Clinical Utility of a Next-Generation Sequencing Panel for Acute Myeloid Leukemia Diagnostics

Analytical Validation of a 37-Gene Next-Generation Sequencing Panel for Myeloid Malignancies and Review of Initial Findings Incorporating Updated 2022 Diagnostic and Prognostic Guidelines

Myeloid neoplasms are clonal disorders that arise via acquisition of genetic mutations leading to excessive proliferation and defective differentiation. Mutational profiling is vital as it has implications for diagnosis, prognosis, and therapeutic decision-making. Next-generation sequencing (NGS) has become a mainstay in the evaluation of myeloid malignancies, as it enables efficient characterization of multiple genetic changes. Herein, the analytical validation of the 37-gene Archer VariantPlex Core Myeloid panel is reported, using 58 DNA specimens with 87 single-nucleotide variants and 23 insertions/deletions. The panel achieved good depth of coverage, 100% analytical sensitivity and specificity for single-nucleotide variants and insertions/deletions ≤21 bp, and 100% reproducibility, with a reportable limit of detection determined as 5%. The Archer NGS panel can accurately and reproducibly detect variants of clinical significance in myeloid neoplasms. A retrospective analysis of 535 clinical specimens tested with the Archer NGS panel showed a frequency and pattern of mutations across myeloid malignancies that were similar to other published studies. A review of the diagnostic classification of patients with acute myeloid leukemia and myelodysplastic syndrome using the World Health Organization 2017/2022 and International Consensus Classification 2022 guidelines, in addition to European LeukemiaNet 2017/2022 risk stratification of patients with acute myeloid leukemia, was also performed to assess the utility of the molecular information provided by the Archer NGS panel.

MLPA in the initial genetic screening of patients with acute myeloid leukemia

INTRODUCTION

This study aimed to assess the effectiveness of multiplex ligase-dependent probe amplification (MLPA) in the initial genetic screening of patients with acute myeloid leukemia (AML) since current risk stratification and clinical management depend on molecular-genetic markers.

METHODS

We performed a prospective case-control study on newly diagnosed patients from the Clinical hematology clinic of UMHAT "St. Marina", Varna, for the period 02.2022 - 02.2023. MLPA - a semiquantitative PCR-based method, was implemented with probes for 40 AML/myelodysplastic syndrome-typical genetic changes. We compared these findings with a parallelly carried out cytogenetic analysis, part of the routine diagnostic process.

RESULTS

We assessed 61 patients - 29 females and 32 males, median age of 61 years for females and 65 for males (min-max 20-89). 34 (56%) of all showed pathological results, while the rest 27 (44%) did not. Of the 34, 22 (65%) had a single gene variant in genes NPM1, DNMT3A, FLT3, and IDH2, isolated or in combination. 18 (53%) of the same 34 also had copy number aberration (CNA) in chromosomes 4, 5, 6, 7, 11, 14, 17, and 21. The latter were either isolated or in combination with other findings. 8 of the 18 cases also underwent cytogenetic analysis, with concordance between the two methods in 4.

CONCLUSION

MLPA is an informative method for initial genetic assessment in addition to cytogenetic analysis. Still, more patients are needed to draw finite conclusions on its eligibility for routine use. Given the significant percentage of normal results - 44%, simultaneous evaluation of more genetic markers, included in current guidelines, is reasonable.

Comprehensive detection of CRLF2 alterations in acute lymphoblastic leukemia: a rapid and accurate novel approach

Introduction: Acute lymphoblastic leukemia (ALL) is a prevalent childhood cancer with high cure rate, but poses a significant medical challenge in adults and relapsed patients. Philadelphia-like acute lymphoblastic leukemia (Ph-like ALL) is a high-risk subtype, with approximately half of cases characterized by CRLF2 overexpression and frequent concomitant IKZF1 deletions. Methods: To address the need for efficient, rapid, and cost-effective detection of CRLF2 alterations, we developed a novel RT-qPCR technique combining SYBR Green and highresolution melting analysis on a single plate. Results: The method successfully identified CRLF2 expression, P2RY8::CRLF2 fusions, and CRLF2 and JAK2 variants, achieving a 100% sensitivity and specificity. Application of this method across 61 samples revealed that 24.59% exhibited CRLF2 overexpression, predominantly driven by IGH::CRLF2 (73.33%). High Resolution Melting analysis unveiled concurrent CRLF2 or JAK2 variants in 8.19% of samples, as well as a dynamic nature of CRLF2 alterations during disease progression. Discussion: Overall, this approach provides an accurate identification of CRLF2 alterations, enabling improved diagnostic and facilitating therapeutic decision-making.

Current and Emerging Techniques for Diagnosis and MRD Detection in AML: A Comprehensive Narrative Review

Acute myeloid leukemia (AML) comprises a group of hematologic neoplasms characterized by abnormal differentiation and proliferation of myeloid progenitor cells. AML is associated with poor outcome due to the lack of efficient therapies and early diagnostic tools. The current gold standard diagnostic tools are based on bone marrow biopsy. These biopsies, apart from being very invasive, painful, and costly, have low sensitivity. Despite the progress uncovering the molecular pathogenesis of AML, the development of novel detection strategies is still poorly explored. This is particularly important for patients that check the criteria for complete remission after treatment, since they can relapse through the persistence of some leukemic stem cells. This condition, recently named as measurable residual disease (MRD), has severe consequences for disease progression. Hence, an early and accurate diagnosis of MRD would allow an appropriate therapy to be tailored, improving a patient's prognosis. Many novel techniques with high potential in disease prevention and early detection are being explored. Among them, microfluidics has flourished in recent years due to its ability at processing complex samples as well as its demonstrated capacity to isolate rare cells from biological fluids. In parallel, surface-enhanced Raman scattering (SERS) spectroscopy has shown outstanding sensitivity and capability for multiplex quantitative detection of disease biomarkers. Together, these technologies can allow early and cost-effective disease detection as well as contribute to monitoring the efficiency of treatments. In this review, we aim to provide a comprehensive overview of AML disease, the conventional techniques currently used for its diagnosis, classification (recently updated in September 2022), and treatment selection, and we also aim to present how novel technologies can be applied to improve the detection and monitoring of MRD.

Patient specific real-time PCR in precision medicine - Validation of IG/TR based MRD assessment in lymphoid leukemia

Detection of patient- and tumor-specific clonally rearranged immune receptor genes using real-time quantitative (RQ)-PCR is an accepted method in the field of precision medicine for hematologic malignancies. As individual primers are needed for each patient and leukemic clone, establishing performance specifications for the method faces unique challenges. Results for series of diagnostic assays for CLL and ALL patients demonstrate that the analytic performance of the method is not dependent on patients' disease characteristics. The calibration range is linear between 10^-1 and 10^-5 for 90% of all assays. The detection limit of the current standardized approach is between 1.8 and 4.8 cells among 100,000 leukocytes. RQ-PCR has about 90% overall agreement to flow cytometry and next generation sequencing as orthogonal methods. Accuracy and precision across different labs, and above and below the clinically applied cutoffs for minimal/measurable residual disease (MRD) demonstrate the robustness of the technique. The here reported comprehensive, IVD-guided analytical validation provides evidence that the personalized diagnostic methodology generates robust, reproducible and specific MRD data when standardized protocols for data generation and evaluation are used. Our approach may also serve as a guiding example of how to accomplish analytical validation of personalized in-house diagnostics under the European IVD Regulation.

The role of next-generation sequencing in acute myeloid leukemia

PURPOSE OF REVIEW

The development of high-throughput techniques like next-generation sequencing (NGS) has unraveled the genetic profile of cancer. In this review, we discuss the role of NGS on the diagnostic, risk stratification, and follow-up of patients with acute myeloid leukemia (AML).

RECENT FINDINGS

NGS has become an essential tool in clinical practice for AML management. Therefore, efforts are being made to improve its applications, automation, and turnaround time. Other high-throughput techniques, such as whole genome sequencing or RNA-sequencing, can be also used to this end. However, not all institutions may be able to implement these approaches. NGS is being investigated for measurable residual disease (MRD) assessment, especially with the development of error-correction NGS. New data analysis approaches like machine learning are being investigated in order to integrate genomic and clinical data and develop comprehensive classifications and risk scores.

SUMMARY

NGS has proven to be a useful approach for the analysis of genomic alterations in patients with AML, which aids patient management. Current research is being directed at reducing turnaround time and simplifying processes so that these techniques can be universally integrated into clinical practice.

Health economic evidence for the use of molecular biomarker tests in hematological malignancies: A systematic review

Objectives

Molecular biomarker tests can inform the clinical management of genomic heterogeneous hematological malignancies, yet their availability in routine care largely depends on the supporting health economic evidence. This study aims to systematically review the economic evidence for recent molecular biomarker tests in hematological malignancies.

Methods

We conducted a systematic search in five electronic databases for studies published between January 2010 and October 2020. Publications were independently screened by two reviewers. Clinical study characteristics, economic methodology, and results were extracted, and reporting quality was assessed.

Results

Fourteen studies were identified, of which half (n = 7; 50%) were full economic evaluations examining both health and economic outcomes. Studies were predominantly conducted in a first‐line treatment setting (n = 7; 50%) and adopted a non‐lifetime time horizon to measure health outcomes and costs (n = 7; 50%). Five studies reported that companion diagnostics for associated therapies were likely cost‐effective for acute myeloid leukemia, chronic myeloid leukemia, diffuse large B‐cell lymphoma, and multiple myeloma. Four studies suggested molecular biomarker tests for treatment monitoring in chronic myeloid leukemia were likely cost‐saving.

Conclusions

Although there is initial confirmation of the promising health economic results, the present research for molecular biomarker tests in hematological malignancies is sparse with many applications of technological advances yet to be evaluated.

Diagnostic Impact of Next-Generation Sequencing Panels for Lymphoproliferative Neoplasms on Small-Volume Biopsies

OBJECTIVES

We investigated the feasibility and utility of next-generation sequencing (NGS)-based targeted somatic mutation panels and IG/TR gene rearrangement assays in the diagnosis of lymphoproliferative disorders (LPDs) in small-volume biopsies.

MATERIALS

We performed a retrospective, single-institution review of all NGS assays requested over a 3-year period by hematopathologists for diagnostic purposes on small-volume biopsies.

RESULTS

We identified 59 small-volume biopsies. The TR assay was most commonly requested (42 [71%]), followed by the somatic mutation panel (32 [54%]) and IG assay (26 [44%]). NGS studies were associated with a change in the diagnostic line in about half of cases (28 [47%]) and in a change in the likelihood of a diagnosis in a further 16 cases (27%); there was no diagnostic impact of NGS testing in 15 cases (25%).

CONCLUSIONS

Implementation of NGS panel somatic mutation or IG/TR gene rearrangement assays on small-volume biopsies contributes to the diagnosis of LPDs in the majority of select cases for diagnostic purposes. The molecular diagnosis is considered in the context of the clinical, histologic, and immunophenotypic findings and does not by itself lead to a definitive diagnosis in small-volume biopsies.

Technical Validation and Clinical Utility of an NGS Targeted Panel to Improve Molecular Characterization of Pediatric Acute Leukemia

Development of next-generation sequencing (NGS) has provided useful genetic information to redefine diagnostic, prognostic, and therapeutic strategies for the management of acute leukemia (AL). However, the application in the clinical setting is still challenging. Our aim was to validate the AmpliSeq™ for Illumina® Childhood Cancer Panel, a pediatric pan-cancer targeted NGS panel that includes the most common genes associated with childhood cancer, and assess its utility in the daily routine of AL diagnostics. In terms of sequencing metrics, the assay reached all the expected values. We obtained a mean read depth greater than 1000×. The panel demonstrated a high sensitivity for DNA (98.5% for variants with 5% variant allele frequency (VAF)) and RNA (94.4%), 100% of specificity and reproducibility for DNA and 89% of reproducibility for RNA. Regarding clinical utility, 49% of mutations and 97% of the fusions identified were demonstrated to have clinical impact. Forty-one percent of mutations refined diagnosis, while 49% of them were considered targetable. Regarding RNA, fusion genes were more clinically impactful in terms of refining diagnostic (97%). Overall, the panel found clinically relevant results in the 43% of patients tested in this cohort. To sum up, we validated a reliable and reproducible method to refine pediatric AL diagnosis, prognosis, and treatment, and demonstrated the feasibility of incorporating a targeted NGS panel into pediatric hematology practice.

Inherited Susceptibility to Hematopoietic Malignancies in the Era of Precision Oncology

As germline predisposition to hematopoietic malignancies has gained increased recognition and attention in the field of oncology, it is important for clinicians to use a systematic framework for the identification, management, and surveillance of patients with hereditary hematopoietic malignancies (HHMs). In this article, we discuss strategies for identifying individuals who warrant diagnostic evaluation and describe considerations pertaining to molecular testing. Although a paucity of prospective data is available to guide clinical monitoring of individuals harboring pathogenic variants, we provide recommendations for clinical surveillance based on consensus opinion and highlight current advances regarding the risk of progression to overt malignancy in HHM variant carriers. We also discuss the prognosis of HHMs and considerations surrounding the utility of allogeneic stem-cell transplantation in these individuals. We close with an overview of contemporary issues at the intersection of HHMs and precision oncology.

The Interpretation of Sequence Variants in Myeloid Neoplasms

OBJECTIVES

To provide an overview of the challenges encountered during the interpretation of sequence variants detected by next-generation sequencing (NGS) in myeloid neoplasms, as well as the limitations of the technology with the goal of preventing the over- or undercalling of alterations that may have a significant effect on patient management.

METHODS

Review of the peer-reviewed literature on the interpretation, reporting, and technical challenges of NGS assays for myeloid neoplasms.

RESULTS

NGS has been integrated widely and rapidly into the standard evaluating of myeloid neoplasms. Review of the literature reveals that myeloid sequence variants are challenging to detect and interpret. Large insertions and guanine-cytosine-heavy areas prove technically challenging while frameshift and truncating alterations may be classified as variants of uncertain significance by tertiary analysis informatics pipelines due to their absence in the literature and databases.

CONCLUSIONS

The analysis and interpretation of NGS results in myeloid neoplasia are challenging due to the varied number of detectable gene alterations. Familiarity with the genomic landscape of myeloid malignancies and knowledge of the tools available for the interpretation of sequence variants are essential to facilitate translation into clinical and therapy decisions.

Application of Next-Generation Sequencing-Based Mutational Profiling in Acute Lymphoblastic Leukemia

PURPOSE OF REVIEW

Recent efforts to characterize hematologic cancers with genetic and molecular detail have largely relied on mutational profiling via next-generation sequencing (NGS). The application of NGS-guided disease prognostication and clinical decision making requires a basic understanding of sequencing advantages, pitfalls, and areas where clinical care might be enhanced by the knowledge generated. This article identifies avenues within the landscape of adult acute lymphoblastic leukemia (ALL) where mutational data hold the opportunity to enhance understanding of disease biology and patient care.

RECENT FINDINGS

NGS-based assessment of measurable residual disease (MRD) after ALL treatment allows for a sensitive and specific molecular survey that is at least comparable, if not superior, to existing techniques. Mutational assessment by NGS has unraveled complex signaling networks that drive pathogenesis of T-cell ALL. Sequencing of patients with familial clustering of ALL has also identified novel germline mutations whose inheritance predisposes to disease development in successive generations. While NGS-based assessment of hematopoietic malignancies often provides actionable information to clinicians, patients with acute lymphoblastic leukemia are left underserved due to a lack of disease classification and prognostication schema that integrate molecular data. Ongoing research is positioned to enrich the molecular toolbox available to clinicians caring for adult ALL patients and deliver new insights to guide therapeutic selection, monitor clinical response, and detect relapse.

The Ups and Downs of STAT Inhibition in Acute Myeloid Leukemia

Aberrant Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling is implicated in the pathogenesis of acute myeloid leukemia (AML), a highly heterogeneous hematopoietic malignancy. The management of AML is complex and despite impressive efforts into better understanding its underlying molecular mechanisms, survival rates in the elderly have not shown a substantial improvement over the past decades. This is particularly due to the heterogeneity of AML and the need for personalized approaches. Due to the crucial role of the deregulated JAK-STAT signaling in AML, selective targeting of the JAK-STAT pathway, particularly constitutively activated STAT3 and STAT5 and their associated upstream JAKs, is of great interest. This strategy has shown promising results in vitro and in vivo with several compounds having reached clinical trials. Here, we summarize recent FDA approvals and current potential clinically relevant inhibitors for AML patients targeting JAK and STAT proteins. This review underlines the need for detailed cytogenetic analysis and additional assessment of JAK-STAT pathway activation. It highlights the ongoing development of new JAK-STAT inhibitors with better disease specificity, which opens up new avenues for improved disease management.

Analytical and Potential Clinical Performance of Oncomine Myeloid Research Assay for Myeloid Neoplasms

INTRODUCTION

Next-generation sequencing (NGS) panels have recently been introduced to efficiently detect genetic variations in hematologic malignancies.

OBJECTIVES

Our aim was to evaluate the performance of the commercialized Oncomine™ myeloid research assay (OMA) for myeloid neoplasms.

METHODS

Certified reference materials and clinical research samples were used, including 60 genomic DNA and 56 RNA samples. NGS was performed using OMA, which enables the interrogation of 40 target genes, 29 gene fusions, and five expression target genes with five expression control genes by the Ion S5 XL Sequencer. The analyzed data were compared with clinical data using karyotyping, reverse transcription polymerase chain reaction (PCR), fluorescence in situ hybridization, Sanger sequencing, customized NGS panel, and fragment analysis.

RESULTS

All targets of reference materials were detected except three (two ASXL1 and one CEBPA) mutations, which we had not expected OMA to detect. In clinical search samples, OMA satisfactorily identified DNA variants, including 90 single nucleotide variants (SNVs), 48 small insertions and deletions (indels), and eight FLT3 internal tandem duplications (ITDs) (Kappa agreement 0.938). The variant allele frequencies of SNVs and indels measured by OMA correlated well with clinical data, whereas those of FLT3-ITDs were significantly lower than with fragment analysis (P = 0.008). Together, OMA showed strong ability to identify RNA gene fusions (Kappa agreement 0.961), except one RUNX1-MECOM. The MECOM gene was highly expressed in all five samples with MECOM-associated rearrangements, including inv(3), t(3;3), and t(3;21).

CONCLUSION

OMA revealed excellent analytical and potential clinical performance and could be a good replacement for conventional molecular tests.

Design, implementation and clinical utility of next generation sequencing in myeloid malignancies: acute myeloid leukaemia and myelodysplastic syndrome

Next generation sequencing (NGS) based technology has contributed enormously to our understanding of the biology of myeloid malignancies including acute myeloid leukaemia (AML) and myelodysplastic syndrome (MDS). Assessment of clinically important mutations by NGS is a powerful tool to define diagnosis, determine prognostic risk, monitor measurable residual disease and uncover predictive mutational markers/therapeutic targets, and is now a routine component in the workup and monitoring of haematological disorders. There are many technical challenges in the design, implementation, analysis and reporting of NGS based results, and expert interpretation is essential. It is vital to distinguish relevant somatic disease associated mutations from those that are known polymorphisms, rare germline variants and clonal haematopoiesis of indeterminate potential (CHIP) associated variants. This review highlights and addresses the technical and biological challenges that should be considered before the implementation of NGS based testing in diagnostic laboratories and seeks to outline the essential and expanding role NGS plays in myeloid malignancies. Broad aspects of NGS panel design and reporting including inherent technological, biological and economic considerations are covered, following which the utility of NGS based testing in AML and MDS are discussed. In current practice, patient care is now strongly shaped by the results of NGS assessment and is considered a vital piece of the puzzle for clinicians as they manage these complex haematological disorders.

Clinical Utility of Next-Generation Sequencing in Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a genetically heterogeneous disease that, even with current advancements in therapy, continues to have a poor prognosis. Recurrent somatic mutations have been identified in a core set of pathogenic genes including FLT3 (25-30% prevalence), NPM1 (25-30%), DNMT3A (25-30%), IDH1/2 (5-15%), and TET2 (5-15%), with direct diagnostic, prognostic, and targeted therapeutic implications. Advances in the understanding of the complex mechanisms of AML leukemogenesis have led to the development and recent US Food and Drug Administration (FDA) approval of several targeted therapies: midostaurin and gilteritinib targeting activated FLT3, and ivosidenib and enasidenib targeting mutated IDH1/2. Several additional drug candidates targeting other recurrently mutated gene pathways in AML are also being actively developed. Furthermore, outside of the realm of predicting responses to targeted therapies, many other mutated genes, which comprise the so-called long tail of oncogenic drivers in AML, have been shown to provide clinically useful diagnostic and prognostic information for AML patients. Many of these recurrently mutated genes have also been shown to be excellent biomarkers for post-treatment minimal residual disease (MRD) monitoring for assessing treatment response and predicting future relapse. In addition, the identification of germline mutations in a set of genes predisposing to myeloid malignancies may directly inform treatment decisions (particularly stem cell transplantation) and impact other family members. Recent advances in sequencing technology have made it practically and economically feasible to evaluate many genes simultaneously using next-generation sequencing (NGS). Mutation screening with NGS panels has been recommended by national and international professional guidelines as the standard of care for AML patients. NGS-based detection of the heterogeneous genes commonly mutated in AML has practical clinical utility for disease diagnosis, prognosis, prediction of targeted therapy response, and MRD monitoring.

Helpful Criteria When Implementing NGS Panels in Childhood Lymphoblastic Leukemia

The development of Next-Generation Sequencing (NGS) has provided useful diagnostic, prognostic, and therapeutic strategies for individualized management of B-cell precursor acute lymphoblastic leukemia (BCP-ALL) patients. Consequently, NGS is rapidly being established in clinical practice. However, the technology’s complexity, bioinformatics analysis, and the different available options difficult a broad consensus between different laboratories in its daily routine introduction. This collaborative study among Spanish centers was aimed to assess the feasibility, pros, and cons of our customized panel and other commercial alternatives of NGS-targeted approaches. The custom panel was tested in three different sequencing centers. We used the same samples to assess other commercial panels (Oncomine^TM Childhood Cancer Research Assay; Archer^®FusionPlex^® ALL, and Human Comprehensive Cancer Panel GeneRead Panel v2^®). Overall, the panels showed a good performance in different centers and platforms, but each NGS approach presented some issues, as well as pros and cons. Moreover, a previous consensus on the analysis and reporting following international guidelines would be preferable to improve the concordance in results among centers. Our study shows the challenges posed by NGS methodology and the need to consider several aspects of the chosen NGS-targeted approach and reach a consensus before implementing it in daily practice.

Assessment of the clinical utility of four NGS panels in myeloid malignancies. Suggestions for NGS panel choice or design

The diagnosis of myeloid neoplasms (MN) has significantly evolved through the last few decades. Next Generation Sequencing (NGS) is gradually becoming an essential tool to help clinicians with disease management. To this end, most specialized genetic laboratories have implemented NGS panels targeting a number of different genes relevant to MN. The aim of the present study is to evaluate the performance of four different targeted NGS gene panels based on their technical features and clinical utility. A total of 32 patient bone marrow samples were accrued and sequenced with 3 commercially available panels and 1 custom panel. Variants were classified by two geneticists based on their clinical relevance in MN. There was a difference in panel’s depth of coverage. We found 11 discordant clinically relevant variants between panels, with a trend to miss long insertions. Our data show that there is a high risk of finding different mutations depending on the panel of choice, due both to the panel design and the data analysis method. Of note, CEBPA, CALR and FLT3 genes, remains challenging the use of NGS for diagnosis of MN in compliance with current guidelines. Therefore, conventional molecular testing might need to be kept in place for the correct diagnosis of MN for now.

Nanopore Targeted Sequencing for Rapid Gene Mutations Detection in Acute Myeloid Leukemia

Acute myeloid leukemia (AML) clinical settings cannot do without molecular testing to confirm or rule out predictive biomarkers for prognostic stratification, in order to initiate or withhold targeted therapy. Next generation sequencing offers the advantage of the simultaneous investigation of numerous genes, but these methods remain expensive and time consuming. In this context, we present a nanopore-based assay for rapid (24 h) sequencing of six genes (NPM1, FLT3, CEBPA, TP53, IDH1 and IDH2) that are recurrently mutated in AML. The study included 22 AML patients at diagnosis; all data were compared with the results of S5 sequencing, and discordant variants were validated by Sanger sequencing. Nanopore approach showed substantial advantages in terms of speed and low cost. Furthermore, the ability to generate long reads allows a more accurate detection of longer FLT3 internal tandem duplications and phasing double CEBPA mutations. In conclusion, we propose a cheap, rapid workflow that can potentially enable all basic molecular biology laboratories to perform detailed targeted gene sequencing analysis in AML patients, in order to define their prognosis and the appropriate treatment.

IDH1-mutated relapsed or refractory AML: current challenges and future prospects

The prognosis of patients with relapsed or refractory acute myeloid leukemia (R/R AML) is discouraging with salvage standard approaches. Mutations of isocitrate dehydrogenase 1 (IDH1^mut), present in 7–14% of AML patients, have been discovered recently, opening the door to targeted agents aiming to improve the outcomes in this setting. Several oral selective IDH1^mut inhibitors are under investigation, ivosidenib being the first approved for R/R AML. We performed a systematic review to analyze the clinical outcomes and safety reported with IDH1^mut inhibitors and other agents in adult patients with IDH1^mut R/R AML. Ivosidenib in monotherapy achieved complete remission (CR) of 24%, overall response of 42%, and median overall survival of 9 months in R/R AML, and promising outcomes were reported with IDH305 and FT-2102. IDH1^mut inhibitors were generally well tolerated, but some therapy-related toxicities should be monitored, including IDH-differentiation syndrome, prolongation of the QT interval, and leukocytosis, all manageable and reversible. Also, venetoclax, CB-839, PARP inhibitors, and IDH1 peptide vaccine are being studied in IDH1^mut AML. The results of the ongoing and upcoming clinical trials will bring new evidence to establish the role of IDH1^mut inhibitors in therapeutic strategies of AML.