDS.

Poor prognostic implications of myelodysplasia-related mutations in both older and younger patients with de novo AML.

A set of myelodysplasia-related (MDS-R) gene mutations are incorporated into the 2022 European LeukemiaNet risk classification as adverse genetic factors for acute myeloid leukemia (AML) based on their poor prognostic impact on older patients. The impact of these mutations on younger patients (age < 60 years) remains elusive. In the study of 1213 patients with de novo non-M3 AML, we identified MDS-R mutations in 32.7% of the total cohort, 44.9% of older patients and 23.4% of younger patients. The patients with MDS-R mutations had a significantly lower complete remission rate in both younger and older age groups. With a median follow-up of 9.2 years, the MDS-R group experienced shorter overall survival (P = 0.034 for older and 0.035 for younger patients) and event-free survival (P = 0.004 for older and 0.042 for younger patients). Furthermore, patients with MDS-R mutations more frequently harbored measurable residual disease that was detectable using next generation sequencing at morphological CR than those without MDS-R mutations. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) might ameliorate the negative impact of MDS-R mutations. In summary, AML patients with MDS-R mutations have significantly poorer outcomes regardless of age. More intensive treatment, such as allo-HSCT and/or novel therapies, is warranted for AML patients with MDS-R mutations.