Epidemiology of acute myeloid leukemia: Recent progress and enduring challenges

Potential effects of liver dysfunction at the time of diagnosis in patients with acute myeloid leukemia

Whilst severe liver dysfunction is rarely encountered at the time of diagnosis for patients with acute myeloid leukemia (AML), mild elevations aminotransferase (<5 times the upper limit of normal) may be more frequently seen. Liver dysfunction at the time of diagnosis of AML is a parameter that requires investigation and can assist the clinicians in predicting prognosis. The aim of the present study was to investigate liver dysfunction at the time of diagnosis using the assoicated parameters in patients with AML. The present retrospective study included 90 patients diagnosed with AML who were hospitalised in the Hematology Clinic of Dışkapı Yıldırım Beyazıt Training and Research Hospital (Ankara, Turkey). The demographic characteristics of the patients were recorded together with hemogram results, anemia parameters, measurable residual disease positivity (MRD) and risk category, the presence of hepatosplenomegaly, infection, neutrophil recovery time (NRT), platelet recovery time (PRT) and liver dysfunction. The patients were analyzed in two groups following sorting into the liver dysfunction (n=45) and normal liver function test group (n=45). In the analysis of independent quantitative data (age, white blood cell count, hemoglobin, platelet, international normalized ratio, albumin, B12 vitamin, NRT, PRT) the Mann Whitney U-test was used. Independent qualitative data (sex, hepatomegaly, splenomegaly, MRD, risk category, infection) were analyzed using the χ2 test or the Fischer test. The effect level was investigated using univariate and multivariate logistic regression. A receiver operating characteristic curve was applied to determine the effect level and cut-off values. In the group with liver dysfunction, NRT, PRT, MRD positivity, risk category and the presence of infection were found to be statistically significantly higher. These findings suggest that during the first evaluation of patients diagnosed with AML, liver function tests are simple, rapid and necessary. The results obtained in the present study showed that liver dysfunction at diagnosis can be associated with the high-risk group, in addition to more frequent infection, poorer prognosis and mortality.

Midostaurin shapes macroclonal and microclonal evolution of FLT3-mutated acute myeloid leukemia

ABSTRACT

Despite the use of midostaurin (MIDO) with intensive chemotherapy (ICT) as frontline treatment for Fms-like tyrosine kinase 3 (FLT3)-mutated acute myeloid leukemia (AML), complete remission rates are close to 60% to 70%, and relapses occur in >40% of cases. Here, we studied the molecular mechanisms underlying refractory/relapsed (R/R) disease in patients with FLT3-mutated AML. We conducted a retrospective and multicenter study involving 150 patients with R/R AML harboring FLT3-internal tandem duplication (ITD) (n = 130) and/or FLT3-tyrosine kinase domain mutation (n = 26) at diagnosis assessed by standard methods. Patients were treated with ICT + MIDO (n = 54) or ICT alone (n = 96) according to the diagnosis date and label of MIDO. The evolution of FLT3 clones and comutations was analyzed in paired diagnosis-R/R samples by targeted high-throughput sequencing. Using a dedicated algorithm for FLT3-ITD detection, 189 FLT3-ITD microclones (allelic ratio [AR] of <0.05) and 225 macroclones (AR ≥ 0.05) were detected at both time points. At R/R disease, the rate of FLT3-ITD persistence was lower in patients treated with ICT + MIDO than in patients not receiving MIDO (68% vs 87.5%; P = .011). In patients receiving ICT + MIDO, detection of multiple FLT3-ITD clones was associated with a higher FLT3-ITD persistence rate at R/R disease (multiple clones: 88% vs single clones: 57%; P = .049). If only 24% of FLT3-ITD microclones detected at diagnosis were retained at relapse, 43% became macroclones. Together, these results identify parameters influencing the fitness of FLT3-ITD clones.

ARTN and CCL23 predicted chemosensitivity in acute myeloid leukemia: an Olink® proteomics approach

BACKGROUND

The standard "7 + 3" induction results in 30% of de novo acute myeloid leukemia (AML) patients not achieving complete remission (CR). We aimed to utilize the Olink® platform to compare the bone marrow plasma proteomic profiles of newly diagnosed de novo AML patients who did and did not achieve CR following "7 + 3" induction treatment.

METHODS

This prospective study included 43 untreated AML patients, stratified into CR (n = 29) and non-CR (n = 14) groups based on their response to "7 + 3" induction therapy. We employed the Olink® Explore-384 Inflammation platform for proteomic analysis to investigate differences in bone marrow plasma protein levels between the CR and non-CR groups.

RESULTS

Proteomic analysis demonstrated that the CR group exhibited significantly higher bone marrow plasma levels of ARTN and CCL23 than did the non-CR group. Immunohistochemical staining confirmed a higher proportion of tissue samples with intense staining for ARTN (25.40% vs. 7.05%, p = 0.013) and CCL23 (24.14% vs. 14.29%, p = 0.039) in the CR group. These findings were corroborated by bulk-RNA-seq, which indicated significantly elevated mRNA expression levels of ARTN (1.93 vs. -0.09; p = 0.003) and CCL23 (1.50 vs. 0.12; p = 0.021) in the CR group. The Human Protein Atlas provided external support for our findings.

CONCLUSIONS

The results suggest that ARTN and CCL23 may serve as biomarkers for predicting responsiveness to the "7 + 3" induction in untreated AML. Using an enzyme-linked immunosorbent assay to identify the roles of ARTN and CCL23 in predicting AML chemosensitivity may enhance clinical applicability in the future.

Hypoxia impairs decitabine-induced expression of HLA-DR in acute myeloid leukaemia cell lines

BACKGROUND

Hypomethylating agents (HMA), such as azacytidine (AZA) and decitabine (DAC), are epigenetic therapies used to treat some patients with acute myeloid leukaemia (AML) and myelodysplastic syndrome. HMAs act in a replication-dependent manner to remove DNA methylation from the genome. However, AML cells targeted by HMA therapy are often quiescent within the bone marrow, where oxygen levels are low. In this study, we investigate the effects of hypoxia on HMA responses in AML cells.

RESULTS

AML cell lines (MOLM-13, MV-4-11, HL-60) were treated with DAC (100 nM) or AZA (500-2000 nM) in normoxic (21% O2) and hypoxic (1% O2) conditions. Hypoxia significantly reduced AML cell growth across all cell lines, with no additional effects observed upon HMA treatment. Hypoxia had no impact on the extent of DNA hypomethylation induced by DAC treatment, but limited AZA-induced loss of methylation from the genome. Transcriptional responses to HMA treatment were also altered, with HMAs failing to up-regulate antigen presentation pathways in hypoxia. In particular, cell surface expression of the MHC class II receptor, HLA-DR, was increased by DAC treatment in normoxia, but not hypoxia.

CONCLUSION

Our results suggest that HMA-induced antigen presentation may be impaired by hypoxia. This study highlights the need to consider microenvironmental factors when designing co-treatment strategies to improve HMA therapeutic efficacy.

Olutasidenib in combination with azacitidine induces durable complete remissions in patients with relapsed or refractory mIDH1 acute myeloid leukemia: a multicohort open-label phase 1/2 trial

BACKGROUND

Olutasidenib is a potent, selective, oral, small molecule inhibitor of mutant IDH1 (mIDH1) which induced durable remissions in high-risk, relapsed/refractory (R/R) mIDH1 AML patients in a phase 1/2 trial. We present a pooled analysis from multiple cohorts of the phase 1/2 trial of patients with R/R AML who received combination olutasidenib and azacitidine therapy.

METHODS

Adult patients with mIDH1R132 AML received 150 mg olutasidenib twice daily plus standard-of-care azacitidine (OLU + AZA) and were evaluated for response and safety.

RESULTS

Sixty-seven patients with R/R mIDH1R132 AML received combination OLU + AZA. Median age was 66 years (range 28-82) and 54% were male. Most patients (83%) had 2 + prior regimens, including a hypomethylating agent in 40%, IDH1 inhibitor therapy in 31% (olutasidenib in 24%), and hematopoietic stem cell transplant in 10%. Cytogenetic risk was intermediate in 72%, poor in 18% and unknown in 10%. CR/CRh was achieved in 21/67 (31%; 95% CI 21-44) patients, with a median duration of 14.7 months (95% CI 4.6-not reached). CR was achieved in 18/67 (27%; 95% CI 17-39) patients, with median duration of 20.3 months (95% CI 3.7-not reached). Overall response (partial remission or better) was achieved in 34/67 (51%; 95% CI 38-63) patients. Median overall survival was 12.9 months (95% CI 18.7-19.3). In a subset analysis excluding patients who had prior OLU exposure (N = 51), CR/CRh was achieved in 19/51 (37%; 95% CI 24-52) patients, CR was achieved in 16/51 (31%; 95% CI 19-46), and overall response was achieved in 30/51 (59%; 95% CI 44-72). In patients who achieved CR/CRh and were transfusion-dependent at baseline, transfusion independence (RBC and platelets) was achieved in 64% (7/11) and 57% (4/7) of patients, respectively. The most common Grade 3 or 4 adverse events (> 20% patients) were decreased platelet count (37%), red blood cell count (25%), and neutrophil count (24%). Six patients (9%) experienced differentiation syndrome. Four (6%) discontinued treatment due to an adverse event.

CONCLUSIONS

Olutasidenib plus azacitidine induced high response rates and durable remissions with a tolerable side effect profile in patients with R/R AML with diverse treatment histories. The results represent another therapeutic option for patients with mIDH1 AML who may benefit from a targeted therapy.

TRIAL REGISTRATION

NCT02719574.

Crosstalk between genomic variants and DNA methylation in FLT3 mutant acute myeloid leukemia

Acute myeloid leukemia (AML) is a type of blood cancer with diverse genetic variations and DNA methylation alterations. By studying the interaction of gene mutations, expression, and DNA methylation, we aimed to gain valuable insights into the processes that lead to block differentiation in AML. We analyzed TCGA-LAML data (173 samples) with RNA sequencing and DNA methylation arrays, comparing FLT3 mutant (48) and wild-type (125) cases. We conducted differential gene expression analysis using cBioPortal, identified DNA methylation differences with ChAMP tool, and correlated them with gene expression changes. Gene set enrichment analysis (g:Profiler) revealed significant biological processes and pathways. ShinyGo and GeneCards were used to find potential transcription factors and their binding sites among significant genes. We found significant differentially expressed genes (DEGs) negatively correlated with their most significant methylation probes (Pearson correlation coefficient of -0.49, P-value <0.001) between FLT3 mutant and wild-type groups. Moreover, our exploration of 450 k CpG sites uncovered a global hypo-methylated status in 168 DEGs. Notably, these methylation changes were enriched in the promoter regions of Homebox superfamily gene, which are crucial in transcriptional-regulating pathways in blood cancer. Furthermore, in FLT3 mutant AML patient samples, we observed overexpress of WT1, a transcription factor known to bind homeobox gene family. This finding suggests a potential mechanism by which WT1 recruits TET2 to demethylate specific genomic regions. Integrating gene expression and DNA methylation analyses shed light on the impact of FLT3 mutations on cancer cell development and differentiation, supporting a two-hit model in AML. This research advances understanding of AML and fosters targeted therapeutic strategy development.

Screening of necroptosis-related genes and evaluating the prognostic capacity, clinical value, and the effect of their copy number variations in acute myeloid leukemia

BACKGROUND

Acute myeloid leukemia (AML) is an aggressive hematological neoplasm. Little improvement in survival rates has been achieved over the past few decades. Necroptosis has relationship with certain types of malignancies outcomes. Here, we evaluated the diagnostic ability, prognostic capacity of necroptosis-related genes (NRGs) and the effect of their copy number variations (CNVs) in AML.

METHODS

Necroptosis-related differentially expressed genes (NRDEGs) were identified after intersecting differentially expressed genes (DEGs) from the Gene Expression Omnibus(GEO) database with NRGs from GeneCards, the Molecular Signatures Database (MSigDB) and literatures. Machine learning was applied to obtain hub-NRDEGs. The expression levels of the hub-NRDEGs were validated in vitro. The mRNA-miRNA and mRNA-TF interaction networks with the hub-NRDEGs were screened using Cytoscape@. Single-sample gene set enrichment analysis (ssGSEA) was utilized to calculate correlations between the hub-NRDEGs and immune cells. CNV analysis of the hub-NRDEGs was carried out on the TCGA-LAML datasets from the TCGA database. Kaplan-Meier (K-M) survival analyses were utilized to evaluate the prognostic values along with Cox model.

RESULTS

Six hub-NRDEGs (SLC25A5, PARP1, CTSS, ZNF217, NFKB1, and PYGL) were obtained and their expression changes derived from CNVs in AML were visualized. In total, 65 mRNA-miRNA and 80 mRNA-TF interaction networks with hub-NRDEGs were screened. The ssGSEA result showed the expression of RAPR1 was inversely related to CD56dim natural killer cells and the expression of CTSS was positive related to Myeloid-derived suppressor cells (MDSCs) in AML. The K-M results demonstrated that ZNF217 had significant difference in the duration of survival in AML patients. Cox regression models revealed that the hub-NRDEGs had better predictive power at year-1 and year-5.

CONCLUSION

These screened NRDEGs can be exploited as clinical prognostic predictions in AML patients, as well as potential biomarkers for diagnosis and therapeutic targeting.

Evaluation of circ_0002232 and circ-vimentin gene expressions as valuable biomarkers in acute myeloid leukemia patients

BACKGROUND AND AIM

Acute myeloid leukemia (AML) is a remarkably complex malignancy; with considerable genetic, epigenetic, and phenotypic heterogenicity. Circ-RNAs are a novel class of non-coding RNA. They may influence leukemia development and offer exciting possibilities for targeted AML diagnosis and therapy. This study aimed to detect circ_0002232 and circ-VIM expression levels in AML patients and their relation to the clinicopathological characteristics and disease outcome to assess the prognostic potential of both circ-RNAs and achieve a new target therapy for the disease.

METHODS

Circ_0002232 and circ-VIM gene expressions were measured in 60 AML patients and 30 controls using qRT-PCR.

RESULTS

Circ_0002232 was significantly downregulated in our patients compared to controls (P value < 0.001). On the other hand, circ-VIM was notably upregulated in our patients (P value = 0.005). Using ROC curve, circ_0002232 and circ-VIM biomarkers could distinguish AML patients from controls with AUC 0.847, 0.683 and P value < 0.0001, = 0.004 respectively. Patients with downregulated circ_0002232 were significantly younger than upregulated patients (p value = 0.003). In addition, downregulated circ_0002232 was significantly associated with decreased hemoglobin level and increased overall survival (OS). Regarding high circ-VIM expression in AML patients, it was significantly correlated with lacking complete remission and leukocytosis.

CONCLUSION

Circ_0002232 and circ-VIM could be valuable diagnostic biomarkers to differentiate AML patients from healthy controls in clinical use. Circ-VIM expression may influence AML prognosis. Further research is needed to validate the clinical utility of circ_0002232 as a prognostic marker for OS in AML patients.

Overcoming CD226-related immune evasion in acute myeloid leukemia with CD38 CAR-engineered NK cells

CD226 plays a vital role in natural killer (NK) cell cytotoxicity, interacting with its ligands CD112 and CD155 to initiate immune synapse formation, primarily through leukocyte function-associated-1 (LFA-1). Our study examined the role of CD226 in NK cell surveillance of acute myeloid leukemia (AML). NK cells in patients with AML had lower expression of CD226. CRISPR-Cas9 deletion of CD226 led to reduced LFA-1 recruitment, poor synapse formation, and decreased NK cell anti-leukemic activity. Engineering NK cells to express a chimeric antigen receptor targeting the AML antigen CD38 (CAR38) could overcome the need for CD226 to establish strong immune synapses. LFA-1 blockade reduced CAR38 NK cell activity, and this depended on the CD38 expression levels of AML cells. This suggests parallel but potentially cooperative roles for LFA-1 and CAR38 in synapse formation. Our findings suggest that CAR38 NK cells could be an effective therapeutic strategy to overcome CD226-mediated immune evasion in AML.

The clinical features and outcomes of elderly patients with acute myeloid leukemia: a real word research

The aim of this study was to investigate the clinical features and outcomes of elderly patients with acute myeloid leukemia (AML) from a real word research. The clinical data of 223 consecutive elderly patients (aged ≥ 60 years) who were newly diagnosed with AML at our medical center between July 2017 and June 2022, including their clinical characteristics, genetic mutations, and survival outcomes, were retrospectively analyzed. Among the 223 patients (median age 67 years), 180 (80.7%) were diagnosed with de novo AML. Genetic mutations were identified in 138 of 149 patients tested (92.6%). The most commonly mutated genes included TET2, DNMT3A, NPM1, FLT3-ITD, ASXL1, IDH2, RUNX1, TP53, and CEBPA. Among these genes, TET2, DNMT3A, FLT3-ITD, and TP53 were associated with a poor outcome. Multivariate Cox's regression analysis revealed that age over 70 years, platelet count less than 100 × 109/L, albumin level less than 35 g/L, presence of infection or bleeding at diagnosis, untreated or best supportive care (BSC) treatment status, and adverse or intermediate ELN 2022 risk classification were independent prognostic factors for overall survival in elderly AML patients. Patients who received at least one induction cycle had longer overall survival times (20 months vs. 6.6 months, P < 0.001) than those who received best supportive care. Patients with ≥ 6 cycles of chemotherapy had longer overall survival times (89.2% vs. 78.5%, P = 0.007) than those with ≤ 5 cycles of therapy. The results of this study indicated that elderly AML patients had multiple genetic abnormalities and poor outcomes. Regular effective treatment can improve patient outcomes and survival. In addition to genetic abnormalities, several other clinical features can influence survival in elderly AML patients.

A Novel In Vitro Model of the Bone Marrow Microenvironment in Acute Myeloid Leukemia Identifies CD44 and Focal Adhesion Kinase as Therapeutic Targets to Reverse Cell Adhesion-Mediated Drug Resistance

BACKGROUND/OBJECTIVES

Acute myeloid leukemia (AML) is an aggressive neoplasm. Although most patients respond to induction therapy, they commonly relapse due to recurrent disease in the bone marrow microenvironment (BMME). So, the disruption of the BMME, releasing tumor cells into the peripheral circulation, has therapeutic potential.

METHODS

Using both primary donor AML cells and cell lines, we developed an in vitro co-culture model of the AML BMME. We used this model to identify the most effective agent(s) to block AML cell adherence and reverse adhesion-mediated treatment resistance.

RESULTS

We identified that anti-CD44 treatment significantly increased the efficacy of cytarabine. However, some AML cells remained adhered, and transcriptional analysis identified focal adhesion kinase (FAK) signaling as a contributing factor; the adhered cells showed elevated FAK phosphorylation that was reduced by the FAK inhibitor, defactinib. Importantly, we demonstrated that anti-CD44 and defactinib were highly synergistic at diminishing the adhesion of the most primitive CD34high AML cells in primary autologous co-cultures.

CONCLUSIONS

Taken together, we identified anti-CD44 and defactinib as a promising therapeutic combination to release AML cells from the chemoprotective AML BMME. As anti-CD44 is already available as a recombinant humanized monoclonal antibody, the combination of this agent with defactinib could be rapidly tested in AML clinical trials.

α-Triazolylboronic Acids: A Novel Scaffold to Target FLT3 in AML

The treatment of acute myeloid leukemia (AML) presents a challenge to current therapies because of the development of drug resistance. Genetic mutation of FMS-like tyrosine kinase-3 (FLT3) is a target of interest for AML treatment, but the use of FLT3-targeting agents on AML patients has so far resulted in poor overall clinical outcomes.[1] The incorporation of the boronic group in a drug scaffold could enhance the bioavailability and pharmacokinetic profile of conventional anticancer chemotypes. Boronic acids represent an intriguing and unexplored class of compounds in the context of AML, and they are only scantly reported as inhibitors of protein kinases. We identified α-triazolylboronic acids as a novel chemotype for targeting FLT3 by screening a library of structurally heterogeneous in-house boronic acids. Selected compounds show low micromolar activities on enzymatic and cellular assays, selectivity against control cell lines and a recurring binding mode in in-silico studies. Furthermore, control analogues synthesized ad hoc and lacking the boronic acid are inactive, confirming that this group is essential for the activity of the series. All together, these results suggest α-triazolylboronic acids could be a promising novel chemotype for FLT3 inhibition, laying the ground for the design of further compounds.

Global assessment of leukemia care quality: insights from the quality of care index (QCI) from 1990 to 2021

Background

While advancements in leukemia care have been made, the global quality of care remains a concern. This study utilizes a modified quality of care index (QCI) to assess the global status of leukemia care.

Methods

We analyzed data from the global burden of disease (GBD) study spanning 1990-2021. The QCI was constructed using principal component analysis, based on the weighted variances of key indicators. We compared the original QCI with our modified version, analyzed QCI trends across different age groups and leukemia subtypes, identified key influencing factors using linear mixed models (LMM), and used spatial autocorrelation analysis to verify the autocorrelation of the socio-demographic index (SDI) region. Then we employed the bayesian age-period-cohort (BAPC) model to predict future QCI trends.

Findings

Between 1990 and 2021, both the age-standardized incidence rate (ASIR) and age-standardized death rate (ASDR) for leukemia exhibited a consistent decline. Our modified QCI method outperformed the original approach, particularly when the variance explained by the first principal component was below 80%, demonstrating higher correlation with the healthcare access and quality index (HAQI) (Pearson r = 0.91 vs. 0.89) and improved explanatory power (R2 = 0.82 vs. 0.79). Over past three decades, QCI was highest in San Marino (97.72%) and lowest in Fiji (3.51%), with significant regional variations across SDI levels (F = 133.40, p < 2e-16). High-SDI regions had the highest QCI (78.50%; 95% confidence interval: 77.20%, 79.70%). QCI trends varied by age, peaking at 94.49% in the 15-19 age group in 2021 and declining to 0.44% in the 75-79 age group. LMM analysis identified sex, age, year, SDI region, and leukemia subtype as significant QCI determinants. Spatial autocorrelation analysis confirmed positive autocorrelation within SDI regions (Global Moran's I = 0.87, p < 2e-16). Projections suggest a generally fluctuating upward trend in QCI for leukemia, reaching 79.58% by 2046.

Interpretation

The QCI serves as an effective metric for evaluating the quality of leukemia care. Our findings reveal a strong association between leukemia QCI and regional economic and educational development. Age is a critical factor, with an aging population contributing to a potential decline in QCI. These results underscore the urgent need for targeted interventions to enhance health services for older adults and to improve care quality in economically disadvantaged regions.

Funding

This study was supported by the National Natural Science Foundation of China (General Program) (No. 82370176) and the Key Research and Development Program of Hubei Province (No. CZKYXM2023036JZ).

Targeting protein tyrosine phosphatase non-receptor type 6 (PTPN6) as a therapeutic strategy in acute myeloid leukemia

Acute myeloid leukemia (AML) is a heterogeneous hematologic malignancy characterized by the clonal expansion of myeloid progenitor cells. Despite advancements in treatment, the prognosis for AML patients remains poor, highlighting the need for novel therapeutic targets. Protein Tyrosine Phosphatase Non-Receptor Type 6 (PTPN6), also known as SHP-1, is a critical regulator of hematopoietic cell signaling and has been implicated in various leukemias. This study investigates the therapeutic potential of targeting PTPN6 in AML. We employed both in vitro and in vivo models to evaluate the effects of PTPN6 inhibition on AML cell proliferation, apoptosis, and differentiation. Our results demonstrate that PTPN6 inhibition leads to a significant reduction in AML cell viability, induces apoptosis, and promotes differentiation of leukemic cells into mature myeloid cells. Mechanistic studies revealed that PTPN6 inhibition disrupts key signaling pathways involved in AML pathogenesis, including the JAK/STAT and PI3K/AKT pathways. Furthermore, the combination of PTPN6 inhibitors with standard chemotherapeutic agents exhibited a synergistic effect, enhancing the overall therapeutic efficacy. These findings suggest that PTPN6 is a promising therapeutic target in AML and warrants further investigation into the development of PTPN6 inhibitors for clinical application in AML treatment.

Bone marrow mesenchymal stem cell exosomes suppress JAK/STAT signaling pathway in acute myeloid leukemia in vitro

INTRODUCTION

Despite advances in the treatment of acute myeloid leukemia (AML), refractory forms of this malignancy and relapse remain common. Therefore, development of novel, synergistic targeted therapies are needed urgently. Recently, mesenchymal stem cells (MSCs) have been shown to be effective in treating various diseases, with most of their therapeutic outcomes attributed to their exosomes. In the current study, we investigated the effects of bone marrow mesenchymal stem cell (BM-MSC) exosomes on the expression of the Janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling genes involved in AML pathogenesis.

MATERIAL AND METHODS

Exosomes were isolated from BM-MSCs and confirmed using transmission electron microscopy, dynamic light scattering, and flow cytometry. Subsequently, the exosome concentration was estimated using the bicinchoninic acid assay, and HL-60 cells were cocultured with 100 µg/mL of BM-MSC exosomes. Finally, the JAK2, STAT3, and STAT5 expression levels were analyzed using qRT-PCR.

RESULTS

The exosome characterization results confirmed that most isolated nanoparticles exhibited a round morphology, expressed CD9, CD63, and CD81, which are specific protein markers for exosome identification, and ranged between 80 and 100 nm in diameter. Furthermore, qRT-PCR analysis revealed a significant downregulation of JAK2, STAT3, and STAT5 in HL-60 cells treated with 100 μg/mL of BM-MSC exosomes.

CONCLUSION

Since JAK/STAT signaling contributes to AML survival, our findings suggest that the downregulation of JAK/STAT genes by BM-MSC exosomes in leukemic cells may aid in designing a potent therapeutic strategy for AML treatment.

FLT3 and NPM1 mRNA expression-based risk stratification of de novo acute Myeloid Leukemia

Prognostication of acute myeloid leukemia (AML) at initial diagnosis relies on identification of pre-determined underlying genetic abnormalities. Nevertheless, the disease course of AML remains highly unpredictable and robust reliable prognostic biomarkers for newly diagnosed AML are lacking. We retrospectively explored two publicly available AML RNA-Seq datasets and found that inferior overall survival was associated with high-FLT3 and low-NPM1 transcript levels ("FLT3 high/NPM1 low") compared to low-FLT3 and high-NPM1 transcript levels ("FLT3 low/NPM1 high") in adult de novo AML patients, with a hazard ratio for death of at least 2. Transcript level-dependent differential overall survival was independent from the underlying FLT3 or NPM1 genotypes. Our two-gene RNA expression-based de novo AML risk stratification may supplement and fine-tune traditional genetic aberration-based prognostication methods.

Targeting menin for precision therapy in high-risk acute myeloid leukemia

Objective

This mini-review provides an overview of the current evidence for Revumenib, a first-in-class menin inhibitor, in treating AML with KMT2A rearrangements or NPM1 mutations. This therapy represents a promising advancement by selectively disrupting leukemogenic pathways.

Summary

The clinical promise of Revumenib in genetically defined AML highlights its potential role in shaping the future treatment landscape. This mini-review underscores the need for ongoing trials to define optimal dosing, safety protocols, and combination therapies, with the ultimate goal of establishing Revumenib as a standard of care for high-risk AML subsets.

Increased IDO expression and regulatory T cells in acute myeloid leukemia: implications for immune escape and therapeutic targeting

PURPOSE

This study aimed to determine the frequency of regulatory T cells (Tregs) (CD4+/FOXP3+) and indoleamine 2,3-dioxygenase (IDO) expression in patients with acute myeloid leukemia (AML).

METHODS

This cross-sectional case-control study was conducted between Jan 2022 and Dec 2023. Bone marrow samples were collected from 20 healthy individuals and 15 patients with AML. Flow cytometry, real-time polymerase chain reaction (PCR), and western blotting were used to evaluate the frequency of Treg and IDO expression levels.

RESULTS

The Treg percentage among total lymphocytes was lower in the AML group than that in the normal group. However, Treg percentage among T-helper (Th) lymphocytes was significantly higher in the AML group than that in the normal group (p < 0.05). The mean IDO expression in the AML group was significantly higher than that in the normal group (p = 0.004). A significant relationship was observed between IDO expression and Treg percentage among Th lymphocytes in the AML group (correlation = 0.637; p = 0.003). Moreover, western blot analysis showed a significant increase in IDO protein intensity in the AML group compared with that in the control group (p < 0.001). A significant difference was observed between the IDO concentrations in the AML group and that in the control group (p < 0.001). In addition, a significant difference between TGF-β levels in the AML group and those in the control group (p < 0.01) was observed.

CONCLUSION

IDO inhibition using novel IDO inhibitors along with chemotherapy is a promising approach to overcome the immune escape mechanisms in patients with AML, who exhibit increased levels of IDO expression and Tregs.

Sulforaphane and Benzyl Isothiocyanate Suppress Cell Proliferation and Trigger Cell Cycle Arrest, Autophagy, and Apoptosis in Human AML Cell Line

Isothiocyanates (ITCs) are naturally occurring sulfur-containing compounds with diverse biological effects. This study investigated the effects of sulforaphane (SFN, an aliphatic ITC) and benzyl isothiocyanate (BITC, an aromatic ITC) on human acute myeloid leukemia SKM-1 cells, focusing on cell proliferation, cell death, and drug resistance. Both drug-sensitive SKM-1 cells and their drug-resistant SKM/VCR variant, which overexpresses the drug transporter P-glycoprotein, were used. SFN and BITC reduced cell viability in a dose-dependent manner, with BITC showing greater potency. IC50 values ranged from 7.0-8.0 µM for SFN and 4.0-5.0 µM for BITC in both cell types, with only slight differences between the variants. Both ITCs induced autophagy as evidenced by increased LC3-II production and caused a significant increase in the sub-G0/G1 cell population, especially with BITC. Apoptosis was more pronounced after BITC treatment, whereas SFN had a weaker effect. These results suggest that autophagy may act as a defense mechanism in response to ITC-induced apoptosis in human AML cells.

Identification of furo[2,3-d]pyrimidin-4-ylsulfanyl-1,3,4-thiadiazole derivatives as novel FLT3-ITD inhibitors

Given the significant prevalence of FLT3 receptor and its mutations in acute myeloid leukemia (AML) pathogenesis, we present a novel series of furo[2,3-d]pyrimidin-1,3,4-thiadiazole-urea derivatives, designed to exhibit FLT3-ITD inhibitory activity. These compounds demonstrated cytotoxicity in FLT3-ITD expressing AML cell lines MOLM-13 and MV4-11 in the nanomolar range, with significant selectivity over the K562 cell line. In-depth evaluations of example compound 49 revealed its efficacy in suppressing FLT3 phosphorylation and the downstream signaling molecules, including STAT5 and ERK1/2. Notably, compound 49 demonstrated cytotoxic effects in Ba/F3 cells expressing FLT3-ITD or FLT3-ITD-F691L mutant, exceeding the potency of both sorafenib and quizartinib. Molecular docking studies suggest that this compound binds to the active site of FLT3 in a type II manner. The study suggests that substituted furo[2,3-d]pyrimidines could be useful additions to the growing field of FLT3-targeted therapy for AML. These compounds have the potential to serve as novel FLT3-ITD inhibitors and may offer insights for developing future therapeutic strategies in AML.

The epigenetic role of EZH2 in acute myeloid leukemia

Acute myeloid leukemia (AML), a malignant disease of the bone marrow, is characterized by the clonal expansion of myeloid progenitor cells and a block in differentiation. The high heterogeneity of AML significantly impedes the development of effective treatment strategies. Enhancer of zeste homolog 2 (EZH2), the catalytic subunit of the polycomb repressive complex 2 (PRC2), regulates the expression of downstream target genes through the trimethylation of lysine 27 on histone 3 (H3K27me3). Increasing evidence suggests that the dysregulation of EZH2 expression in various cancers is closely associated with tumorigenesis. In the review, we examine the role of EZH2 in AML, highlighting its crucial involvement in regulating stemness, proliferation, differentiation, immune response, drug resistance and recurrence. Furthermore, we summarize the application of EZH2 inhibitors in AML treatment and discuss their potential in combination with other therapeutic modalities. Therefore, targeting EZH2 may represent a novel and promising strategy for the treatment of AML.

Clinical Peptidomics in Acute Leukemias: Current Advances and Future Perspectives

The study of circulating peptides in the blood offers significant opportunities for diagnosing, stratifying, and managing various diseases. With recent technological advances and the ongoing need to understand complex diseases such as acute leukemias (AL), peptidomic analysis of peripheral blood, especially serum and plasma, has become increasingly important for studying human biology and pathophysiology. Here, we provide insights and perspectives on technological developments and potential clinical applications using widely used peptidomic analysis methods. We discuss examples where peptidomics using serum or plasma has contributed to the understanding of AL. Specifically, we highlight the scarcity of peptidomic studies applied to AL and emphasize the importance of exploring this area, as the few published studies present promising results that can significantly contribute to precision medicine.

Advancing Chimeric Antigen Receptor T-Cell Therapy for Acute Myeloid Leukemia: Current Limitations and Emerging Strategies

Chimeric antigen receptor (CAR) T-cell therapy represents one of the most impressive advances in anticancer therapy of the last decade. While CAR T-cells are gaining ground in various B cell malignancies, their use in acute myeloid leukemia (AML) remains limited, and no CAR-T product has yet received approval for AML. The main limitation of CAR-T therapy in AML is the lack of specific antigens that are expressed in leukemic cells but not in their healthy counterparts, such as hematopoietic stem cells (HSCs), as their targeting would result in an on-target/off-tumor toxicity. Moreover, the heterogeneity of AML and the tendency of blasts to modify surface antigens' expression in the course of the disease make identification of suitable targets even more challenging. Lastly, AML's immunosuppressive microenvironment dampens CAR-T therapeutic activities. In this review, we focus on the actual pitfalls of CAR T-cell therapy in AML, and we discuss promising approaches to overcome them.

Incidence of myelosuppression in AML is higher compared with that in ALL

Acute myeloid leukemia (AML) and acute lymphocytic leukemia (ALL) are two subtypes of acute leukemia. However, studies investigating the ability of complete blood count (CBC) parameters to distinguish between patients with AML and ALL remain scarce in the literature. The objective of the present study was to compare the parameters of CBC analysis between Chinese patients with AML and ALL and between patients with M3 AML and non-M3 AML. Prognostic factors for overall survival were also estimated, including sex, age, white blood cell count and hemoglobin. The present study included 147 patients, including children and adults, with newly diagnosed acute leukemia. Information on the age, sex, leukemia subtype, initial CBC results and clinical follow-up findings was recorded and compared between the indicated groups using statistical tests of Mann-Whitney U test and χ2 test. Leukopenia (white blood cell count <3.5x109/l), both leukopenia and anemia, both leukopenia and thrombocytopenia and pancytopenia were found to be significantly more frequent among patients with AML compared with that in patients with ALL (P=0.015, 0.016, 0.015 and 0.019, respectively). For patients with ALL, anemia was recognized as a predictor of a favorable outcome (Hazard ratio, 0.185; 95% CI, 0.046-0.747; P=0.018). These findings suggest that normal hematopoiesis is more frequently inhibited in patients with AML compared with that in patients with ALL. Patients with AL with peripheral blood findings indicative of leukopenia, pancytopenia, or both leukopenia and anemia or both leukopenia and thrombocytopenia are more likely to have AML.

Splicing the Difference: Harnessing the Complexity of the Transcriptome in Hematopoiesis

Alternative splicing has long been recognized as a powerful tool to expand the diversity of the transcriptome and the proteome. The study of hematopoiesis, from hematopoietic stem cell maintenance and differentiation into committed progenitors to maturation into functional blood cells, has led the field of stem cell research and cellular differentiation for decades. The importance of aberrant splicing due to mutations in cis has been exemplified in thalassemias, resulting from aberrant expression of β-globin. The simultaneous development of increasingly sophisticated technologies, in particular the combination of multicolor flow cytometric cell sorting with bulk and single-cell sequencing, has provided sophisticated insights into the complex regulation of the blood system. The recognition that mutations in key splicing factors drive myeloid malignancies, in particular myelodysplastic syndromes, has galvanized research into alternative splicing in hematopoiesis and its diseases. In this review, we will update the audience on the exciting novel technologies, highlight alternative splicing events and their regulators with essential functions in hematopoiesis, and provide a high-level overview how splicing factor mutations contribute to hematologic malignancies.

Immunosuppressive microenvironment in acute myeloid leukemia: overview, therapeutic targets and corresponding strategies

Similar to other malignancies, immune dysregulation is a key feature of acute myeloid leukemia (AML), manifesting as suppressed anti-leukemia immune cells, immune evasion by leukemia blasts, and disease progression. Various immunosuppressive factors within the AML microenvironment contribute to the weakening of host immune responses and the efficacy of cellular immunotherapy. To address these challenges, strategies targeting immunosuppressive elements within the AML microenvironment aim to bolster host or adoptive immune effector cells, ultimately enhancing leukemia treatment. Additionally, the off-target effects of certain targeted drugs (venetoclax, sorafenib, ivosidenib, etc.) may also positively impact anti-AML immunity and immunotherapy. This review provides an overview of the immunosuppressive factors present in AML microenvironment and the strategies developed to rescue immune cells from immunosuppression. We also outline how targeted agents can alter the immune landscape in AML patients, and discuss the potential of targeted drugs to benefit host anti-leukemia immunity and immunotherapy for AML.

DNMT3A-R882: a mutation with many paradoxes

Understanding the underlying mechanism of acute myeloid leukemia (AML) has led to the discovery of novel biomarkers to help predict, treat and monitor leukemia. DNA (cytosine-5)-methyltransferase 3 A (DNMT3A) is considered a prognostic and therapeutic epigenetic target in AML patients with a hotspot mutation of R882. R882 mutation is associated with impaired differentiation of Hematopoietic stem cells in the bone marrow and disease progression. The prevalence of R882 mutation varied in different ethnicities and countries, and similarly, its prognostic impact differed among numerous studies. Nevertheless, the co-occurrence of mutations in R882 with NPM1 and FLT3 has been reported more frequently and is associated with a worse prognosis. These studies also suggest diverse results regarding bone marrow transplantation response as a treatment, while chemoresistance is reached as a conclusive outcome These findings highlight the crucial need for an in-depth discussion on the significance of the R882 mutation in AML patients. Understanding its impact on leukemic transformation, prognosis, and treatment is vital for advancing clinical implications.

Efficacy and safety of the combination of decitabine and CHAG priming regimen in the relapsed or refractory acute myeloid leukemia

Efficacy and safety analysis of the combination of decitabine priming followed by CHAG chemotherapy in treatment of relapsed/refractory(r/r) acute myeloid leukemia (AML). Between January 2013 and June 2020, 62 r/r AML patients in our center receiving therapy including combination of decitabine and CHAG pre-excitation regimen were enrolled. Primary objectives were overall response (ORR: complete remission + partial remission), adverse events, overall survival (OS) and relapse-free survival (RFS). There were 46 patients (74.2%) with complete remission (CR), 5 patients (8.06%) with partial remission (PR), ORR was 82.2%. Main adverse events were bone marrow suppression, fever and infection, and no chemotherapy-related deaths occurred. The median RFS time was 4.3 months (0.3 ~ 65 months), and median OS time was 7.75 months (1 ~ 66.3 months). Decitabine priming followed by CHAG regimen is effective and tolerated in patients with r/r AML, and can be used as a salvage treatment for patients with r/r AML.

Plasma concentrations of venetoclax and Pharmacogenetics correlated with drug efficacy in treatment naive leukemia patients: a retrospective study

Venetoclax (VEN) was the only Bcl-2 inhibitor approved yet and showed large differences in clinical efficacy. The aim of the study was to explore the relationships between the plasma concentration and efficacy of VEN, and identify potential influencing factors. A retrospective cohort study was conducted and a total of 76 trough (C0h) and 91 6 h post-dose plasma concentration (C6h) blood concentrations of VEN were collected in 54 patients. C6h/D concentration of VEN was found to be significantly correlated with treatment efficacy (p = 0.006) in leukemia patients with good or intermediate prognosis stratification. A ROC curve was then established and the cut-off value was calculated as 0.2868 μg/ml (AUC = 0.7097, p = 0.1081). Besides, patients co-administered with triazoles or carrying CYP3A5 rs776746 AA/AG genotypes were prone to induce higher VEN plasma concentration regardless of whether VEN dosage was reduced or not. Through LASSO-logistic regression and nomogram analysis, chemotherapy regimens and neutrophil percentages were identified as the critical elements that may predict drug response. Above all, in addition to identify prognostic stratification, AML patients taken with VEN were suggested to test plasma concentration routinely so as to achieve desired efficacy, especially when co-administered with triazoles or carried with CYP3A5 rs776746 AA/AG.

METTL3/YTDHF1 Stabilizes CSRP1 mRNA to Regulate Glycolysis and Promote Acute Myeloid Leukemia Progression

CSRP1 (Cysteine and Glycine-Rich Protein 1) is a protein often overactivated in various cancers, promoting cell proliferation and survival, making it a key factor in cancer development. However, it is worth noting that the effect of this protein on the glycolysis process in Acute Myeloid Leukemia (AML) has not yet been studied. This study aims to investigate the role of the METTL3/YTHDF1 axis in regulating Glycolysis and its impact on AML progression by stabilizing CSRP1 mRNA. We analyzed CSRP1 expression in AML tissues and cell lines using quantitative real-time PCR (qRT-PCR) and Western blotting. Functional assays, including cell viability, colony formation, glycolysis related indicators, were performed to assess the impact of CSRP1 knockdown or overexpression on AML cells. RNA immunoprecipitation (RIP) and RNA stability assays were conducted to elucidate the mechanism of METTL3/YTHDF1-mediated regulation of CSRP1 mRNA. CSRP1 was significantly upregulated in AML tissues and cell lines. Knockdown of CSRP1 inhibited AML cell proliferation and glycolysis. Overexpression of CSRP1 promoted AML cell survival. Mechanistically, METTL3 enhanced CSRP1 mRNA stability via m6A modification, recognized and bound by YTHDF1, preventing mRNA degradation. The METTL3/YTHDF1/ CSRP1 axis plays a critical role in AML progression by regulating glycolysis. Targeting this pathway may provide a novel therapeutic strategy for AML treatment.

IL-21/IL-21R signaling renders acute myeloid leukemia stem cells more susceptible to cytarabine treatment and CAR T cell therapy

Self-renewal programs in leukemia stem cells (LSCs) predict poor prognosis in patients with acute myeloid leukemia (AML). We identify CD4+ T cell-derived interleukin (IL)-21 as an important negative regulator of self-renewal of LSCs. IL-21/IL-21R signaling favors asymmetric cell division and differentiation in LSCs through the activation of p38-MAPK signaling, resulting in reduced LSC numbers and significantly prolonged survival in murine AML models. In human AML, serum IL-21 at diagnosis is identified as an independent positive prognostic biomarker for outcome and correlates with improved survival and higher complete remission rates in patients that underwent high-dose chemotherapy. IL-21 treatment inhibits primary LSC function and enhances the effect of cytarabine and CD70 CAR T cell treatment on LSCs in vitro. Low-dose IL-21 treatment prolongs the survival of AML mice in syngeneic and xenograft experiments. Therefore, promoting IL-21/IL-21R signaling on LSCs may be an approach to reduce stemness and increase differentiation in AML.

Acute Myeloid Leukemia: Diagnosis and Evaluation by Flow Cytometry

With recent technological advances and significant progress in understanding the pathogenesis of acute myeloid leukemia (AML), the updated fifth edition WHO Classification (WHO-HAEM5) and the newly introduced International Consensus Classification (ICC), as well as the European LeukemiaNet (ELN) recommendations in 2022, require the integration of immunophenotypic, cytogenetic, and molecular data, alongside clinical and morphologic findings, for accurate diagnosis, prognostication, and guiding therapeutic strategies in AML. Flow cytometry offers rapid and sensitive immunophenotyping through a multiparametric approach and is a pivotal laboratory tool for the classification of AML, identification of therapeutic targets, and monitoring of measurable residual disease (MRD) post therapy. The association of immunophenotypic features and recurrent genetic abnormalities has been recognized and applied in informing further diagnostic evaluation and immediate therapeutic decision-making. Recently, the evolving role of machine learning models in assisting flow cytometric data analysis for the automated diagnosis and prediction of underlying genetic alterations has been illustrated.

High-dimensional Immune Profiles and Machine Learning May Predict Acute Myeloid Leukemia Relapse Early following Transplant

Identification of early immune signatures associated with acute myeloid leukemia (AML) relapse following hematopoietic stem cell transplant (HSCT) is critical for patient outcomes. We analyzed PBMCs from 58 patients with AML undergoing HSCT, focusing on T cell subsets and functional profiles. High-dimensional flow cytometry coupled with Uniform Manifold Approximation and Projection dimensionality reduction and PhenoGraph clustering revealed distinct changes in CD4+ and CD8+ T cell populations in 16 patients who relapsed within 1 y of HSCT. We observed increased IL-2, IL-10, and IL-17-producing CD4+ T cells, alongside decreased CD8+ T cell function early in relapsing patients. Notably, relapsing patients exhibited increased TCF-1intermediate cells, which lacked granzyme B or IFN-γ production in the CD4+ T cell compartment. We then developed a supervised machine learning algorithm that predicted AML relapse with 90% accuracy within 30 d after HSCT using high-throughput assays. The algorithm leverages condensed immune phenotypic data, alongside the ADASYN algorithm, for data balancing and 100 rounds of XGBoost supervised learning. This approach holds potential for detecting relapse-associated immune signatures months before clinical manifestation. Our findings demonstrate a distinct immunological signature potentially capable of predicting AML relapse as early as 30 d after HSCT.

Relationship Between Age, Conditioning Intensity, and Outcome After Allografting in Adults Age ≥60 Years with AML

Methodological advancements now allow older adults with AML to receive allografts although conflicting data exist regarding relative outcomes across age groups and benefits of different conditioning intensities. We retrospectively analyzed 495 adults aged 60-64 (n = 184), 65-69 (n = 189), or ≥ 70 (n = 122) who underwent allogeneic HCT for AML in remission at our institution from 2006 to 2023. There were no significant differences in relapse or relapse-free survival (RFS) among the 3 age cohorts after multivariable adjustment. Patients aged ≥ 70 years had a higher risk of non-relapse mortality (NRM) than those aged ≥ 60-64 (P = 0.022) but their overall survival (OS) was only statistically non-significantly shorter (P = 0.11). There was an important interplay between age, conditioning intensity, and outcomes. Age ≥ 70 years was associated with a higher risk of relapse (hazard ratio [HR] = 3.47; P = 0.012) and NRM (HR = 3.88; P = 0.001) with reduced intensity conditioning (RIC), leading to shorter RFS (HR = 3.79; P < 0.001) and OS (HR = 3.46; P < 0.001), while no association was found with nonmyeloablative conditioning. Conversely, patients aged 60-64 and 65-69, not those aged ≥ 70, had a significantly lower risk of relapse with RIC, but NRM risk increased with age. Our findings support allogeneic HCT for adults with AML in remission even if aged beyond 70, especially with nonmyeloablative conditioning.

The Cancer Incidence Pattern in Isfahan Province: An Industrial Region in the Central Part of Iran

Background: We aimed to study age-standardized incidence rates (ASRs) of different cancer sites in Isfahan province, an industrialized city in the central part of Iran. Method: We obtained cancer incidence data from 2014 to 2018 in the Isfahan population-based cancer registry (PBCR). We studied quality indicators of PBCR and the validity of residential places for cancer patients. ASRs per 100,000 of common cancers were reported overall and at subprovincial levels. Results: Overall, 42,994 new cancer cases were registered in Isfahan PBCR in 2014-2018, and 51.4% were male. A high percentage of microscopic verification (MV%) (78.1%) and a low percentage of death certificate-only (DCO%) cases (7%) indicate the acceptable validity and completeness of this registry. The ASRs per 100,000 for all cancers combined were 173.7 in men and 171.1 in women. The most common cancers were prostate (ASR = 26.1), bladder (ASR = 19.9), and colorectum (ASR = 19.6) cancers in men and breast (ASR = 49.9), thyroid (ASR = 11.5), and colorectal (ASR = 15.6) cancers in women. Compared to the national reports in Iran, Isfahan province had a higher ASR of leukemia (13.6 in men and 8.9 in women), non-Hodgkin lymphoma (14 in men and 9 in women), and bladder (19.9 in men and 3.4 in women) cancer. The ASR of childhood cancers was 182.7. Notably, the most frequent cancer was leukemia (ASR = 73.4). We observed a wide geographic heterogeneity of cancer incidence in different counties for some cancers like breast, prostate, leukemia, and colorectal cancers. Conclusion: High incidence rates of hematological malignancies and bladder cancers in Isfahan province suggest further research to study the association between occupational and environmental exposures due to industrial pollution.

Homoharringtonine in the treatment of acute myeloid leukemia: A review

Acute myeloid leukemia (AML) is a hematological malignancy characterized by the accumulation of immature myeloid precursor cells. Over half of AML patients fail to achieve long-term disease-free survival under existing therapy, and the overall prognosis is poor, necessitating the urgent development of novel therapeutic approaches. The plant alkaloid homoharringtonine (HHT), which has anticancer properties, was first identified more than 40 years ago. It works in a novel method of action that prevents the early elongation phase of protein synthesis. HHT has been widely utilized in the treatment of AML, with strong therapeutic effects, few toxic side effects, and the ability to enhance AML patients' prognoses. In AML, HHT can induce cell apoptosis through multiple pathways, exerting synergistic antitumor effects, according to clinical and pharmacological research. About its modes of action, some findings have been made recently. This paper reviews the development of research on the mechanisms of HHT in treating AML to offer insights for further research and clinical therapy.

Oral decitabine/cedazuridine versus intravenous decitabine for acute myeloid leukaemia: A randomised, crossover, registration, pharmacokinetics study

This study compared decitabine exposure when administered IV (DEC-IV) at a dose of 20 mg/m2 for 5-days with orally administered decitabine with cedazuridine (DEC-C), as well as the clinical efficacy and safety of DEC-C in patients with acute myeloid leukaemia (AML) who were ineligible for intensive induction chemotherapy. In all, 89 patients were randomised 1:1 to DEC-IV or oral DEC-C (days 1-5 in a 28-day treatment cycle), followed by 5 days of the other formulation in the next treatment cycle. All patients received oral DEC-C for subsequent treatment cycles until treatment discontinuation. Equivalent systemic decitabine exposures were demonstrated (5-day area under the curve ratio between the two decitabine formulations of 99.64 [90% confidence interval 91.23%, 108.80%]). Demethylation rates also were similar (≤1.1% difference). Median overall survival (OS), clinical response and safety profile with oral DEC-C were consistent with those previously observed with DEC-IV. Next-generation sequencing was performed to identify molecular abnormalities that impact OS and TP53 mutations were associated with a poor outcome. These findings support the use of oral DEC-C in patients with AML.

Breaking down frailty: Assessing vulnerability in acute myeloid leukemia

Acute myeloid leukemia (AML) is a disease primarily affecting older adults. However, not all patients at older ages are suitable for curative treatment with intensive chemotherapy due to "frailty" demonstrated by their functional status, physiologic reserve, and vulnerability to disease and treatment morbidity. Lack of consensus exists on how to select older, less fit patients most appropriate for standard intensive chemotherapy (IC), hypomethylating agents (HMA) with venetoclax, or less intensive regimens. A total of 37 studies of frailty assessments and composite indices in AML show heterogeneous results regarding the ability of frailty and Comprehensive Geriatric Assessment (CGA) measures to predict treatment outcomes. CGA, Geriatric 8 (G8) risk score, and hematopoietic cell transplant comorbidity index (HCT-CI) show association with prognosis, and should be validated in larger therapeutic trials. Studies of biomarkers, like albumin and C-reactive protein, and patient-reported outcomes demonstrate the potential to enhance information gained from rigorous geriatric assessment.

A review of the isocitrate dehydrogenase inhibitors in management of adult patients with AML and MDS

INTRODUCTION

The development of oral therapies impacts the management of acute myeloid leukemia and myelodysplastic syndromes, especially for targetable mutations including IDH1/2.

AREAS COVERED

We discuss IDH1/2 activity and inhibitor therapy in various settings, including monotherapy, combination therapy with hypomethylating agents, and other approaches.

EXPERT OPINION

Olutasidenib, enasidenib, and ivosidenib are approved for relapsed AML. Ivosidenib is approved for relapsed MDS and alone or with azacitidine in newly diagnosed AML. However, unanswered questions exist. In newly diagnosed AML, ivosidenib + azacitidine shows a survival benefit compared to azacitidine, but it is unknown whether ivosidenib + azacitidine demonstrates improved survival compared to ivosidenib. Ivosidenib + azacitidine demonstrated a survival benefit not seen with enasidenib + azacitidine. It is unclear whether newly diagnosed AML should be treated with azacitidine + ivosidenib or azacitidine + venetoclax. Azacitidine + venetoclax shows excellent response rates in IDH mutated disease. Retrospective data show low response rates of IDH inhibitor therapy post-venetoclax whereas HMA + venetoclax retains activity post IDH inhibition. The role of IDH inhibition post-transplant is unclear. Single-arm studies show post-transplant maintenance is safe; however, randomized trials are needed. Similarly, IDH inhibitors can be combined with chemotherapy however randomized studies are needed.

Licochalcone A decreases cancer cell proliferation and enhances ferroptosis in acute myeloid leukemia through suppressing the IGF2BP3/MDM2 cascade

Licochalcone A (Lico A), a naturally bioactive flavonoid, has shown antitumor activity in several types of cancers. However, few studies have focused on its effect on acute myeloid leukemia (AML). Cell viability and colony formation potential were detected by CCK-8 assay and colony formation assay, respectively. Cell cycle distribution and apoptosis were assessed by flow cytometry. Ferroptosis was assessed by measuring reactive oxygen species (ROS), lipid ROS, malondialdehyde (MDA), and glutathione (GSH). Protein expression levels were determined by immunoblotting and immunohistochemistry (IHC), and mRNA expression was detected by real-time qPCR. The m6A modification of MDM2 mRNA was verified by methylated RNA immunoprecipitation (MeRIP) assay, and the interaction of IGF2BP3 and MDM2 mRNA was analyzed by RIP assay. Actinomycin D was used to evaluate mRNA stability. The efficacy of Lico A in vivo was examined by a murine xenograft model. Lico A suppressed cell proliferation and induced ferroptosis in MOLM-13 and U-937 in vitro, and slowed the growth of xenograft tumors in vivo. IGF2BP3 was highly expressed in human AML specimens and cells, and Lico A suppressed IGF2BP3 expression in AML cells. Lico A exerted the anti-proliferative and pro-ferroptosis effects by downregulating IGF2BP3. Moreover, IGF2BP3 enhanced the stability and expression of MDM2 mRNA through an m6A-dependent manner. Downregulation of IGF2BP3 impeded AML cell proliferation and enhanced ferroptosis via repressing MDM2. Furthermore, Lico A could affect the MDM2/p53 pathway by downregulating IGF2BP3 expression. Lico A exerts the anti-proliferative and pro-ferroptosis activity in AML cells by affecting the IGF2BP3/MDM2/p53 pathway, providing new evidence for Lico A as a promising agent for the treatment of AML.

Efficacy of Haploidentical Allogeneic Hematopoietic Cell Transplantation following Two Courses of Venetoclax and Azacytidine Therapy in Patients over 55 Years Old with Acute Myelogenous Leukemia

INTRODUCTION

The combination of venetoclax (VEN) and azacytidine (AZA) has demonstrated potential in achieving rapid and effective remissions in elderly patients with acute myeloid leukemia (AML). Allogeneic hematopoietic stem cell transplantation is a promising potential cure for high-risk AML, as VEN-based therapies have a worse prognosis in elderly patients. This study aimed to assess the efficacy of sequential haploidentical HSCT following two courses of VEN and AZA therapy in patients with AML aged 55 years and older.

METHODS

We conducted a retrospective study on AML patients aged 55-70 years who received intensive chemotherapy or two courses of VEN/AZA therapy, followed by haploidentical allo-HSCT (haplo-HSCT) based on disease risk degree, measurable residual disease status, and patient's preference.

RESULTS

Between January 2019 and December 2023, 141 newly diagnosed AML patients received initial treatment with intensive chemotherapy or VEN/AZA therapy. Among them, 64 patients received haplo-HSCT, while 77 did not. The 1-year overall survival (OS) and relapse-free survival (RFS) of patients who received haplo-HSCT were significantly higher than those who did not receive haplo-HSCT (p < 0.05). Among patients who received transplantation, there was no significant difference in 1-year OS and RFS between the VEN/AZA and intensive chemotherapy groups: 76.3% versus 69.3% (p = 0.367) for OS, and 74.5% versus 69.7% (p = 0.473) for RFS. High-risk ELN stratification and the presence of ≥4 gene mutations were associated with lower OS and RFS in both univariate and multivariate analyses.

CONCLUSIONS

AML patients over 55 years of age who received haplo-HSCT after two courses of VEN/AZA therapy had outcomes similar to those who received haplo-HSCT after intensive chemotherapy, suggesting that two courses of VEN/AZA therapy as a bridge to haplo-HSCT are feasible for patients over 55 years old.

Anti-IL-1RAP scFv-mSA-S19-TAT fusion carrier as a multifunctional platform for versatile delivery of biotinylated payloads to myeloid leukemia cells

Acute myeloid leukemia (AML) is an aggressive blood cancer with frequently poor clinical outcomes. This heterogeneous malignancy encompasses genetically, molecularly, and even clinically different subgroups. This makes it difficult to develop therapeutic agents that are effective for all subtypes of the disease. Therefore, a selective, universal, and adaptable delivery platform capable of carrying various types of anti-neoplastic agents is an unmet requirement in this area. Two multifunctional fusion proteins were designed for the delivery of biotinylated cargoes to human myeloid leukemia cells by fusing an anti-IL-1RAP single-chain antibody with streptavidin (tetramer or monomer), a cell-penetrating peptide (CPP), and an endosomolytic peptide in a single biomacromolecule. The designed fusions were analyzed primarily in silico, and the biofunctionality of the selected fusion was fully characterized via several binding assays, hemolysis assay, confocal microscopy and cell cytotoxicity assay after production via the Escherichia coli (E. coli) system. The refolded protein exhibited desirable binding activity to leukemic cells, pure antigen and biotinylated BSA. Further analyses revealed efficient cellular uptake, endosomolytic activity, and nuclear penetration without any detectable cytotoxicity toward normal epithelial cells. The described platform seems to have great potential for targeted delivery of different therapeutics to malignant myeloid cells.

A Dual-Function LipoAraN-E5 Coloaded with N4-Myristyloxycarbonyl-1-β-d-arabinofuranosylcytosine (AraN) and a CXCR4 Antagonistic Peptide (E5) for Blocking the Dissemination of Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a hematological malignancy with a high recurrence rate. The interaction of chemokine receptor 4/chemokine ligand 12 (CXCR4/CXCL12) mediates homing and adhesion of AML cells in bone marrow, leading to minimal residual disease in patients, which brings a hidden danger for future AML recurrence. Ara-C is a nonselective chemotherapeutic agent against AML. Due to its short half-life and severe side effects, a lipid-like Ara-C derivative (AraN) was synthesized and a dual-function LipoAraN-E5 (135 nm, encapsulation efficiency 99%) was developed, which coloaded AraN and E5, a peptide of the CXCR4 antagonist. LipoAraN-E5 effectively improved the uptake, enhanced the inhibition of leukemia cell proliferation, migration, and adhesion to stromal cells in bone marrow, and mobilized the leukemia cells from bone marrow to peripheral blood via interfering with the CXCR4/CXCL12 axis. LipoAraN-E5 prolonged the plasma half-life of AraN (8.31 vs 0.56 h) and was highly enriched in peripheral blood (3.67 vs 0.05 μmol/g at 8 h) and bone marrow (379 vs 148 μmol/g at 24 h). LipoAraN-E5 effectively prevented the infiltration of leukemia cells in peripheral blood, bone marrow, spleen, and liver, prolonged the mice survival, and showed outstanding antineoplastic efficacy with negligible toxicity, which were attributed to the ingenious design of AraN, the use of a liposomal delivery carrier, and the introduction of E5. Our work revealed that LipoAraN-E5 may be a promising nanocandidate against AML.

Dynamic survival analysis: Modelling the hazard function via ordinary differential equations

The hazard function represents one of the main quantities of interest in the analysis of survival data. We propose a general approach for parametrically modelling the dynamics of the hazard function using systems of autonomous ordinary differential equations (ODEs). This modelling approach can be used to provide qualitative and quantitative analyses of the evolution of the hazard function over time. Our proposal capitalises on the extensive literature on ODEs which, in particular, allows for establishing basic rules or laws on the dynamics of the hazard function via the use of autonomous ODEs. We show how to implement the proposed modelling framework in cases where there is an analytic solution to the system of ODEs or where an ODE solver is required to obtain a numerical solution. We focus on the use of a Bayesian modelling approach, but the proposed methodology can also be coupled with maximum likelihood estimation. A simulation study is presented to illustrate the performance of these models and the interplay of sample size and censoring. Two case studies using real data are presented to illustrate the use of the proposed approach and to highlight the interpretability of the corresponding models. We conclude with a discussion on potential extensions of our work and strategies to include covariates into our framework. Although we focus on examples of Medical Statistics, the proposed framework is applicable in any context where the interest lies in estimating and interpreting the dynamics of the hazard function.

Small extracellular vesicles derived from acute myeloid leukemia cells promote leukemogenesis by transferring miR-221-3p

Small extracellular vesicles (sEV) transfer cargos between cells and participate in various physiological and pathological processes through their autocrine and paracrine effects. However, the pathological mechanisms employed by sEV-encapsulated microRNA (miRNA) in acute myeloid leukemia (AML) are still obscure. In this study, we aimed to investigate the effects of AML cell-derived sEV (AML-sEV) on AML cells and delineate the underlying mechanisms. We initially used high-throughput sequencing to identify miR-221-3p as the miRNA prominently enriched in AML-sEV. Our findings revealed that miR-221-3p promoted AML cell proliferation and leukemogenesis by accelerating cell cycle entry and inhibiting apoptosis. Furthermore, Gbp2 was confirmed as a target gene of miR-221-3p by dual luciferase reporter assays and rescue experiments. Additionally, AML-sEV impaired the clonogenicity, particularly the erythroid differentiation ability, of hematopoietic stem and progenitor cells. Taken together, our findings reveal how sEV-delivered miRNA contribute to AML pathogenesis, which can be exploited as a potential therapeutic target to attenuate AML progression.

Treatment challenges and outcomes of older patients with acute myeloid leukemia from India

Globally, overall survival (OS) of older patients with AML continues to be suboptimal with very little data from India. In a multicenter registry analysis, we evaluated 712 patients with AML older than 55 years. Only 323 (45.3%) underwent further treatment, of which 239 (74%) received HMAs, and 60 (18%) received intensive chemotherapy (IC). CR was documented in 39% of those receiving IC and 42% after HMAs. Overall, 100 (31%) patients died within 60 days of diagnosis, most commonly due to progressive disease (47%) or infections (30%). After a median follow-up of 176 days, 228 (76%) of patients had discontinued treatment. At one year from diagnosis, 211 (65%) patients had died, and the median OS was 186 days (IQR, 137-234). Only 12 (3.7%) patients underwent stem cell transplantation. Survival was significantly lower for those older than 60 years (p < 0.001). Patients who died had a higher median age (p = .027) and baseline WBC counts (p = .006). Our data highlights suboptimal outcomes in older AML patients, which are evident from 55 years of age onwards, making it necessary to evaluate HMA and targeted agent combinations along with novel consolidation strategies to improve survival in this high-risk population.

Triplet therapy with gilteritinib, venetoclax, and azacitidine for relapsed/refractory FLT3mut acute myeloid leukemia

The FMS-related tyrosine kinase 3 (FLT3) inhibitor gilteritinib is standard therapy for relapsed/refractory (R/R) FLT3-mutated (FLT3mut) acute myeloid leukemia (AML) but the overall survival (OS) is only approximately 20 % and few patients achieve deep and/ or durable response. We retrospectively analyzed 29 R/R FLT3mut AML patients treated on triplet regimens (gilteritinib+ venetoclax［VEN] +azacitidine［AZA]). Nineteen patients (65.5 %) had received prior FLT3 inhibitor therapy. The modified composite complete remission (mCRc) rate was 62.1 % (n = 18; CR, 4/29,13.8 %; CRi, 6/29, 20.7 %; MLFS, 8/29, 27.6 %). Among 18 patients achieved mCRc, FLT3-PCR negativity was 94.4 % (n=17), and flow-cytometry negativity was 77.7 % (n=14). The mCRc rate was 70 % (n=7) in 10 patients without prior FLT3 TKI exposure and 57.8 % (n=11) in 19 patients with prior FLT3 TKI exposure (P=0.52). At the end of the first cycle, the median time to ANC > 0.5× 109/L was 38 days and platelet > 50× 109/L was 31 days among responders, but 60-day mortality was 0 %. The estimated 2-year OS was 60.9 % for all R/R FLT3mut patients. The 1-year OS was 80 % and 58.8 % in patients without and with prior FLT3 TKI exposure, respectively (P=0.79). The estimated 2-year OS was 62 % in 19 (65.5 %) patients who received allo-HSCT after triplet therapy and 37 % in 10 patients who did not receive allo-HSCT (P=0.03). In conclusion, triplet therapy with gilteritinib, VEN, and AZA is effective and safe and an excellent frontline option for R/R FLT3mut AML.

Phosphoproteomics predict response to midostaurin plus chemotherapy in independent cohorts of FLT3-mutated acute myeloid leukaemia

BACKGROUND

Acute myeloid leukaemia (AML) is a bone marrow malignancy with poor prognosis. One of several treatments for AML is midostaurin combined with intensive chemotherapy (MIC), currently approved for FLT3 mutation-positive (FLT3-MP) AML. However, many patients carrying FLT3 mutations are refractory or experience an early relapse following MIC treatment, and might benefit more from receiving a different treatment. Development of a stratification method that outperforms FLT3 mutational status in predicting MIC response would thus benefit a large number of patients.

METHODS

We employed mass spectrometry phosphoproteomics to analyse 71 diagnosis samples of 47 patients with FLT3-MP AML who subsequently received MIC. We then used machine learning to identify biomarkers of response to MIC, and validated the resulting predictive model in two independent validation cohorts (n = 20).

FINDINGS

We identified three distinct phosphoproteomic AML subtypes amongst long-term survivors. The subtypes showed similar duration of MIC response, but different modulation of AML-implicated pathways, and exhibited distinct, highly-predictive biomarkers of MIC response. Using these biomarkers, we built a phosphoproteomics-based predictive model of MIC response, which we called MPhos. When applied to two retrospective real-world patient test cohorts (n = 20), MPhos predicted MIC response with 83% sensitivity and 100% specificity (log-rank p < 7∗10-5, HR = 0.005 [95% CI: 0-0.31]).

INTERPRETATION

In validation, MPhos outperformed the currently-used FLT3-based stratification method. Our findings have the potential to transform clinical decision-making, and highlight the important role that phosphoproteomics is destined to play in precision oncology.

FUNDING

This work was funded by Innovate UK grants (application numbers: 22217 and 10054602) and by Kinomica Ltd.