Acute myeloid leukemia with translocation (8;21) or inversion (16) in elderly patients treated with conventional chemotherapy: a collaborative study of the French CBF-AML intergroup

Nomogram models predicting prognosis for patients with t(8;21) acute myeloid leukemia: a SEER-based study

BACKGROUND

Acute myeloid leukemia (AML) with t(8;21) manifests as a diverse hematological malignancy. Although it was categorized into a favorable subtype, 30-40% of patients experience relapse. The objective of this research was to devise a nomogram for the accurate anticipation of both overall survival (OS) and cancer-specific survival (CSS) in t(8;21) AML.

METHODS

From the Surveillance, Epidemiology, and End Results (SEER) database, individuals diagnosed with t(8;21) AML from 2000 to 2018 were selected. Prognostic factors for t(8;21) AML were identified using Cox regression analysis and Akaike Information Criterion (AIC), forming the basis for constructing prognostic nomograms.

RESULTS

Key variables, including first primary tumor, age group, race, and chemotherapy, were identified and integrated into the nomogram. The C-index values for the nomograms predicting OS and CSS were 0.753 (validation: 0.765) and 0.764 (validation: 0.757), respectively. Ultimately, based on nomogram scores, patients were stratified into high-risk and low-risk groups, revealing significant disparities in both OS and CSS between these groups (P < 0.001).

CONCLUSION

This study innovatively crafted nomograms, incorporating clinical and therapeutic variables, to forecast the 1-, 3-, and 5-year survival rates for individuals with t(8;21) AML.

Neratinib impairs function of m6A recognition on AML1-ETO pre-mRNA and induces differentiation of t (8;21) AML cells by targeting HNRNPA3

Acute myeloid leukemia (AML) is frequently linked to genetic abnormalities, with the t (8; 21) translocation, resulting in the production of a fusion oncoprotein AML1-ETO (AE), being a prevalent occurrence. This protein plays a pivotal role in t (8; 21) AML's onset, advancement, and recurrence, making it a therapeutic target. However, the development of drug molecules targeting AML1-ETO are markedly insufficient, especially used in clinical treatment. In this study, it was uncovered that Neratinib could significantly downregulate AML1-ETO protein level, subsequently promoting differentiation of t (8; 21) AML cells. Based on "differentiated active" probes, Neratinib was identified as a functional inhibitor against HNRNPA3 through covalent binding. The further studies demonstrated that HNRNPA3 function as a putative m6A reader responsible for recognizing and regulating the alternative splicing of AML-ETO pre-mRNA. These findings not only contribute to a novel insight to the mechanism governing post-transcriptional modification of AML1-ETO transcript, but also suggest that Neratinib would be promising therapeutic potential for t (8; 21) AML treatment.

Treating acute myelogenous leukemia in patients aged 70 and above: Recommendations from the International Society of Geriatric Oncology (SIOG)

Acute myeloid leukemia (AML) treatment is challenging in older patients. There is a lack of evidence-based recommendations for older patients ≥70, a group largely underrepresented in clinical trials. With new treatment options being available in recent years, recommendations are needed for these patients. As such the International Society of Geriatric Oncology (SIOG) assembled a task force to review the evidence specific to treatment and outcomes in this population of patients ≥70 years. Six questions were selected by the expert panel in domains of (1) baseline assessment, (2) frontline therapy, (3) post-remission therapy, (4) treatment for relapse, (5) targeted therapies, and (6) patient reported outcome/function and enhancing treatment tolerance. Information from current literature was extracted, combining evidence from systematic reviews/meta-analyses, decision models, individual trials targeting these patients, and subgroup data. Accordingly, recommendations were generated using a GRADE approach upon reviewing current evidence by consensus of the whole panel. It is our firm recommendation and hope that direct evidence should be generated for patients aged ≥70 as a distinct group in high need of improvement of their survival outcomes. Such studies should integrate information from a geriatric assessment to optimize external validity and outcomes.

Hypomethylating agent monotherapy in core binding factor acute myeloid leukemia: a French multicentric retrospective study

Very few data are available about hypomethylating agent (HMA) efficiency in core binding factor acute myeloid leukemias (CBF-AML). Our main objective was to evaluate the efficacy and safety of HMA in the specific subset of CBF-AML. Here, we report the results of a multicenter retrospective French study about efficacy of HMA monotherapy, used frontline or for R/R CBF-AML. Forty-nine patients were included, and received a median of 5 courses of azacitidine (n = 46) or decitabine (n = 3). ORR was 49% for the whole cohort with a median time to response of 112 days. After a median follow-up of 72.3 months, median OS for the total cohort was 10.6 months. In multivariate analysis, hematological relapse of CBF-AML at HMA initiation was significantly associated with a poorer OS (HR: 2.13; 95%CI: 1.04-4.36; p = 0.038). Responders had a significantly improved OS (1-year OS: 75%) compared to non-responders (1-year OS: 15.3%; p < 0.0001). Hematological improvement occurred for respectively 28%, 33% and 48% for patients who were red blood cell or platelet transfusion-dependent, or who experienced grade 3/4 neutropenia at HMA initiation. Adverse events were consistent with the known safety profile of HMA. Our study highlights that HMA is a well-tolerated therapeutic option with moderate clinical activity for R/R CBF-AML and for patients who cannot handle intensive chemotherapy.

Improving long-term outcomes with intensive induction chemotherapy for patients with AML

Intensive chemotherapy in combination with allogeneic hematopoietic cell transplantation and supportive care can induce long-term remissions in around 50% of acute myeloid leukemia patients eligible for intensive treatment. Several treatment optimization trials helped to refine schedule and dosing of the historic "7 + 3" combination. Together with the addition of novel agents, increased efficacy and tolerability led to improved long-term outcomes. Unsatisfactory outcomes in fit elderly patients and unfavorable genetic subgroups have raised the question of whether less-intensive venetoclax-based approaches may be beneficial as an alternative. Although tempting and worth exploring, this issue will remain controversial until the results of randomized comparisons appear. To date, intensive chemotherapy remains the only evident curative treatment option for long-term disease eradication in a fixed treatment time. With the advent of more novel agents and advances in minimal residual disease (MRD) detection and maintenance approaches, the face of intensive treatment could change in many ways. Several are being explored in clinical trials, such as (1) combinations of more than 1 novel agent with the intensive backbone, (2) head-to-head comparisons of novel agents, (3) replacement or dose reduction of cytotoxic components such as anthracyclines, and (4) MRD-guided escalation and de-escalation strategies. The combination of intensive treatment with individualized tailored innovative strategies will most certainly reduce treatment-related toxicities and increase the chances for long-term remission in the future.

Application of prophylactic or pre-emptive therapy after allogeneic transplantation for high-risk patients with t(8;21) acute myeloid leukemia

OBJECTIVES

To determine the impact of pretransplant measurable residual disease (pre-MRD) and the efficacy of maintenance therapy in t(8;21) acute myeloid leukemia (AML) patients after allogeneic hematopoietic cell transplantation (allo-HCT).

METHODS

We retrospectively analyzed 100 t(8;21) AML patients who underwent allo-HCT between 2013 and 2022. 40 patients received pre-emptive therapy including immunosuppressant adjustment, azacitidine, and donor lymphocyte infusion (DLI) combined with chemotherapy. 23 patients received prophylactic therapy, including azacitidine or chidamide.

RESULTS

Patients with a positive pre-MRD (pre-MRDpos) had a higher 3-year cumulative incidence of relapse (CIR) (25.90% [95% CI, 13.87%-39.70%] vs 5.00% [95% CI, 0.88%-15.01%]; P = 0.008). Pre-MRDpos patients were less likely to have a superior 3-year disease-free survival (DFS) (40.83% [95% CI, 20.80%-80.16%]) if their MRD was still positive at 28 days after transplantation (post-MRD₂₈pos). The 3-year DFS and CIR were 53.17% (95% CI, 38.31% - 73.80%) and 34.87% (95% CI, 18.84% - 51.44%), respectively, for patients receiving pre-emptive interventions after molecular relapse. The 3-year DFS and CIR were 90.00% (95%CI, 77.77% - 100%) and 5.00% (95%CI, 0.31% - 21.10%), respectively, for high-risk patients receiving prophylactic therapy. In most patients, epigenetic-drug-induced adverse events were reversible with dose adjustment or temporary discontinuation.

CONCLUSION

Patients with pre-MRDpos and post-MRD₂₈pos were more likely to have higher rates of relapse and inferior DFS, even after receiving pre-emptive interventions. Prophylactic therapy may be a better option for high-risk t(8;21) AML patients; however, this warrants further investigation.

Approach to the Older Patient with Acute Myeloid Leukemia

PURPOSE OF REVIEW

This study aims to review the challenges of treating AML in older patients, the spectrum of genomic aberrancies in this cohort, and discuss treatment options for newly diagnosed AML in this patient population.

RECENT FINDINGS

Greater understanding of biological underpinnings of AML and availability of newer, effective, targeted therapies have allowed us to move away from intensification of chemotherapy, to prioritize better tolerability while still maintaining efficacy. Increasing knowledge of the genomic complexity and adverse karyotypes in older AML patients drives the need for ongoing investigations of targeted and lower-intensity therapies in the frontline, relapsed/refractory setting, and post-remission.

The core concepts of core binding factor acute myeloid leukemia: Current considerations for prognosis and treatment

Core binding factor acute myeloid leukemia (CBF AML), defined by t(8;21) or inv(16), is a subset of favorable risk AML. Despite its association with a high complete remission rate after induction and relatively good prognosis overall compared with other subtypes of AML, relapse risk after induction chemotherapy remains high. Optimizing treatment planning to promote recurrence free survival and increase the likelihood of survival after relapse is imperative to improving outcomes. Recent areas of research have included evaluation of the role of gemtuzumab in induction and consolidation, the relative benefit of increased cycles of high dose cytarabine in consolidation, the utility of hypomethylating agents and kinase inhibitors, and the most appropriate timing of stem cell transplant. Surveillance with measurable residual disease testing is increasingly being utilized for monitoring disease in remission, and ongoing investigation seeks to determine how to use this tool for early identification of patients who would benefit from proceeding to transplant. In this review, we outline the current therapeutic approach from diagnosis to relapse while highlighting the active areas of investigation in each stage of treatment.

Comparison of efficacy between homoharringtonine, aclarubicin, cytarabine (HAA) and idarubicin, cytarabine (IA) regimens as induction therapy in patients with de novo core binding factor acute myeloid leukemia

To compare efficacy between homoharringtonine combined with cytarabine and aclarubicin (HAA) and idarubicin and cytarabine (IA) regimens as first induction chemotherapy in patients with core binding factor acute myeloid leukemia (CBF-AML). Cox regression model and propensity score matching (PSM) were used to identify the regimen associated with a better remission rate and outcomes. In total, 374 patients with CBF-AML (243 with RUNX1::RUXN1T1 and 131 with CBFB::MYH11) were included in this study. The patients received the HAA or IA regimen (187 each) as the first induction therapy. For patients with RUNX1::RUXN1T1, multivariate analyses showed that the HAA regimen was significantly associated with a higher CR/CRi rate after the first induction (hazard ratio [HR] = 5.3 [95% CI 2.3, 12.2]; p < 0.001) and more favorable relapse-free survival (RFS) (HR = 0.5 [0.3, 0.8], p = 0.01). In PSM analysis, the HAA regimen also had a higher CR/CRi rate (96% vs. 77%, p < 0.001), especially for those harboring wild-type KIT (KITWT) (96% vs. 83%, p = 0.02) or non-D816 KIT mutation (100% vs. 63%, p = 0.002), as well as more favorable RFS (p = 0.01), compared with the IA regimen. However, there was no difference in the remission rate or outcomes between the two regimens for patients with CBFB::MYH11. The HAA regimen as first induction chemotherapy resulted in a higher CR/CRi rate in AML patients with RUNX1::RUNX1T1, especially those harboring KITWT and non-D816 KIT mutation, and a more favorable RFS compared with the IA regimen. The efficacy between the two regimens did not differ in those with CBFB::MYH11.

Dual intron-targeted CRISPR-Cas9-mediated disruption of the AML RUNX1-RUNX1T1 fusion gene effectively inhibits proliferation and decreases tumor volume in vitro and in vivo

Oncogenic fusion drivers are common in hematological cancers and are thus relevant targets of future CRISPR-Cas9-based treatment strategies. However, breakpoint-location variation in patients pose a challenge to traditional breakpoint-targeting CRISPR-Cas9-mediated disruption strategies. Here we present a new dual intron-targeting CRISPR-Cas9 treatment strategy, for targeting t(8;21) found in 5-10% of de novo acute myeloid leukemia (AML), which efficiently disrupts fusion genes without prior identification of breakpoint location. We show in vitro growth rate and proliferation reduction by 69 and 94% in AML t(8;21) Kasumi-1 cells, following dual intron-targeted disruption of RUNX1-RUNX1T1 compared to a non t(8;21) AML control. Furthermore, mice injected with RUNX1-RUNX1T1-disrupted Kasumi-1 cells had in vivo tumor growth reduction by 69 and 91% compared to controls. Demonstrating the feasibility of RUNX1-RUNX1T1 disruption, these findings were substantiated in isolated primary cells from a patient diagnosed with AML t(8;21). In conclusion, we demonstrate proof-of-principle of a dual intron-targeting CRISPR-Cas9 treatment strategy in AML t(8;21) without need for precise knowledge of the breakpoint location.

Role of Measurable Residual Disease in Older Adult Acute Myeloid Leukemia

There is overwhelming evidence indicating that the use of measurable residual disease (MRD) as a biomarker provides critical prognostic information and that MRD may have a role in directing postremission decisions. There are a variety of assays for MRD assessment, such as multiparameter flow cytometry and molecular assessment of MRD, which present different characteristics in patients older than 60 years of age. Due to multiple reasons related to age, the progress of older adult AML patients is rarely investigated, especially with respect to MRD. In this review, we will clarify the characteristics of different assays for assessing MRD, focusing on its role as a risk-stratification biomarker to predict prognostic information and its role in optimal postremission therapy among older adult AML patients. These characteristics also provide guidance regarding the potential to apply personalized medicine in older adult AML patients.

Identification of Ultrasound-Sensitive Prognostic Markers of LAML and Construction of Prognostic Risk Model Based on WGCNA

Background

Acute myeloid leukemia (LAML) is the most widely known acute leukemia in adults. Chemotherapy is the main treatment method, but eventually many individuals who have achieved remission relapse, the disease will ultimately transform into refractory leukemia. Therefore, for the improvement of the clinical outcome of patients, it is crucial to identify novel prognostic markers.

Methods

The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases were utilized to retrieve RNA-Seq information and clinical follow-up details for patients with acute myeloid leukemia, respectively, whereas samples that received or did not receive ultrasound treatment were analyzed using differential expression analysis. For consistent clustering analysis, the ConsensusClusterPlus package was utilized, while by utilizing weighted correlation network analysis (WGCNA), important modules were found and the generation of the coexpression network of hub gene was generated using Cytoscape. CIBERSORT, ESTIMATE, and xCell algorithms of the "IOBR" R package were employed for the calculation of the relative quantity of immune infiltrating cells, whereas the mutation frequency of cells was estimated by means of the "maftools" R package. The pathway enrichment score was calculated using the single sample Gene Set Enrichment Analysis (ssGSEA) algorithm of the "Gene Set Variation Analysis (GSVA)" R package. The IC₅₀ value of the drug was predicted by utilizing the "pRRophetic." The indications linked with prognosis were selected by means of the least absolute shrinkage and selection operator (Lasso) Cox analysis.

Results

Two categories of samples were created as follows: Cluster 1 and Cluster 2 depending on the differential gene consistent clustering of ultrasound treatment. The prognosis of patients in Cluster 2 was better than that in Cluster 1, and a considerable variation was observed in the immune microenvironment of Cluster 1 and Cluster 2. Lasso analysis finally obtained an 8-gene risk model (GASK1A, LPO, LTK, PRRT4, UGT3A2, BLOCK1S1, G6PD, and UNC93B1). The model acted as an independent risk factor for the patients' prognosis, and it showed good robustness in different datasets. Considerable variations were observed in the abundance of immune cell infiltration, genome mutation, pathway enrichment score, and chemotherapeutic drug resistance between the low and high-risk groups in accordance with the risk score (RS). Additionally, model-based RSs in the immunotherapy cohort were significantly different between complete remission (CR) and other response groups.

Conclusion

The prognosis of people with LAML can be predicted using the 8-gene signature.

Moving toward individualized target-based therapies in acute myeloid leukemia

Acute myeloid leukemia (AML) is a heterogeneous disease at the genetic level. The field of AML therapy is increasingly shifting away from uniform approaches based solely on intensive chemotherapy (such as '7 + 3') toward personalized therapy. The treatment of AML can now be individualized based on patient characteristics and cytogenetic/molecular disease features. In this review, we provide a comprehensive updated summary of personalized, target-directed therapy in AML. We first discuss the selection of intensive versus low-intensity treatment approaches based on the patient's age and/or comorbidities. We follow with a detailed review of specific molecularly defined AML subtypes that benefit from the addition of targeted agents. In this context, we highlight the urgent need for novel therapies in tumor protein p53 (TP53)-mutated AML. We then propose approaches to optimize AML therapy in patients without directly actionable mutations. We conclude with a discussion on the emerging role of using measurable residual disease to modify therapy based on the quality of response.

Prognosis of older patients with newly diagnosed AML undergoing antileukemic therapy: A systematic review

BACKGROUND AND OBJECTIVE

The prognostic value of age and other non-hematological factors in predicting outcomes in older patients with newly diagnosed acute myeloid leukemia (AML) undergoing antileukemic therapy is not well understood. We performed a systematic review to determine the association between these factors and mortality and health-related quality of life or fatigue among these patients.

METHODS

We searched Medline and Embase through October 2021 for studies in which researchers quantified the relationship between age, comorbidities, frailty, performance status, or functional status; and mortality and health-related quality of life or fatigue in older patients with AML receiving antileukemic therapy. We assessed the risk of bias of the included studies using the Quality in Prognostic Studies tool, conducted random-effects meta-analyses, and assessed the quality of the evidence using the Grading of Recommendations, Assessment, Development and Evaluation approach.

RESULTS

We included 90 studies. Meta-analysis showed that age (per 5-year increase, HR 1.16 95% CI 1.11-1.21, high-quality evidence), comorbidities (Hematopoietic Cell Transplantation-specific Comorbidity Index: 3+ VS less than 3, HR 1.60 95% CI 1.31-1.95, high-quality evidence), and performance status (Eastern Cooperative Oncology Group/ World Health Organization (ECOG/WHO): 2+ VS less than 2, HR 1.63 95% CI 1.43-1.86, high-quality evidence; ECOG/WHO: 3+ VS less than 3, HR 2.00 95% CI 1.52-2.63, moderate-quality evidence) were associated with long-term mortality. These studies provided inconsistent and non-informative results on short-term mortality (within 90 days) and quality of life.

CONCLUSION

High-quality or moderate-quality evidence support that age, comorbidities, performance status predicts the long-term prognosis of older patients with AML undergoing antileukemic treatment.

Acute Myeloid Leukemia with Concurrent Inversion 16 and Trisomy 9: A Case Report

Acute myeloid leukemia (AML) are a diverse group of hematological malignancies, each with a distinct clinical, morphological, immunophenotypic, and molecular profile. The World Health Organization (WHO) classifies AML into various subtypes based on recurrent genetic abnormalities, each of which has clinico-pathological and prognostic significance. Inversion(16)(p13q22) or t(16;16)(p13q22) is a balanced structural chromosomal abnormality associated with complete remission and a favorable response to treatment. Trisomy 9 is a numerical chromosomal abnormality with an intermediate risk and is often seen in association with other cytogenetic abnormalities. We describe a case of a 36-year-old female patient who was diagnosed as AML-M4 on peripheral smear and bone marrow evaluation. Cytogenetic studies revealed concurrent presence of inv(16) and trisomy 9. To the best of our knowledge, this is the first case in published literature with simultaneous presence of inv(16)(p13q22) and trisomy 9 in de novo AML.

Myeloid neoplasms and clonal hematopoiesis from the RUNX1 perspective

RUNX1 is a critical transcription factor for the emergence of definitive hematopoiesis and the precise regulation of adult hematopoiesis. Dysregulation of its regulatory network causes aberrant hematopoiesis. Recurrent genetic alterations in RUNX1, including chromosomal translocations and mutations, have been identified in both inherited and sporadic diseases. Recent genomic studies have revealed a vast mutational landscape surrounding genetic alterations in RUNX1. Accumulating pieces of evidence also indicate the leukemogenic role of wild-type RUNX1 in certain situations. Based on these efforts, part of the molecular mechanisms of disease development as a consequence of dysregulated RUNX1-regulatory networks have become increasingly evident. This review highlights the recent advances in the field of RUNX1 research and discusses the critical roles of RUNX1 in hematopoiesis and the pathobiological function of its alterations in the context of disease, particularly myeloid neoplasms, and clonal hematopoiesis.

Evolution of Therapy for Older Patients With Acute Myeloid Leukemia

ABSTRACT

Most patients with newly diagnosed acute myeloid leukemia (AML) are 65 years or older. The treatment of AML in older patients has been characterized by distinct patient- and disease-related challenges that have impeded the meaningful progress that has been observed in younger patients with AML. Higher rates of comorbidities and frailty contribute to higher rates of treatment-related complications, whereas adverse disease features such as poor-risk genomics and secondary AML are associated with therapeutic resistance and shortened survival. Intensive chemotherapy and allogeneic stem cell transplant, although still considered standard for many newly diagnosed patients with AML, may not be appropriate for a larger subset of older patients with AML. Lower-intensity approaches such as hypomethylating agents have been widely applied for newly diagnosed older and unfit patients with AML, improving tolerability among this subset, but providing more modest response rates. Numerous analyses have attempted to tackle the utility of higher- versus lower-intensity therapy in older AML and identify the factors that can help choose the approach that best optimizes tolerability and efficacy. Recently, a greater understanding of the genomic and biologic heterogeneity of AML has led to better risk stratification and has contributed to the development of specific targeted therapies that are starting to narrow the gap between safety and efficacy. Newly approved agents, such FLT3 (FMS-like tyrosine kinase 3) inhibitors, IDH1 and IDH2 inhibitors, and the BCL2 inhibitor venetoclax, as well postremission maintenance therapy with CC-486 (oral 5-azacitidine), are being systematically incorporated into the evolving treatment of older patients with newly diagnosed AML.

Molecular genetic characterization of acute myeloid leukemia with isolated trisomy of chromosomes 4, 11, and 21

BACKGROUND

Autosomal trisomy is a relatively rare abnormality observed in AML, occurring singly or as a secondary event in association with other karyotypic changes, and associated with prognosis. The molecular genetic and clinical characterizations of acute myeloid leukemia (AML) with isolated trisomy 4, 11, or 21 have been poorly investigated.

MATERIALS AND METHODS

Interphase fluorescence in situ hybridization, reverse transcriptase-quantitative polymerase chain reaction for 41 chromosomal gene translocations/fusion genes, and next-generation sequencing (NGS) were performed on 29 AML patients with trisomy 4, 11, or 21 as the sole chromosomal anomaly.

RESULTS

Of the 29 patients, one or more mutations were detected in 93.1% of patients. CEBPA had the highest mutation frequency, followed by TET2, NPM1, DNMT3A, and FLT3-ITD. The sole +11 AML patients exhibited more mutations in FLT3-ITD (P = .031) than the sole +21 AML patients, while CEBPA mutation was more frequently found in the sole +21 AML patients than that in the sole +11 AML patients(P = .07). The median overall survival (OS) and disease-free survival (DFS) for patients with +11 were shorter than those with +4(P = .015, 0.046) or +21 (0.057, 0.064), but no difference was found between +4 patients and +21 patients. In the whole cohort, only the FLT3-ITD mutation was significantly associated with inferior OS (18 vs. 35 months, P = .023) and DFS (12 months vs. NR, P = .046). There were no significant differences in OS and DFS according to the gene mutation status of CEBPA, TET2, NPM1, DNMT3A, and IDH1/2.

CONCLUSION

There was a significantly different mutation profile among the sole +4, +11, +21 AML patients. Our research provided new insight into the molecular characteristics of AML with isolated trisomy.

Targeting miR-126 in inv(16) acute myeloid leukemia inhibits leukemia development and leukemia stem cell maintenance

Acute myeloid leukemia (AML) harboring inv(16)(p13q22) expresses high levels of miR-126. Here we show that the CBFB-MYH11 (CM) fusion gene upregulates miR-126 expression through aberrant miR-126 transcription and perturbed miR-126 biogenesis via the HDAC8/RAN-XPO5-RCC1 axis. Aberrant miR-126 upregulation promotes survival of leukemia-initiating progenitors and is critical for initiating and maintaining CM-driven AML. We show that miR-126 enhances MYC activity through the SPRED1/PLK2-ERK-MYC axis. Notably, genetic deletion of miR-126 significantly reduces AML rate and extends survival in CM knock-in mice. Therapeutic depletion of miR-126 with an anti-miR-126 (miRisten) inhibits AML cell survival, reduces leukemia burden and leukemia stem cell (LSC) activity in inv(16) AML murine and xenograft models. The combination of miRisten with chemotherapy further enhances the anti-leukemia and anti-LSC activity. Overall, this study provides molecular insights for the mechanism and impact of miR-126 dysregulation in leukemogenesis and highlights the potential of miR-126 depletion as a therapeutic approach for inv(16) AML.

miR-126 is highly expressed in inv(16) Acute myeloid leukemia (AML) but its role is unclear. Here, the authors show that the aberrant expression of miR-126 in inv(16) AML is directly due to the CBFB-MYH11 fusion gene and that it can promote AML development and leukemia stem cell maintenance, highlighting miR-126 as a therapeutic target for inv(16) AML patients

Evolving Therapeutic Approaches for Older Patients with Acute Myeloid Leukemia in 2021

Simple Summary

The better understanding of disease biology, the availability of new effective drugs and the increased awareness of patients’ heterogeneity in terms of fitness and personal expectations has made the current treatment paradigm of AML in the elderly very challenging. Here, we discuss the evolving criteria used to define eligibility for induction chemotherapy and transplantation, the introduction of new agents in the treatment of patients with very different clinical conditions, the implications of precision medicine and the importance of quality of life and supportive care, proposing a simplified algorithm that we follow in 2021.

Abstract

Acute myeloid leukemia (AML) in older patients is characterized by unfavorable prognosis due to adverse disease features and a high rate of treatment-related complications. Classical therapeutic options range from intensive chemotherapy in fit patients, potentially followed by allogeneic hematopoietic cell transplantation (allo-HCT), to hypomethylating agents or palliative care alone for unfit/frail ones. In the era of precision medicine, the treatment paradigm of AML is rapidly changing. On the one hand, a plethora of new targeted drugs with good tolerability profiles are becoming available, offering the possibility to achieve a prolonged remission to many patients not otherwise eligible for more intensive therapies. On the other hand, better tools to assess patients’ fitness and improvements in the selection and management of those undergoing allo-HCT will hopefully reduce treatment-related mortality and complications. Importantly, a detailed genetic characterization of AML has become of paramount importance to choose the best therapeutic option in both intensively treated and unfit patients. Finally, improving supportive care and quality of life is of major importance in this age group, especially for the minority of patients that are still candidates for palliative care because of very poor clinical conditions or unwillingness to receive active treatments. In the present review, we discuss the evolving approaches in the treatment of older AML patients, which is becoming increasingly challenging following the advent of new effective drugs for a very heterogeneous and complex population.

A precision medicine classification for treatment of acute myeloid leukemia in older patients

Background

Older patients (≥ 60 years) with acute myeloid leukemia (AML) often have multiple, sequentially acquired, somatic mutations that drive leukemogenesis and are associated with poor outcome. Beat AML is a Leukemia and Lymphoma Society-sponsored, multicenter umbrella study that algorithmically segregates AML patients based upon cytogenetic and dominant molecular abnormalities (variant allele frequencies (VAF) ≥ 0.2) into different cohorts to select for targeted therapies. During the conception of the Beat AML design, a historical dataset was needed to help in the design of the genomic algorithm for patient assignment and serve as the basis for the statistical design of individual genomic treatment substudies for the Beat AML study.

Methods

We classified 563 newly diagnosed older AML patients treated with standard intensive chemotherapy on trials conducted by Cancer and Leukemia Group B based on the same genomic algorithm and assessed clinical outcomes.

Results

Our classification identified core-binding factor and NPM1-mutated/FLT3-ITD-negative groups as having the best outcomes, with 30-day early death (ED) rates of 0 and 20%, respectively, and median overall survival (OS) of > 1 year and 3-year OS rates of ≥ 20%. All other genomic groups had ED rates of 17–42%, median OS ≤ 1 year and 3-year OS rates of ≤ 15%.

Conclusions

By classifying patients through this genomic algorithm, outcomes were poor and not unexpected from a non-algorithmic, non-dominant VAF approach. The exception is 30-day ED rate typically is not available for intensive induction for individual genomic groups and therefore difficult to compare outcomes with targeted therapeutics. This Alliance data supported the use of this algorithm for patient assignment at the initiation of the Beat AML study. This outcome data was also used for statistical design for Beat AML substudies for individual genomic groups to determine goals for improvement from intensive induction and hopefully lead to more rapid approval of new therapies.

Trial registration ClinicalTrials.gov Identifiers: NCT00048958 (CALGB 8461), NCT00900224 (CALGB 20202), NCT00003190 (CALGB 9720), NCT00085124 (CALGB 10201), NCT00742625 (CALGB 10502), NCT01420926 (CALGB 11002), NCT00039377 (CALGB 10801), and NCT01253070 (CALGB 11001).

Supplementary Information

The online version contains supplementary material available at 10.1186/s13045-021-01110-5.

Core binding factor acute myelogenous leukemia-2021 treatment algorithm

Core binding factor acute myelogenous leukemia (CBF-AML), characterized by the presence of either t(8;21) (q22;q22) or inv(16) (p13q22)/t(16;16), is considered good-risk AML in the context of cytarabine based intensive chemotherapy. Still, outcome can be improved significantly through the effective implementation of available therapeutic measures and appropriate disease monitoring. The incorporation of gemtuzumab ozogamicin into frontline therapy should be standard. Cytarabine based induction/consolidation regimen may be combined with anthracycline (3 + 7 standard) or antimetabolite, fludarabine. Serial quantitative polymerase chain reaction (QPCR) monitoring of unique fusion transcripts allows monitoring for measurable residual disease clearance; this allows for better prognostication and well as treatment modifications.

Incidental identification of inv(16)(p13.1q22)/CBFB-MYH11 variant transcript in a patient with therapy-related acute myeloid leukemia by routine leukemia translocation panel screen: implications for diagnosis and therapy

A 52-yr-old woman presented with therapy-related acute myeloid leukemia. A bone marrow biopsy showed 21% blasts with a myeloid phenotype and no other notable features such as abnormal eosinophils. Routine nanofluidics-based reverse transcriptase polymerase chain reaction (PCR) leukemia translocation panel designed to screen for recurrent genetic abnormalities in acute leukemia detected an inversion 16 transcript variant E. This prompted rereview of karyotype and fluorescence in situ hybridization studies, which confirmed inv(16), leading to appropriate prognostication and modification of treatment. This case underscores the utility of a powerful molecular screening method for the routine detection of recurrent genetic abnormalities of acute myeloid leukemia. It was especially useful in this case because of the lack of characteristic morphologic findings seen in inversion 16 and the difficulty in its detection by conventional karyotype analysis.

Comparable Outcomes After Alternative and Matched Sibling Donor Hematopoietic Stem Cell Transplantation and the Role of Molecular Measurable Residual Disease for Acute Myeloid Leukemia in Elderly Patients

Allogeneic hematopoietic stem cell transplantation (HSCT) remains the most effective postremission therapy conferring the chance of cure for acute myeloid leukemia (AML), including elderly patients. Although the number of transplantations for elderly patients with AML (eAML) is increasing owing to greater availability of various graft sources together with the adoption of advanced supportive care and reduced-intensity conditioning (RIC) regimen, there are relatively limited data on the impact of donor type in eAML compared to younger patients. In addition, few studies have evaluated the role of pretransplantation measurable residual disease (MRD) in the elderly population. Given the lack of prospective comparative study, we retrospectively compared transplantation outcomes of elderly patient with AML receiving allo-HSCT from matched sibling donor (MSD-HSCT), matched unrelated donor (MUD-HSCT) or haploidentical related donor (Haplo-HSCT), or autologous HSCT (Auto-HSCT). A total of 154 patients with a median age of 63 years (range 60-74) underwent MSD-HSCT (n = 41), MUD-HSCT (n = 36), Haplo-HSCT (n = 55), or Auto-HSCT (n = 22) for AML. RIC regimens were used in the majority of patients. In Haplo-HSCT, T-cell-replete peripheral blood stem cells with unique RIC regimens using anti-thymocyte globulin (ATG)-based GVHD prophylaxis was used. In the analysis, adjustment for MRD status at the time of transplantation was performed. MRD was measured by the quantitative molecular assays of the targets, including RUNX1-RUNX1T1, CBFB-MYH11, and NPM1, or WT1 in the absence of abnormalities in the aforementioned targets. At a median follow-up of 48 months, survival rates were similar between different donor types, whereas nonrelapse mortality (NRM) was lower in MUD-HSCT compared to MSD-HSCT (P = .002). MSD-HSCT, in which the majority of patients received a conditioning regimen not including ATG, showed more frequent severe chronic graft-versus-host disease (cGVHD). The major causes of non-relapse deaths in MSD-HSCT were related to cGVHD (71%), whereas infectious complications were mainly related to NRM in Haplo-HSCT (50%) or Auto-HSCT (100%). In the MUD-HSCT, GVHD (57%) and infection (43%) contributed similarly to non-relapse death. Cytomegalovirus infection was more frequent in Haplo-HSCT. In multivariate models, pre-transplant MRD-positivity was an independent risk factor for relapse (P = .001), whereas older age (P = .002) and the hematopoietic cell transplantation-comorbidity index (P = .009) were useful in predicting NRM. The current study demonstrated comparable outcomes after alternative and matched sibling donor HSCT in eAML aged 60 years or older, and the results also suggest the necessity for more sophisticated strategies to reduce NRM or relapse according to each donor type. The usefulness of molecular MRD assays demonstrated herein will facilitate trials for MRD-driven decision-making or risk-adaptive approaches in eAML.

Co-occurrence of KIT and NRAS mutations defines an adverse prognostic core-binding factor acute myeloid leukemia

Molecular abnormalities are frequent in core-binding factor (CBF) AMLs, but their prognostic relevance is controversial. Sixty-two patients were retrospectively analyzed and 47 harbored at least one gene mutation with a next-generation-sequencing assay. The most common molecular mutation was KIT mutation (30.6%), followed by NRAS (24.2%) and ASXL1 (14.5%) mutations, which was associated with a higher number of bone marrow blasts (p = .049) and older age (p = .027). The survival analysis showed KIT mutation adversely affected the overall survival (OS) (p = .046). NRAS mutation was associated with inferior OS (p = .016) and RFS (p = .039). Eight patients carried co-mutations of KIT and NRAS and had worse OS (p = .012) and RFS (p = .034). The multivariate analysis showed age ≥60 years and additional chromosomal abnormalities were significant adverse factors for OS. Thus, co-mutations of KIT and NRAS were significantly associated with a poor prognosis and should be taken into account when assessing for prognostic stratification in patients with CBF-AML.

Anthracycline-related cardiotoxicity in older patients with acute myeloid leukemia: a Young SIOG review paper

The incidence of acute myeloid leukemia (AML) increases with age. Intensive induction chemotherapy containing cytarabine and an anthracycline has been part of the upfront and salvage treatment of AML for decades. Anthracyclines are associated with a significant risk of cardiotoxicity (especially anthracycline-related left ventricular dysfunction [ARLVD]). In the older adult population, the higher prevalence of cardiac comorbidities and risk factors may further increase the risk of ARLVD. In this article of the Young International Society of Geriatric Oncology group, we review the prevalence of ARLVD in patients with AML and factors predisposing to ARLVD, focusing on older adults when possible. In addition, we review the assessment of cardiac function and management of ARLVD during and after treatment. It is worth noting that only a minority of clinical trials focus on alternative treatment strategies in patients with mildly declined left ventricular ejection fraction or at a high risk for ARLVD. The limited evidence for preventive strategies to ameliorate ARLVD and alternative strategies to anthracycline use in the setting of cardiac comorbidities are discussed. Based on extrapolation of findings from younger adults and nonrandomized trials, we recommend a comprehensive baseline evaluation of cardiac function by imaging, cardiac risk factors, and symptoms to risk stratify for ARLVD. Anthracyclines remain an appropriate choice for induction although careful risk-stratification based on cardiac disease, risk factors, and predicted chemotherapy-response are warranted. In case of declined left ventricular ejection fraction, alternative strategies should be considered.

YTHDF2 is a potential target of AML1/ETO-HIF1α loop-mediated cell proliferation in t(8;21) AML

The t(8;21) fusion product, AML1/ETO, and hypoxia-inducible factor 1α (HIF1α) form a feed-forward transcription loop that cooperatively transactivates the DNA methyltransferase 3a gene promoter that leads to DNA hypermethylation and drives leukemia cell growth. Suppression of the RNA N⁶-methyladenosine (m⁶A)-reader enzyme YTH N⁶-methyladenosine RNA binding protein 2 (YTHDF2) specifically compromises cancer stem cells in acute myeloid leukemia (AML) but promotes hematopoietic stem cell expansion without derailing normal hematopoiesis. However, the relevance of expression between AML1/ETO-HIF1α loop and YTHDF2, and its functional relationship with t(8;21) AML have not been documented. Here, we show that YTHDF2 is highly expressed in t(8;21) AML patients and associated with a higher risk of relapse and inferior relapse-free survival. Knockdown of YTHDF2 in leukemia cells causes an impaired cell proliferation rate in vitro and in mice. Mechanistically, HIF1α is able to bind to the hypoxia-response elements of the 5'-untranslated region of the YTHDF2 gene and promotes the transactivity of the YTHDF2 promoter. Knockdown and overexpression of either AML1/ETO or HIF1α resulted in decreased and increased YTHDF2 protein and mRNA expression in t(8;21) AML cells. In particular, knockdown of YTHDF2 resulted in increased global mRNA m⁶A levels in t(8;21) AML cells, accompanied by increased TNF receptor superfamily member 1b (TNFRSF1b) mRNA and protein expression levels. Last, we demonstrated that the m⁶A methylation and expression levels of the TNFRSF1b gene were both negatively correlated with HIF1α expression levels. In conclusion, YTHDF2 is a downstream target of the AML1/ETO-HIF1α loop and promotes cell proliferation probably by modulating the global m⁶A methylation in t(8;21) AML.

Allogeneic Stem Cell Transplantation for Acute Myeloid Leukemia: Who, When, and How?

Although the majority of patients with acute myeloid leukemia (AML) treated with intensive chemotherapy achieve a complete remission (CR), many are destined to relapse if treated with intensive chemotherapy alone. Allogeneic stem cell transplant (allo-SCT) represents a pivotally important treatment strategy in fit adults with AML because of its augmented anti-leukemic activity consequent upon dose intensification and the genesis of a potent graft-versus-leukemia effect. Increased donor availability coupled with the advent of reduced intensity conditioning (RIC) regimens has dramatically increased transplant access and consequently allo-SCT is now a key component of the treatment algorithm in both patients with AML in first CR (CR1) and advanced disease. Although transplant related mortality has fallen steadily over recent decades there has been no real progress in reducing the risk of disease relapse which remains the major cause of transplant failure and represents a major area of unmet need. A number of therapeutic approaches with the potential to reduce disease relapse, including advances in induction chemotherapy, the development of novel conditioning regimens and the emergence of the concept of post-transplant maintenance, are currently under development. Furthermore, the use of genetics and measurable residual disease technology in disease assessment has improved the identification of patients who are likely to benefit from an allo-SCT which now represents an increasingly personalized therapy. Future progress in optimizing transplant outcome will be dependent on the successful delivery by the international transplant community of randomized prospective clinical trials which permit examination of current and future transplant therapies with the same degree of rigor as is routinely adopted for non-transplant therapies.

Resistance to venetoclax and hypomethylating agents in acute myeloid leukemia

Despite the success of the combination of venetoclax with the hypomethylating agents (HMA) decitabine or azacitidine in inducing remission in older, previously untreated patients with acute myeloid leukemia (AML), resistance - primary or secondary - still constitutes a significant roadblock in the quest to prolong the duration of response. Here we review the proposed and proven mechanisms of resistance to venetoclax monotherapy, HMA monotherapy, and the doublet of venetoclax and HMA for the treatment of AML. We approach the mechanisms of resistance to HMAs and venetoclax in the light of the agents' mechanisms of action. We briefly describe potential therapeutic strategies to circumvent resistance to this promising combination, including alternative scheduling or the addition of other agents to the HMA and venetoclax backbone. Understanding the mechanisms of action and evolving resistance in AML remains a priority in order to maximize the benefit from novel drugs and combinations, identify new therapeutic targets, define potential prognostic markers, and avoid treatment failure.

Autologous hematopoietic cell transplantation following high-dose cytarabine consolidation for core-binding factor-acute myeloid leukemia in first complete remission: a phase 2 prospective trial

Core-binding factor (CBF)-acute myeloid leukemia (AML) generally have a favorable prognosis. However, approximately 50% of patients experience disease relapse during or after post-remission therapy. Retrospective studies on autologous hematopoietic cell transplantation (AHCT) have shown improved survival with decreased relapse rate in CBF-AML. In this prospective study, we evaluate the outcomes of AHCT following high-dose cytarabine (HiDAC) consolidation in patients with CBF-AML in first complete remission (CR). Adult patients with CBF-AML achieving first CR after induction chemotherapy were eligible for the study. High-dose chemotherapy before AHCT included intravenous busulfan (3.2 mg/kg/day, days - 7 to - 5) and etoposide (400 mg/m²/day, days - 3 to - 2). Twenty-nine patients, 17 with t(8;21) and 12 with inv(16), underwent AHCT following 2 or 3 courses of HiDAC consolidation. The estimated 5-year overall and disease-free survival rates were between 89.0% and 82.5%, respectively. The cumulative incidences of relapse and non-relapse mortality were between 17.5% and 0%, respectively. Presence of measurable residual disease (MRD) before AHCT and KIT mutation were significantly associated with relapse after transplantation. In conclusion, the post-remission strategy of AHCT following HiDAC consolidation in CBF-AML was feasible and efficacious. Assays for MRD and KIT mutation may guide selection of patients who will benefit from AHCT in CBF-AML in first CR.

Treatment options for older unfit patients with acute myeloid leukemia

Older acute myeloid leukemia patients usually experience a bleak outcome, especially those in the unfit group. For this unfit category, intensive chemotherapy and allogeneic stem cell transplantation are usually accompanied by higher early mortality, which results from higher risk genetic profiles and worse psychological and physiological conditions. The significant improvement in genetic technology recently has driven the appearance of several mutation-targeted therapies, such as FLT3, Bcl-2, IDH and Hedgehog pathway inhibitors and an anti-CD33 antibody-drug conjugate, which have changed enormously the therapeutic landscape of acute myeloid leukemia. This review describes the treatment dilemma of the unfit group and discusses the objective clinical data of each targeted drug and mechanisms of resistance, with a focus on combination strategies with fewer toxicities and abrogation of drug resistance.

Both the subtypes of KIT mutation and minimal residual disease are associated with prognosis in core binding factor acute myeloid leukemia: a retrospective clinical cohort study in single center

Core binding factor acute myeloid leukemia (CBF-AML), including cases with KIT mutation, is currently defined as a low-risk AML. However, some patients have poor response to treatment, and the prognostic significance of KIT mutation is still controversial. This study aimed to explore the prognostic significance of different KIT mutation subtypes and minimal residual disease (MRD) in CBF-AML. We retrospectively evaluated continuous patients diagnosed with CBF-AML in our center between January 2014 and April 2019. Of the 215 patients, 147 (68.4%) and 68 (31.6%) patients were RUNX1-RUNX1T1- and CBFB-MYH11 positive, respectively. KIT mutations were found in 71 (33.0%) patients; of them, 38 (53.5%) had D816/D820 mutations. After excluding 10 patients who died or were lost to follow-up within a half year, 42.0% (n = 86) of the remaining 205 patients received allogeneic hematopoietic stem cell transplantation (allo-HSCT). An MRD > 0.1% at the end of two cycles of consolidation predicted relapse (P < 0.001). Multivariate analysis showed that D816 or D820 mutations and MRD > 0.1% at the end of two cycles of consolidation were independent adverse factors affecting relapse-free survival (RFS) and overall survival (OS). Allo-HSCT could improve RFS (74.4% vs. 34.6%, P < 0.001) and OS (78.1% vs. 52.3%, P = 0.002). In conclusion, high-risk CBF-AML patients must be identified before treatment. D816/D820 mutation, MRD > 0.1% at the end of two cycles of consolidation chemotherapy predicted poor survivals, and allo-HSCT can improve the survival of properly identified patients.

American Society of Hematology 2020 guidelines for treating newly diagnosed acute myeloid leukemia in older adults

BACKGROUND

Older adults with acute myeloid leukemia (AML) represent a vulnerable population in whom disease-based and clinical risk factors, patient goals, prognosis, and practitioner- and patient-perceived treatment risks and benefits influence treatment recommendations.

OBJECTIVE

These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in their decisions about management of AML in older adults.

METHODS

ASH formed a multidisciplinary guideline panel that included specialists in myeloid leukemia, geriatric oncology, patient-reported outcomes and decision-making, frailty, epidemiology, and methodology, as well as patients. The McMaster Grading of Recommendations Assessment, Development and Evaluation (GRADE) Centre supported the guideline-development process, including performing systematic evidence reviews (up to 24 May 2019). The panel prioritized clinical questions and outcomes according to their importance to patients, as judged by the panel. The panel used the GRADE approach, including GRADE's Evidence-to-Decision frameworks, to assess evidence and make recommendations, which were subject to public comment.

RESULTS

The panel agreed on 6 critical questions in managing older adults with AML, mirroring real-time practitioner-patient conversations: the decision to pursue antileukemic treatment vs best supportive management, the intensity of therapy, the role and duration of postremission therapy, combination vs monotherapy for induction and beyond, duration of less-intensive therapy, and the role of transfusion support for patients no longer receiving antileukemic therapy.

CONCLUSIONS

Treatment is recommended over best supportive management. More-intensive therapy is recommended over less-intensive therapy when deemed tolerable. However, these recommendations are guided by the principle that throughout a patient's disease course, optimal care involves ongoing discussions between clinicians and patients, continuously addressing goals of care and the relative risk-benefit balance of treatment.

Comparison of therapy-related and de novo core binding factor acute myeloid leukemia: A bone marrow pathology group study

This multi-institutional study retrospectively evaluated clinicopathologic and genetic characteristics in 351 patients with core-binding-factor acute myeloid leukemia (CBF-AML), comprising 69 therapy-related (t-CBF-AML) and 282 de novo cases. The T-CBF-AML patients were older, had lower WBC counts, and slightly higher hemoglobin than patients with de novo disease. Secondary cytogenetic abnormalities were more frequent in patients with de novo disease than t-CBF-AML (57.1% vs 41.1%, P = .026). Patients with secondary cytogenetic abnormalities had longer overall survival (OS) than those without abnormalities (median 190 vs 87 months, P = .021); trisomy 8, trisomy 22, and loss of the X or Y chromosome were associated with longer OS. In the 165 cases performed of targeted gene sequencing, pathogenic mutations were detected in 75.7% of cases, and were more frequent in de novo than in therapy-related disease (P = .013). Mutations were found in N/KRAS (37.0%), FLT3 (27.8%), KIT (17.2%), TET2 (4.9%), and ASXL1 (3.9%). The TET2 mutations were associated with shorter OS (P = .012) while N/KRAS mutation was associated with longer OS in t(8;21) AML patients (P = .001). The KIT mutation did not show prognostic significance in this cohort. Although they received similar therapy, t-CBF-AML patients had shorter OS than de novo patients (median 69 vs 190 months, P = .038). In multivariate analysis of all patients, older age and absence of any secondary cytogenetic abnormalities were significant predictors of shorter OS. Among the t-CBF-AML subset, age and hemoglobin were significant on multivariate analysis. This study demonstrated that although de novo and t-CBF-AML patients share many features, t-CBF-AML patients have worse clinical outcome than de novo patients.

NPM1 mutations define a specific subgroup of MDS and MDS/MPN patients with favorable outcomes with intensive chemotherapy

Nucleophosmin (NPM1) mutations are common in acute myeloid leukemia and are associated with high remission rates and prolonged survival with intensive chemotherapy. NPM1 mutations are rare in myelodysplastic syndromes (MDS) or myelodysplastic/myeloproliferative neoplasm (MDS/MPN), and the clinical outcomes of these patients, when treated with intensive chemotherapy, are unknown. We retrospectively evaluated the clinicopathologic characteristics and the impact of therapy in 31 patients with MDS or MDS/MPN and NPM1 mutations. Next-generation sequencing was performed at diagnosis in 22 patients. Median age was 62 years (range, 19-86). Twenty-four patients (77%) had normal karyotype, and all had multilineage dysplasia. Most patients could be classified as MDS with excess blasts (19/31, 61%). NPM1 mutations were detected at a median allele frequency of 0.38 (range, 0.09-0.49). Mutation burden did not correlate with bone marrow blast frequency, and its clearance seemed to be associated with decreased morphologic dysplasia. Ten of the 31 patients (32%) received cytotoxic chemotherapy, 20 (65%) hypomethylating agents, and 1 (4%) lenalidomide. Sequential sequencing was available in 16 (52%) patients, and mutation burden correlated with disease status and response to therapy. Patients treated with chemotherapy had higher complete response rates (90% vs 28%, P = .004), longer median progression-free survival (not reached vs 7.5 months, P = .023), and overall survival (not reached vs 16 months, P = .047). Intensive chemotherapy and allogeneic stem cell transplantation (SCT) may be associated with improved clinical outcomes in patients with NPM1-mutated MDS or MDS/MPN who are candidates for this form of therapy.

Post-remission therapy of adults aged 60 and older with acute myeloid leukemia in first complete remission: role of treatment intensity on the outcome

Although complete remission (CR) is achieved in 50 to 70% of older fit patients with acute myeloid leukemia (AML), consolidation therapy in this age group remains challenging. In this retrospective study, we aimed to compare outcome in elderly patients treated with different post-remission modalities, including allogenic and autologous hematopoietic stem cell transplantation (HSCT), intensive chemotherapy, and standard-dose chemotherapy (repeated 1 + 5 regimen). We collected data of 441 patients ≥ 60 years in first CR from a single institution. Median age was 67 years. Sixty-one (14%) patients received allo-HSCT, 51 (12%) auto-HSCT, 70 (16%) intensive chemotherapy with intermediate- or high-dose cytarabine (I/HDAC), and 190 (43%) 1 + 5 regimen. Median follow-up was 6.5 years. In multivariate analysis, allo-HSCT, cytogenetics, and PS had a significant impact on OS and LFS. In spite of a more favorable-risk profile, the patients who received I/HDAC had no significantly better LFS as compared with patients treated with 1 + 5 (median LFS 8.8 months vs 10.6 months, p = 0.96). In transplanted patients, median LFS was 13.3 months for auto-HSCT and 25.8 months for allo-HSCT. Pre-transplant chemotherapy with I/HDAC had no effect on the outcome. Toxicity was significantly increased for both transplanted and non-transplanted patients treated with I/HDAC, with more units of blood and platelet transfusion and more time spent in hospitalization, but no higher non-relapse mortality. This study shows that post-remission chemotherapy intensification is not associated with significantly better outcome as compared with standard-dose chemotherapy in elderly patients for whom, overall results remain disappointing.

Measurable residual disease monitoring in acute myeloid leukemia with t(8;21)(q22;q22.1): results from the AML Study Group

We performed serial measurable residual disease (MRD) monitoring in bone marrow (BM) and peripheral blood (PB) samples of 155 intensively treated patients with RUNX1-RUNX1T1+ AML, using a qRT-PC-based assay with a sensitivity of up to 10-6. We assessed both reduction of RUNX1-RUNX1T1 transcript levels (TLs) and achievement of MRD negativity (MRD-) for impact on prognosis. Achievement of MR2.5 (>2.5 log reduction) after treatment cycle 1 and achievement of MR3.0 after treatment cycle 2 were significantly associated with a reduced risk of relapse (P = .034 and P = .028, respectively). After completion of therapy, achievement of MRD- in both BM and PB was an independent, favorable prognostic factor in cumulative incidence of relapse (4-year cumulative incidence relapse: BM, 17% vs 36%, P = .021; PB, 23% vs 55%, P = .001) and overall survival (4-year overall survival rate BM, 93% vs 70%, P = .007; PB, 87% vs 47%, P < .0001). Finally, during follow-up, serial qRT-PCR analyses allowed prediction of relapse in 77% of patients exceeding a cutoff value of 150 RUNX1-RUNX1T1 TLs in BM, and in 84% of patients exceeding a value of 50 RUNX1-RUNX1T1 TLs in PB. The KIT mutation was a significant factor predicting a lower CR rate and inferior outcome, but its prognostic impact was outweighed by RUNX1-RUNX1T1 TLs during treatment. Virtually all relapses occurred within 1 year after the end of treatment, with a very short latency from molecular to morphologic relapse, necessitating MRD assessment at short intervals during this time period. Based on our data, we propose a refined practical guideline for MRD assessment in RUNX1-RUNX1T1+ AML.

Venetoclax in acute myeloid leukemia - current and future directions

B-cell leukemia/lymphoma-2 (BCL-2) inhibition with the targeted oral agent venetoclax (ABT-199) has reshaped the treatment landscape for multiple hematological malignancies. Venetoclax in combination with hypomethylating agents (HMAs) or low-dose cytarabine (LDAC) has led to improved outcomes in acute myeloid leukemia (AML) and represents a new standard of care for frontline AML treatment in older patients or those unfit for intensive chemotherapy. Combinations of venetoclax with standard induction therapy or targeted agents such as FLT-3 inhibitors and IDH inhibitors are leading to improved clinical outcomes, representing major advancements in a field that has been without significant changes in treatments for the last 30 years. This review provides biological and clinical rationale for current venetoclax based treatments in AML, addresses common adverse events encountered with venetoclax based therapy, and explores emerging clinical data regarding combinations of novel targeted therapeutics used in conjunction with venetoclax for the treatment of AML.

Comparisons of commonly used front-line regimens on survival outcomes in patients aged 70 years and older with acute myeloid leukemia

In older patients with acute myeloid leukemia, the more frequent presence of biologically inherent therapy-resistant disease and increased comorbidities translate to poor overall survival and therapeutic challenges. Optimal front-line therapies for older patients with acute myeloid leukemia remain controversial. We retrospectively evaluated survival outcomes in 980 elderly (≥70 years) acute myeloid leukemia patients from a single institution between 1995 and 2016. Four treatment categories were compared: high-intensity (daunorubicin/cytarabine or equivalent), hypomethylating agent, low-intensity (low-dose cytarabine or similar without hypomethylating agents), and supportive care therapy (including hydroxyurea). At a median follow up of 20.5 months, the median overall survival for the entire cohort was 7.1 months. Multivariate analysis identified secondary acute myeloid leukemia, poor-risk cytogenetics, performance status, front-line therapy, age, white blood cell count, platelet count, and hemoglobin level at diagnosis as having an impact on survival. High-intensity therapy was used in 360 patients (36.7%), hypomethylating agent in 255 (26.0%), low-intensity therapy in 91 (9.3%), and supportive care in 274 (28.0%). Pairwise comparisons between hypomethylating agent therapy and the three other treatment groups demonstrated statistically significant superior median overall survival with hypomethylating agent [14.4 months) vs. high-intensity therapy 10.8 months, hazard ratio 1.35, 95% confidence interval (CI): 1.10-1.65; P =0.004], low-intensity therapy (5.9 months, hazard ratio 2.01, 95%CI: 1.53-2.62; P<0.0001), and supportive care (2.1 months, hazard ratio 2.94, 95%CI: 2.39-3.61; P<0.0001). Our results indicate a significant survival benefit with hypomethylating agents compared to high-intensity, low-intensity, or supportive care. Additionally, high-intensity chemotherapy resulted in superior overall outcomes compared to low-intensity therapy and supportive care. Results from this study highlight the need for novel therapeutic approaches besides utilization of intensive chemotherapy in this specific aged population.

Clinical, Cytogenetic, and Molecular Findings in Two Cases of Variant t(8;21) Acute Myeloid Leukemia (AML)

t(8;21)(q22;q22) is present in ~5–10% of patients with de novo acute myeloid leukemia (AML) and is associated with a better overall prognosis. Variants of the t(8;21) have been described in the literature, however, their clinical and prognostic significance has not been well-characterized. Molecular profiling of these cases has not previously been reported but may be useful in better defining the prognosis of this subset of patients. We present two cases of variant t(8;21) AML including clinical, cytogenetic, and molecular data.

MicroRNA-144 targets APP to regulate AML1/ETO+ leukemia cell migration via the p-ERK/c-Myc/MMP-2 pathway

Extramedullary infiltration (EMI) is common in patients with acute myeloid leukemia (AML) and is closely associated with the prognosis of disease. We previously reported that patients carrying the AML1/ETO (A/E) fusion gene and expressing the amyloid precursor protein (APP) tended to develop EMI, and had a poor prognosis. In the present study, the relapse-free survival (RFS) time and overall survival (OS) time were significantly lower in patients with EMI. The results demonstrated that the EMI incidence was significantly higher (P<0.05), while the RFS and OS rates were significantly lower (P<0.05), in patients with high APP expression. Kasumi-1 cells, which are A/E⁺, and the APP gene were used as the in vitro cell model to detect the mechanism of action in detail. Following the knockdown of APP expression, cell migration was significantly reduced (P<0.05). Furthermore, western blotting demonstrated that the protein expression of phosphorylated extracellular-signal-regulated kinase (p-ERK), matrix metalloproteinase-2 (MMP-2) and c-Myc was markedly reduced following interference of APP, while the expression of CXCR4 and MMP-9 was not altered. Kasumi-1 cells were co-cultured with p-ERK or c-Myc inhibitors and demonstrated that the APP/p-ERK/c-Myc/MMP-2 pathway was involved in signal transduction and regulation of cell migration. MicroRNA-144 (miR-144) mimics and transfected Kasumi-1 cells were generated. Reverse transcription-quantitative polymerase chain reaction and western blotting demonstrated that miR-144 was a negative regulator of APP. Taken together, the findings of the present study suggest that miR-144 negatively targets the APP gene and regulates cell migration via the APP/p-ERK/c-Myc/MMP-2 pathway.

RUNX1-ETO: Attacking the Epigenome for Genomic Instable Leukemia

Oncogenic fusion protein RUNX1-ETO is the product of the t(8;21) translocation, responsible for the most common cytogenetic subtype of acute myeloid leukemia. RUNX1, a critical transcription factor in hematopoietic development, is fused with almost the entire ETO sequence with the ability to recruit a wide range of repressors. Past efforts in providing a comprehensive picture of the genome-wide localization and the target genes of RUNX1-ETO have been inconclusive in understanding the underlying mechanism by which it deregulates native RUNX1. In this review; we dissect the current data on the epigenetic impact of RUNX1 and RUNX1-ETO. Both share similarities however, in recent years, research focused on epigenetic factors to explain their differences. RUNX1-ETO impairs DNA repair mechanisms which compromises genomic stability and favors a mutator phenotype. Among an increasing pool of mutated factors, regulators of DNA methylation are frequently found in t(8;21) AML. Together with the alteration of both, histone markers and distal enhancer regulation, RUNX1-ETO might specifically disrupt normal chromatin structure. Epigenetic studies on the fusion protein uncovered new mechanisms contributing to leukemogenesis and hopefully will translate into clinical applications.

Role of Minimal (Measurable) Residual Disease Assessment in Older Patients with Acute Myeloid Leukemia

Minimal (or measurable) residual (MRD) disease provides a biomarker of response quality for which there is robust validation in the context of modern intensive treatment for younger patients with Acute Myeloid Leukemia (AML). Nevertheless, it remains a relatively unexplored area in older patients with AML. The lack of progress in this field can be attributed to two main reasons. First, physicians have a general reluctance to submitting older adults to intensive chemotherapy due to their frailty and to the unfavourable biological disease profile predicting a poor outcome following conventional chemotherapy. Second, with the increasing use of low-intensity therapies (i.e., hypomethylating agents) differing from conventional drugs in mechanism of action and dynamics of response, there has been concomitant skepticism that these schedules can produce deep hematological responses. Furthermore, age dependent differences in disease biology also contribute to uncertainty on the prognostic/predictive impact in older adults of certain genetic abnormalities including those validated for MRD monitoring in younger patients. This review examines the evidence for the role of MRD as a prognosticator in older AML, together with the possible pitfalls of MRD evaluation in older age.

Acute Myeloid Leukemia: The Good, the Bad, and the Ugly

Acute myeloid leukemia (AML) was initially subdivided according to morphology (the French-American-British system), which proved helpful in pathologic categorization. Subsequently, clinical and genomic factors were found to correlate with response to chemotherapy and with overall survival. These included a history of antecedent hematologic disease, a history of chemotherapy or radiation therapy, the presence of various recurrent cytogenetic abnormalities, and, more recently, the presence of specific point mutations. This article reviews the biology and responses of one AML subgroup with consistent response and good outcomes following chemotherapy (core-binding factor leukemia), and two subgroups with persistently bad, and even ugly, outcomes (secondary AML and TP53-mutated AML).

How and when to decide between epigenetic therapy and chemotherapy in patients with AML

Remission induction with chemotherapy has long been the frontline treatment of acute myeloid leukemia (AML). However, intensive therapy is limited in frail patients by its associated toxicity and higher rates of failure or relapse in patients with chemoresistant disease, such as secondary AML or poor-risk cytogenetics. Frailty and chemoresistance are more frequent in older adults with AML. In recent years, epigenetic therapies with the hypomethylating agents decitabine and azacitidine have been thoroughly explored in AML. The results of two pivotal studies carried out with these agents in older adults with newly diagnosed AML have challenged the role of intensive chemotherapy as the frontline treatment option in this high-risk population. Here, we review the results of treatment with intensive chemotherapy and hypomethylating agents in older patients with AML; discuss the patient- and disease-specific criteria to integrate into treatment decision making; and also, highlight the methodological limitations of cross-study comparison in this population.

Polymorphisms at microRNA binding sites of Ara-C and anthracyclines-metabolic pathway genes are associated with outcome of acute myeloid leukemia patients

Background

Gene polymorphisms at microRNA-binding sites (poly-miRTS) may affect gene transcription and expression through miRNA regulation, which is associated with cancer susceptibility, sensitivity to chemotherapy and prognosis. This study investigated the association between poly-miRTS of Ara-C/anthracycline metabolic pathways genes and the outcome of acute myeloid leukemia (AML) in Chinese patients after Ara-C-based chemotherapy.

Methods

A total of 17 poly-miRTS were selected from the SNPinfo Web Server and genotyped in 206 Chinese Han non-FAB-M3 AML patients using the SEQUENOM Mass-ARRAY system.

Results

Among these 17 poly-miRTS, five Ara-C metabolic gene single nucleotide polymorphisms (SNPs, NT5C2 rs10786736 and rs8139, SLC29A1 rs3734703, DCTD rs7278, and RRM1 rs1042919) were identified to significantly associate with complete AML remission and/or overall and relapse-free survival (OS and RFS, respectively), and four anthracycline-metabolic gene SNPs (ABCC1 rs3743527, rs212091, and rs212090 and CBR1 rs9024) were significantly associated with chemotherapy-related toxicities. Moreover, SLC29A1 rs3734703 was shown to associate with both chemotherapy response and survival (adjusted OR 2.561 in the overdominant model; adjusted HR 2.876 for OS and 2.357 for RFS in the dominant model).

Conclusions

The data from the current study demonstrated that the poly-miRTS of Ara-C/anthracyclines metabolic genes predicted the sensitivity and side effects of AML to Ara-C-based chemotherapy and patient survival. Further study will confirm them as biomarkers for AML patients after Ara-C-based chemotherapy.

Electronic supplementary material

The online version of this article (10.1186/s12967-017-1339-9) contains supplementary material, which is available to authorized users.

Initial Diagnostic Workup of Acute Leukemia: Guideline From the College of American Pathologists and the American Society of Hematology

CONTEXT

- A complete diagnosis of acute leukemia requires knowledge of clinical information combined with morphologic evaluation, immunophenotyping and karyotype analysis, and often, molecular genetic testing. Although many aspects of the workup for acute leukemia are well accepted, few guidelines have addressed the different aspects of the diagnostic evaluation of samples from patients suspected to have acute leukemia.

OBJECTIVE

- To develop a guideline for treating physicians and pathologists involved in the diagnostic and prognostic evaluation of new acute leukemia samples, including acute lymphoblastic leukemia, acute myeloid leukemia, and acute leukemias of ambiguous lineage.

DESIGN

- The College of American Pathologists and the American Society of Hematology convened a panel of experts in hematology and hematopathology to develop recommendations. A systematic evidence review was conducted to address 6 key questions. Recommendations were derived from strength of evidence, feedback received during the public comment period, and expert panel consensus.

RESULTS

- Twenty-seven guideline statements were established, which ranged from recommendations on what clinical and laboratory information should be available as part of the diagnostic and prognostic evaluation of acute leukemia samples to what types of testing should be performed routinely, with recommendations on where such testing should be performed and how the results should be reported.

CONCLUSIONS

- The guideline provides a framework for the multiple steps, including laboratory testing, in the evaluation of acute leukemia samples. Some aspects of the guideline, especially molecular genetic testing in acute leukemia, are rapidly changing with new supportive literature, which will require on-going updates for the guideline to remain relevant.