Updates on targeted therapies for acute myeloid leukaemia

Discovery of novel and potent CDK8 inhibitors for the treatment of acute myeloid leukaemia

It has been reported that CDK8 plays a key role in acute myeloid leukaemia. Here, a total of 40 compounds were rational designed and synthesised based on the previous SAR. Among them, compound 12 (3-(3-(furan-3-yl)-1H-pyrrolo[2,3-b]pyridin-5-yl)benzamide) showed the most potent inhibiting activity against CDK8 with an IC50 value of 39.2 ± 6.3 nM and anti AML cell proliferation activity (molm-13 GC50 = 0.02 ± 0.01 μM, MV4-11 GC50 = 0.03 ± 0.01 μM). Mechanistic studies revealed that this compound 12 could inhibit the phosphorylation of STAT-1 and STAT-5. Importantly, compound 12 showed relative good bioavailability (F = 38.80%) and low toxicity in vivo. This study has great significance for the discovery of more efficient CDK8 inhibitors and the development of drugs for treating AML in the future.

Machine learning-based biomarker screening for acute myeloid leukemia prognosis and therapy from diverse cell-death patterns

Acute myeloid leukemia (AML) exhibits pronounced heterogeneity and chemotherapy resistance. Aberrant programmed cell death (PCD) implicated in AML pathogenesis suggests PCD-related signatures could serve as biomarkers to predict clinical outcomes and drug response. We utilized 13 PCD pathways, including apoptosis, pyroptosis, ferroptosis, autophagy, necroptosis, cuproptosis, parthanatos, entotic cell death, netotic cell death, lysosome-dependent cell death, alkaliptosis, oxeiptosis, and disulfidptosis to develop predictive models based on 73 machine learning combinations from 10 algorithms. Bulk RNA-sequencing, single-cell RNA-sequencing transcriptomic data, and matched clinicopathological information were obtained from the TCGA-AML, Tyner, and GSE37642-GPL96 cohorts. These datasets were leveraged to construct and validate the models. Additionally, in vitro experiments were conducted to substantiate the bioinformatics findings. The machine learning approach established a 6-gene pan-programmed cell death-related genes index (PPCDI) signature. Validation in two external cohorts showed high PPCDI associated with worse prognosis in AML patients. Incorporating PPCDI with clinical variables, we constructed several robust prognostic nomograms that accurately predicted prognosis of AML patients. Multi-omics analysis integrating bulk and single-cell transcriptomics revealed correlations between PPCDI and immunological features, delineating the immune microenvironment landscape in AML. Patients with high PPCDI exhibited resistance to conventional chemotherapy like doxorubicin but retained sensitivity to dasatinib and methotrexate (FDA-approved drugs for other leukemias), suggesting the potential of PPCDI to guide personalized therapy selection in AML. In summary, we developed a novel PPCDI model through comprehensive analysis of diverse programmed cell death pathways. This PPCDI signature demonstrates great potential in predicting clinical prognosis and drug sensitivity phenotypes in AML patients.

A novel iheyamine A derivative L42 suppresses acute myeloid leukemia via dual regulation of the PI3K/AKT/FOXO3a axis and TNF signaling pathway

Acute myeloid leukemia (AML) is one of the most common hematopoietic malignancies and the development of new drugs is crucial for the treatment of this lethal disease. Iheyamine A is a nonmonoterpenoid azepinoindole alkaloid from the ascidian Polycitorella sp., and its anticancer mechanism has not been investigated in leukemias. Herein, we showed the significant antileukemic activity of L42 in AML cell lines HEL, HL-60 and THP-1. The IC50 values were 0.466±0.099 µM, 0.356±0.023 µM, 0.475±0.084 µM in the HEL, HL-60 and THP-1 cell lines, respectively, which were lower than the IC50 (2.594±0.271 µM) in the normal liver cell line HL-7702. Furthermore, L42 significantly inhibited the growth of peripheral blood mononuclear cells (PBMCs) from an AML patient. In vivo, L42 effectively suppressed leukemia progression in a mouse model induced by Friend murine leukemia virus (F-MuLV). Mechanistically, we showed that L42 induced cell cycle arrest and apoptosis in leukemia cell lines. RNA sequencing analysis of L42-treated THP-1 cells revealed that the differentially expressed genes (DEGs) were enriched in the cell cycle and apoptosis and predominantly enriched in the PI3K/AKT pathway. Accordingly, L42 decreased the expression of the phospho-PI3K (p85), phospho-AKT and phospho-FOXO3a. Docking and CETSA analysis indicated that L42 bound to the PI3K isoform p110α (PIK3CA), which was implicated in the suppression of the PI3K/AKT pathway. L42 was also shown to initiate the TNF signaling-mediated apoptosis. Moreover, L42 exhibited stronger anti-leukemia activity and sensitivity in IDH2-mutant HEL cells than in IDH2-wild-type control. In conclusion, L42 effectively suppresses cell proliferation and triggers apoptosis in AML cell lines in part through inhibition of the PI3K/AKT signaling pathway to restore FOXO3a expression and activation of the TNF signaling pathway. Thus, the iheyamine A derivative L42 represents a novel candidate for AML therapy.

FLT3-PROTACs for combating AML resistance: Analytical overview on chimeric agents developed, challenges, and future perspectives

The urgent and unmet medical demand of acute myeloid leukemia (AML) patients has driven the drug discovery process for expansion of the landscape of AML treatment. Despite the several agents developed for treatment of AML, more than 60 % of treated patients undergo relapse again after re-emission, thus, no complete cure for this complex disease has been reached yet. Targeted oncoprotein degradation is a new paradigm that can be employed to solve drug resistance, disease relapse, and treatment failure in complex diseases as AML, the most lethal hematological malignancy. AML is an aggressive blood cancer form and the most common type of acute leukemia, with bad outcomes and a very poor 5-year survival rate. FLT3 mutations occur in about 30 % of AML cases and FLT3-ITD is associated with poor prognosis of this disease. Prevalent FLT3 mutations include internal tandem duplication and point mutations (e.g., D835) in the tyrosine kinase domain, which induce FLT3 kinase activation and result in survival and proliferation of AML cells again. Currently approved FLT3 inhibitors suffer from limited clinical efficacy due to FLT3 reactivation by mutations, therefore, alternative new treatments are highly needed. Proteolysis-targeting chimera (PROTAC) is a bi-functional molecule that consists of a ligand of the protein of interest, FLT3 inhibitor in our case, that is covalently linked to an E3 ubiquitin ligase ligand. Upon FLT3-specific PROTAC binding to FLT3, the PROTAC can recruit E3 for FLT3 ubiquitination, which is subsequently subjected to proteasome-mediated degradation. In this review we tried to address the question if PROTAC technology has succeeded in tackling the disease relapse and treatment failure of AML. Next, we explored the latest FLT3-targeting PROTACs developed in the past few years such as quizartinib-based PROTACs, dovitinib-based PROTACs, gilteritinib-based PROTACs, and others. Then, we followed with a deep analysis of their advantages regarding potency improvement and overcoming AML drug resistance. Finally, we discussed the challenges facing these chimeric molecules with proposed future solutions to circumvent them.

Targeting the redox vulnerability of acute myeloid leukaemia cells with a combination of auranofin and vitamin C

Acute myeloid leukaemia (AML) is a heterogeneous disease characterized by complex molecular and cytogenetic abnormalities. Pro-oxidant cellular redox status is a common hallmark of AML cells, providing a rationale for redox-based anticancer strategy. We previously discovered that auranofin (AUF), initially used for the treatment of rheumatoid arthritis and repositioned for its anticancer activity, can synergize with a pharmacological concentration of vitamin C (VC) against breast cancer cell line models. In this study, we observed that this drug combination synergistically and efficiently killed cells of leukaemic cell lines established from different myeloid subtypes. In addition to an induced elevation of reactive oxygen species and ATP depletion, a rapid dephosphorylation of 4E-BP1 and p70S6K, together with a strong inhibition of protein synthesis were early events in response to AUF/VC treatment, suggesting their implication in AUF/VC-induced cytotoxicity. Importantly, a study on 22 primary AML specimens from various AML subtypes showed that AUF/VC combinations at pharmacologically achievable concentrations were effective to eradicate primary leukaemic CD34+ cells from the majority of these samples, while being less toxic to normal cord blood CD34+ cells. Our findings indicate that targeting the redox vulnerability of AML with AUF/VC combinations could present a potential anti-AML therapeutic approach.

Design, synthesis, and biological activity evaluation of novel HDAC3 selective inhibitors for combination with Venetoclax against acute myeloid leukemia

Histone deacetylases (HDACs) are highly attractive targets in the drug development process, and the development of subtype-selective HDAC inhibitors is the research direction for HDAC inhibitors. As an important member of the HDAC family, HDAC3 has been found to be closely related to the pathological progression of many diseases due to its abnormal expression. In previous studies, we discovered compound 13a, which has potent inhibitory activity against HDAC1, 2, and 3. In this work, we improved the HDAC3 isotype selectivity of 13a, and obtained compound 9c through rational drug design. 9c shows a selectivity of 71 fold for HDAC3 over HDAC1 and can significantly inhibit the proliferation activity of MV4-11 cells in vitro. Furthermore, when combined with Venetoclax, 9c can effectively induce apoptosis in MV4-11 cells in vitro and reduce the expression of anti-apoptotic proteins, the development of HDAC3 selective inhibitors may serve as a potential lead compound to reverse Venetoclax resistance.

MICAL1 promotes the proliferation in acute myeloid leukemia and is associated with clinical prognosis and immune infiltration

Acute myeloid leukemia (AML) is one of the most common hematopoietic malignancies that has a poor prognosis and a high rate of relapse. Dysregulated metabolism plays an important role in AML progression. This study aimed to conduct a comprehensive analysis of MRGs using TCGA and GEO datasets and further explore the potential function of critical MRGs in AML progression. In this study, we identified 17 survival-related differentially expressed MRGs in AML using TCGA and GEO datasets. The 150 AML samples were divided into three molecular subtypes using 17 MRGs, and we found that three molecular subtypes exhibited a different association with ferroptosis, cuproptosis and m6A related genes. Moreover, a prognostic signature that comprised nine MRGs and had good predictive capacity was established by LASSO-Cox stepwise regression analysis. Among the 17 MRGs, our attention focused on MICAL1 which was highly expressed in many types of tumors, including AML and its overexpression was also confirmed in several AML cell lines. We also found that the expression of MICAL1 was associated with several immune cells. Moreover, functional experiments revealed that knockdown of MICAL1 distinctly suppressed the proliferation of AML cells. Overall, this study not only contributes to a deeper understanding of the molecular mechanisms underlying AML but also provides potential targets and prognostic markers for AML treatment. These findings offer robust support for further research into therapeutic strategies and mechanisms related to AML, with the potential to improve the prognosis and quality of life for AML patients. Nevertheless, further research is needed to validate these findings and explore more in-depth molecular mechanisms.

Identification of two key biomarkers CD93 and FGL2 associated with survival of acute myeloid leukaemia by weighted gene co-expression network analysis

Acute myeloid leukaemia (AML) is a biologically heterogeneous haematological malignancy. This study was performed to identify the potential biomarkers for the prognosis and treatment of AML. We applied weighted gene co-expression network analysis to identify key modules and hub genes related to the prognosis of AML using data from The Cancer Genome Atlas (TCGA). In total, 1581 differentially expressed genes (1096 upregulated and 485 downregulated) were identified between AML patients and healthy controls, with the blue module being the most significant among 14 modules associated with AML morphology. Through functional enrichment analysis, we identified 217 genes in the blue module significantly enriched in 'neutrophil degranulation' and 'neutrophil activation involved in immune response' pathways. The survival analysis revealed six genes (S100A9, S100A8, HK3, CD93, CXCR2 and FGL2) located in the significantly enriched pathway that were notably related to AML survival. We validated the expression of these six genes at gene and single-cell levels and identified methylation loci of each gene, except for S100A8. Finally, in vitro experiments were performed to demonstrate whether the identified hub genes were associated with AML survival. After knockdown of CD93 and FGL2, cell proliferation was significantly reduced in U937 cell line over 5 days. In summary, we identified CD93 and FGL2 as key hub genes related to AML survival, with FGL2 being a novel biomarker for the prognosis and treatment of AML.

Advances in Drug Delivery Systems for the Treatment of Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a common and catastrophic hematological neoplasm with high mortality rates. Conventional therapies, including chemotherapy, hematopoietic stem cell transplantation (HSCT), immune therapy, and targeted agents, have unsatisfactory outcomes for AML patients due to drug toxicity, off-target effects, drug resistance, drug side effects, and AML relapse and refractoriness. These intrinsic limitations of current treatments have promoted the development and application of nanomedicine for more effective and safer leukemia therapy. In this review, the classification of nanoparticles applied in AML therapy, including liposomes, polymersomes, micelles, dendrimers, and inorganic nanoparticles, is reviewed. In addition, various strategies for enhancing therapeutic targetability in nanomedicine, including the use of conjugating ligands, biomimetic-nanotechnology, and bone marrow targeting, which indicates the potential to reverse drug resistance, are discussed. The application of nanomedicine for assisting immunotherapy is also involved. Finally, the advantages and possible challenges of nanomedicine for the transition from the preclinical phase to the clinical phase are discussed.

Targetable leukaemia dependency on noncanonical PI3Kγ signalling

Phosphoinositide-3-kinase-γ (PI3Kγ) is implicated as a target to repolarize tumour-associated macrophages and promote antitumour immune responses in solid cancers1-4. However, cancer cell-intrinsic roles of PI3Kγ are unclear. Here, by integrating unbiased genome-wide CRISPR interference screening with functional analyses across acute leukaemias, we define a selective dependency on the PI3Kγ complex in a high-risk subset that includes myeloid, lymphoid and dendritic lineages. This dependency is characterized by innate inflammatory signalling and activation of phosphoinositide 3-kinase regulatory subunit 5 (PIK3R5), which encodes a regulatory subunit of PI3Kγ5 and stabilizes the active enzymatic complex. We identify p21 (RAC1)-activated kinase 1 (PAK1) as a noncanonical substrate of PI3Kγ that mediates this cell-intrinsic dependency and find that dephosphorylation of PAK1 by PI3Kγ inhibition impairs mitochondrial oxidative phosphorylation. Treatment with the selective PI3Kγ inhibitor eganelisib is effective in leukaemias with activated PIK3R5. In addition, the combination of eganelisib and cytarabine prolongs survival over either agent alone, even in patient-derived leukaemia xenografts with low baseline PIK3R5 expression, as residual leukaemia cells after cytarabine treatment have elevated G protein-coupled purinergic receptor activity and PAK1 phosphorylation. Together, our study reveals a targetable dependency on PI3Kγ-PAK1 signalling that is amenable to near-term evaluation in patients with acute leukaemia.

Diagnosis and management of acute promyelocytic leukemia: Brazilian consensus guidelines 2024 on behalf of the Brazilian Association of Hematology, Hemotherapy and Cellular Therapy

Improvements in clinical assessment have occurred since the last published recommendations on the diagnosis and treatment of acute promyelocytic leukemia in 2013. Here, a committee of specialists of the Brazilian Association of Hematology, Hemotherapy and Cellular Therapy presents a comprehensive review on the current knowledge, focusing on the advances in diagnosis, risk assessment, and frontline and salvage therapy. The concept of urgent diagnosis is explored as well as the management of critical situations such as coagulopathy and differentiation syndrome. Recent adjustments in risk stratification based on white blood cell counts only are presented together with the incorporation of chemo-free regimens for non-high-risk patients. Special conditions such as acute promyelocytic leukemia in children, the elderly and pregnant women are discussed. Finally, acute promyelocytic leukemia is presented as a highly curable disease because of the real possibility of targeted therapy towards differentiation, and, paradoxically, as a serious and urgent condition that deserves prompt recognition and management to avoid early mortality.

Case report: Donor-derived CLL-1 chimeric antigen receptor T-cell therapy for relapsed/refractory acute myeloid leukemia bridging to allogeneic hematopoietic stem cell transplantation after remission

Background

Explore the efficacy and safety of donor-derived CLL-1 chimeric antigen receptor T-cell therapy (CAR-T) for relapsed/refractory acute myeloid leukemia (R/R AML) bridging to allogeneic hematopoietic stem cell transplantation (allo-HSCT) after remission.

Case presentation

An adult R/R AML patient received an infusion of donor-derived CLL-1 CAR-T cells, and the conditioning regimen bridging to allo-HSCT was started immediately after remission on day 11 after CAR-T therapy upon transplantation. Then, routine post-HSCT monitoring of blood counts, bone marrow (BM) morphology, flow cytometry, graft-versus-host disease (GVHD) manifestations, and chimerism status were performed.

Result

After CAR-T therapy, cytokine release syndrome was grade 1. On day 11 after CAR-T therapy, the BM morphology reached complete remission (CR), and the conditioning regimen bridging to allo-HSCT started. Leukocyte engraftment, complete donor chimerism, and platelet engraftment were observed on days +18, +23, and +26 post-allo-HSCT, respectively. The BM morphology showed CR and flow cytometry turned negative on day +23. The patient is currently at 4 months post-allo-HSCT with BM morphology CR, negative flow cytometry, complete donor chimerism, and no extramedullary relapse/GVHD.

Conclusion

Donor-derived CLL-1 CAR-T is an effective and safe therapy for R/R AML, and immediate bridging to allo-HSCT after remission may better improve the long-term prognosis of R/R AML.

[SFCE harmonization workshops: Neonatal acute myeloid leukemia]

Neonatal acute myeloid leukemias (AML) occurred within the first 28 days of life and constitute only a small proportion of all AL. They are distinguished from leukemias of older children by their clinical presentation, which frequently includes cutaneous localizations ("blueberry muffin rash syndrome") and a leukocytosis above 50 ×109/L. This proliferation may be transient, causing a transient leukemoid reaction in a background of constitutional trisomy 21 ("Transient Abnormal Myelopoieseis" or TAM) or Infantile Myeloproliferative Disease in the absence of constitutional trisomy 21 ("Infantile Myeloproliferative Disease" or IMD). In cases of true neonatal AML, the prognosis of patients is poor. Overall survival is around 35 % in the largest historical series. This poor prognosis is mainly due to the period of onset of this pathology making the use of chemotherapy more limited and involving many considerations, both ethical and therapeutic. The objective of this work is to review this rare pathology by addressing the clinical, biological, therapeutic and ethical particularities of patients with true neonatal AML or transient leukemoid reactions occurring in a constitutional trisomy 21 (true TAM) or somatic background (IMD).

CRISPR screens in mechanism and target discovery for AML

CRISPR-based screens have discovered novel functional genes involving in diverse tumor biology and elucidated the mechanisms of the cancer pathological states. Recently, with its randomness and unbiasedness, CRISPR screens have been used to discover effector genes with previously unknown roles for AML. Those novel targets are related to AML survival resembled cellular pathways mediating epigenetics, synthetic lethality, transcriptional regulation, mitochondrial and energy metabolism. Other genes that are crucial for pharmaceutical targeting and drug resistance have also been identified. With the rapid development of novel strategies, such as barcodes and multiplexed mosaic CRISPR perturbation, more potential therapeutic targets and mechanism in AML will be discovered. In this review, we present an overview of recent progresses in the development of CRISPR-based screens for the mechanism and target identification in AML and discuss the challenges and possible solutions in this rapidly growing field.

A novel α,β-unsaturated ketone inhibits leukemia cell growth as PARP1 inhibitor

Leukemia is a malignant disease of the hematopoietic system, in which clonal leukemia cells accumulate and inhibit normal hematopoiesis in the bone marrow and other hematopoietic tissues as a result of uncontrolled proliferation and impaired apoptosis, among other mechanisms. In this study, the anti-leukemic effect of a compound (SGP-17-S) extracted from Chloranthus multistachys, a plant with anti-inflammatory, antibacterial and anti-tumor effects, was evaluated. The effect of SGP-17-S on the viability of leukemic cell was demonstrated by MTT assay, cell cycle, and apoptosis were assessed by flow cytometry using PI staining and Annexin V/PI double staining. Combinations of network pharmacology and cellular thermal shift assay (CETSA) with western blot were used to validate agents that act on leukemia targets. The results showed that SGP-17-S inhibited the growth of leukemia cells in a time- and dose-dependent manner. SGP-17-S blocked HEL cells in the G2 phase, induced apoptosis, decreased Bcl-2 and caspase-8 protein expression, and increased Bax and caspase-3 expression. In addition, CETSA revealed that PARP1 is an important target gene for the inhibition of HEL cell growth, and SGP-17-S exerted its action on leukemia cells by targeting PARP1. Therefore, this study might provide new solutions and ideas for the treatment of leukemia.

Licochalcone A induces mitochondria-dependent apoptosis and interacts with venetoclax in acute myeloid leukemia

The management of patients with acute myeloid leukemia (AML) remains a challenge because of the complexity and heterogeneity of this malignancy. Despite the recent approval of several novel targeted drugs, resistance seems inevitable, and clinical outcomes are still suboptimal. Increasing evidence supports the use of natural plants as an important source of anti-leukemic therapeutics. Licochalcone A (LCA) is an active flavonoid isolated from the roots of licorice, Glycyrrhiza uralensis Fisch., possessing extensive anti-tumor activities. However, its effects on AML and the underlying mechanisms remain unknown. Here, we showed that LCA decreased the viability of established human AML cell lines in a dose- and time-dependent manner. LCA significantly induced mitochondrial apoptotic cell death, accompanied by the downregulation of MCL-1, upregulation of BIM, truncation of BID, and cleavage of PARP. A prominent decline in the phosphorylation of multiple critical molecules, including AKT, glycogen synthase kinase-3β (GSK3β), ERK, and P38 was observed upon LCA treatment, indicating PI3K and MAPK signals were suppressed. Both transcription and translation of c-Myc were also inhibited by LCA. In addition, LCA enhanced the cytotoxicity of the BCL-2 inhibitor venetoclax. Furthermore, the anti-survival and pro-apoptotic effects were confirmed in primary blasts from 10 patients with de novo AML. Thus, our results expand the applications of LCA, which can be regarded as a valuable agent in treating AML.

CD8 + T cell-based molecular subtypes with heterogeneous immune landscapes and clinical significance in acute myeloid leukemia

BACKGROUND

Acute myeloid leukemia (AML) is a heterogeneous hematological malignancy. Although high-dose chemotherapy is the primary treatment option, it cannot cure the disease, and new approaches need to be developed. The tumor microenvironment (TME) plays a crucial role in tumor biology and immunotherapy. CD8 + T cells are the main anti-tumor immune effector cells, and it is essential to understand their relationship with the TME and the clinicopathological characteristics of AML.

METHODS

In this study, we conducted a systematic analysis of CD8 + T cell infiltration through multi-omics data and identified molecular subtypes with significant differences in CD8 + T cell infiltration and prognosis. We aimed to provide a comprehensive evaluation of the pathological factors affecting the prognosis of AML patients and to offer theoretical support for the precise treatment of AML.

RESULTS

Our results indicate that CD8 + T cell infiltration is accompanied by immunosuppression, and that there are two molecular subtypes, with the C2 subtype having a significantly worse prognosis than the C1 subtype, as well as less CD8 + T cell infiltration. We developed a signature to distinguish molecular subtypes using multiple machine learning algorithms and validated the prognostic predictive power of molecular subtypes in nine AML cohorts including 2059 AML patients. Our findings suggest that there are different immunosuppressive characteristics between the two subtypes. The C1 subtype has up-regulated expression of immune checkpoints such as CTLA4, PD-1, LAG3, and TIGITD, while the C2 subtype infiltrates more immunosuppressive cells such as Tregs and M2 macrophages. The C1 subtype is more responsive to anti-PD-1 immunotherapy and induction chemotherapy, as well as having higher immune and cancer-promoting variant-related pathway activity. Patients with the C2 subtype had a higher FLT3 mutation rate, higher WBC counts, and a higher percentage of blasts, as indicated by increased activity of signaling pathways involved in energy metabolism and cell proliferation. Analysis of data from ex vivo AML cell drug assays has identified a group of drugs that differ in therapeutic sensitivity between molecular subtypes.

CONCLUSIONS

Our results suggest that the molecular subtypes we constructed have potential application value in the prognosis evaluation and treatment guidance of AML patients.

Roles of Glutathione and AP-1 in the Enhancement of Vitamin D-Induced Differentiation by Activators of the Nrf2 Signaling Pathway in Acute Myeloid Leukemia Cells

Active vitamin D derivatives (VDDs)-1α,25-dihydroxyvitamin D3/D2 and their synthetic analogs-are well-known inducers of cell maturation with the potential for differentiation therapy of acute myeloid leukemia (AML). However, their dose-limiting calcemic activity is a significant obstacle to using VDDs as an anticancer treatment. We have shown that different activators of the NF-E2-related factor-2/Antioxidant Response Element (Nrf2/ARE) signaling pathway, such as the phenolic antioxidant carnosic acid (CA) or the multiple sclerosis drug monomethyl fumarate (MMF), synergistically enhance the antileukemic effects of various VDDs applied at low concentrations in vitro and in vivo. This study aimed to investigate whether glutathione, the major cellular antioxidant and the product of the Nrf2/ARE pathway, can mediate the Nrf2-dependent differentiation-enhancing activity of CA and MMF in HL60 human AML cells. We report that glutathione depletion using L-buthionine sulfoximine attenuated the enhancing effects of both Nrf2 activators concomitant with downregulating vitamin D receptor (VDR) target genes and the activator protein-1 (AP-1) family protein c-Jun levels and phosphorylation. On the other hand, adding reduced glutathione ethyl ester to dominant negative Nrf2-expressing cells restored both the suppressed differentiation responses and the downregulated expression of VDR protein, VDR target genes, as well as c-Jun and P-c-Jun levels. Finally, using the transcription factor decoy strategy, we demonstrated that AP-1 is necessary for the enhancement by CA and MMF of 1α,25-dihydroxyvitamin D3-induced VDR and RXRα protein expression, transactivation of the vitamin D response element, and cell differentiation. Collectively, our findings suggest that glutathione mediates, at least in part, the potentiating effect of Nrf2 activators on VDDs-induced differentiation of AML cells, likely through the positive regulation of AP-1.

Immunological dynamic characteristics in acute myeloid leukemia predict the long-term outcomes and graft-versus host-disease occurrences post-transplantation

To investigate the relationship between immune dynamic and graft-versus-host-disease (GVHD) risk, 111 initial diagnostic acute myeloid leukemia patients were reviewed. The flow cytometry data of 12 major lymphocyte subsets in bone marrow (BM) from 60 transplant patients at four different time points were analyzed. Additionally, 90 immune subsets in peripheral blood (PB) of 11 post-transplantation on day 100 were reviewed. Our results demonstrated that transplant patients had longer OS compared to non-transplant patients (P < 0.001). Among transplant patients, those who developed GVHD showed longer OS than those without GVHD (P < 0.05). URD donors and CMV-negative status donors were associated with improved OS in transplant patients (P < 0.05). Importantly, we observed a decreased Th/Tc ratio in BM at initial diagnostic in patients with GVHD compared to those without GVHD (P = 0.034). Receiver operating characteristic analysis indicated that a low Th/Tc ratio predicted an increased risk of GVHD with a sensitivity of 44.44% and specificity of 87.50%. Moreover, an increased T/NK ratio in BM of post-induction chemotherapy was found to be associated with GVHD, with a sensitivity of 75.76% and specificity of 65.22%. Additionally, we observed a decreased percentage of NK1 (CD56-CD16+NK) in PB on day 100 post-transplantation in the GVHD group (P < 0.05). These three indicators exhibit promising potential as specific and useful biomarkers for predicting GVHD. These findings provide valuable insights for the early identification and management of GVHD risk, thereby facilitating the possibility of improving patient outcomes.

Rational design and optimization of novel 4-methyl quinazoline derivatives as PI3K/HDAC dual inhibitors with benzamide as zinc binding moiety for the treatment of acute myeloid leukemia

Simultaneous inhibition of PI3K and HDAC has shown promise for treating various cancers, leading to discovery and development of their dual inhibitors as novel anticancer agents. Herein, we disclose a new series of PI3K/HDAC dual inhibitors bearing a benzamide moiety as the pharmacophore of HDAC inhibition. Based on systematic structure-activity relationship study, compounds 36 and 51 featuring an alkyl and benzoyl linker respectively were identified with favorable potencies against both PI3K and HDAC. In cellular assays, compounds 36 and 51 showed significantly enhanced antiproliferative activities against various cancer cell lines relative to single-target inhibitors. Furthermore, western blotting analysis shows compounds 36 and 51 suppressed AKT phosphorylation and increased H3 acetylation in MV4-11 cells, while flow cytometry analysis reveals both compounds dose-dependently induced cell cycle arrest and cell apoptosis. Supported by pharmacokinetic studies, compounds 36 and 51 were subjected to the in vivo evaluation in a MV4-11 xenograft model, demonstrating significant and dose-dependent anticancer efficacies. Overall, this work provides a promising approach for the treatment of AML by simultaneously inhibiting PI3K and HDAC with a dual inhibitor.

Global burden of leukemia attributable to occupational exposure to formaldehyde from 1990 to 2019

The objective of this study was to evaluate the worldwide burden of leukemia owing to occupational exposure to formaldehyde (OEF) from 1990 to 2019. Data on leukemia due to OEF were obtained from the Global Burden of Disease Study (GBD) 2019. By region, age, sex, and disease subtype, the numbers and age-standardized rates (ASRs) associated with deaths, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life years (DALYs) were analyzed. Annual average percentage change (AAPC) was used to estimate disease burden trends from 1990 to 2019. To measure the risk of leukemia due to OEF, the population attributable fraction (PAF) was introduced. From 1990 to 2019, the number of deaths, DALYs, YLLs, and YLDs for leukemia caused by OEF increased by 44%, 34%, 33%, and 124%, respectively. Regarding the change in ASRs, the age-standardized YLDs (ASYLDs) rate of leukemia due to OEF, which was 38.03% (AAPC = 1.17 [95% confidence interval [CI] 1.11, 1.23]), indicated an increased trend. But the age-standardized mortality rate (ASMR), age-standardized DALY (ASDALY) rate, and age-standardized YLL (ASYLL) rate showed decline trends, with - 11.90% (AAPC =  - 0.41 [95% CI - 0.45, - 0.37]), - 14.19% (AAPC =  - 0.5 [95% CI - 0.55, - 0.45]), and - 14.97% (AAPC =  - 0.53 [95% CI - 0.58, - 0.48]), respectively. In terms of PAFs, there were increasing trends in PAFs of age-standardized deaths, ASDALYs, ASYLLs, and ASYLDs for leukemia caused by OEF, with 20.15% (95% uncertainty interval [UI] 11.76%, 30.25%), 36.28% (95% UI 21.46%, 53.42%), 51.91% (95% UI 35.05%, 72.07%), and 36.34% (95% UI 21.58%, 53.63%), respectively. Across the socio-demographic index (SDI) regions, the leukemia burden caused by OEF was concentrated in middle and high-middle SDI regions. Besides, OEF poses a more serious risk for acute leukemia among the leukemia subtype. Globally, leukemia caused by OEF remains a public health burden. Policies must be developed to avoid the burden of leukemia caused by OEF.

PIEZO1 is essential for the survival and proliferation of acute myeloid leukemia cells

INTRODUCTION

Leukemogenesis is a complex process that interconnects tumoral cells with their microenvironment, but the effect of mechanosensing in acute myeloid leukemia (AML) blasts is poorly known. PIEZO1 perceives and transmits the constraints of the environment to human cells by acting as a non-selective calcium channel, but very little is known about its role in leukemogenesis.

RESULTS

For the first time, we show that PIEZO1 is preferentially expressed in healthy hematopoietic stem and progenitor cells in human hematopoiesis, and globally overexpressed in AML cells. In AML subtypes, PIEZO1 expression associates with favorable outcomes as better overall (OS) and disease-free survival (DFS). If PIEZO1 is expressed and functional in THP1 leukemic myeloid cell line, its chemical activation doesn't impact the proliferation, differentiation, nor survival of cells. However, the downregulation of PIEZO1 expression dramatically reduces the proliferation and the survival of THP1 cells. We show that PIEZO1 knock-down blocks the cell cycle in G0/G1 phases of AML cells, impairs the DNA damage response pathways, and critically increases cell death by triggering extrinsic apoptosis pathways.

CONCLUSIONS

Altogether, our results reveal a new role for PIEZO1 mechanosensing in the survival and proliferation of leukemic blasts, which could pave the way for new therapeutic strategies to target AML cells.

Preclinical characterization of danatinib as a novel FLT3 inhibitor with excellent efficacy against resistant acute myeloid leukemia

The therapeutic benefits of available FLT3 inhibitors for AML are limited by drug resistance, which is related to mutations, as well toxicity caused by off-target effects. In this study, we introduce a new small molecule FLT3 inhibitor called danatinib, which was designed to overcome the limitations of currently approved agents. Danatinib demonstrated greater potency and selectivity, resulting in cytotoxic activity specific to FLT3-ITD and/or FLT3-TKD mutated models. It also showed a superior kinome inhibition profile compared to several currently approved FLT3 inhibitors. In diverse FLT3-TKD models, danatinib exhibited substantially improved activity at clinically relevant doses, outperforming approved FLT3 inhibitors. In vivo safety evaluations performed on the granulopoiesis of transgenic myeloperoxidase (MPO) zebrafish and mice models proved danatinib to have an acceptable safety profile. Danatinib holds promise as a new and improved FLT3 inhibitor for the treatment of AML, offering long-lasting remissions and improved overall survival rates.

Gemtuzumab ozogamicin for relapsed or primary refractory acute myeloid leukemia in children-the Polish Pediatric Leukemia and Lymphoma Study Group experience

Background

Gemtuzumab ozogamicin (GO), one of the first targeted drugs used in oncology, consists of an anti-cluster of differentiation 33 (CD33) monoclonal antibody bound to a derivative of cytotoxic calicheamicin. After the drug withdrawn in 2010 due to a significantly higher rate of early deaths, GO regained approval in 2017 for the treatment of newly diagnosed, refractory, or relapsed acute myeloid leukemia (AML) in adults and children over 15 years of age. The objective of the study was a retrospective analysis of clinical characteristics, treatment outcomes, and GO toxicity profile in children with primary refractory or relapsed (R/R) AML treated in Poland from 2008 to 2022.

Methods

Data were collected through the Polish Registry of Acute Myeloid Leukemia. From January 2008 to December 2022, 35 children with R/R AML were treated with GO in seven centers of the Polish Pediatric Leukemia and Lymphoma Study Group.

Results

Most of the children (30 of 35) received only one GO cycle in combination with various chemotherapy cycles (IDA-FLA, DOXO-FLA, FLA, FLAG, and others). Eighteen children (51%) achieved complete remission (CR), 14 did not respond to treatment, and three progressed. GO therapy was followed by allogeneic hematopoietic stem cell transplantation (allo-HSCT) in 18 children in CR. The 5-year overall survival (OS) after GO therapy was 37.1% ± 8.7% for the total cohort. There was a trend toward a superior outcome in patients with strong expression of CD33 expression (over 50% positive cells) compared with that in patients with lower expression of CD33 (OS, 41.2% ± 11.9% versus 27.8% ± 13.2%; p = 0.5; 5-year event-free survival, 35.4% ± 11.6% versus 25.7% ± 12.3%; p = 0.5, respectively). Children under 15 years have better outcome (OS, 34.9% ± 10.4% versus 30% ± 14.5%, p = 0.3). The most common adverse events were bone marrow aplasia, fever of unknown origin, infections, and elevated liver enzyme elevation. Sinusoidal obstruction syndrome occurred in two children.

Conclusions

The use of GO in severely pretreated children, including those under 15 years of age, with previous failure of AML treatment is a feasible and effective bridging therapy to allo-HSCT with an acceptable toxicity profile.

Targetable leukemia dependency on noncanonical PI3Kγ signaling

Phosphoinositide 3-kinase gamma (PI3Kγ) is implicated as a target to repolarize tumor-associated macrophages and promote anti-tumor immune responses in solid cancers. However, cancer cell-intrinsic roles of PI3Kγ are unclear. Here, by integrating unbiased genome-wide CRISPR interference screening with functional analyses across acute leukemias, we define a selective dependency on the PI3Kγ complex in a high-risk subset that includes myeloid, lymphoid, and dendritic lineages. This dependency is characterized by innate inflammatory signaling and activation of phosphoinositide 3-kinase regulatory subunit 5 ( PIK3R5 ), which encodes a regulatory subunit of PI3Kγ and stabilizes the active enzymatic complex. Mechanistically, we identify p21 (RAC1) activated kinase 1 (PAK1) as a noncanonical substrate of PI3Kγ that mediates this cell-intrinsic dependency independently of Akt kinase. PI3Kγ inhibition dephosphorylates PAK1, activates a transcriptional network of NFκB-related tumor suppressor genes, and impairs mitochondrial oxidative phosphorylation. We find that treatment with the selective PI3Kγ inhibitor eganelisib is effective in leukemias with activated PIK3R5 , either at baseline or by exogenous inflammatory stimulation. Notably, the combination of eganelisib and cytarabine prolongs survival over either agent alone, even in patient-derived leukemia xenografts with low baseline PIK3R5 expression, as residual leukemia cells after cytarabine treatment have elevated G protein-coupled purinergic receptor activity and PAK1 phosphorylation. Taken together, our study reveals a targetable dependency on PI3Kγ/PAK1 signaling that is amenable to near-term evaluation in patients with acute leukemia.

Systematic evaluation of AML-associated antigens identifies anti-U5 SNRNP200 therapeutic antibodies for the treatment of acute myeloid leukemia

Despite recent advances in the treatment of acute myeloid leukemia (AML), there has been limited success in targeting surface antigens in AML, in part due to shared expression across malignant and normal cells. Here, high-density immunophenotyping of AML coupled with proteogenomics identified unique expression of a variety of antigens, including the RNA helicase U5 snRNP200, on the surface of AML cells but not on normal hematopoietic precursors and skewed Fc receptor distribution in the AML immune microenvironment. Cell membrane localization of U5 snRNP200 was linked to surface expression of the Fcγ receptor IIIA (FcγIIIA, also known as CD32A) and correlated with expression of interferon-regulated immune response genes. Anti-U5 snRNP200 antibodies engaging activating Fcγ receptors were efficacious across immunocompetent AML models and were augmented by combination with azacitidine. These data provide a roadmap of AML-associated antigens with Fc receptor distribution in AML and highlight the potential for targeting the AML cell surface using Fc-optimized therapeutics.

Pharmacological Inhibition of PIP4K2 Potentiates Venetoclax-Induced Apoptosis in Acute Myeloid Leukemia

Phosphatidylinositol-5-phosphate 4-kinase type 2 (PIP4K2) protein family members (PIP4K2A, PIP4K2B, and PIP4K2C) participate in the generation of PIP4,5P2, which acts as a secondary messenger in signal transduction, a substrate for metabolic processes, and has structural functions. In patients with acute myeloid leukemia (AML), high PIP4K2A and PIP4K2C levels are independent markers of a worse prognosis. Recently, our research group reported that THZ-P1-2 (PIP4K2 pan-inhibitor) exhibits anti-leukemic activity by disrupting mitochondrial homeostasis and autophagy in AML models. In the present study, we characterized the expression of PIP4K2 in the myeloid compartment of hematopoietic cells, as well as in AML cell lines and clinical samples with different genetic abnormalities. In ex vivo assays, PIP4K2 expression levels were related to sensitivity and resistance to several antileukemia drugs and highlighted the association between high PIP4K2A levels and resistance to venetoclax. The combination of THZ-P1-2 and venetoclax showed potentiating effects in reducing viability and inducing apoptosis in AML cells. A combined treatment differentially modulated multiple genes, including TAp73, BCL2, MCL1, and BCL2A1. In summary, our study identified the correlation between the expression of PIP4K2 and the response to antineoplastic agents in ex vivo assays in AML and exposed vulnerabilities that may be exploited in combined therapies, which could result in better therapeutic responses.

Pan-cancer analysis revealing that PTPN2 is an indicator of risk stratification for acute myeloid leukemia

The non-receptor protein tyrosine phosphatases gene family (PTPNs) is involved in the tumorigenesis and development of many cancers, but the role of PTPNs in acute myeloid leukemia (AML) remains unclear. After a comprehensive evaluation on the expression patterns and immunological effects of PTPNs using a pan-cancer analysis based on RNA sequencing data obtained from The Cancer Genome Atlas, the most valuable gene PTPN2 was discovered. Further investigation of the expression patterns of PTPN2 in different tissues and cells showed a robust correlation with AML. PTPN2 was then systematically correlated with immunological signatures in the AML tumor microenvironment and its differential expression was verified using clinical samples. In addition, a prediction model, being validated and compared with other models, was developed in our research. The systematic analysis of PTPN family reveals that the effect of PTPNs on cancer may be correlated to mediating cell cycle-related pathways. It was then found that PTPN2 was highly expressed in hematologic diseases and bone marrow tissues, and its differential expression in AML patients and normal humans was verified by clinical samples. Based on its correlation with immune infiltrates, immunomodulators, and immune checkpoint, PTPN2 was found to be a reliable biomarker in the immunotherapy cohort and a prognostic predictor of AML. And PTPN2'riskscore can accurately predict the prognosis and response of cancer immunotherapy. These findings revealed the correlation between PTPNs and immunophenotype, which may be related to cell cycle. PTPN2 was differentially expressed between clinical AML patients and normal people. It is a diagnostic biomarker and potentially therapeutic target, providing targeted guidance for clinical treatment.

Platycodin D induces apoptotic cell death through PI3K/AKT and MAPK/ERK pathways and synergizes with venetoclax in acute myeloid leukemia

Acute myeloid leukemia (AML) is a highly heterogeneous and rapidly progressive hematopoietic neoplasm characterized by frequent relapses and variable prognoses. The development of new treatment options, therefore, is of crucial importance. Platycodin D (PD) is a triterpenoid saponin, extracted from the roots of the traditional Chinese herbal medicine Platycodon grandiflorum (Jacq.) A. DC., which has been reported to exhibit therapeutic potential against a broad range of cancers. Although the effects of PD on AML remain unclear, in the present study, we observed a concentration-dependent reduction in the viability of multiple human AML cell lines in response to treatment with PD. In addition to triggering mitochondria-dependent apoptosis via the upregulation of BAK and BIM, treatment with PD also induced cell cycle arrest at the G0/G1 phase. Western blot analyses revealed marked suppression of the phosphorylation of protein kinase B (AKT), glycogen synthase kinase-3β, ribosomal protein S6, and extracellular signal-regulated kinase (ERK) by PD, in turn implying the participation of the phosphoinositide 3-kinase (PI3K)/AKT and mitogen-activated protein kinase (MAPK)/ERK pathways. Pre-incubation with LY294002, MK2206, AR-A014418, or U0126 was consistently found to significantly aggravate PD-induced inhibition of viability. Additionally, PD combined with the B-cell lymphoma 2 (BCL2) inhibitor venetoclax elicited synergistically enhanced cytotoxic effects. The anti-leukemic activity of PD was further validated using primary samples from de novo AML patients. Given the results of the present study, PD may be a potent therapeutic candidate for the treatment of AML.

A comprehensive overview on antibody-drug conjugates: from the conceptualization to cancer therapy

Antibody-Drug Conjugates (ADCs) represent an innovative class of potent anti-cancer compounds that are widely used in the treatment of hematologic malignancies and solid tumors. Unlike conventional chemotherapeutic drug-based therapies, that are mainly associated with modest specificity and therapeutic benefit, the three key components that form an ADC (a monoclonal antibody bound to a cytotoxic drug via a chemical linker moiety) achieve remarkable improvement in terms of targeted killing of cancer cells and, while sparing healthy tissues, a reduction in systemic side effects caused by off-tumor toxicity. Based on their beneficial mechanism of action, 15 ADCs have been approved to date by the market approval by the Food and Drug Administration (FDA), the European Medicines Agency (EMA) and/or other international governmental agencies for use in clinical oncology, and hundreds are undergoing evaluation in the preclinical and clinical phases. Here, our aim is to provide a comprehensive overview of the key features revolving around ADC therapeutic strategy including their structural and targeting properties, mechanism of action, the role of the tumor microenvironment and review the approved ADCs in clinical oncology, providing discussion regarding their toxicity profile, clinical manifestations and use in novel combination therapies. Finally, we briefly review ADCs in other pathological contexts and provide key information regarding ADC manufacturing and analytical characterization.

Retinoic acid and proteotoxic stress induce AML cell death overcoming stromal cell protection

BACKGROUND

Acute myeloid leukemia (AML) patients bearing the ITD mutation in the tyrosine kinase receptor FLT3 (FLT3-ITD) present a poor prognosis and a high risk of relapse. FLT3-ITD is retained in the endoplasmic reticulum (ER) and generates intrinsic proteotoxic stress. We devised a strategy based on proteotoxic stress, generated by the combination of low doses of the differentiating agent retinoic acid (R), the proteasome inhibitor bortezomib (B), and the oxidative stress inducer arsenic trioxide (A).

METHODS

We treated FLT3-ITD+ AML cells with low doses of the aforementioned drugs, used alone or in combinations and we investigated the induction of ER and oxidative stress. We then performed the same experiments in an in vitro co-culture system of FLT3-ITD+ AML cells and bone marrow stromal cells (BMSCs) to assess the protective role of the niche on AML blasts. Eventually, we tested the combination of drugs in an orthotopic murine model of human AML.

RESULTS

The combination RBA exerts strong cytotoxic activity on FLT3-ITD+ AML cell lines and primary blasts isolated from patients, due to ER homeostasis imbalance and generation of oxidative stress. AML cells become completely resistant to the combination RBA when treated in co-culture with BMSCs. Nonetheless, we could overcome such protective effects by using high doses of ascorbic acid (Vitamin C) as an adjuvant. Importantly, the combination RBA plus ascorbic acid significantly prolongs the life span of a murine model of human FLT3-ITD+ AML without toxic effects. Furthermore, we show for the first time that the cross-talk between AML and BMSCs upon treatment involves disruption of the actin cytoskeleton and the actin cap, increased thickness of the nuclei, and relocalization of the transcriptional co-regulator YAP in the cytosol of the BMSCs.

CONCLUSIONS

Our findings strengthen our previous work indicating induction of proteotoxic stress as a possible strategy in FLT3-ITD+ AML therapy and open to the possibility of identifying new therapeutic targets in the crosstalk between AML and BMSCs, involving mechanotransduction and YAP signaling.

Current clinical practices and challenges in molecular testing: a GOAL Consortium Hematopathology Working Group report

While molecular testing of hematologic malignancies is now standard of care, there is variability in practice and testing capabilities between different academic laboratories, with common questions arising on how to best meet clinical expectations. A survey was sent to hematopathology subgroup members of the Genomics Organization for Academic Laboratories consortium to assess current and future practice and potentially establish a reference for peer institutions. Responses were received from 18 academic tertiary-care laboratories regarding next-generation sequencing (NGS) panel design, sequencing protocols and metrics, assay characteristics, laboratory operations, case reimbursement, and development plans. Differences in NGS panel size, use, and gene content were reported. Gene content for myeloid processes was reported to be generally excellent, while genes for lymphoid processes were less well covered. The turnaround time (TAT) for acute cases, including acute myeloid leukemia, was reported to range from 2 to 7 calendar days to 15 to 21 calendar days, with different approaches to achieving rapid TAT described. To help guide NGS panel design and standardize gene content, consensus gene lists based on current and future NGS panels in development were generated. Most survey respondents expected molecular testing at academic laboratories to continue to be viable in the future, with rapid TAT for acute cases likely to remain an important factor. Molecular testing reimbursement was reported to be a major concern. The results of this survey and subsequent discussions improve the shared understanding of differences in testing practices for hematologic malignancies between institutions and will help provide a more consistent level of patient care.

The landscape of novel strategies for acute myeloid leukemia treatment: Therapeutic trends, challenges, and future directions

Acute myeloid leukemia (AML) is a highly heterogeneous subtype of hematological malignancies with a wide spectrum of cytogenetic and molecular abnormalities, which makes it difficult to manage and cure. Along with the deeper understanding of the molecular mechanisms underlying AML pathogenesis, a large cohort of novel targeted therapeutic approaches has emerged, which considerably expands the medical options and changes the therapeutic landscape of AML. Despite that, resistant and refractory cases caused by genomic mutations or bypass signalling activation remain a great challenge. Therefore, discovery of novel treatment targets, optimization of combination strategies, and development of efficient therapeutics are urgently required. This review provides a detailed and comprehensive discussion on the advantages and limitations of targeted therapies as a single agent or in combination with others. Furthermore, the innovative therapeutic approaches including hyperthermia, monoclonal antibody-based therapy, and CAR-T cell therapy are also introduced, which may provide safe and viable options for the treatment of patients with AML.

Real-world experience with selinexor-containing chemotherapy-free or low-dose chemotherapy regimens for patients with relapsed/refractory acute myeloid leukemia and myeloid sarcoma

Introduction: Treatment of relapsed or refractory acute myeloid leukemia (R/R AML) and myeloid sarcoma (MS) has presented challenges for decades. Studies on selinexor in combination with various standard or intensive chemotherapy regimens for the treatment of R/R AML have demonstrated promising results. This study aimed to evaluate the efficacy and safety of chemotherapy-free or low-dose chemotherapy regimens with selinexor for R/R AML and MS patients. Methods: Ten patients with R/R AML or MS who received chemotherapy-free or low-dose chemotherapy regimens in combination with selinexor at Tongji Hospital from October 2021 to August 2022 were included in this study. The primary endpoint was overall response rate (ORR) and secondary endpoints included complete remission (CR), CR with incomplete hematological recovery (CRi), partial remission (PR), transplantation rate, and safety. Results: All patients were evaluable for response, achieving CR in four (40.0%) patients and CRi in two (20.0%) patients for a total CR/CRi of 60.0%. The ORR was 80.0% when patients with PR were included. Five (50.0%) patients underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) after treatment with selinexor-containing regimens. At the end of the follow-up, seven (70.0%) patients were alive, and three patients died of transplant-related complications or disease progression. The most frequently reported nonhematologic adverse events (AEs) in patients were grade 1 or 2 asymptomatic hyponatremia. Conclusion: The chemotherapy-free or low-dose chemotherapy regimens in combination with selinexor for R/R AML are feasible and tolerable and provide an opportunity for patients to receive transplantation.

Real-world treatment outcomes of medicines used in special situations (off-label and compassionate use) in oncology and hematology: A retrospective study from a comprehensive cancer institution

PURPOSE

Medicines in special situations (MSS) refer to off-label or to unlicensed drugs under investigation (compassionate use). Our objectives were to evaluate characteristics and to estimate overall survival (OS), event-free survival (EFS), and the duration of treatment (DT) of MSS used for cancer treatment at a multicentre comprehensive cancer institution.

METHODS

Retrospective cohort study on adult cancer patients for whom an MSS treatment was requested (January 2011-December 2020). A descriptive analysis was performed and median OS and EFS and 95% confidence intervals (CIs) were estimated. Survival curves were stratified by type of tumor, ECOG (Eastern Cooperative Oncology Group) performance status (PS), age, sex, treatment stage and type of drug (mechanism of action and target).

RESULTS

Treatment was initiated in 2092 episodes (1930 patients) out of 2377 MSS episodes (2189 patients) requested, 33% for hematological treatment and 87% for advanced stage cancer. Median OS (months) was 21.1 (95% CI 19.4-22.7), median EFS was 5.6 (95% CI 5.1-6.0) months, and median DT was 4.5 [0.0; 115.3] months. OS and EFS statistically significantly favored female patients, ECOG PS ≥2 episodes showed worse OS and EFS outcomes (p < 0.0001). Statistically significant differences in survival were found within solid and hematological cancer, disease stage, drug mechanism of action, and type of cancer (p < 0.001) but not for age. Survival outcomes by tumor subtype and drug are presented both globally and separately based on disease stage.

CONCLUSION

MSS uses are practiced across almost all cancer types, mostly for advanced disease. ECOG PS ≥2, along with advanced disease, was related to worse survival. Information about real-world outcomes is valuable and contributes to better decision-making regarding MSS and our experience in this field could be of interest for other colleagues.

FLT3-ITD Mutation and Allogeneic Stem Cell Transplantation in Acute Myeloid Leukemia: A Case Study

Acute myeloid leukemia (AML) is a hematologic cancer that is characterized by unchecked myeloid precursor cell growth in the bone marrow and peripheral circulation, which results in an overabundance of immature myeloid cells. The 22-year-old man featured in this case report had a fever, tiredness, and easy bruising. Pancytopenia was discovered through laboratory testing, and an AML diagnosis was confirmed by a bone marrow biopsy, with myeloid blasts making up 85% of the nucleated cells. FLT3-ITD and NPM1 mutations were found by genetic testing. After receiving induction chemotherapy using the drugs daunorubicin and cytarabine, the patient experienced complete remission after just one cycle of treatment. He then had an allogeneic stem cell transplant and was still in remission during follow-up. This example highlights the significance of early AML diagnosis and detection, as well as the function of molecular profiling and risk stratification in directing treatment choices. It emphasizes the requirement for continued study to produce novel treatments and enhance results for AML patients. In general, this case study advances knowledge of AML and its management techniques. For AML patients to experience the best results, early diagnosis, risk assessment, and individualized therapy plans based on molecular profiling are essential. AML patients' prognosis and quality of life can be improved by the development of targeted medicines, which require ongoing study to better understand the disease.

ART714 is a best-in-class antileukemic 2-carbon-linked dimeric artemisinin derivative

PURPOSE

It has become increasingly clear that new multiagent combination regimens are required to improve survival rates in acute myeloid leukemia (AML). We recently reported that ART631, a first-in-class 2-carbon-linked artemisinin-derived dimer (2C-ART), was not only efficacious as a component of a novel three-drug combination regimen to treat AML, but, like other synthetic artemisinin derivatives, demonstrated low clinical toxicity. However, we ultimately found ART631 to have suboptimal solubility and stability properties, thus limiting its potential for clinical development.

METHODS

We assessed 22 additional 2C-ARTs with documented in vivo antimalarial activity for antileukemic efficacy and physicochemical properties. Our strategy involved culling out 2C-ARTs inferior to ART631 with respect to potency, stability, and solubility in vitro, and then validating in vivo pharmacokinetics, pharmacodynamics, and efficacy of one 2C-ART lead compound.

RESULTS

Of the 22 2C-ARTs, ART714 was found to have the most optimal in vitro solubility, stability, and antileukemic efficacy, both alone and in combination with the BCL2 inhibitor venetoclax (VEN) and the kinase inhibitor sorafenib (SOR). ART714 was also highly effective in combination with VEN and the FMS-like tyrosine kinase 3 inhibitor gilteritinib (GILT) against MOLM14 AML xenografts.

CONCLUSION

We identified ART714 as our best-in-class antileukemic 2C-ART, based on in vitro potency and pharmacologic properties. We established its in vivo pharmacokinetics and demonstrated its in vitro cooperativity with VEN and SOR and in vivo activities of combinations of ART714, VEN, and GILT. Additional research is indicated to define the optimal niche for the use of ART714 in treatment of AML.

Clinical status of induction therapy incorporating a hypomethylating agent for newly diagnosed adult acute myeloid leukemia compared to the standard 7+3 regimen

INTRODUCTION

Cytarabine and anthracycline combination therapy (7 + 3 regimen) is the standard care for induction chemotherapy in adult patients with acute myeloid leukemia (AML). Although this intensive regimen achieves a high response rate, it is highly toxic, especially in elderly or frail patients. Hypomethylating agents approved initially for high-risk myelodysplastic syndrome had longer survival times than conventional care in elderly patients with newly diagnosed AML.

AREAS COVERED

We summarize the latest information regarding induction therapy using hypomethylating agents (azacitidine and decitabine) for newly diagnosed AML.

EXPERT OPINION

For untreated patients ineligible for an intensive regimen, a phase III trial exhibited the survival benefit of adding the highly selective BCL2 inhibitor venetoclax to azacitidine. The National Comprehensive Cancer Network guidelines recommend azacitidine or decitabine plus venetoclax as an option for patients with poor-risk AML, including those with TP53 mutations and AML with the cytogenetic features of myelodysplastic syndrome. Future studies should evaluate positioning this combination as an induction therapy for younger patients eligible for hematopoietic stem cell transplantation. Without randomized trials, propensity score matching analysis suggested a comparable prognosis between azacitidine combination and intensive chemotherapy. Considering the feasibility of a doublet regimen incorporating azacitidine, a triplet regimen should be examined.

Emerging small molecular inhibitors as targeted therapies for high-risk acute myeloid leukemias

INTRODUCTION

Acute myeloid leukemia (AML) is an aggressive disease which has traditionally been treated with intensive chemotherapy. Survival in patients with high-risk cytogenetic and molecular subsets has been poor with this approach due to suboptimal responses seen with intensive chemotherapy and due to many patients with higher risk disease being older and unable to tolerate intensive therapies. In recent years, several targeted therapies have been under investigation for patients with high-risk AML subsets.

AREAS COVERED

This review covers four different subsets of high-risk AML including TP53-mutated, KMT2A-rearranged, FLT3-mutated, and secondary AML developing after prior hypomethylating agent exposure. The research discussed in this review focuses on small molecule inhibitors that have been studied in the treatment of these high-risk AML subsets.

EXPERT OPINION

There are several small molecule inhibitors that have demonstrated promise in these high-risk AML subsets. Longer follow-up and ongoing investigation are needed to continue to optimize therapy for patients with high-risk AML.

A Panorama of Immune Fighters Armored with CARs in Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a devastating disease. Intensive chemotherapy is the mainstay of treatment but results in debilitating toxicities. Moreover, many treated patients will eventually require hematopoietic stem cell transplantation (HSCT) for disease control, which is the only potentially curative but challenging option. Ultimately, a subset of patients will relapse or have refractory disease, posing a huge challenge to further therapeutic decisions. Targeted immunotherapies hold promise for relapsed/refractory (r/r) malignancies by directing the immune system against cancer. Chimeric antigen receptors (CARs) are important components of targeted immunotherapy. Indeed, CAR-T cells have achieved unprecedented success against r/r CD19+ malignancies. However, CAR-T cells have only achieved modest outcomes in clinical studies on r/r AML. Natural killer (NK) cells have innate anti-AML functionality and can be engineered with CARs to improve their antitumor response. CAR-NKs are associated with lower toxicities than CAR-T cells; however, their clinical efficacy against AML has not been extensively investigated. In this review, we cite the results from clinical studies of CAR-T cells in AML and describe their limitations and safety concerns. Moreover, we depict the clinical and preclinical landscape of CAR used in alternative immune cell platforms with a specific focus on CAR-NKs, providing insight into the future optimization of AML.

Development, efficacy and side effects of antibody‑drug conjugates for cancer therapy (Review)

Antibody-drug conjugates (ADCs) are anticancer drugs that combine cytotoxic small-molecule drugs (payloads) with monoclonal antibodies through a chemical linker and that transfer toxic payloads to tumor cells expressing target antigens. All ADCs are based on human IgG. In 2009, the Food and Drug Administration (FDA) approved gemtuzumab ozogamicin as the initial first-generation ADC. Since then, at least 100 ADC-related projects have been initiated, and 14 ADCs are currently being tested in clinical trials. The limited success of gemtuzumab ozogamicin has led to the development of optimization strategies for the next generation of drugs. Subsequently, experts have improved the first-generation ADCs and have developed second-generation ADCs such as ado-trastuzumab emtansine. Second-generation ADCs have higher specific antigen levels, more stable linkers and longer half-lives and show great potential to transform cancer treatment models. Since the first two generations of ADCs have served as a good foundation, the development of ADCs is accelerating, and third-generation ADCs, represented by trastuzumab deruxtecan, are ready for wide application. Third-generation ADCs are characterized by strong pharmacokinetics and high pharmaceutical activity, and their drug-to-antibody ratio mainly ranges from 2 to 4. In the past decade, the research prospects of ADCs have broadened, and an increasing number of specific antigen targets and mechanisms of cytotoxic drug release have been discovered and studied. To date, seven ADCs have been approved by the FDA for lymphoma, and three have been approved to treat breast cancer. The present review explores the function and development of ADCs and their clinical use in cancer treatment.

Discovery of a high potent PIM kinase inhibitor for acute myeloid leukemia based on N-pyridinyl amide scaffold by optimizing the fragments toward to Lys67 and Asp128/Glu171

Despite the recent development of PIM inhibitors based on N-(pyridin-3-yl)acetamide scaffold for acute myeloid leukemia (AML), the structural-activity relationship (SAR) associated with the effects of positional isomerization of N toward to Lys67 and freedom of solvent fragment toward to Asp128/Glu171 still remains an open question. In this work, a structurally novel compound based on N-pyridinyl amide was designed by fragment hybridization and then our SAR exploration revealed that the positional isomerization would lead to a decrease in activity, while increase of the freedom of solvent fragment by breaking the intramolecular hydrogen bond unprecedentedly leads to an increase in activity. These studies finally resulted in the screening out of a potent PIM inhibitor FD1024 (compound 24) which exerts strong antiproliferative activity against the tested AML cell lines and achieves profound antitumor efficacy in mice at well-tolerated dose schedules.

Synergistic Action of MCL-1 Inhibitor with BCL-2/BCL-XL or MAPK Pathway Inhibitors Enhances Acute Myeloid Leukemia Cell Apoptosis and Differentiation

Acute myeloid leukemia (AML) is a hematological malignancy characterized by excessive proliferation of abnormal myeloid precursors accompanied by a differentiation block and inhibition of apoptosis. Increased expression of an anti-apoptotic MCL-1 protein was shown to be critical for the sustained survival and expansion of AML cells. Therefore, herein, we examined the pro-apoptotic and pro-differentiating effects of S63845, a specific inhibitor of MCL-1, in a single-agent treatment and in combination with BCL-2/BCL-XL inhibitor, ABT-737, in two AML cell lines: HL-60 and ML-1. Additionally, we determined whether inhibition of the MAPK pathway had an impact on the sensitivity of AML cells to S63845. To assess AML cells' apoptosis and differentiation, in vitro studies were performed using PrestoBlue assay, Coulter electrical impedance method, flow cytometry, light microscopy and Western blot techniques. S63845 caused a concentration-dependent decrease in the viability of HL-60 and ML-1 cells and increased the percentage of apoptotic cells. Combined treatment with S63845 and ABT-737 or MAPK pathway inhibitor enhanced apoptosis but also induced differentiation of tested cells, as well as altering the expression of the MCL-1 protein. Taken together, our data provide the rationale for further studies regarding the use of MCL-1 inhibitor in combination with other pro-survival protein inhibitors.

What’s New in the Classification, Diagnosis and Therapy of Myeloid Leukemias

Myeloid leukemias are a broad group of hematological disorders, characterized by heterogeneous clinical and biological features. In recent years, unprecedented genetic discoveries and clinical–biological correlations have revolutionized the field of myeloid leukemias. The most relevant changes have specifically occurred in acute myeloid leukemia (AML), chronic myelomonocytic leukemia (CMML), chronic myeloid leukemia (CML) and myeloid neoplasms (MNs) with eosinophilia. The recently published International Consensus Classification (ICC) of myeloid neoplasms has addressed these changes, providing an updated framework and revised diagnostic criteria for such entities. This is also the aim of the 5th edition of the WHO classification of hematopoietic tumors, whose preliminary version was published in 2022. Parallel to this, new therapeutic options and novel molecular targets have changed the management of many myeloid entities, including AML and CML. This review aims to address the most relevant updates in the classification and diagnosis of AML, CMML, CML and MNs with eosinophilia. The state of the art of treatment and future therapeutic options for such disorders are also discussed.

Targeting Measurable Residual Disease (MRD) in Acute Myeloid Leukemia (AML): Moving beyond Prognostication

Measurable residual disease (MRD) assessment in acute myeloid leukemia (AML) has an established role in disease prognostication, particularly in guiding decisions for hematopoietic cell transplantation in first remission. Serial MRD assessment is now routinely recommended in the evaluation of treatment response and monitoring in AML by the European LeukemiaNet. The key question remains, however, if MRD in AML is clinically actionable or "does MRD merely portend fate"? With a series of new drug approvals since 2017, we now have more targeted and less toxic therapeutic options for the potential application of MRD-directed therapy. Recent approval of NPM1 MRD as a regulatory endpoint is also foreseen to drastically transform the clinical trial landscape such as biomarker-driven adaptive design. In this article, we will review (1) the emerging molecular MRD markers (such as non-DTA mutations, IDH1/2, and FLT3-ITD); (2) the impact of novel therapeutics on MRD endpoints; and (3) how MRD might be used as a predictive biomarker to guide therapy in AML beyond its prognostic role, which is the focus of two large collaborative trials: AMLM26 INTERCEPT (ACTRN12621000439842) and MyeloMATCH (NCT05564390).

Association of genetic variants and survival in patients with acute myeloid leukemia in rural Appalachia

BACKGROUND

Previous population health studies examining adults with acute myeloid leukemia (AML); however many of these, such as the Cancer Genome Atlas, are derived from databases collected by large urban centers. Due to its unique industry and environmental exposures, we hypothesized the West Virginia Appalachian population may have different mutational trends and clinical outcomes.

AIMS

To address the concern of under-representation of rural minorities in cancer genomic databases, we performed exploratory whole exome sequencing in patients with newly diagnosed AML in rural Appalachia.

METHODS & RESULTS

Correlations between genetic variants and clinical outcome variables were examined via retrospective chart review. A total of 26 patients were identified and whole exome sequencing was performed. Median age was 68 years old. Twenty-one patients had de novo AML (84%). As per European LeukemiaNet (ELN) criteria, 8 patients were favorable (32%), 12 were intermediate (48%), and 5 were adverse risk (20%). Eight patients proceeded to transplant. The median progression-free survival and overall survival were 16.5 months and 26.6 months, respectively. We noted an increased tumor mutation burden and a higher frequency of specific known driver mutations when compared to The Cancer Genome Atlas database; we also found novel mutations in MUC3A, MUC5AC, HCAR3, ORT2B, and PABPC. Survival outcomes were slightly lower than national average and BCOR mutation correlated with inferior outcomes.

CONCLUSION

Our findings provide novel insight into detrimental mutations in AML in a rural, underrepresented population. We discovered several novel mutations and higher frequency of some known driver mutations, which will help us identify therapeutic targets to improve patient outcomes.

The Heterogeneous Complexity of Myeloid Neoplasm: Multi-Level Approaches to Study the Disease

Myeloid neoplasms (MNs) include a spectrum of bone marrow malignancies that result from the clonal expansion and arrest of differentiation of myeloid progenitor cells [...].

Discovery of a novel oral type Ⅰ CDK8 inhibitor against acute myeloid leukemia

CDK8 plays a key role in acute myeloid leukemia, colorectal cancer and other cancers. Here, a total of 54 compounds were designed and synthesized. Among them, the most potent one compound 43 (3-(1H-pyrrolo[2,3-b]pyridin-5-yl)benzamide), a novel CDK8 Ⅰ inhibitor, showed strong inhibitory activity against CDK8 (IC₅₀ = 51.9 nM), good kinase selectivity, good anti AML cell proliferation activity (molm-13 GC₅₀ = 1.57 ± 0.59 μM) and low toxicity in vivo (acute toxicity: 2000 mg/kg). Further mechanistic studies revealed that this compound could target CDK8 and then phosphorylate STAT-1 and STAT-5 thereby inhibiting of AML cell proliferation. In addition, compound 43 showed relatively good bioavailability (F = 28.00%) and could inhibit the growth of AML tumors in a dose-dependent manner in vivo. This study facilitates the further development of more potent CDK8 inhibitors for the treatment of the AML.

The clinical impact of the molecular landscape of acute myeloid leukemia

Research into the underlying pathogenic mechanisms of acute myeloid leukemia (AML) has led to remarkable advances in our understanding of the disease. Mutations now allow us to explore the enormous diversity among cytogenetically defined subsets of AML, particularly the large subset of cytogenetically normal AML. Despite the progress in unraveling the tumor genome, only a small number of recurrent mutations have been incorporated into risk-stratification schemes and have been proven to be clinically relevant, targetable lesions. The current World Health Organization Classification of myeloid neoplasms and leukemia includes eight AML categories defined by recurrent genetic abnormalities as well as three categories defined by gene mutations. We here discuss the utility of molecular markers in AML in prognostication and treatment decision-making. New therapies based on targetable markers include IDH inhibitors (ivosidenib, enasidenib), venetoclax-based therapy, FLT3 inhibitors (midostaurin, gilteritinib, and quizartinib), gemtuzumab ozogamicin, magrolimab and menin inhibitors.

Downregulation of IRAIN long non-coding RNA predicts unfavourable clinical outcome in acute myeloid leukaemia patients

BACKGROUND

Although it has been shown that the long non-coding RNA (lncRNA) insulin-like growth factor type 1 receptor (IGF1R) antisense imprinted non-protein coding RNA (IRAIN) is downregulated in leukaemia cell lines, its usefulness as a prognostic marker in acute myeloid leukaemia (AML) has not yet been thoroughly investigated. Here, we sought to determine whether the expression of IRAIN is associated with clinical outcome of AML patients.

SUBJECTS & METHODS

Using quantitative real-time polymerase chain reaction (qRT-PCR), IRAIN expression levels were assessed in peripheral blood leukocyte samples from 150 patients with AML and 50 healthy controls. Analysis was done on the relationship between IRAIN expression and clinical outcomes in AML patients.

RESULTS

When compared to healthy controls, IRAIN expression was markedly reduced in AML patients (P = 0.019). IRAIN expression could distinguish French-American-British (FAB) subtypes of AML (P = 0.024). Low IRAIN expression status was associated with shorter event-free survival (EFS) in the non-t(15;17) cytogenetically abnormal AML subset (P = 0.004). IRAIN downregulation was identified as an independent adverse prognostic marker for complete remission (CR) not only in the in the non-t(15;17) cytogenetically abnormal AML subset (P = 0.006) but also in the AML-M4/M5 subgroup (P = 0.033).

CONCLUSION

Aberrantly low IRAIN expression is closely associated with lower CR rates in AML patients, particularly in non-t(15;17) cytogenetically abnormal AML and M4/M5 AML, suggesting that the determination of IRAIN expression level at diagnosis provides valuable prognostic information, serves as a promising biomarker for evaluating treatment response, and helps predicting clinical outcome of AML patients.