A phase II trial of ruxolitinib in combination with azacytidine in myelodysplastic syndrome/myeloproliferative neoplasms

Chronic neutrophilic leukemia and atypical chronic myeloid leukemia: 2024 update on diagnosis, genetics, risk stratification, and management

Chronic neutrophilic leukemia (CNL) is a rare BCR::ABL1-negative myeloproliferative neoplasm (MPN) defined by persistent mature neutrophilic leukocytosis and bone marrow granulocyte hyperplasia. Atypical chronic myeloid leukemia (aCML) (myelodysplastic "[MDS]/MPN with neutrophilia" per World Health Organization [WHO]) is a MDS/MPN overlap disorder featuring dysplastic neutrophilia and circulating myeloid precursors. Both manifest with frequent hepatosplenomegaly and less commonly, bleeding, with high rates of leukemic transformation and death. The 2022 revised WHO classification conserved CNL diagnostic criteria of leukocytosis ≥25 × 109/L, neutrophils ≥80% with <10% circulating precursors, absence of dysplasia, and presence of an activating CSF3R mutation. ICC criteria are harmonized with those of other myeloid entities, with a key distinction being lower leukocytosis threshold (≥13 × 109/L) for cases CSF3R-mutated. Criteria for aCML include leukocytosis ≥13 × 109/L, dysgranulopoiesis, circulating myeloid precursors ≥10%, and at least one cytopenia for MDS-thresholds (ICC). In both classifications ASXL1 and SETBP1 (ICC), or SETBP1 ± ETNK1 (WHO) mutations can be used to support the diagnosis. Both diseases show hypercellular bone marrow due to a granulocytic proliferation, aCML distinguished by dysplasia in granulocytes ± other lineages. Absence of monocytosis, rare/no basophilia, or eosinophilia, <20% blasts, and exclusion of other MPN, MDS/MPN, and tyrosine kinase fusions, are mandated. Cytogenetic abnormalities are identified in ~1/3 of CNL and ~15-40% of aCML patients. The molecular signature of CNL is a driver mutation in colony-stimulating factor 3 receptor-classically T618I, documented in >80% of cases. Atypical CML harbors a complex genomic backdrop with high rates of recurrent somatic mutations in ASXL1, SETBP1, TET2, SRSF2, EZH2, and less frequently in ETNK1. Leukemic transformation rates are ~10-25% and 30-40% for CNL and aCML, respectively. Overall survival is poor: 15-31 months in CNL and 12-20 months in aCML. The Mayo Clinic CNL risk model for survival stratifies patients according to platelets <160 × 109/L (2 points), leukocytes >60 × 109/L (1 point), and ASXL1 mutation (1 point); distinguishing low- (0-1 points) versus high-risk (2-4 points) categories. The Mayo Clinic aCML risk model attributes 1 point each for: age >67 years, hemoglobin <10 g/dL, and TET2 mutation, delineating low- (0-1 risk factor) and high-risk (≥2 risk factors) subgroups. Management is risk-driven and symptom-directed, with no current standard of care. Most commonly used agents include hydroxyurea, interferon, Janus kinase inhibitors, and hypomethylating agents, though none are disease-modifying. Hematopoietic stem cell transplant is the only potentially curative modality and should be considered in eligible patients. Recent genetic profiling has disclosed CBL, CEBPA, EZH2, NRAS, TET2, and U2AF1 to represent high-risk mutations in both entities. Actionable mutations (NRAS/KRAS, ETNK1) have also been identified, supporting novel agents targeting involved pathways. Preclinical and clinical studies evaluating new drugs (e.g., fedratinib, phase 2) and combinations are detailed.

Management of adult patients with CMML undergoing allo-HCT: recommendations from the EBMT PH&G Committee

ABSTRACT

Chronic myelomonocytic leukemia (CMML) is a heterogeneous disease presenting with either myeloproliferative or myelodysplastic features. Allogeneic hematopoietic cell transplantation (allo-HCT) remains the only potentially curative option, but the inherent toxicity of this procedure makes the decision to proceed to allo-HCT challenging, particularly because patients with CMML are mostly older and comorbid. Therefore, the decision between a nonintensive treatment approach and allo-HCT represents a delicate balance, especially because prospective randomized studies are lacking and retrospective data in the literature are conflicting. International consensus on the selection of patients and the ideal timing of allo-HCT, specifically in CMML, could not be reached in international recommendations published 6 years ago. Since then, new, CMML-specific data have been published. The European Society for Blood and Marrow Transplantation (EBMT) Practice Harmonization and Guidelines (PH&G) Committee assembled a panel of experts in the field to provide the first best practice recommendations on the role of allo-HCT specifically in CMML. Recommendations were based on the results of an international survey, a comprehensive review of the literature, and expert opinions on the subject, after structured discussion and circulation of recommendations. Algorithms for patient selection, timing of allo-HCT during the course of the disease, pretransplant strategies, allo-HCT modality, as well as posttransplant management for patients with CMML were outlined. The keynote message is, that once a patient has been identified as a transplant candidate, upfront transplantation without prior disease-modifying treatment is preferred to maximize chances of reaching allo-HCT whenever possible, irrespective of bone marrow blast counts.

VEXAS and Myelodysplastic Syndrome: An Interdisciplinary Challenge

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is a recently recognized systemic autoinflammatory disease caused by somatic mutations in hematopoietic progenitor cells. This case series of four patients with VEXAS syndrome and comorbid myelodysplastic syndrome (MDS) aims to describe clinical, imaging, and hematologic disease presentations as well as response to therapy. Four patients with VEXAS syndrome and MDS are described. A detailed analysis of imaging features, hemato-oncological presentation including bone marrow microscopy and clinical-rheumatological disease features and treatment outcomes is given. All patients were male; ages ranged between 64 and 81 years; all were diagnosed with MDS. CT imaging was available for three patients, all of whom exhibited pulmonary infiltrates of varying severity, resembling COVID-19 or hypersensitivity pneumonitis without traces of scarring. Bone marrow microscopy showed maturation-disordered erythropoiesis and pathognomonic vacuolation. Somatic mutation in the UBA1 codon 41 were found in all patients by next-generation sequencing. Therapy regimes included glucocorticoids, JAK1/2-inhibitors, nucleoside analogues, as well as IL-1 and IL-6 receptor antagonists. No fatalities occurred (observation period from symptom onset: 18-68 months). Given the potential underreporting of VEXAS syndrome, we highly recommend contemporary screening for UBA1 mutations in patients presenting with ambiguous signs of systemic autoinflammatory symptoms which persist over 18 months despite treatment. The emergence of cytopenia, especially macrocytic hyperchromic anemia, should prompt early testing for UBA1 mutations. Notably conspicuous, pulmonary alterations in CT imaging of patients with therapy-resistant systemic autoinflammatory symptoms should be discussed in interdisciplinary medical teams (Rheumatology, Hematology, Radiology and further specialist departments) to facilitate timely diagnosis during the clinical course of the disease.

Case report: Safety and efficacy of synergistic treatment using selinexor and azacitidine in patients with atypical chronic myeloid leukemia with resistance to decitabine

Background

Atypical chronic myeloid leukemia (aCML) is a BCR::ABL1 negative myelodysplastic/myeloproliferative neoplasm with poor overall survival. Some patients can be treated by allogeneic hematopoietic stem cell transplantation (allo-HSCT) from suitable donors. The effectiveness of decitabine or azacitidine (AZA) has recently been reported; however, their combined efficacy with selinexor has not yet been reported.

Case description

In this study, we report the case of a patient with aCML who was successfully treated with selinexor combined with AZA. A 67-year-old man with a history of gastric mucosa-associated lymphoid tissue (MALT) lymphoma was admitted to the hospital with fatigue and emaciation. He was diagnosed with aCML and no longer responded to decitabine treatment after undergoing seven cycles. The patient was subsequently administered hydroxyurea (HU), selinexor, and AZA. After four courses of combination therapy, his blood cell counts improved; he no longer required transfusions and was able to discontinue HU. The patient continued receiving selinexor and AZA without severe complications. This case is the first to show that combinatorial selinexor and AZA therapy can effectively treat aCML.

Conclusion

Our case sheds light on the importance of selinexor and AZA combined therapy in the exploration of new treatment strategies for aCML. Moreover, this treatment approach offers the possibility of bridging with allo-HSCT.

Phase to phase: Navigating drug combinations with hypomethylating agents in higher-risk MDS trials for optimal outcomes

Recent developments in high-risk Myelodysplastic Neoplasms (HR MDS) treatment are confronted with challenges in study design due to evolving drug combinations with Hypomethylating Agents (HMAs). The shift from the International Prognostic Scoring System (IPSS) to its molecular revision (IPSS-M) has notably influenced research and clinical practice. Introducing concepts like the MDS/AML overlap complicate classifications and including chronic myelomonocytic leukemia (CMML) in MDS studies introduces another layer of complexity. The International Consortium for MDS emphasizes aligning HR MDS criteria with the 2022 ELN criteria for AML. Differences in advancements between AML and MDS treatments and hematological toxicity in HR MDS underline the importance of detailed trial designs. Effective therapeutic strategies require accurate reporting of adverse events, highlighting the need for clarity in criteria like the Common Terminology Criteria for Adverse Events (CTCAE). We provide an overview on negative clinical trials in HR MDS, analyze possible reasons and explore possibilities to optimize future clinical trials in this challenging patient population.

Proposals for Clinical Trials in Chronic Myelomonocytic Leukemia

OPINION STATEMENT

Chronic myelomonocytic leukemia (CMML) is a clonal hematologic malignancy of mostly older individuals that exhibits both myelodysplastic and myeloproliferative features. CMML presentation and outcome are variable, reflecting genetic and clinical heterogeneity. Hypomethylating agents are the mainstay of therapy but induce complete remissions in less than 20% of patients and do not prolong survival compared to hydroxyurea. Allogeneic stem cell transplant (ASCT) is potentially curative, but few patients qualify due to advanced age and/or comorbidities. Work of the past several years has identified key molecular pathways that drive disease proliferation and transformation to acute leukemia, including JAK/STAT and MAPK signaling and epigenetic dysregulation. There is increasingly compelling evidence that inflammation is a major driver of CMML progression. Thus far however, this mechanistic knowledge has not yet been translated into improved outcomes, suggesting that fundamentally new approaches are required. In this review, we discuss the disease course, new classifications, and current treatment landscape of CMML. We review ongoing clinical studies and discuss options for rationally based future clinical trials.

Novel treatment strategy of targeting epigenetic dysregulation in pancreatic neuroendocrine tumors

BACKGROUND

Epigenetic dysregulation is an integral step in the progression of pancreatic neuroendocrine tumors. We hypothesized that tumor suppressor repression by DNA methyltransferase 1 in pancreatic neuroendocrine tumors could be targeted with epigenetic treatment.

METHODS

Resected pancreatic neuroendocrine tumors from 32 patients were stained for DNA methyltransferase 1 and scored. Human (BON1) and murine (STC) pancreatic neuroendocrine tumor cells were treated with DNA methyltransferase 1 inhibitor 5-azacytidine and chemotherapeutic agents 5-fluorouracil and temozolomide. Cell proliferation assay and tumor suppressor gene analysis were performed with qRT-PCR and Clarion S microarray. Tumor measurements were compared in a murine treatment model.

RESULTS

High DNA methyltransferase scores were associated with high Ki-67 (6.7% vs 70.6% P < .01), mitotic rate (0.0% vs 31.3%), and grade (20.0% vs 80.4%, P < .01). Treatment with 5-azacytidine and chemotherapy resulted in a reduction of cell proliferation compared to chemotherapy alone in BON1 (77.3% vs 53.1%, P < .001) and STC (73.4% vs 34.2%, P < .001). Treatment with 5-azacytidine and chemotherapy resulted in upregulation of tumor suppressors CDKN1A (7.6 rel. fold, P < .001), BRCA2 (4.3 rel. fold, P < .001), and CDH1 (6.0 rel. fold, P = .026) in BON1 and CDKN1a (14.5 rel. fold, P < .001) and CDH (17.5 rel. fold, P < .001) in STC. In microarray, 5-azacytidine drove global genetic changes in combination treatment. In vivo tumors treated with chemotherapy measured 88.6 ± 19.54 mm³ vs 52.89 ± 10.51 mm³ in those treated with combination therapy (P = .009).

CONCLUSION

Epigenetic dysregulation with DNA methyltransferase 1 is associated with pancreatic neuroendocrine tumors and is a potential targetable strategy. 5-azacytidine and chemotherapy in combination can reduce cell proliferation, upregulate silenced tumor suppressor genes, and decrease in vivo tumors in pancreatic neuroendocrine tumors.

Molecular genetics and management of world health organization defined atypical chronic myeloid leukemia

Atypical chronic myeloid leukemia (CML) is a rare BCR::ABL1-negative hematopoietic stem cell disease characterized by granulocytic proliferation and granulocytic dysplasia. Due to both the challenging diagnosis and the rarity of atypical CML, comprehensive molecular annotation-based analyses of this disease population have been scarce, and it is currently difficult to identify the optimal treatment for atypical CML. To explore atypical CML genomic landscape and treatment options, we performed a systematic retrospective of the clinical data and outcomes of 31 atypical CML patients. We observed that the molecular landscape of atypical CML was highly heterogeneous, with multiple molecular events driving its pathogenesis. Patients with atypical CML had a low response to current therapies, with an overall response rate (ORR) of 33.3% to hypomethylating agent (HMA)-based therapy. The current treatment strategies, including hematopoietic stem cell transplantation (HSCT), did not improve overall survival (OS) in atypical CML patients, with a median survival of 20 months. Thus, the benefits from HSCT and candidates for HSCT remain to be further evaluated. Acute myeloid leukemia (AML)-like chemotherapy followed by bridging allogeneic HSCT may be an ideal regimen for suitable individuals. The large-scale and prospective clinical studies will help to address the dilemma.

Recombinant Interferon-β in the Treatment of Polycythemia Vera and Related Neoplasms: Rationales and Perspectives

About 30 years ago, the first clinical trials of the safety and efficacy of recombinant interferon-α2 (rIFN-α2) were performed. Since then, several single-arm studies have shown rIFN-α2 to be a highly potent anticancer agent against several cancer types. Unfortunately, however, a high toxicity profile in early studies with rIFN-α2 -among other reasons likely due to the high dosages being used-disqualified rIFN-α2, which was accordingly replaced with competitive drugs that might at first glance look more attractive to clinicians. Later, pegylated IFN-α2a (Pegasys) and pegylated IFN-α2b (PegIntron) were introduced, which have since been reported to be better tolerated due to reduced toxicity. Today, treatment with rIFN-α2 is virtually outdated in non-hematological cancers, where other immunotherapies-e.g., immune-checkpoint inhibitors-are routinely used in several cancer types and are being intensively investigated in others, either as monotherapy or in combination with immunomodulatory agents, although only rarely in combination with rIFN-α2. Within the hematological malignancies, rIFN-α2 has been used off-label for decades in patients with Philadelphia-negative chronic myeloproliferative neoplasms (MPNs)-i.e., essential thrombocythemia, polycythemia vera, and myelofibrosis-and in recent years rIFN-α2 has been revived with the marketing of ropeginterferon-α2b (Besremi) for the treatment of polycythemia vera patients. Additionally, rIFN-α2 has been revived for the treatment of chronic myelogenous leukemia in combination with tyrosine kinase inhibitors. Another rIFN formulation-recombinant interferon-β (rIFN-β)-has been used for decades in the treatment of multiple sclerosis but has never been studied as a potential agent to be used in patients with MPNs, although several studies and reviews have repeatedly described rIFN-β as an effective anticancer agent as well. In this paper, we describe the rationales and perspectives for launching studies on the safety and efficacy of rIFN-β in patients with MPNs.

The ABNL-MARRO 001 study: a phase 1–2 study of randomly allocated active myeloid target compound combinations in MDS/MPN overlap syndromes

Background

Myelodysplastic/myeloproliferative neoplasms (MDS/MPN) comprise several rare hematologic malignancies with shared concomitant dysplastic and proliferative clinicopathologic features of bone marrow failure and propensity of acute leukemic transformation, and have significant impact on patient quality of life. The only approved disease-modifying therapies for any of the MDS/MPN are DNA methyltransferase inhibitors (DNMTi) for patients with dysplastic CMML, and still, outcomes are generally poor, making this an important area of unmet clinical need. Due to both the rarity and the heterogeneous nature of MDS/MPN, they have been challenging to study in dedicated prospective studies. Thus, refining first-line treatment strategies has been difficult, and optimal salvage treatments following DNMTi failure have also not been rigorously studied. ABNL-MARRO (A Basket study of Novel therapy for untreated MDS/MPN and Relapsed/Refractory Overlap Syndromes) is an international cooperation that leverages the expertise of the MDS/MPN International Working Group (IWG) and provides the framework for collaborative studies to advance treatment of MDS/MPN and to explore clinical and pathologic markers of disease severity, prognosis, and treatment response.

Methods

ABNL MARRO 001 (AM-001) is an open label, randomly allocated phase 1/2 study that will test novel treatment combinations in MDS/MPNs, beginning with the novel targeted agent itacitinib, a selective JAK1 inhibitor, combined with ASTX727, a fixed dose oral combination of the DNMTi decitabine and the cytidine deaminase inhibitor cedazuridine to improve decitabine bioavailability.

Discussion

Beyond the primary objectives of the study to evaluate the safety and efficacy of novel treatment combinations in MDS/MPN, the study will (i) Establish the ABNL MARRO infrastructure for future prospective studies, (ii) Forge innovative scientific research that will improve our understanding of pathogenetic mechanisms of disease, and (iii) Inform the clinical application of diagnostic criteria, risk stratification and prognostication tools, as well as response assessments in this heterogeneous patient population.

Trial registration

This trial was registered with ClinicalTrials.gov on August 19, 2019 (Registration No. NCT04061421).

Trametinib: Could It Be a Promising Drug to Treat Atypical Chronic Myeloid Leukemia?

Atypical chronic myeloid leukemia (aCML) is a rare disease that is currently classified under the myelodysplastic (MDS)/myeloproliferative neoplasm (MPN) disease spectrum. MDS/MPN diseases are characterized by the absence of the Philadelphia (Ph) chromosome and the overlap between bone marrow fibrosis and dysplastic features. The Ph chromosome, resulting from BCR-ABL1 translocation, helps to distinguish aCML from chronic myeloid leukemia (CML). The currently reported incidence of aCML is imprecise because aCML is diagnosed primarily based on morphological features and other unspecified laboratory findings, and there is an especially high chance of under-diagnosis of aCML and other MDS/MPN diseases. Recent advances in next-generation sequencing (NGS) have allowed a greater understanding of the nature of aCML, providing better opportunities to achieve higher diagnostic accuracy and for the use of more targeted treatment to achieve better outcomes. Herein, we present a case of a 68-year-old woman who came to our hospital complaining of shortness of breath, fatigue, and weakness, who was found to have significantly increased leukocytosis, hepatosplenomegaly, and was negative for the Ph chromosome. Further investigations with NGS revealed mutations in ASXL1, GATA2, NRAS, and SRSF2 but not CSF3R. In addition to this, peripheral smear and bone marrow aspiration findings were suggestive of aCML based on specific morphological findings. Since the patient was ineligible for a stem cell transplant (SCT), symptomatic treatment was started with cell transfusion; however, the patient continued to have symptomatic anemia that required multiple transfusions. A trial with trametinib, a mitogen-activated protein kinase kinase (MEK) inhibitor, was later started as a targeted therapy based on one of her genetic mutations. Interestingly, the patient’s blood counts stabilized, she reported feeling better, and she did not need any blood transfusions for four consecutive months during treatment with trametinib. Unfortunately, our patient later died from sepsis resulting from secondary infections. In light of the significant advancements in NGS, clinicians should always consider utilizing it as a helpful tool to not only establish a rare diagnosis of aCML but also to offer the best available targeted therapy when applicable. This might alleviate the burden associated with the poor prognosis of aCML.

A Phase 1/2 Study of the Oral Janus Kinase 1 Inhibitors INCB052793 and Itacitinib Alone or in Combination With Standard Therapies for Advanced Hematologic Malignancies

BACKGROUND

The Janus kinase (JAK)/signal transducers and activators of transcription pathway has been implicated in the pathogenesis and progression of various hematologic malignancies. JAK1-regulated cytokines stimulate proliferation and growth of malignant cells and resistance to certain therapies.

PATIENTS AND METHODS

This phase 1/2 study evaluated 2 oral, novel JAK1 inhibitors (INCB052793 and itacitinib) in advanced hematologic malignancies. Phase 1a assessed dose escalation and expansion of INCB052793 monotherapy. Phase 1b evaluated INCB052793 plus standard therapy in relapsed/refractory multiple myeloma, acute myeloid leukemia (AML), or myelodysplastic syndrome (MDS). Phase 2 evaluated INCB052793 or itacitinib plus azacitidine in DNA methyltransferase inhibitor (DNMTi)-refractory AML or MDS. Primary endpoints included safety and tolerability for phase 1, and objective response rate for phase 2.

RESULTS

Fifty-eight patients were enrolled, all received study treatment and discontinued either treatment or participation in the study. The most common reasons for treatment discontinuation were progressive disease (35.4% and 50.0%) and adverse events (22.9% and 20.0%) for INCB052793 and itacitinib plus azacitidine, respectively. In phase 1, 12 of 39 patients (31%) achieved an objective response; 35 mg once daily was selected as the phase 2 dose. Two patients with DNMTi-refractory disease had an objective response in phase 2. The study was terminated for lack of efficacy.

CONCLUSION

Inhibition of JAK1 with INCB052793 (monotherapy or combination therapy) or itacitinib plus azacitidine did not demonstrate clinically meaningful responses in these patients with hematopoietic malignancies.

Atypical Chronic Myeloid Leukemia: New Developments from Molecular Diagnosis to Treatment

Atypical Chronic Myeloid Leukemia, BCR-ABL1 negative (aCML) is a rare hematological entity, included in the group of myelodysplastic (MDS)/myeloproliferative (MPN) overlap syndromes. It is characterized by an aggressive course, a high rate of acute myeloid leukemia (AML) transformation, and a dismal outcome. The clinical presentation includes splenomegaly and leukocytosis with neutrophilia and left-shifted granulocytosis accompanied by granulocytic dysplasia and sometimes multilineage dysplasia. In past years, the disease incidence was likely underestimated, as diagnosis was only based on morphological features. Recently, the improving knowledge in the molecular biology of MDS/MPN neoplasms has made it possible to distinguish aCML from other overlapping syndromes, basing on next generation sequencing. Among the most commonly mutated genes, several involve the Jak-STAT, MAPK, and ROCK signaling pathways, which could be actionable with targeted therapies that are already used in clinical practice, opening the way to tailored treatment in aCML. However, currently, there are few data available for small samples, and allogeneic transplant remains the only curative option for eligible patients.

Increasing recognition and emerging therapies argue for dedicated clinical trials in chronic myelomonocytic leukemia

Chronic myelomonocytic leukemia (CMML) is a clonal hematopoietic stem cell disorder with overlapping features of myelodysplastic syndromes (MDS) and myeloproliferative neoplasms (MPN). Median overall survival of this aggressive myeloid malignancy is only 2-3 years, with a 15-30% risk of acute leukemic transformation. The paucity of clinical trials specifically designed for CMML has made therapeutic management of CMML patients challenging. As a result, treatment paradigms for CMML patients are largely borrowed from MDS and MPN. The standard of care still relies on hydroxyurea, hypomethylating agents (HMA), and allogeneic stem cell transplantation, this latter option remaining the only potentially curative therapy. To date, approved drugs for CMML treatment are HMA, including azacitidine, decitabine, and more recently the oral combination of decitabine and cedazuridine. However, HMA treatment does not meaningfully alter the natural course of this disease. New treatment approaches for improving CMML-associated cytopenias or targeting the CMML malignant clone are emerging. More than 25 therapeutic agents are currently being evaluated in phase 1 or phase 2 clinical trials for CMML and other myeloid malignancies, often in combination with a HMA backbone. Several novel agents, such as sotatercept, ruxolitinib, lenzilumab, and tagraxofusp have shown promising clinical efficacy in CMML. Current evidence supports the idea that effective treatment in CMML will likely require combination therapy targeting multiple pathways, which emphasizes the need for additional new therapeutic options. This review focuses on recent therapeutic advances and innovative treatment strategies in CMML, including global and molecularly targeted approaches. We also discuss what may help to make progress in the design of rationally derived and disease-modifying therapies for CMML.

Pathogenic Mutations and Atypical Flow Cytometric Findings Characterize the Majority of Unclassifiable Myelodysplastic/Myeloproliferative Neoplasms

OBJECTIVES

Myelodysplastic/myeloproliferative neoplasms (MDS/MPN) are a group of rare and heterogeneous hematopoietic disorders that frequently present a diagnostic challenge. Here we present our institutional experience with next-generation sequencing (NGS), together with morphologic, flow cytometric, and cytogenetic evaluation, in the diagnosis of MDS/MPN, with particular emphasis on MDS/MPN unclassifiable (MPN-U).

METHODS

We evaluated the morphologic, flow cytometric, cytogenetic, and molecular characteristics of all MDS/MPN cases that underwent NGS at our institution between April 2016 and February 2019.

RESULTS

Thirty-seven cases of MDS/MPN were identified, including 14 cases of MDS/MPN-U. Ninety-seven percent harbored mutations and immunophenotypic aberrancies (36/37), while only 38% had cytogenetic abnormalities (12/32). The MDS/MPN-U group had the highest rate of myeloblast phenotypic abnormalities and had a high mutation rate of approximately 2.7 mutated genes per case, most commonly in JAK2, SRSF2, and ASXL1.

CONCLUSIONS

No single ancillary study was abnormal in every case, but all cases had at least one abnormal finding, demonstrating the usefulness of a multiparameter approach to the diagnosis of MDS/MPN. Although a few specific mutations were found exclusively in MDS/MPN-U and JAK2 mutations were most prevalent, larger studies are needed to determine whether MDS/MPN-U has a mutational "fingerprint," which may aid in diagnosis and targeted therapy.

Development of a myelodysplastic/myeloproliferative neoplasm-unclassifiable in a patient with acute myeloid leukemia: a case report and literature review

Myelodysplastic/myeloproliferative neoplasms (MDS/MPNs) are a heterogeneous group of hematologic malignancies characterized by dysplastic and myeloproliferative overlapping features in the bone marrow and blood. The occurrence of the disease is related to age, prior history of MPN or MDS, and recent cytotoxic or growth factor therapy, but it rarely develops after acute myeloid leukemia (AML). We report a rare case of a patient diagnosed with AML with t(8; 21)(q22; q22) who received systematic chemotherapy. After 4 years of follow-up, MDS/MPN-unclassifiable occurred without signs of primary AML recurrence.

Chronic myelomonocytic leukemia diagnosis and management

Chronic myelomonocytic leukemia (CMML) is a rare, heterogeneous myeloid malignancy classified as a myelodysplastic syndromes/myeloproliferative neoplasm (MDS/MPN) overlap syndrome by the World Health Organization (WHO). Its initial presentation can be incidental or associated with myelodysplastic or myeloproliferative symptoms and up to 20% of patients harbor a concurrent inflammatory or autoimmune condition. Persistent monocytosis is the hallmark of CMML but diagnosis can be challenging. Increased understanding of human monocyte subsets, chromosomal abnormalities, and somatic gene mutations have led to more accurate diagnosis and improved prognostication. A number of risk stratification systems have been developed and validated but using those that incorporate molecular information such as CMML Prognostic Scoring System (CPSS)-Mol, Mayo Molecular, and Groupe Francophone des Myelodysplasies (GFM) are preferred. Symptom-directed approaches forms the basis of CMML management. Outcomes vary substantially depending on risk ranging from observation for a number of years to rapidly progressive disease and acute myeloid leukemia (AML) transformation. Patients who are low risk but with symptoms from cytopenias or proliferative features such as splenomegaly may be treated with hypomethylating agents (HMAs) or cytoreductive therapy, respectively, with the goal of durable symptoms control. Allogeneic hematopoietic cell transplantation should be considered for intermediate to high risk patients. The lack of effective pharmaceutical options has generated interest in novel therapeutics for this disease, and early phase clinical trial results are promising.

Contemporary Risk Stratification and Treatment of Chronic Myelomonocytic Leukemia

Chronic myelomonocytic leukemia (CMML) is a hematologic malignancy characterized by absolute monocytosis, one or more lineage dysplasia, and proliferative features including myeloid hyperplasia, splenomegaly, and constitutional symptoms. Because of vast clinical heterogeneity in presentation and course, risk stratification is used for a risk-adapted treatment strategy. Numerous prognostic scoring systems exist, some of which incorporate mutational information. Treatment ranges from observation to allogeneic hematopoietic stem cell transplantation. Therapies include hydroxyurea for cytoreduction, hypomethylating agents, and the JAK1/2 inhibitor ruxolitinib to address splenomegaly and constitutional symptoms. Recently, oral decitabine with cedazuridine was approved and represents a convenient treatment option for CMML patients. Although novel therapeutics are in development for CMML, further work is needed to elucidate possible targets unique to the CMML clone. In this review, we will detail the pathophysiology, risk stratification, available treatment modalities, and novel therapies for CMML, and propose a modern treatment algorithm. IMPLICATIONS FOR PRACTICE: Chronic myelomonocytic leukemia (CMML) is a clinically heterogenous disease, which poses significant management challenges. The diagnosis of CMML requires bone marrow biopsy and aspirate with thorough evaluation. Risk stratification and symptom assessment are essential to designing an effective treatment plan, which may include hypomethylating agents (HMAs) in intermediate or high-risk patients. The recently approved oral decitabine/cedazuridine provides a convenient alternative to parenteral HMAs. Ruxolitinib may be effective in ameliorating proliferative symptoms and splenomegaly. Allogeneic stem cell transplantation remains the only treatment with curative potential; however, novel therapies are in clinical development which may significantly alter the therapeutic landscape of CMML.

Mutations in chronic myelomonocytic leukemia and their prognostic relevance

Chronic myelomonocytic leukemia (CMML) is a hematologic malignancy that overlaps with myeloproliferative neoplasms (MPN) and myelodysplastic syndromes (MDS) and tends to transform into acute myeloid leukemia (AML). Among cases of CMML, > 90% have gene mutations, primarily involving TET2 (~ 60%), ASXL1 (~ 40%), SRSF2 (~ 50%), and the RAS pathways (~ 30%). These gene mutations are associated with both the clinical phenotypes and the prognosis of CMML, special CMML variants and pre-phases of CMML. Cytogenetic abnormalities and the size of genome are also associated with prognosis. Meanwhile, cases with ASXL1, DNMT3A, NRAS, SETBP1, CBL and RUNX1 mutations may have inferior prognoses, but only ASXL1 mutations were confirmed to be independent predictors of the patient outcome and were included in three prognostic models. Novel treatment targets related to the various gene mutations are emerging. Therefore, this review provides new insights to explore the correlations among gene mutations, clinical phenotypes, prognosis, and novel drugs in CMML.

Treatment advances for pediatric and adult onset neoplasms with monocytosis

PURPOSE OF REVIEW

For decades, the management of chronic myelomonocytic leukemia (CMML) or juvenile myelomonocytic leukemia (JMML) has been largely inextricable from myelodysplastic syndromes (MDS), myeloproliferative neoplasms, and acute myeloid leukemia. Hallmarks of these diseases have been the emergence of unique genomic signatures and discouraging responses to available therapies. Here, we will critically examine the current options for management and review the rapidly developing opportunities based on advances in CMML and JMML disease biology.

RECENT FINDINGS

Few clinical trials have exclusively been done in CMML, and in JMML, the rarity of the disease limits wide scale participation. Recent case series in JMML suggest that hypomethylating agents (HMAs) are a viable option for bridging to curative intent with allogeneic hematopoietic stem cell transplant or as posttransplant maintenance. Emerging evidence has demonstrated targeting the RAS-pathway via MEK inhibition may also be considered. In CMML, treatment with HMAs is largely derived from data inclusive of MDS patients, including a small number of patients with dysplastic CMML variants. Based on CMML disease biology, additional therapeutic targets being investigated include inhibitors of splicing, CD123/dendritic cell axis, inherent GM-CSF progenitor cell hypersensitivity, and targeting the JAK/STAT pathway. Current evidence is also expanding for oral HMAs. The management of CMML and JMML is rapidly evolving and clinicians must be aware of the genetic landscape and expanding treatment options to ensure these rare populations are afforded therapeutic interventions best suited to their needs.

Type I interferon upregulation and deregulation of genes involved in monopoiesis in chronic myelomonocytic leukemia

Chronic myelomonocytic leukemia (CMML) is characterized by myelomonocytic bias and monocytic proliferation. Whether cell-intrinsic innate immune or inflammatory upregulation mediate disease pathogenesis and phenotype or whether the degree of aberrant monocytic differentiation influences outcomes remains unclear. We compared the transcriptomic features of bone marrow CD34+ cells from 19 patients with CMML and compared to healthy individuals. A total of 1495 genes had significantly differential expression in CMML (q<0.05, fold change>2), including 1271 genes that were significantly upregulated and 224 that were significantly downregulated in CMML. Top upregulated genes were associated with interferon (IFN) alpha and beta signaling, chemokine receptors, IFN gamma, G protein-coupled receptor ligand signaling, and genes involved in immunomodulatory interactions between lymphoid and non-lymphoid cells. Additionally, 6 gene sets were differentially upregulated and 139 were significantly downregulated in patients with myeloproliferative compared to myelodysplastic CMML. A total of 23 genes involved in regulation of monopoiesis were upregulated in CMML compared to healthy controls. We developed a prediction model using Cox regression including 3 of these genes, which differentiated patients into two prognostic subsets with distinct survival outcomes. This data warrants further evaluation of the roles and therapeutic potential of type I IFN signaling and monopoiesis in CMML.

Emerging drugs for the treatment of chronic myelomonocytic leukemia

Introduction: Chronic myelomonocytic leukemia (CMML) is a clonal hematologic disorder with heterogenous prognosis, but with no curative therapies with exception of allogeneic transplant. Therapeutic options for patients with CMML are limited, and although hypomethylating agents such as azacitidine and decitabine are the standard of care, only 40% of patients achieve a response, and most responses are transient. Over the last 5 years, significant advances have been made in the understanding of the clonal landscape of CMML, some of the mechanisms associated to resistance to HMA, and other key biological processes involved in disease pathogenesis. Areas covered: The current article reviews the most relevant emerging therapies currently undergoing clinical trials for the treatment of previously untreated or relapsed CMML. Expert opinion: The presence of recurrent somatic mutations in CMML represents therapeutic opportunities to utilize specific small molecule inhibitors such as IDH, FLT3, MEK/ERK, PLK1, or splicing inhibitors and modulators. In addition, other novel agents such as immune therapies, BCL2 or MCL1 inhibitors and other monoclonal antibodies could lead to therapeutic advances. Identifying specific patient populations likely to benefit from some of these interventions, and development of optimal combinations will remain the challenge when determining their role in therapy.

Chronic myelomonocytic leukemia - a review

INTRODUCTION

Chronic myelomonocytic leukemia (CMML) is a clonal myeloid neoplasm, denoted by overlapping myelodysplastic and myeloproliferative features, with poor overall survival and high transformation rate to acute myeloid leukemia.

AREAS COVERED

This review, following a thorough Medline search of pertinent published literature, discusses the diagnostic criteria, the pathogenesis, and the complex genetic landscape of the disease. Prognostication, response criteria, therapeutic management of patients, efficacy of established and novel treatment modalities are thoroughly reviewed.

EXPERT OPINION

Cytogenetic abnormalities and mutations in genes involved in epigenetic and transcriptional regulation, and cell-signaling are abundant in CMML and implicated in its complex pathogenesis. As presence of these mutations carry a prognostic impact, they are increasingly incorporated in risk-stratification schemes. Novel response criteria have been proposed, considering the unique features of the disease. Although allogeneic hematopoietic stem cell transplantation remains the only treatment with curative intent, it is reserved for a minority of patients; therefore, there is an unmet need for optimizing treatment modalities, such as hypomethylating agents, and introducing novel agents, which could substantially improve survival and quality of life of CMML patients. Clinical trials dedicated specifically to CMML are needed to explore the efficacy and safety of novel treatment modalities.

Efficacy of ruxolitinib in a patient with myelodysplastic/myeloproliferative neoplasm unclassifiable and co-mutated JAK2, SF3B1 and TP53

Myelodysplastic/myeloproliferative neoplasm, unclassifiable (MDS/MPN-U) is a rare but heterogeneous subtype of MDS/MPN, with no specific genetic alterations and standard treatments. ASXL1, SRSF2, TET2, JAK2 and NRAS are commonly mutated in MDS/MPN-U. Double gene mutations could be detected in MDS/MPN-U, however, co-mutations of 3 and more genes in this disease entity are very rare. Here, we present a case of MDS/MPN-U with triple mutations involving JAK2, SF3B1, and TP53. After failure of traditional therapy including hydroxyurea and interferon-α, the patient received ruxolitinib monotherapy and achieved hematological response quickly. Though mutations in TP53 implied a poor prognosis in myeloid malignancies, this patient has maintained no AML transformation for 26 months since diagnosis. Further research on complex mutations in the pathogenesis and prognosis of MDS/MPN-U is warranted.

Ruxolitinib Plus Decitabine Effectively Treats Myelodysplastic Syndrome/Myeloproliferative Neoplasm, Unclassifiable, by Decreasing the Variant Allele Frequency of KRAS

Myelodysplastic syndrome/myeloproliferative neoplasm, unclassifiable (MDS/MPN-U) is a subtype of MDS/MPN that exhibits a combination of the features of both MDS and MPN. To date, no curative treatment is available for MDS/MPN-U; however, previous studies have suggested a potential survival advantage for ruxolitinib and hypomethylating agents. We reported a case of a JAK2-negative but KRAS-positive MDS/MPN-U patient treated with ruxolitinib plus decitabine. After treatment, the patient’s clinical symptoms were moderated, and the size of the spleen and the peripheral blood cell counts were reduced. These effects might be due to the regimen’s ability to reduce STAT5 activation and upregulate microRNA-181c to downregulate the variant allele frequency (VAF) of KRAS.

Comparison and Implications of Mutational Profiles of Myelodysplastic Syndromes, Myeloproliferative Neoplasms, and Myelodysplastic/Myeloproliferative Neoplasms: A Meta-Analysis

Dysplasia and proliferation are histological properties that can be used to diagnose and categorize myeloid tumors in myelodysplastic syndromes (MDS) and myeloproliferative neoplasms (MPN). However, these conditions are not exclusive, and overlap between them leads to another classification, MDS/MPN. As well as phenotype continuity, these three conditions may have genetic relationships that have not yet been identified. This study aimed to obtain their mutational profiles by meta-analysis and explore possible similarities and differences. We reviewed screening studies of gene mutations, published from January 2000 to March 2020, from PubMed and Web of Science. Fifty-three articles were eligible for the meta-analysis, and at most 9,809 cases were involved for any gene. The top mutant genes and their pooled mutation rates were as follows: SF3B1 (20.2% [95% CI 11.6-30.5%]) in MDS, TET2 (39.2% [95% CI 21.7-52.0%]) in MDS/MPN, and JAK2 (67.9% [95% CI 64.1-71.6%]) in MPN. Subgroup analysis revealed that leukemic transformation-related genes were more commonly mutated in high-risk MDS (MDS with multilineage dysplasia and MDS with excess blasts) than that in other MDS entities. Thirteen genes including ASXL1, U2AF1, SRSF2, SF3B1, and ZRSR2 had significantly higher mutation frequencies in primary myelofibrosis (PMF) compared with essential thrombocythemia and polycythemia vera; this difference distinguished PMF from MPN and likened it to MDS. Chronic myelomonocytic leukemia and atypical chronic myeloid leukemia were similar entities but showed several mutational differences. A heat map demonstrated that juvenile myelomonocytic leukemia and MDS/MPN with ring sideroblasts and thrombocytosis were two distinct entities, whereas MDS/MPN-unclassifiable was closest to high-risk MDS. Such genetic closeness or difference reflected features in the pathogenesis, diagnosis, treatment, and progression of these conditions, and could inspire future genetic studies.

Atypical Chronic Myeloid Leukemia: Where Are We Now?

Atypical chronic myeloid leukemia, BCR-ABL1 negative (aCML) is a rare myelodysplastic syndrome (MDS)/myeloproliferative neoplasm (MPN) with a high rate of transformation to acute myeloid leukemia, and poor survival. Until now, the diagnosis has been based on morphological grounds only, possibly making the real frequency of the disease underestimated. Only recently, new insights in the molecular biology of MDS/MPN syndromes have deepened our knowledge of aCML, enabling us to have a better molecular profile of the disease. The knowledge gleaned from next generation sequencing has complemented morphologic and laboratory WHO criteria for myeloid neoplasms and can provide greater specificity in distinguishing aCML from alternative MDS/MPN or MPNs. The most commonly mutated genes (>20%) in aCML are SETBP1, ASXL1, N/K-RAS, SRSF2, and TET2, and less frequently (< 10%) CBL, CSFR3, JAK2, EZH2, and ETNK1. Several of these mutations affect the JAK-STAT, MAPK, and ROCK signaling pathways, which are targetable by inhibitors that are already in clinical use and may lead to a personalized treatment of aCML patients unfit for allogeneic transplant, which is currently the only curative option for fit patients. In this review, we present two emblematic clinical cases and address the new molecular findings in aCML and the available treatment options.

Chronic myelomonocytic leukaemia stem cell transcriptomes anticipate disease morphology and outcome

BACKGROUND

Chronic myelomonocytic leukaemia (CMML) is a clinically heterogeneous stem cell malignancy with overlapping features of myelodysplasia and myeloproliferation. Over 90% of patients carry mutations in epigenetic and/or splicing genes, typically detectable in the Lin-CD34+CD38- immunophenotypic stem cell compartment in which the leukaemia-initiating cells reside. Transcriptional dysregulation at the stem cell level is likely fundamental to disease onset and progression.

METHODS

We performed single-cell RNA sequencing on 6826 Lin-CD34+CD38-stem cells from CMML patients and healthy controls using the droplet-based, ultra-high-throughput 10x platform.

FINDINGS

We found substantial inter- and intra-patient heterogeneity, with CMML stem cells displaying distinctive transcriptional programs. Compared with normal controls, CMML stem cells exhibited transcriptomes characterized by increased expression of myeloid-lineage and cell cycle genes, and lower expression of genes selectively expressed by normal haematopoietic stem cells. Neutrophil-primed progenitor genes and a MYC transcription factor regulome were prominent in stem cells from CMML-1 patients, whereas CMML-2 stem cells exhibited strong expression of interferon-regulatory factor regulomes, including those associated with IRF1, IRF7 and IRF8. CMML-1 and CMML-2 stem cells (stages distinguished by proportion of downstream blasts and promonocytes) differed substantially in both transcriptome and pseudotime, indicating fundamentally different biology underpinning these disease states. Gene expression and pathway analyses highlighted potentially tractable therapeutic vulnerabilities for downstream investigation. Importantly, CMML patients harboured variably-sized subpopulations of transcriptionally normal stem cells, indicating a potential reservoir to restore functional haematopoiesis.

INTERPRETATION

Our findings provide novel insights into the CMML stem cell compartment, revealing an unexpected degree of heterogeneity and demonstrating that CMML stem cell transcriptomes anticipate disease morphology, and therefore outcome.

FUNDING

Project funding was supported by Oglesby Charitable Trust, Cancer Research UK, Blood Cancer UK, and UK Medical Research Council.

Myelodysplastic syndrome/myeloproliferative neoplasm overlap syndromes - Advances in treatment

Optimal treatment for myelodysplastic syndrome/myeloproliferative neoplasm (MDS/MPN) overlap syndromes remain to be defined and are currently extrapolated from MDS and MPN. The heterogeneity of these diseases and their rare occurrences add to this void. Supportive care therapies such as erythropoiesis stimulating agents, iron chelation and cytoreductive therapy do not have prospective evidence in these disorders and the only approved treatments, hypomethylating agents, are based on the inclusion of a small number of chronic myelomonocytic leukaemia patients in MDS predominant trials. While allogeneic stem cell transplant remains the only curative option, the median age at presentation (7th decade), comorbidities, risk of disease relapse, and transplant related morbidity and mortality, make this option accessible to < 10% of patients. The advent of next generation sequencing has better defined the genomic landscape and opened the doors for personalized medicine. Herein we focus on recent therapeutic advances and options in MDS/MPN overlap syndromes.

Hypomethylating agent based combinations in higher risk myelodysplastic syndrome

For over a decade the hypomethylating agents (HMA) azacitidine and decitabine have been the mainstay of therapy for myelodysplastic syndrome (MDS). There is a critical need to improve frontline therapy, given that only up to half of high-risk MDS patients will respond to HMA therapy, and responses are short-lived. Currently, a key strategy has been to combine HMAs with other novel agents to improve patient outcomes. While synergy of agents is the goal of combination therapy, combinations often come at the cost of increased side effects that are often intolerable in this vulnerable population. The purpose of this review is to critically examine clinically relevant HMA combinations and discuss the future of MDS management.

Aggressive Merkel Cell Carcinoma After Janus Kinase Inhibitor Ruxolitinib for Polycythemia Vera

Merkel cell carcinoma (MCC) is a rare neuroendocrine carcinoma of the skin. It is highly aggressive and represents the second most common cause of skin cancer-related death. Ruxolitinib is an orally administered selective inhibitor of Janus associated kinases1 and 2, which is used in the management of patients with symptomatic myelofibrosis and polycythemia vera who are non-responders or intolerant to hydroxyurea. Herein, we report the case of a 47-year-old woman with a 14-year history of chronic myeloproliferative syndrome initially treated with hydroxyurea for 4 years. She was then enrolled in the Response trial and treated for 7 years with ruxolitinib subsequently developing an MCC. This report shows the possibility of development of MCC in patients treated with ruxolitinib. Periodic skin examination is indicated in patients who undergo ruxolitinib therapy, especially if they have a history of skin cancer; dermatologists and oncohematologists should be aware of this possibility in order to introduce appropriate preventive strategies.

Myelodysplastic/myeloproliferative neoplasm, unclassifiable (MDS/MPN-U): More than just a "catch-all" term?

The clinicopathology of MDS and MPN are not mutually exclusive and for this reason the category of myelodysplastic syndrome/myeloproliferative neoplasm (MDS/MPN) exists. Several sub-entities have been included under the MDS/MPN umbrella, including MDS/MPN-unclassifiable (MDS/MPN-U) for those cases whose morphologic and clinical phenotype do not meet criteria to be classified as any other MDS/MPN sub-entity. Though potentially regarded as a wastebasket diagnosis, since its integration into myeloid disease classification, MDS/MPN-U has been refined with increasing understanding of the mutational and genomic events that drive particular clinicopathologic phenotypes, even within MDS/MPN-U. The prototypical example is the identification of SF3B1 mutations and its durable association with MDS/MPN with ring sideroblasts and thrombocytosis (MDS/MPN-RS-T), an entity previously buried within, but now a separate category outside of MDS/MPN-U. Continued and enhanced study of those entities under MDS/MPN-U, a perhaps provisional category itself, is likely to progressively identify commonality between many "unclassifiables" to establish a new classifiable diagnosis.

Myelofibrosis: best practices, controversies and 2019 update

Introduction: Recent advances in the prognostic scheme and treatment of primary and secondary myelofibrosis (MF) have resulted in an overwhelming amount of clinical information to assimilate. The authors believe a comprehensive review that summarizes the most recent published literature, could serve as guidelines for the practicing hematologist.Areas covered: The authors provide a summary of landmark articles regarding epidemiology, symptoms, and pathogenesis of disease. The authors conducted a systematic literature review to answer questions regarding differences between primary myelofibrosis (PMF) and secondary myelofibrosis (SMF), appropriate use and selection of the current risk-stratification models, early versus late treatment of MF and current practices in allogeneic hematopoietic stem cell transplantation (allo-HCT) for MF. The authors conclude the article with their clinical opinion based on their experience and literature review. The purpose of this article is to identify current practices, address any variation, identify and investigate conflicting results and produce statements to guide decision-making.Expert opinion: In this section, the authors advocate for and provide examples of a standardized way of incorporating future discoveries in the pathogenesis and risk-stratification models of MF. They also discuss the importance of using only one risk-stratification model for PMF and one for SMF and their reasoning for early instead of late treatment of MF.

Defining the Boundary Between Myelodysplastic Syndromes and Myeloproliferative Neoplasms

In this article we provide a practical and comprehensive review of myeloid neoplasms with overlapping myelodysplastic (MDS) and myeloproliferative (MPN) features, with emphasis on recent updates in classification, particularly the utility of morphologic, cytogenetic, and molecular findings in better defining and classifying these disease entities. We provide the reader with a summary of the most recent developments and updates that have helped further our understanding of the genomic landscape, clinicopathologic features, and prognostic elements of myeloid neoplasms with MDS/MPN features.

Treatment of myelodysplastic syndrome in the era of next-generation sequencing

Next-generation sequencing (NGS) is rapidly changing the clinical care of patients with myelodysplastic syndrome (MDS). NGS can be used for various applications: (i) in the diagnostic process to discriminate between MDS and other diseases such as aplastic anaemia, myeloproliferative disorders and idiopathic cytopenias; (ii) for classification, for example, where the presence of SF3B1 mutation is one criterion for the ring sideroblast anaemia subgroups in the World Health Organization 2016 classification; (iii) for identification of patients suitable for targeted therapy (e.g. IDH1/2 inhibitors); (iv) for prognostication, for example, where specific mutations (e.g. TP53 and RUNX1) are associated with inferior prognosis, whereas others (e.g. SF3B1) are associated with superior prognosis; and (v) to monitor patients for progression or treatment failure. Most commonly, targeted sequencing for genes (normally 50-100 genes) reported to be recurrently mutated in myeloid disease is used. At present, NGS is rarely incorporated into clinical guidelines although an increasing number of studies have demonstrated the benefit of using NGS in the clinical management of MDS patients.

Challenges in Myelodysplastic/Myeloproliferative Neoplasms (MDS/MPN)

Myelodysplastic/myeloproliferative neoplasms (MDS/MPN) are hybrid group of chronic myeloid neoplasms combining features of both MDS and MPN. The World Health Organization classification coined this group designation in 2008 to include chronic myelomonocytic leukemia, atypical chronic myeloid leukemia, juvenile myelomoncoytic leukemia, refractory anemia with ring sideroblasts and thrombocytosis as a provisional entity, and MDS/MPN unclassified. In this review, we highlight the challenges in diagnosing this group of the diseases, summarize the updates in classification, and discuss recent evolving understanding of the genetic landscape. We review risk-stratification models and overview the current management largely adapted from current MDS or MPN therapies. We define clinical benefit of therapy based on new proposed response criteria developed specifically for these groups of neoplasms. Finally, we introduce future opportunities including the planned international ABN MARRO (A Novel therapy combinations in untreated MDS/MPN And Relapsed/Refractory Overlap Syndromes) clinical study led by the MDS/MPN International Working Group.

Low clinical trial accrual of patients with myelodysplastic syndromes: Causes and potential solutions

Despite few effective therapies, only a small percentage of patients diagnosed with myelodysplastic syndromes (MDS) in the United States are enrolled in prospective, interventional clinical trials. MDS-specific barriers to trial accrual include a high frequency of elderly patients with comorbid conditions, atypical disease features and uncertainty regarding the diagnosis (because other nonclonal processes also can cause dysplasia and cytopenias), a history of another nonmyeloid neoplasm resulting in therapy-related MDS, rapid disease recurrence after allogeneic stem cell transplantation, and an arbitrary division between MDS and acute myeloid leukemia. In addition, barriers to accrual that are common to other oncology populations, such as difficulty traveling to clinical trial enrollment sites and narrow trial eligibility criteria, also prevent patients with MDS from enrolling in studies. Collectively these barriers must be assessed systematically, and creative solutions are needed to improve outcomes for this needy patient population.

Abortigenic but Not Neurotropic Equine Herpes Virus 1 Modulates the Interferon Antiviral Defense

Equine herpesvirus 1 (EHV1) is considered as a major pathogen of Equidae, causing symptoms from mild respiratory disease to late-term abortion and neurological disorders. Different EHV1 strains circulating in the field have been characterized to be of abortigenic or neurovirulent phenotype. Both variants replicate in a plaque-wise manner in the epithelium of the upper respiratory tract (URT), where the abortigenic strains induce more prominent viral plaques, compared to the neurovirulent strains. Considering the differences in replication at the URT, we hypothesized that abortigenic strains may show an increased ability to modulate the type I IFN secretion/signaling pathway, compared to strains that display the neurovirulent phenotype. Here, we analyze IFN levels induced by abortigenic and neurovirulent EHV1 using primary respiratory epithelial cells (EREC) and respiratory mucosa ex vivo explants. Similar levels of IFNα (~70 U/ml) were detected in explants inoculated with both types of EHV1 strains from 48 to 72 hpi. Second, EREC and mucosa explants were treated with recombinant equine IFNα (rEqIFNα) or Ruxolitinib (Rux), an IFN signaling inhibitor, prior to and during inoculation with abortigenic or neurovirulent EHV1. Replication of both EHV1 variants was suppressed by rEqIFNα. Further, addition of Rux increased replication in a concentration-dependent manner, indicating an IFN-susceptibility for both variants. However, in two out of three horses, at a physiological concentration of 100 U/ml of rEqIFNα, an increase in abortigenic EHV1 replication was observed compared to 10 U/ml of rEqIFNα, which was not observed for the neurovirulent strains. Moreover, in the presence of Rux, the plaque size of the abortigenic variants remained unaltered, whereas the typically smaller viral plaques induced by the neurovirulent variants became larger. Overall, our results demonstrate the importance of IFNα in the control of EHV1 replication in the URT for both abortigenic and neurovirulent variants. In addition, our findings support the speculation that abortigenic variants of EHV1 may have developed anti-IFN mechanisms that appear to be absent or less pronounced in neurovirulent EHV1 strains.

Perspectives on interferon-alpha in the treatment of polycythemia vera and related myeloproliferative neoplasms: minimal residual disease and cure?

The first clinical trials of the safety and efficacy of interferon-alpha2 (IFN-alpha2) were performed about 30 years ago. Since then, several single-arm studies have convincingly demonstrated that IFN-alpha2 is a highly potent anti-cancer agent in several cancer types but unfortunately not being explored sufficiently due to a high toxicity profile when using non-pegylated IFN-alpha2 or high dosages or due to competitive drugs, that for clinicians at first glance might look more attractive. Within the hematological malignancies, IFN-alpha2 has only recently been revived in patients with the Philadelphia-negative myeloproliferative neoplasms—essential thrombocytosis, polycythemia vera, and myelofibrosis (MPNs)—and in patients with chronic myelogenous leukemia (CML) in combination with tyrosine kinase inhibitors. In this review, we tell the IFN story in MPNs from the very beginning in the 1980s up to 2018 and describe the perspectives for IFN-alpha2 treatment of MPNs in the future. The mechanisms of actions are discussed and the impact of chronic inflammation as the driving force for clonal expansion and disease progression in MPNs is discussed in the context of combination therapies with potent anti-inflammatory agents, such as the JAK1–2 inhibitors (licensed only ruxolitinib) and statins as well. Interferon-alpha2 being the cornerstone treatment in MPNs and having the potential of inducing minimal residual disease (MRD) with normalization of the bone marrow and low-JAK2V617F allele burden, we believe that combination therapy with ruxolitinib may be even more efficacious and hopefully revert disease progression in many more patients to enter the path towards MRD. In patients with advanced and transforming disease towards leukemic transformation or having transformed to acute myeloid leukemia, “triple therapy” is proposed as a novel treatment modality to be tested in clinical trials combining IFN-alpha2, DNA-hypomethylator, and ruxolitinib. The rationale for this “triple therapy” is given, including the fact that even in AML, IFN-alpha2 as monotherapy may revert disease progression. We envisage a new and bright future with many more patients with MPNs obtaining MRD on the above therapies. From this stage—and even before—vaccination strategies may open a new horizon with cure being the goal for some patients.

Underlying Causes and Therapeutic Targeting of the Inflammatory Tumor Microenvironment

Historically, the link between chronic inflammation and cancer has long been speculated. Only more recently, pre-clinical and epidemiologic data as well as clinical evidence all point to the role of the tumor microenvironment as inextricably connected to the neoplastic process. The tumor microenvironment (TME), a complex mix of vasculature, inflammatory cells, and stromal cells is the essential "soil" helping to modulate tumor potential. Increasingly, evidence suggests that chronic inflammation modifies the tumor microenvironment, via a host of mechanisms, including the production of cytokines, pro-inflammatory mediators, angiogenesis, and tissue remodeling. Inflammation can be triggered by a variety of different pressures, such as carcinogen exposure, immune dysfunction, dietary habits, and obesity, as well as genetic alterations leading to oncogene activation or loss of tumor suppressors. In this review, we examine the concept of the tumor microenvironment as related to both extrinsic and intrinsic stimuli that promote chronic inflammation and in turn tumorigenesis. Understanding the common pathways inherent in an inflammatory response and the tumor microenvironment may shed light on new therapies for both primary and metastatic disease. The concept of personalized medicine has pushed the field of oncology to drill down on the genetic changes of a cancer, in the hopes of identifying individually targeted agents. Given the complexities of the tumor microenvironment, it is clear that effective oncologic therapies will necessitate targeting not only the cancer cells, but their dynamic relationship to the tumor microenvironment as well.