Presence of isocitrate dehydrogenase mutations may predict clinical response to hypomethylating agents in patients with acute myeloid leukemia

Multidisciplinary Management of Isocitrate Dehydrogenase-Mutated Gliomas in a Contemporary Molecularly Defined Era

Mutations in isocitrate dehydrogenase (IDH) genes, an early step in the ontogeny of lower-grade gliomas, induce global epigenetic changes characterized by a hypermethylation phenotype and are critical to tumor classification, treatment decision making, and estimation of patient prognosis. The introduction of IDH inhibitors to block the oncogenic neomorphic function of the mutated protein has resulted in new therapeutic options for these patients. To appreciate the implications of these recent IDH inhibitor results, it is important to juxtapose historical outcomes with chemoradiotherapy. Herein, we rationally evaluate recent IDH inhibitor data within historical precedents to guide contemporary decisions regarding the role of observation, maximal safe resection, adjuvant therapies, and the import of patient and tumor variables. The biological underpinnings of the IDH pathway and the mechanisms, impact, and limitations of IDH inhibitors, the actual magnitude of tumor regression and patient benefit, and emergence of resistance pathways are presented to guide future trial development. Management in the current, molecularly defined era will require careful patient selection and risk factor assessment, followed by an open dialog about the results of studies such as INDIGO, as well as mature data from legacy trials, and a discussion about risk-versus-benefit for the choice of treatment, with multidisciplinary decision making as an absolute prerequisite.

RIPK3 deficiency blocks R-2-hydroxyglutarate-induced necroptosis in IDH-mutated AML cells

Mutant isocitrate dehydrogenases (IDHs) produce R-2-hydroxyglutarate (R-2HG), which inhibits the growth of most acute myeloid leukemia (AML) cells. Here, we showed that necroptosis, a form of programmed cell death, contributed to the antileukemia activity of R-2HG. Mechanistically, R-2HG competitively inhibited the activity of lysine demethylase 2B (KDM2B), an α-ketoglutarate-dependent dioxygenase. KDM2B inhibition increased histone 3 lysine 4 trimethylation levels and promoted the expression of receptor-interacting protein kinase 1 (RIPK1), which consequently caused necroptosis in AML cells. The expression of RIPK3 was silenced because of DNA methylation in IDH-mutant (mIDH) AML cells, resulting in R-2HG resistance. Decitabine up-regulated RIPK3 expression and repaired endogenous R-2HG-induced necroptosis pathway in mIDH AML cells. Together, R-2HG induced RIPK1-dependent necroptosis via KDM2B inhibition in AML cells. The loss of RIPK3 protected mIDH AML cells from necroptosis. Restoring RIPK3 expression to exert R-2HG's intrinsic antileukemia effect will be a potential therapeutic strategy in patients with AML.

Single-center, observational study of AML/MDS-EB with IDH1/2 mutations: genetic profile, immunophenotypes, mutational kinetics and outcomes

OBJECTIVE

IDH1/2 mutations, intervening in epigenetic procedures, are frequently encountered in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS). Knowledge of the genetics, immunophenotypes, and mutational kinetics of IDH1/2-mutated AML can contribute to the understanding of AML clonal architecture and inform therapeutics and monitoring.

METHODS

We retrospectively analyzed 50 IDH1/2-mutated AML/MDS-EB cases of our institution, to identify recurrent co-mutations, immunophenotypes, patterns of co-variance of IDH1/2 allele burdens with those of recurrent co-mutations, frequency of persistent IDH1/2 mutation as clonal hematopoiesis of indeterminate potential (CHIP) in remission and response to hypomethylating agents.

RESULTS

Most frequently co-mutated genes were DNMT3A, SRSF2 and NPM1. Most cases with co-existent IDH1/2 and NPM1 mutations (11/13) showed an 'APL-like' immunophenotype (CD34-HLADR-). Allele burdens of mutated IDH1/2 were identical to mutated SRSF2 allele burdens at diagnosis and remission, but not always to mutated NPM1 allele burden in remission. We show persistence of significant mutIDH1/2 allele burden in approximately one-fourth of patients with deep remissions. IDH1/2 mutations were significantly more frequent among responders to first-line HMA-based regimens than among non-responders, in patients treated for myeloid neoplasms with excess blasts.

CONCLUSIONS

IDH1/2 mutations are most frequently accompanied by DNMT3A, SRSF2 and NPM1 mutations. NPM1-IDH1/2 mutated AML has a mature phenotype possibly amenable to differentiation therapies. IDH1/2 and SRSF2 mutations probably arise at the same developmental stage of the disease, as their allele burdens covariate. IDH1/2 mutation represents CHIP in a substantial proportion of cases and is therefore no reliable residual disease marker. The preferential presence of IDH1/2 mutations among HMA-responders could inform therapeutic decisions if confirmed in larger series.

The Role of Epigenetic Modifier Mutations in Peripheral T-Cell Lymphomas

Peripheral T-cell lymphomas (PTCLs) are a group of diseases with a low incidence, high degree of heterogeneity, and a dismal prognosis in most cases. Because of the low incidence of these diseases, there have been few therapeutic novelties developed over time. Nevertheless, this fact is changing presently as epigenetic modifiers have been shown to be recurrently mutated in some types of PTCLs, especially in the cases of PTCLs not otherwise specified (PTCL-NOS), T follicular helper (TFH), and angioimmunoblastic T-cell lymphoma (AITL). These have brought about more insight into PTCL biology, especially in the case of PTCLs arising from TFH lymphocytes. From a biological perspective, it has been observed that ten-eleven translocators (TET2) mutated T lymphocytes tend to polarize to TFH, while Tregs lose their inhibitory properties. IDH2 R172 was shown to have inhibitory effects on TET2, mimicking the effects of TET2 mutations, as well as having effects on histone methylation. DNA methyltransferase 3A (DNMT3A) loss-of-function, although it was shown to have opposite effects to TET2 from an inflammatory perspective, was also shown to increase the number of T lymphocyte progenitors. Aside from bringing about more knowledge of PTCL biology, these mutations were shown to increase the sensitivity of PTCLs to certain epigenetic therapies, like hypomethylating agents (HMAs) and histone deacetylase inhibitors (HDACis). Thus, to answer the question from the title of this review: We found the Achilles heel, but only for one of the Achilles.

IDH2 mutations in acute myeloid leukemia

Advances in the treatment of acute myeloid leukemia (AML) over the last 40 years have been limited. With an improved understanding of the pathophysiology of the disease, the advent of new treatment options has enriched the armamentarium of the physician to combat the disease. Mutations of the isocitrate dehydrogenase (IDHs) genes are common in AML and occur in 20-30% of cases. These mutations lead to DNA hypermethylation, aberrant gene expression, cell proliferation, and abnormal differentiation. Targeting mutant IDH, either as monotherapy or in combination with hypomethylating agents (HMAs) or BCL-2 inhibitors, has opened new avenues of therapy for these patients.This review will outline the function of IDHs and focus on the biological effects of IDH2 mutations in AML, their prognosis and treatment options.

Mechanisms of Resistance to Small Molecules in Acute Myeloid Leukemia

In recent years, great progress has been made in the therapy of AML by targeting cellular processes associated with specific molecular features of the disease. Various small molecules inhibiting FLT3, IDH1/IDH2, and BCL2 have already gained approval from the respective authorities and are essential parts of personalized therapeutic regimens in modern therapy of AML. Unfortunately, primary and secondary resistance to these inhibitors is a frequent problem. Here, we comprehensively review the current state of knowledge regarding molecular processes involved in primary and secondary resistance to these agents, covering both genetic and nongenetic mechanisms. In addition, we introduce concepts and strategies for how these resistance mechanisms might be overcome.

Crosstalk between DNA methylation and hypoxia in acute myeloid leukaemia

BACKGROUND

Acute myeloid leukaemia (AML) is a deadly disease characterised by the uncontrolled proliferation of immature myeloid cells within the bone marrow. Altered regulation of DNA methylation is an important epigenetic driver of AML, where the hypoxic bone marrow microenvironment can help facilitate leukaemogenesis. Thus, interactions between epigenetic regulation and hypoxia signalling will have important implications for AML development and treatment.

MAIN BODY

This review summarises the importance of DNA methylation and the hypoxic bone marrow microenvironment in the development, progression, and treatment of AML. Here, we focus on the role hypoxia plays on signalling and the subsequent regulation of DNA methylation. Hypoxia is likely to influence DNA methylation through altered metabolic pathways, transcriptional control of epigenetic regulators, and direct effects on the enzymatic activity of epigenetic modifiers. DNA methylation may also prevent activation of hypoxia-responsive genes, demonstrating bidirectional crosstalk between epigenetic regulation and the hypoxic microenvironment. Finally, we consider the clinical implications of these interactions, suggesting that reduced cell cycling within the hypoxic bone marrow may decrease the efficacy of hypomethylating agents.

CONCLUSION

Hypoxia is likely to influence AML progression through complex interactions with DNA methylation, where the therapeutic efficacy of hypomethylating agents may be limited within the hypoxic bone marrow. To achieve optimal outcomes for AML patients, future studies should therefore consider co-treatments that can promote cycling of AML cells within the bone marrow or encourage their dissociation from the bone marrow.

DNA methyltransferase inhibitor exposure-response: Challenges and opportunities

Although DNA methyltransferase inhibitors (DNMTis), such as azacitidine and decitabine, are used extensively in the treatment of myelodysplastic syndromes and acute myeloid leukemia, there remain unanswered questions about DNMTi's mechanism of action and predictors of clinical response. Because patients often remain on single-agent DNMTis or DNMTi-containing regimens for several months before knowing whether clinical benefit can be achieved, the development and clinical validation of response-predictive biomarkers represents an important unmet need in oncology. In this review, we will summarize the clinical studies that led to the approval of azacitidine and decitabine, as well as the real-world experience with these drugs. We will then focus on biomarker development for DNMTis-specifically, efforts at determining exposure-response relationships and challenges that remain impacting the broader clinical translation of these methods. We will highlight recent progress in liquid-chromatography tandem mass spectrometry technology that has allowed for the simultaneous measurement of decitabine genomic incorporation and global DNA methylation, which has significant potential as a mechanism-of-action based biomarker in patients on DNMTis. Last, we will cover important research questions that need to be addressed in order to optimize this potential biomarker for clinical use.

Impact of IDH1 and IDH2 mutational subgroups in AML patients after allogeneic stem cell transplantation

Background

The role of allogeneic hematopoietic cell transplantation (alloHCT) in acute myeloid leukemia (AML) with mutated IDH1/2 has not been defined. Therefore, we analyzed a large cohort of 3234 AML patients in first complete remission (CR1) undergoing alloHCT or conventional chemo-consolidation and investigated outcome in respect to IDH1/2 mutational subgroups (IDH1 R132C, R132H and IDH2 R140Q, R172K).

Methods

Genomic DNA was extracted from bone marrow or peripheral blood samples at diagnosis and analyzed for IDH mutations with denaturing high-performance liquid chromatography, Sanger sequencing and targeted myeloid panel next-generation sequencing, respectively. Statistical as-treated analyses were performed using R and standard statistical methods (Kruskal–Wallis test for continuous variables, Chi-square test for categorical variables, Cox regression for univariate and multivariable models), incorporating alloHCT as a time-dependent covariate.

Results

Among 3234 patients achieving CR1, 7.8% harbored IDH1 mutations (36% R132C and 47% R132H) and 10.9% carried IDH2 mutations (77% R140Q and 19% R172K). 852 patients underwent alloHCT in CR1. Within the alloHCT group, 6.2% had an IDH1 mutation (43.4% R132C and 41.4% R132H) and 10% were characterized by an IDH2 mutation (71.8% R140Q and 24.7% R172K). Variants IDH1 R132C and IDH2 R172K showed a significant benefit from alloHCT for OS (p = .017 and p = .049) and RFS (HR = 0.42, p = .048 and p = .009) compared with chemotherapy only. AlloHCT in IDH2 R140Q mutated AML resulted in longer RFS (HR = 0.4, p = .002).

Conclusion

In this large as-treated analysis, we showed that alloHCT is able to overcome the negative prognostic impact of certain IDH mutational subclasses in first-line consolidation treatment and could pending prognostic validation, provide prognostic value for AML risk stratification and therapeutic decision making.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13045-022-01339-8.

Refining AML Treatment: The Role of Genetics in Response and Resistance Evaluation to New Agents

Simple Summary

Acute myeloid leukemia (AML) is an aggressive cancer of the hematopoietic system. At present, we know that AML is heterogeneous and varies from one patient to another, often characterized by specific changes in the DNA (mutations). Likewise, we know that the mutational landscape of the disease predicts its response to certain therapies and that it can change under the influence of therapy. Since 2017, the number of potential drugs intended to treat AML has substantially increased and so has our knowledge about the role of certain mutations in the prediction of disease response, relapse and resistance. In this article, we review the current state of knowledge of genetic aberrations with respect to clinical decision making.

Abstract

The number of treatment options for acute myeloid leukemia (AML) has greatly increased since 2017. This development is paralleled by the broad implantation of genetic profiling as an integral part of clinical studies, enabling us to characterize mutation–response, mutation–non-response, or mutation–relapse patterns. The aim of this review is to provide a concise overview of the current state of knowledge with respect to newly approved AML treatment options and the association of response, relapse and resistance with genetic alterations. Specifically, we will highlight current genetic data regarding FLT3 inhibitors, IDH inhibitors, hypomethylating agents (HMA), the BCL-2 inhibitor venetoclax (VEN), the anti-CD33 antibody conjugate gemtuzumab ozogamicin (GO) and the liposomal dual drug CPX-351.

Potential of IDH mutations as immunotherapeutic targets in gliomas: a review and meta-analysis

INTRODUCTION

Gliomas are stratified by the presence of a hotspot mutation in the enzyme isocitrate dehydrogenase genes (IDH1/2). While mutated IDH (mIDH) correlates with better prognosis, the role of this mutation in antitumor immunity and the response to immunotherapy is not completely understood. Understanding the relationship between the genetic features of these tumors and the tumor immune microenvironment (TIME) may help to develop appropriate therapeutic strategies.

AREAS COVERED

In this review we discussed the available literature related to the potential role of IDH mutations as an immunotherapeutic target in gliomas and profiled the immune transcriptome of glioma biopsies. We aimed to shed light on the role of mIDH on the immunological landscape of the different subtypes of gliomas, taking into account the most recent WHO classification of tumors of the central nervous system (CNS). We also discussed different immunotherapeutic approaches to target mIDH tumors and to overcome their immunosuppressive microenvironment.

EXPERT OPINION

Data presented here indicates that the TIME not only differs in association with IDH mutation status, but also within glioma subtypes, suggesting that the cellular context affects the overall effect of this genetic lesion. Thus, specific therapeutic combinations may help patients diagnosed with different glioma subtypes.

Investigation of Isocitrate Dehydrogenase 1 and 2 Mutations in Acute Leukemia Patients in Saudi Arabia

Different forms of human cancer show mutations for isocitrate dehydrogenases 1 and 2 (IDH1/2). Mutation of these genes can cause aberrant methylation of the genome CpG islands (CGIs), which leads to an increase of suppressed oncogenes transcription or repression of active tumor suppressor gene transcription. This study aimed to identify the prevalence of IDH1/2 mutations in acute leukemia patients. The study cohort included 43 AML patients and 30 childhood ALL patients, from whom DNA bone marrow samples were taken. The alteration hotspots in codons IDH1 (R132) and IDH2 (R172 and R140) were examined via direct sequencing. Mutations in IDH1 were detected in 7 out of 43 (16.2%) AML patients; 5 of them occurred at codon R132. The other two mutations included a single-nucleotide polymorphism, which affected codon G105 in one patient. However, no mutation was detected in the IDH2 in any of the patients. Moreover, no mutations were detected in either IDH1 or IDH2 in ALL patients. The dominance of IDH1 mutations in AML, which was 16%, emphasizes the existence of the mutation in our population. On the other hand, IDH2 mutation was observed to be less frequent in both illnesses. Due to the limitation of using a small sample size, larger cohort screening is recommended to determine their usefulness as prognostic indicators.

Activation of Vitamin D Receptor Pathway Enhances Differentiating Capacity in Acute Myeloid Leukemia with Isocitrate Dehydrogenase Mutations

Relapses and resistance to therapeutic agents are major barriers in the treatment of acute myeloid leukemia (AML) patients. These unfavorable outcomes emphasize the need for new strategies targeting drug-resistant cells. As IDH mutations are present in the preleukemic stem cells and systematically conserved at relapse, targeting IDH mutant cells could be essential to achieve a long-term remission in the IDH mutant AML subgroup. Here, using a panel of human AML cell lines and primary AML patient specimens harboring IDH mutations, we showed that the production of an oncometabolite (R)-2-HG by IDH mutant enzymes induces vitamin D receptor-related transcriptional changes, priming these AML cells to differentiate with pharmacological doses of ATRA and/or VD. This activation occurs in a CEBPα-dependent manner. Accordingly, our findings illuminate potent and cooperative effects of IDH mutations and the vitamin D receptor pathway on differentiation in AML, revealing a novel therapeutic approach easily transferable/immediately applicable to this subgroup of AML patients.

Resistance to Hypomethylating Agents in Myelodysplastic Syndrome and Acute Myeloid Leukemia From Clinical Data and Molecular Mechanism

The nucleoside analogs decitabine (5-AZA-dC) and azacitidine (5-AZA) have been developed as targeted therapies to reverse DNA methylation in different cancer types, and they significantly improve the survival of patients who are not suitable for traditional intensive chemotherapies or other treatment regimens. However, approximately 50% of patients have a response to hypomethylating agents (HMAs), and many patients have no response originally or in the process of treatment. Even though new combination regimens have been tested to overcome the resistance to 5-AZA-dC or 5-AZA, only a small proportion of patients benefited from these strategies, and the outcome was very poor. However, the mechanisms of the resistance remain unknown. Some studies only partially described management after failure and the mechanisms of resistance. Herein, we will review the clinical and molecular signatures of the HMA response, alternative treatment after failure, and the causes of resistance in hematological malignancies.

Targeting IDH Mutations in AML: Wielding the Double-edged Sword of Differentiation

The genomic characterization of acute myeloid leukemia (AML) by DNA sequencing has illuminated subclasses of the disease, with distinct driver mutations, that might be responsive to targeted therapies. Approximately 15-23% of AML genomes harbor mutations in one of two isoforms of isocitrate dehydrogenase (IDH1 or IDH2). These enzymes are constitutive mediators of basic cellular metabolism, but their mutated forms in cancer synthesize an abnormal metabolite, 2- hydroxyglutarate, that in turn acts as a competitive inhibitor of multiple gene regulatory enzymes. As a result, leukemic IDH mutations cause changes in genome structure and gene activity, culminating in an arrest of normal myeloid differentiation. These discoveries have motivated the development of a new class of selective small molecules with the ability to inhibit the mutant IDH enzymes while sparing normal cellular metabolism. These agents have shown promising anti-leukemic activity in animal models and early clinical trials, and are now entering Phase 3 study. This review will focus on the growing preclinical and clinical data evaluating IDH inhibitors for the treatment of IDH-mutated AML. These data suggest that inducing cellular differentiation is central to the mechanism of clinical efficacy for IDH inhibitors, while also mediating toxicity for patients who experience IDH Differentiation Syndrome. Ongoing trials are studying the efficacy of IDH inhibitors in combination with other AML therapies, both to evaluate potential synergistic combinations as well as to identify the appropriate place for IDH inhibitors within existing standard-of-care regimens.

Pre-transplant therapy for patients with myelodysplastic syndromes: A systematic review and meta-analysis

BACKGROUND

The value of pre-transplant cytoreductive therapy for patients with myelodysplastic syndromes (MDS) is controversial. Here, we conducted a meta-analysis to explore the effects of cytoreduction before transplantation.

METHODS

PubMed, Embase, Cochrane, and Chinese databases were searched to identify studies comparing post-transplant outcomes in MDS patients receiving different pre-transplant therapy. Pooled hazard ratios (HRs) and 95 % confidence intervals (CI) were calculated.

RESULTS

Eighteen reports were included. Post-transplant outcomes were similar for MDS patients receiving pre-transplant cytoreductive therapy and upfront transplantation in terms of overall survival (OS: HR, 0.92; 95 % CI, 0.79-1.07), relapse-free survival (RFS: HR, 1.18; 95 % CI, 0.94-1.47), cumulative incidence of relapse (CIR: HR, 1.08; 95 % CI, 0.88-1.33), and non-relapse mortality (NRM: HR, 0.93; 95 % CI, 0.74-1.18). Pre-transplant hypomethylating agents (HMAs) and chemotherapy were not different regarding post-transplant OS, RFS, CIR, and NRM. Achieving complete remission (CR) before transplantation was associated with increased RFS (HR, 0.80; 95 %CI, 0.63-1.00) and decreased NRM (HR, 0.53; 95 % CI, 0.32-0.90) when compared with upfront transplantation.

CONCLUSIONS

Timely transplantation is of great value for MDS patients. Suitable pre-transplant cytoreduction could be used during the search for donors.

Genetic features and efficacy of decitabine-based chemotherapy in elderly patients with acute myeloid leukemia

OBJECTIVES

The outcome of elderly acute myeloid leukemia (AML) patients is poor, which was traditionally attributed to patient- and leukemia-related factors. However, studies about the genetic features of these elderly patients have not been integrated and the genetic mechanism of their poor outcome is less known.

METHODS

Here, we used next generation sequencing (NGS) to identify the genetic features of elderly AML patients and confirmed the efficacy of chemotherapy based on molecular aberrations. Mutations in 111 genes relevant to hematological malignancy was analysed by virtue of NGS and the genetic differences were compared between elderly (n=52) and young (n=161) AML patients. Furthermore, the outcome of decitabine-based chemotherapy was identified in elderly patients.

RESULTS

Frequencies of adverse genetic alterations, such as RUNX1 and secondary-type mutations (ASXL1, STAG2 and spliceosome), were much higher in elderly patients, while the frequency of WT1 mutations was much lower. Moreover, epigenetic mutations such as DNMT3A, TET2, ASXL1 and IDH2, were also more common in elderly patients. Furthermore, there were 39 elderly patients receiving the decitabine-based chemotherapy, and the results showed that the overall response rate (ORR) and complete remission rate (CR) were 76.9% and 71.8%, respectively. The median overall survival (OS) for those older patients was 12 months, and the 2-year OS probability was 20.5%.

DISCUSSION

Our study provides deep understanding into the molecular mechanisms of the poor outcome of elderly AML patients.

CONCLUSION

Epigenetic mutations play an important role, and decitabine-based regimen can be used as alternative first-line chemotherapy for elderly patients.

Clinical developments in epigenetic-directed therapies in acute myeloid leukemia

Acute myeloid leukemia (AML) is a highly heterogeneous disease arising from acquired genetic and epigenetic aberrations which stifle normal development and differentiation of hematopoietic precursors. Despite the complex and varied biological underpinnings, induction therapy for AML has remained fairly uniform over 4 decades and outcomes remain poor for most patients. Recently, enhanced understanding of the leukemic epigenome has resulted in the translational investigation of a number of epigenetic modifying agents currently in various stages of clinical development. These novel therapies are based on mechanistic rationale and offer the potential to improve AML patient outcomes. In light of many recent advances in this field, we provide an updated, clinically oriented review of the evolving landscape of epigenetic modifying agents for the treatment of AML.

Ibrutinib added to 10-day decitabine for older patients with AML and higher risk MDS

The treatment of older, unfit patients with acute myeloid leukemia (AML) is challenging. Based on preclinical data of Bruton tyrosine kinase expression/phosphorylation and ibrutinib cytotoxicity in AML blasts, we conducted a randomized phase 2 multicenter study to assess the tolerability and efficacy of the addition of ibrutinib to 10-day decitabine in unfit (ie, Hematopoietic Cell Transplantation Comorbidity Index ≥3) AML patients and higher risk myelodysplasia patients (HOVON135/SAKK30/15 trial). In total, 144 eligible patients were randomly (1:1) assigned to either 10-day decitabine combined with ibrutinib (560 mg; sequentially given, starting the day after the last dose of decitabine) (n = 72) or to 10-day decitabine (n = 72). The addition of ibrutinib was well tolerated, and the number of adverse events was comparable for both arms. In the decitabine plus ibrutinib arm, 41% reached complete remission/complete remission with incomplete hematologic recovery (CR/CRi), the median overall survival (OS) was 11 months, and 2-year OS was 27%; these findings compared with 50% CR/CRi, median OS of 11.5 months, and 2-year OS of 21% for the decitabine group (not significant). Extensive molecular profiling at diagnosis revealed that patients with STAG2, IDH2, and ASXL1 mutations had significantly lower CR/CRi rates, whereas patients with mutations in TP53 had significantly higher CR/CRi rates. Furthermore, multicolor flow cytometry revealed that after 3 cycles of treatment, 28 (49%) of 57 patients with available bone marrow samples had no measurable residual disease. In this limited number of cases, measurable residual disease revealed no apparent impact on event-free survival and OS. In conclusion, the addition of ibrutinib does not improve the therapeutic efficacy of decitabine. This trial was registered at the Netherlands Trial Register (NL5751 [NTR6017]) and has EudraCT number 2015-002855-85.

Controversies in the Treatment of Peripheral T-cell Lymphoma

Peripheral T-cell lymphomas are a heterogeneous group of rare diseases with an aggressive behavior and dismal prognosis. Their classification is complex and still evolving, and several biomolecular markers now help refine the prognosis of specific disease entities, although still have limited impact in tailoring the treatment. First-line treatment strategies can cure only a minority of patients and relapsed-refractory disease still represents the major cause of failure. Frontline autologous transplantation may have an impact in the consolidation of response; however, its role is still questioned as far as complete responses obtained after induction chemotherapy are concerned. Newer drugs are now being evaluated in clinical trials, but effective salvage strategies for those who experience treatment failures are lacking. Here we review and discuss the most controversial aspects of diagnosis and treatment of peripheral T-cell lymphomas.

Monosomal karyotype and chromosome 17p loss or TP53 mutations in decitabine-treated patients with acute myeloid leukemia

TP53 aberrations reportedly predict favorable responses to decitabine (DAC) in acute myeloid leukemia (AML). We evaluated clinical features and outcomes associated with chromosome 17p loss or TP53 gene mutations in older, unfit DAC-treated AML patients in a phase II trial. Of 178 patients, 25 had loss of 17p in metaphase cytogenetics; 24 of these had a complex (CK+) and 21 a monosomal karyotype (MK+). In analyses in all patients and restricted to CK+ and MK+ patients, 17p loss tended to associate with higher rates of complete remission (CR), partial remission (PR), or antileukemic effect (ALE). Despite favorable response rates, there was no significant OS difference between patients with or without loss of 17p in the entire cohort or in the CK+ and MK+ cohort. TP53 mutations were identified in eight of 45 patients with material available. Five of the eight TP53-mutated patients had 17p loss. TP53-mutated patients had similar rates of CR/PR/ALE but shorter OS than those with TP53 wild type (P = 0.036). Moreover, patients with a subclone based on mutation data had shorter OS than those without (P = 0.05); only one patient with TP53-mutated AML had a subclone. In conclusion, 17p loss conferred a favorable impact on response rates, even among CK+ and MK+ patients that however could not be maintained. The effect of TP53 mutations appeared to be different; however, patient numbers were low. Future research needs to further dissect the impact of the various TP53 aberrations in HMA-based combination therapies. The limited duration of favorable responses to HMA treatment in adverse-risk genetics AML should prompt physicians to advance allografting for eligible patients in a timely fashion.

A phase 1 study of azacitidine with high-dose cytarabine and mitoxantrone in high-risk acute myeloid leukemia

In this phase 1 study, azacitidine (AZA) was given before high-dose cytarabine (HiDAC) and mitoxantrone (mito) based on the hypothesis that epigenetic priming with a hypomethylating agent before cytotoxic chemotherapy would improve response rates in patients with high-risk acute myeloid leukemia (AML), including relapsed/refractory disease. The primary objective was to establish the recommended phase 2 dose of AZA given before standard HiDAC/mito. In a dose escalation scheme, 46 patients (median age, 66 years) received AZA at 37.5, 50, or 75 mg/m2 subcutaneously or IV once daily on days 1 to 5 followed by HiDAC (3000 mg/m2) and mitoxantrone (30 mg/m2) once each on days 6 and 10 (the HiDAC/mito dose was reduced 33% in elderly subjects). Two dose-limiting toxicities occurred (both in the same patient): acute liver failure and kidney injury at the 50 mg/m2 dose. The 30-day induction death rate was 2.2% (1 of 46). The overall response rate, including complete remission and complete remission with incomplete count recovery, was 61% (28 of 46). Previously untreated patients aged ≥60 years with therapy-related AML and de novo AML were more likely to respond than untreated patients with AML progressing from an antecedent hematologic disorder (myelodysplastic syndrome and chronic myelomonocytic leukemia). Patients with favorable European Leukemia Network risk (P = .008), NPM1 mutations (P = .007), or IDH2 mutations (P = .03) were more likely to respond, and those with TP53 mutations (P = .03) were less likely to respond. The recommended phase 2 dose of AZA is 75 mg/m2 per day on days 1 to 5 followed by HiDAC (3000 mg/m2) and mitoxantrone (30 mg/m2) once each on days 6 and 10. This trial was registered at www.clinicaltrials.gov as #NCT01839240.

Epigenetic modifier gene mutations-positive AML patients with intermediate-risk karyotypes benefit from decitabine with CAG regimen

It remains unclear whether there is a relationship between therapeutic effects of hypomethylating agents (HMAs) and epigenetic modifier gene mutations (EMMs) in patients with cytogenetically intermediate-risk acute myeloid leukemia (IR-AML). Based on targeted-capture sequencing, we retrospectively analyzed the correlation between EMMs and prognosis in 83 IR-AML patients treated with decitabine in combination with cytarabine, aclarubicin hydrochloride and granulocyte colony-stimulating factor (DCAG, n = 35) or "7 + 3" induction regimens (n = 48). In the multivariate analyses, EMM (+) patients did not show any statistically significant difference in remission rates from EMM (-) patients in the DCAG group (p > 0.05), but achieved inferior complete remission (CR; p = 0.03) and overall remission rates (ORR; p = 0.04) after the first course of standard induction regimens (p < 0.05). In the EMM (-) cohort, the DCAG group showed the tendency of adverse total CR (p = 0.06). Besides, DCAG group with EMMs achieved the best survival outcome independent of baseline characteristics, whereas it was opposite in EMM (+) patients receiving standard induction regimens (p < 0.05). Additionally, in the EMM (+) cohort, the survival rate of isolated DCAG group was statistically similar to that of the combination of standard chemotherapies and allogeneic hematopoietic stem cell transplantation (allo-HSCT) (p > 0.40), whereas patients who received only standard regimens had the worst survival rate (0.0%, p < 0.01). It can be concluded that the EMMs might be regarded as the potentially predictive biomarkers of better response to DCAG in IR-AML patients.

Clinical update on hypomethylating agents

Hypomethylating agents (HMAs), azacitidine and decitabine, are standards of care in higher-risk myelodysplastic syndromes and in acute myeloid leukemia patients ineligible for intensive therapy. Over the last 10 years, research efforts have sought to better understand their mechanism of action, both at the molecular and cellular level. These efforts have yet to robustly identify biomarkers for these agents. The clinical activity of HMAs in myeloid neoplasms has been firmly established now but still remains of limited magnitude. Besides optimized use at different stages of the disease, most of the expected clinical progress with HMAs will come from the development of second-generation compounds orally available and/or with improved pharmacokinetics, and from the search, so far mostly empirical, of HMA-based synergistic drug combinations.

2-hydroxyglutarate inhibits MyoD-mediated differentiation by preventing H3K9 demethylation

Oncogenic IDH1/2 mutations produce 2-hydroxyglutarate (2HG), resulting in competitive inhibition of DNA and protein demethylation. IDH-mutant cancer cells show an inability to differentiate but whether 2HG accumulation is sufficient to perturb differentiation directed by lineage-specifying transcription factors is unknown. A MyoD-driven model was used to study the role of IDH mutations in the differentiation of mesenchymal cells. The presence of 2HG produced by oncogenic IDH2 blocks the ability of MyoD to drive differentiation into myotubes. DNA 5mC hypermethylation is dispensable while H3K9 hypermethylation is required for this differentiation block. IDH2-R172K mutation results in H3K9 hypermethylation and impaired accessibility at myogenic chromatin regions but does not result in genome-wide decrease in accessibility. The results demonstrate the ability of the oncometabolite 2HG to block transcription factor-mediated differentiation in a molecularly defined system.

Hypomethylating agents in the treatment of acute myeloid leukemia: A guide to optimal use

The hypomethylating agents (HMAs), decitabine and azacitidine, are valuable treatment options in acute myeloid leukemia patients who are not eligible for intensive chemotherapy. Both agents are generally well tolerated, and complications most commonly relate to myelosuppression. Antibiotic / antifungal use, regular monitoring, and proactive patient education are important to minimize these events, and reduce the need for dose delay. Responses to HMAs are often not evident for up to 6 cycles, and there is currently no validated clinical marker for predicting response. Hence, treatment should be continued for at least 4-6 cycles to ensure that patients have sufficient opportunity to respond. Delivery of insufficient numbers of cycles is a key reason for HMA failure, and premature discontinuation must be avoided. Genetic factors offer potential for better predicting responders to HMAs in future, but require further study.

Mutant Isocitrate Dehydrogenase Inhibitors as Targeted Cancer Therapeutics

The identification of heterozygous neomorphic isocitrate dehydrogenase (IDH) mutations across multiple cancer types including both solid and hematologic malignancies has revolutionized our understanding of oncogenesis in these malignancies and the potential for targeted therapeutics using small molecule inhibitors. The neomorphic mutation in IDH generates an oncometabolite product, 2-hydroxyglutarate (2HG), which has been linked to the disruption of metabolic and epigenetic mechanisms responsible for cellular differentiation and is likely an early and critical contributor to oncogenesis. In the past 2 years, two mutant IDH (mutIDH) inhibitors, Enasidenib (AG-221), and Ivosidenib (AG-120), have been FDA-approved for IDH-mutant relapsed or refractory acute myeloid leukemia (AML) based on phase 1 safety and efficacy data and continue to be studied in trials in hematologic malignancies, as well as in glioma, cholangiocarcinoma, and chondrosarcoma. In this review, we will summarize the molecular pathways and oncogenic consequences associated with mutIDH with a particular emphasis on glioma and AML, and systematically review the development and preclinical testing of mutIDH inhibitors. Existing clinical data in both hematologic and solid tumors will likewise be reviewed followed by a discussion on the potential limitations of mutIDH inhibitor monotherapy and potential routes for treatment optimization using combination therapy.

Can we predict responsiveness to hypomethylating agents in AML?

DNA-hypomethylating agents (HMAs) were developed as nonintensive treatment alternatives to standard chemotherapy in older, unfit patients with acute myeloid leukemia and myelodysplastic syndrome. Given their distinct effects on the methylome and transcriptome of malignant cells compared to cytarabine (Ara-C) and other cytotoxic drugs not inhibiting DNA methyltransferases, it is of great interest to define their specific clinical ``signature.'' Here, we present and discuss clinical, genetic, and epigenetic predictors of responsiveness to HMAs. Indeed, mounting evidence supports the notion that HMAs are not "just another kind of low-dose Ara-C." Not only patient factors (age, performance status, comorbidities, etc.), blast counts, and early platelet response, but also adverse genetics (monosomal karyotype and/or a TP53 mutation) have predictive potential. Given the surprising-and initially counterintuitive-responses observed in patients with the latter features, these are subject to mechanistic studies to elucidate their as yet unresolved interaction with HMAs. Finally, other potential biomarkers for HMA response such as elevated fetal hemoglobin might also contribute to overcome the present challenges in predicting responsiveness to HMAs.

Comprehensive Genomic Profiling Reveals Diverse but Actionable Molecular Portfolios across Hematologic Malignancies: Implications for Next Generation Clinical Trials

Background: The translation of genomic discoveries to the clinic is the cornerstone of precision medicine. However, incorporating next generation sequencing (NGS) of hematologic malignancies into clinical management remains limited. Methods: We describe 235 patients who underwent integrated NGS profiling (406 genes) and analyze the alterations and their potential actionability. Results: Overall, 227 patients (96.5%) had adequate tissue. Most common diagnoses included myelodysplastic syndrome (22.9%), chronic lymphocytic leukemia (17.2%), non-Hodgkin lymphoma (13.2%), acute myeloid leukemia (11%), myeloproliferative neoplasm (9.2%), acute lymphoblastic leukemia (8.8%), and multiple myeloma (7.5%). Most patients (N = 197/227 (87%)) harbored ≥1 genomic alteration(s); 170/227 (75%), ≥1 potentially actionable alteration(s) targetable by an FDA-approved (mostly off-label) or an investigational agent. Altogether, 546 distinct alterations were seen, most commonly involving TP53 (10.8%), TET2 (4.6%), and DNMT3A (4.2%). The median tumor mutational burden (TMB) was low (1.7 alterations/megabase); 12% of patients had intermediate or high TMB (higher TMB correlates with favorable response to anti-PD1/PDL1 inhibition in solid tumors). In conclusion, 96.5% of patients with hematologic malignancies have adequate tissue for comprehensive genomic profiling. Most patients had unique molecular signatures, and 75% had alterations that may be pharmacologically tractable with gene- or immune-targeted agents.

Multiple Ways to Detect IDH2 Mutations in Angioimmunoblastic T-Cell Lymphoma from Immunohistochemistry to Next-Generation Sequencing

Angioimmunoblastic T-cell lymphoma (AITL) is a peripheral T-cell lymphoma associated with chemoresistance and a poor prognosis. Various nonsynonymous mutations in the R172 residue of IDH2 are present in 20% to 30% of AITL patients. In addition to their diagnostic value, these mutations are potentially targetable, especially by isocitrate dehydrogenase (IDH) 2 inhibitor, and therefore their identification in a routine setting is clinically relevant. However, in AITL, the neoplastic cells may be scarce, making the identification of molecular anomalies difficult. We evaluated the diagnostic value of different methods to detect IDH2 mutations in formalin-fixed, paraffin-embedded tumor samples. Immunohistochemistry with an anti-IDH2 R172K antibody, Sanger sequencing, high-resolution melting PCR, allele-specific real-time quantitative PCR, and next-generation sequencing (NGS) were applied to biopsy specimens from 42 AITL patients. We demonstrate that the IDH2 R172K antibody is specific to this amino acid substitution and highly sensitive for the detection of the IDH2^R172K variant, the most frequent substitution in this disease. In our study, NGS and allele-specific real-time quantitative PCR displayed a good sensitivity, detecting 96% and 92% of IDH2 mutations, respectively, in contrast to Sanger sequencing and high-resolution melting PCR, which showed a significantly lower detection rate (58% and 42%, respectively). These results suggest that a combination of immunohistochemistry and AS-PCR or NGS should be considered for the identification of IDH2 mutations in AITL in a routine setting.

Genomics of Peritoneal Malignancies

The peritoneum protects the intraabdominal organs. This function is exploited by aggressive cancers originating from organs within the abdomen, resulting in peritoneal metastasis. We discuss genomic variants that may lead to peritoneal metastasis from multiple cancers. Peritoneal malignancies are attributed to epithelial-mesenchymal transition. These metastatic lesions harbor similar genetic mutations to the primary tumor yet may manifest clone-specific aberrations that promote propagation. Peritoneal metastasis are increasingly being treated with surgical resection as an adjunct to radiation, chemotherapy, and other biologic therapies. We describe genetic and genomic variances that are predictive markers for metastasis and burgeoning indicators for peritoneal malignancies.

RNA N6-methyladenosine modification in cancers: current status and perspectives

N6-methyladenosine (m6A), the most abundant internal modification in eukaryotic messenger RNAs (mRNAs), has been shown to play critical roles in various normal bioprocesses such as tissue development, stem cell self-renewal and differentiation, heat shock or DNA damage response, and maternal-to-zygotic transition. The m6A modification is deposited by the m6A methyltransferase complex (MTC; i.e., writer) composed of METTL3, METTL14 and WTAP, and probably also VIRMA and RBM15, and can be removed by m6A demethylases (i.e., erasers) such as FTO and ALKBH5. The fates of m6A-modified mRNAs rely on the functions of distinct proteins that recognize them (i.e., readers), which may affect the stability, splicing, and/or translation of target mRNAs. Given the functional importance of the m6A modification machinery in normal bioprocesses, it is not surprising that evidence is emerging that dysregulation of m6A modification and the associated proteins also contributes to the initiation, progression, and drug response of cancers. In this review, we focus on recent advances in the study of biological functions and the underlying molecular mechanisms of dysregulated m6A modification and the associated machinery in the pathogenesis and drug response of various types of cancers. In addition, we also discuss possible therapeutic interventions against the dysregulated m6A machinery to treat cancers.

The role of IDH mutations in acute myeloid leukemia

Isocitrate dehydrogenases (IDHs) are enzymes involved in multiple metabolic and epigenetic cellular processes. Mutations in IDH1 or IDH2 are detected in approximately 20% of patients with acute myeloid leukemia (AML) and induce amino acid changes in conserved residues resulting in neomorphic enzymatic function and production of an oncometabolite, 2-hydroxyglutarate (R-2-HG). This leads to DNA hypermethylation, aberrant gene expression, cell proliferation and abnormal differentiation. IDH mutations diversely affect prognosis of patients with AML based on the location of the mutation and other co-occurring genomic abnormalities. Recently, novel therapies specifically targeting mutant IDH have opened new avenues of therapy for these patients. In the present review, we will provide an overview of the biological, clinical and therapeutic implications of IDH mutations in AML.

Azacitidine in Lower-Risk Myelodysplastic Syndromes: A Meta-Analysis of Data from Prospective Studies

BACKGROUND

After erythropoiesis-stimulating agent (ESA) failure, lenalidomide and hypomethylating agents are the only remaining treatment options for most patients with lower-risk myelodysplastic syndromes (LR-MDS). Optimal choice of these agents as front-line therapy in non-del(5q) LR-MDS is unclear. Because azacitidine clinical data mainly describe experience in higher-risk MDS, we performed a meta-analysis of patient-level data to evaluate azacitidine in patients with red blood cell (RBC) transfusion-dependent LR-MDS.

MATERIALS AND METHODS

We searched English-language articles for prospective phase II and III azacitidine clinical trials and patient registries published between 2000 and 2015, and Embase abstracts from 2015 conferences. Patient-level data from identified relevant studies were provided by investigators. Meta-analyses followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Efficacy endpoints were RBC transfusion independence (TI) and Clinical Benefit (RBC-TI, erythroid response, and complete or partial remission, per International Working Group 2006 criteria for MDS).

RESULTS

Data for 233 patients from 6 clinical studies and 1 registry study met criteria for inclusion in analyses. Overall, 90.3% of patients had non-del(5q) LR-MDS. Pooled estimates from random-effects models of RBC-TI and Clinical Benefit were 38.9% and 81.1%, respectively; for the ESA-refractory subgroup, they were 40.5% and 77.3%; and for patients with isolated anemia, they were 41.9% and 82.5%. In multivariate analyses, planned use of ≥6 azacitidine treatment cycles was significantly predictive of response.

CONCLUSION

Azacitidine effects in these patients, most with non-del(5q) LR-MDS, were promising and generally similar to those reported for lenalidomide in similar patients. The choice of initial therapy is important because most patients eventually stop responding to front-line therapy and alternatives are limited.

IMPLICATIONS FOR PRACTICE

Lower-risk myelodysplastic syndromes (LR-MDS) are primarily characterized by anemia. After erythropoiesis-stimulating agent (ESA) failure, lenalidomide and hypomethylating agents are the only remaining treatment options for most patients. This meta-analysis of 233 azacitidine-treated red blood cell (RBC) transfusion-dependent patients with LR-MDS (92.3% non-del[5q]) from 7 studies showed 38.9% became RBC transfusion-independent. There is no clear guidance regarding the optimal choice of lenalidomide or hypomethylating agents for patients with non-del(5q) LR-MDS following ESA failure. Clinical presentation (e.g., number of cytopenias) and potential outcomes after hypomethylating agent failure are factors to consider when making initial treatment decisions for LR-MDS patients.

R-2HG Exhibits Anti-tumor Activity by Targeting FTO/m6A/MYC/CEBPA Signaling

R-2-hydroxyglutarate (R-2HG), produced at high levels by mutant isocitrate dehydrogenase 1/2 (IDH1/2) enzymes, was reported as an oncometabolite. We show here that R-2HG also exerts a broad anti-leukemic activity in vitro and in vivo by inhibiting leukemia cell proliferation/viability and by promoting cell-cycle arrest and apoptosis. Mechanistically, R-2HG inhibits fat mass and obesity-associated protein (FTO) activity, thereby increasing global N⁶-methyladenosine (m⁶A) RNA modification in R-2HG-sensitive leukemia cells, which in turn decreases the stability of MYC/CEBPA transcripts, leading to the suppression of relevant pathways. Ectopically expressed mutant IDH1 and S-2HG recapitulate the effects of R-2HG. High levels of FTO sensitize leukemic cells to R-2HG, whereas hyperactivation of MYC signaling confers resistance that can be reversed by the inhibition of MYC signaling. R-2HG also displays anti-tumor activity in glioma. Collectively, while R-2HG accumulated in IDH1/2 mutant cancers contributes to cancer initiation, our work demonstrates anti-tumor effects of 2HG in inhibiting proliferation/survival of FTO-high cancer cells via targeting FTO/m⁶A/MYC/CEBPA signaling.

Hypomethylating Agents as a Therapy for AML

Acute myeloid leukemia (AML) is predominantly a disease of older adults associated with poor long-term outcomes with available therapies. Used as single agents, hypomethylating agents (HMAs) induce only 15 to 25% complete remissions, but current data suggest that median OS observed after HMAs is comparable to that observed after more intensive therapies. Whether long-term cure may be obtained in some patients treated with HMAs is unknown. Combinations of HMAs to novel agents are now extensively investigated and attractive response rates have been reported when combining HMAs to different drug classes. The absence of reliable predictive biomarkers of efficacy of HMAs in AML and the uncertainties regarding their most relevant mechanisms of action hinder the rational design of the combinations to be tested in priority, usually in untreated older AML patients.

Altered Metabolism of Leukemic Cells: New Therapeutic Opportunity

The cancer metabolic program alters bioenergetic processes to meet the higher demands of tumor cells for biomass production, nucleotide synthesis, and NADPH-balancing redox homeostasis. It is widely accepted that cancer cells mostly utilize glycolysis, as opposed to normal cells, in which oxidative phosphorylation is the most employed bioenergetic process. Still, studies examining cancer metabolism had been overlooked for many decades, and it was only recently discovered that metabolic alterations affect both the oncogenic potential and therapeutic response. Since most of the published works concern solid tumors, in this comprehensive review, we aim to summarize knowledge about the metabolism of leukemia cells. Leukemia is a malignant disease that ranks first and fifth in cancer-related deaths in children and adults, respectively. Current treatment has reached its limits due to toxicity, and there has been a need for new therapeutic approaches. One of the possible scenarios is improved use of established drugs and another is to introduce new druggable targets. Herein, we aim to describe the complexity of leukemia metabolism and highlight cellular processes that could be targeted therapeutically and enhance the effectiveness of current treatments.

Wilms tumor 1 mutations in the pathogenesis of acute myeloid leukemia

Wilms tumor 1 (WT1) has long been implicated in acute myeloid leukemia. It has been described to be both overexpressed and mutated in different forms of acute myeloid leukemia, and overexpression has been reported to play a prognostic role in this disease. However, the precise mechanism through which WT1 may play a role in leukemogenesis has remained elusive. In recent years, new evidence has emerged that points towards a novel role of WT1 mutations in the deregulation of epigenetic programs in leukemic cells through its interaction with TET proteins. Herein we review the current status of the field and its therapeutic and prognostic implications in acute myeloid leukemia.

Comprehensive genomic profiling of different subtypes of nasopharyngeal carcinoma reveals similarities and differences to guide targeted therapy

BACKGROUND

To date, no targeted therapy has been approved for nasopharyngeal carcinoma (NPC), and this underscores the need for an in-depth understanding of clinically relevant genomic alterations (CRGAs).

METHODS

Comprehensive genomic profiling was performed for 190 NPC patients, including 20 patients with nasopharyngeal adenocarcinoma (NPAC), 62 patients with nasopharyngeal squamous cell carcinoma (NPSCC), and 108 patients with nasopharyngeal undifferentiated carcinoma (NPUC). The associations of genes and pathways with subtypes, Epstein-Barr virus (EBV) infections, and the tumor mutation burden (TMB) were statistically evaluated.

RESULTS

Although the overall rates of genomic alterations were similar, the 3 NPC subtypes exhibited different mutational landscapes. Notably, mutations in a proven-treatable target gene, isocitrate dehydrogenase 2 (IDH2), were significantly associated with NPUC but not with NPAC or NPSCC. The top 5 ranked CRGAs included CDKN2A (29%), IDH2 (16%), SMARCB1 (7%), PIK3CA (6%), and NF1 (5%) in NPUC; CDKN2A (27%), PIK3CA (23%), FBXW7 (11%), PTEN (11%), and EGFR (8%) in NPSCC; and CDKN2A (20%), KRAS (15%), CCND1 (10%), MAP3K1 (10%), and NOTCH1 (10%) in NPAC. The incidence of EBV infections significantly correlated with the subtypes and with TP53, CDKN2A, and CDKN2B. The TMB status correlated with the subtypes and with LRP1B, FBXW7, and PIK3CA mutations as well as DNA repair, phosphoinositide 3-kinase/mammalian target of rapamycin, and mitogen-activated protein kinase pathways.

CONCLUSIONS

These results indicate that different NPC subtypes harbor different CRGAs. Both EBV infections and the TMB are associated with the NPC subtypes as well as the alterations of individual genes and pathways. The high frequency of IDH2 mutations in NPUC may facilitate potential targeted therapy and will ultimately point to new therapeutic strategies. Cancer 2017;123:3628-37. © 2017 American Cancer Society.

Azacitidine in adult patients with acute myeloid leukemia

Azacitidine is recommended front-line treatment for older patients with acute myeloid leukemia (AML) who are not candidates for intensive treatment regimens, and was recently granted approval in the European Union for treatment of adult AML. Reviewed here is azacitidine experience in AML, including: mechanistic and pharmacokinetic data; safety and efficacy in controlled trials; treatment effects in AML subpopulations defined by disease characteristics; experience in unselected patients treated in the community setting; clinical outcomes relative to other approved AML therapies; and experience with azacitidine-based combination treatment regimens. Collectively, these data suggest that (a) azacitidine may prolong overall survival to a similar or greater extent than do other approved AML treatments, but with less toxicity, (b) azacitidine may be the preferred treatment option for older patients with unfavorable cytogenetics, and (c) experience and outcomes with azacitidine in the clinic are similar to those seen in clinical trials. Continued investigation of combination regimens on an azacitidine backbone is warranted.

Next Generation Sequencing Reveals Potentially Actionable Alterations in the Majority of Patients with Lymphoid Malignancies

Next generation sequencing (NGS) identifies alterations that may be potentially targetable by Food and Drug Administration (FDA) approved drugs and/or by available experimental agents that may not have otherwise been contemplated. Many targeted drugs have been developed for diverse solid cancers; a smaller number of genomically targeted drugs have been approved for lymphoid malignancies. We analyzed NGS results from 60 patients with various lymphoid malignancies and found a total of 224 alterations (median per patient = 3). Forty-nine patients (82%) had potentially actionable alterations using FDA-approved drugs and/or experimental therapies; only 11 patients (18%) had no theoretically actionable alterations. Only three patients (5%) had an alteration for which an approved drug in the disease is available (on-label); 45 patients (75%) had an alteration for which an approved drug is available in another disease (off-label). The median number of alterations per patient potentially actionable by an FDA-approved drug was 1. Interestingly, 19 of 60 patients (32%) had intermediate to high tumor mutational burden, which may predict response to certain immunotherapy agents. In conclusion, NGS identifies alterations that may be pharmacologically tractable in most patients with lymphoid malignancies, albeit with drugs that have usually been developed in the context of solid tumors. These observations merit expanded exploration in the clinical trials setting.

Clinical implications of genome-wide DNA methylation studies in acute myeloid leukemia

Acute myeloid leukemia (AML) is the most common type of acute leukemia in adults. AML is a heterogeneous malignancy characterized by distinct genetic and epigenetic abnormalities. Recent genome-wide DNA methylation studies have highlighted an important role of dysregulated methylation signature in AML from biological and clinical standpoint. In this review, we will outline the recent advances in the methylome study of AML and overview the impacts of DNA methylation on AML diagnosis, treatment, and prognosis.

A targeted next-generation sequencing in the molecular risk stratification of adult acute myeloid leukemia: implications for clinical practice

Conventional cytogenetics can categorize patients with acute myeloid leukemia (AML) into favorable, intermediate, and unfavorable-risk groups; however, patients with intermediate-risk cytogenetics represent the major population with variable outcomes. Because molecular profiling can assist with AML prognosis and next-generation sequencing allows simultaneous sequencing of many target genes, we analyzed 260 genes in 112 patients with de novo AML who received standard treatment. Multivariate analysis showed that karyotypes and mutation status of TET2, PHF6, KIT, and NPM1^mutation /FLT3- internal tandem duplication (ITD)^negative were independent prognostic factors for the entire cohort. Among patients with intermediate-risk cytogenetics, patients with mutations in CEBPA^{double mutation} , IDH2, and NPM1 in the absence of FLT3-ITD were associated with improved Overall survival (OS), similar to those with favorable-risk cytogenetics; patients with mutations in TET2, RUNX1, ASXL1, and DNMT3A were associated with reduced OS, similar to those with unfavorable-risk cytogenetics. We concluded that integration of cytogenetic and molecular profiling improves prognostic stratification of patients into three groups with more distinct prognoses (P < 0.001) and significantly reduces the number of patients classified as intermediate risk. In addition, our study demonstrates that next-generation sequencing (NGS)-based multi-gene sequencing is clinically applicable in establishing an accurate risk stratification system for guiding therapeutic decisions.