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Sastow D, Tremblay D. Emerging Treatment Options for Myelofibrosis: Focus on Anemia. Ther Clin Risk Manag 2023; 19:535-547. [PMID: 37404252 PMCID: PMC10315142 DOI: 10.2147/tcrm.s386802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 06/25/2023] [Indexed: 07/06/2023] Open
Abstract
Myelofibrosis (MF) is a hematologic malignancy characterized by abnormal proliferation of myeloid cells and the release of pro-inflammatory cytokines, leading to progressive bone marrow dysfunction. The introduction of ruxolitinib just over a decade ago marked a significant advancement in MF therapy, with JAK inhibitors now being the first-line treatment for reducing spleen size and managing symptoms. However, early JAK inhibitors (ruxolitinib and fedratinib) are often associated with cytopenias, particularly thrombocytopenia and anemia, which limit their tolerability. To address these complications, pacritinib has been developed and recently approved for patients with thrombocytopenia, while momelotinib is in development for those with anemia. Although JAK inhibitors have significantly improved the quality of life of MF patients, they have not demonstrated the ability to reduce leukemic transformation and their impact on survival is debated. Numerous drugs are currently being developed and investigated in clinical trials, both as standalone therapy and in combination with JAK inhibitors, with promising results enhancing the benefits of JAK inhibitors. In the near future, MF treatment strategies will involve selecting the most suitable JAK inhibitor based on individual patient characteristics and prior therapy. Ongoing and future clinical trials are crucial for advancing the field and expanding therapeutic options for MF patients.
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Affiliation(s)
- Dahniel Sastow
- Department of Internal Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Douglas Tremblay
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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2
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Abstract
OPINION STATEMENT Currently approved therapies for myelofibrosis (MF) consist of JAK inhibitors, which produce meaningful improvements in spleen size and symptom burden but do not significantly impact leukemic progression. In addition, many patients develop resistance or intolerance to existing therapies and are left without meaningful therapeutic options. There has been recent rapid development of agents in MF that may be able to fill these unmet needs. Importantly, most treatments currently in clinical development have targets outside the JAK-STAT pathway, including BET, BCL-2/BCL-xL, PI3k, HDM2, PIM-1, SINE, telomerase, LSD1, and CD123. These therapies are being tested in combination with JAK inhibitors in the front-line setting and in patients with a suboptimal response, as well as a single agent after JAK inhibitor failure. This next generation of agents is likely to produce a paradigm shift in MF treatment with a focus on combination treatment targeting multiple areas of MF pathophysiology.
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Affiliation(s)
- Douglas Tremblay
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ruben Mesa
- UT Health San Antonio Cancer Center, San Antonio, TX, USA.
- Mays Cancer Center at UT Health San Antonio MD Anderson, San Antonio, TX, USA.
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3
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Li J, Williams MJ, Park HJ, Bastos HP, Wang X, Prins D, Wilson NK, Johnson C, Sham K, Wantoch M, Watcham S, Kinston SJ, Pask DC, Hamilton TL, Sneade R, Waller AK, Ghevaert C, Vassiliou GS, Laurenti E, Kent DG, Göttgens B, Green AR. STAT1 is essential for HSC function and maintains MHCIIhi stem cells that resist myeloablation and neoplastic expansion. Blood 2022; 140:1592-1606. [PMID: 35767701 PMCID: PMC7614316 DOI: 10.1182/blood.2021014009] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 04/21/2022] [Indexed: 02/02/2023] Open
Abstract
Adult hematopoietic stem cells (HSCs) are predominantly quiescent and can be activated in response to acute stress such as infection or cytotoxic insults. STAT1 is a pivotal downstream mediator of interferon (IFN) signaling and is required for IFN-induced HSC proliferation, but little is known about the role of STAT1 in regulating homeostatic hematopoietic stem/progenitor cells (HSPCs). Here, we show that loss of STAT1 altered the steady state HSPC landscape, impaired HSC function in transplantation assays, delayed blood cell regeneration following myeloablation, and disrupted molecular programs that protect HSCs, including control of quiescence. Our results also reveal STAT1-dependent functional HSC heterogeneity. A previously unrecognized subset of homeostatic HSCs with elevated major histocompatibility complex class II (MHCII) expression (MHCIIhi) displayed molecular features of reduced cycling and apoptosis and was refractory to 5-fluorouracil-induced myeloablation. Conversely, MHCIIlo HSCs displayed increased megakaryocytic potential and were preferentially expanded in CALR mutant mice with thrombocytosis. Similar to mice, high MHCII expression is a feature of human HSCs residing in a deeper quiescent state. Our results therefore position STAT1 at the interface of stem cell heterogeneity and the interplay between stem cells and the adaptive immune system, areas of broad interest in the wider stem cell field.
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Affiliation(s)
- Juan Li
- Wellcome–Medical Research Council Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - Matthew J. Williams
- Wellcome–Medical Research Council Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - Hyun Jung Park
- Wellcome–Medical Research Council Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - Hugo P. Bastos
- Wellcome–Medical Research Council Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - Xiaonan Wang
- Wellcome–Medical Research Council Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - Daniel Prins
- Wellcome–Medical Research Council Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - Nicola K. Wilson
- Wellcome–Medical Research Council Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - Carys Johnson
- Wellcome–Medical Research Council Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - Kendig Sham
- Wellcome–Medical Research Council Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - Michelle Wantoch
- Wellcome–Medical Research Council Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - Sam Watcham
- Wellcome–Medical Research Council Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - Sarah J. Kinston
- Wellcome–Medical Research Council Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - Dean C. Pask
- Wellcome–Medical Research Council Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - Tina L. Hamilton
- Wellcome–Medical Research Council Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - Rachel Sneade
- Wellcome–Medical Research Council Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - Amie K. Waller
- Wellcome–Medical Research Council Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - Cedric Ghevaert
- Wellcome–Medical Research Council Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - George S. Vassiliou
- Wellcome–Medical Research Council Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - Elisa Laurenti
- Wellcome–Medical Research Council Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - David G. Kent
- Department of Biology, University of York, York, United Kingdom
| | - Berthold Göttgens
- Wellcome–Medical Research Council Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
| | - Anthony R. Green
- Wellcome–Medical Research Council Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge, United Kingdom
- Department of Haematology, University of Cambridge, Cambridge, United Kingdom
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4
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Novel treatments for myelofibrosis: beyond JAK inhibitors. Int J Hematol 2022; 115:645-658. [PMID: 35182376 DOI: 10.1007/s12185-022-03299-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 01/24/2022] [Accepted: 01/24/2022] [Indexed: 10/19/2022]
Abstract
Myelofibrosis is a chronic hematologic malignancy characterized by constitutional symptoms, bone marrow fibrosis, extramedullary hematopoiesis resulting in splenomegaly and a propensity toward leukemic progression. Given the central role of the JAK-STAT pathway in the pathobiology of myelofibrosis, JAK inhibitors are the mainstay of current pharmacologic management. Although these therapies have produced meaningful improvements in splenomegaly and symptom burden, JAK inhibitors do not significantly impact disease progression. In addition, many patients are ineligible because of disease-related cytopenias, which are exacerbated by JAK inhibitors. Therefore, there is a continued effort to identify targets outside the JAK-STAT pathway. In this review, we discuss novel therapies in development for myelofibrosis. We focus on the preclinical rationale, efficacy and safety data for non-JAK inhibitor therapies that have published or presented clinical data. Specifically, we discuss agents that target epigenetic modification (pelabresib, bomedemstat), apoptosis (navitoclax, navtemdalin), signaling pathways (parsaclisib), bone marrow fibrosis (AVID200, PRM-151), in addition to other targets including telomerase (imetelstat), selective inhibitor of nuclear transport (selinexor), CD123 (tagraxofusp) and erythroid maturation (luspatercept). We end by providing commentary on the ongoing and future therapeutic development in myelofibrosis.
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Tremblay D, Hoffman R. Emerging drugs for the treatment of myelofibrosis: phase II & III clinical trials. Expert Opin Emerg Drugs 2021; 26:351-362. [PMID: 34875179 DOI: 10.1080/14728214.2021.2015320] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
INTRODUCTION Myelofibrosis is a clonal hematologic malignancy with clinical manifestations that include cytopenias, debilitating constitutional symptoms, splenomegaly, bone marrow fibrosis and a propensity toward leukemic progression. While allogeneic hematopoietic stem cell transplantation can be curative, this therapy is not available for the majority of patients. Ruxolitinib and fedratinib are approved JAK2 inhibitors that have produced meaningful benefits in terms of spleen reduction and symptom improvement, but there remain several unmet needs. AREAS COVERED We discuss novel therapies based upon published data from phase II or III clinical trials. Specifically, we cover novel JAK inhibitors (momelotinib and pacritinib), and agents that target bromodomain and extra-terminal domain (pelabresib), the antiapoptotic proteins BCL-2/BCL-xL (navitoclax), MDM2 (navtemadlin), phosphatidylinositol 3-kinase (parsaclisib), or telomerase (imetelstat). EXPERT OPINION Patients with disease related cytopenias are ineligible for currently approved JAK2 inhibitors. However, momelotinib and pacritinib may be able to fill this void. Novel therapies are being evaluated in the upfront setting to improve the depth and duration of responses with ruxolitinib. Future evaluation of agents must be judged on their potential to modify disease progression, which current JAK2 inhibitors lack. Combination therapy, possibly with an immunotherapeutic agent might serve as key components of future myelofibrosis treatment options.
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Affiliation(s)
- Douglas Tremblay
- Division of Hematology and Medical Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA10029
| | - Ronald Hoffman
- Division of Hematology and Medical Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA10029
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Takei H, Coelho-Silva JL, Tavares Leal C, Queiroz Arantes Rocha A, Mantello Bianco T, Welner RS, Mishima Y, Kobayashi IS, Mullally A, Lima K, Machado-Neto JA, Kobayashi SS, Lobo de Figueiredo-Pontes L. Suppression of multiple anti-apoptotic BCL2 family proteins recapitulates the effects of JAK2 inhibitors in JAK2V617F driven myeloproliferative neoplasms. Cancer Sci 2021; 113:597-608. [PMID: 34808021 PMCID: PMC8819353 DOI: 10.1111/cas.15210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 11/16/2021] [Accepted: 11/18/2021] [Indexed: 11/28/2022] Open
Abstract
Several lines of research suggest that Bcl‐xL‐mediated anti‐apoptotic effects may contribute to the pathogenesis of myeloproliferative neoplasms driven by JAK2V617F and serve as therapeutic target. Here, we used a knock‐in JAK2V617F mouse model and confirmed that Bcl‐xL was overexpressed in erythroid progenitors. The myeloproliferative neoplasm (MPN)‐induced phenotype in the peripheral blood by conditional knock‐in of JAK2V617F was abrogated by conditional knockout of Bcl2l1, which presented anemia and thrombocytopenia independently of JAK2 mutation status. Mx1‐Cre Jak2V617W/VF/Bcl2l1f/f mice presented persistent splenomegaly as a result of extramedullary hematopoiesis and pro‐apoptotic stimuli in terminally differentiated erythroid progenitors. The pan‐BH3 mimetic inhibitor obatoclax showed superior cytotoxicity in JAK2V617F cell models, and reduced clonogenic capacity in ex vivo assay using Vav‐Cre Jak2V617F bone marrow cells. Both ruxolitinib and obatoclax significantly reduced spleen weights in a murine Jak2V617F MPN model but did not show additive effect. The tumor burden reduction was observed with either ruxolitinib or obatoclax in terminal differentiation stage neoplastic cells but not in myeloid‐erythroid precursors. Therefore, disrupting the BCL2 balance is not sufficient to treat MPN at the stem cell level, but it is certainly an additional option for controlling the critical myeloid expansion of the disease.
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Affiliation(s)
- Hisashi Takei
- Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA.,Department of Hematology, Gunma University Graduate School of Medicine, Maebashi-shi, Japan
| | - Juan Luiz Coelho-Silva
- Department of Medical Images, Hematology, and Clinical Oncology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Cristina Tavares Leal
- Department of Medical Images, Hematology, and Clinical Oncology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | | | - Thiago Mantello Bianco
- Department of Medical Images, Hematology, and Clinical Oncology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Robert S Welner
- Department of Medicine, Division Hematology/Oncology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Yuta Mishima
- Department of Clinical Medicine, Faculty of Medicine, Transborder Medical Research Center, University of Tsukuba, Tsukuba, Japan
| | - Ikei S Kobayashi
- Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Ann Mullally
- Division of Hematology, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Keli Lima
- Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | | | - Susumu S Kobayashi
- Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA.,Division of Translational Genomics, Exploratory Oncology Research and Clinical Trial Center, National Cancer Center, Kashiwa, Japan.,Harvard Stem Cell Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Lorena Lobo de Figueiredo-Pontes
- Department of Medical Images, Hematology, and Clinical Oncology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
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7
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Levy G, Mambet C, Pecquet C, Bailly S, Havelange V, Diaconu CC, Constantinescu SN. Targets in MPNs and potential therapeutics. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2021; 366:41-81. [PMID: 35153006 DOI: 10.1016/bs.ircmb.2021.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Philadelphia-negative classical Myeloproliferative Neoplasms (MPNs), including Polycythemia Vera (PV), Essential Thrombocythemia (ET) and Primary Myelofibrosis (PMF), are clonal hemopathies that emerge in the hematopoietic stem cell (HSC) compartment. MPN driver mutations are restricted to specific exons (14 and 12) of Janus kinase 2 (JAK2), thrombopoietin receptor (MPL/TPOR) and calreticulin (CALR) genes, are involved directly in clonal myeloproliferation and generate the MPN phenotype. As a result, an increased number of fully functional erythrocytes, platelets and leukocytes is observed in the peripheral blood. Nevertheless, the complexity and heterogeneity of MPN clinical phenotypes cannot be solely explained by the type of driver mutation. Other factors, such as additional somatic mutations affecting epigenetic regulators or spliceosomes components, mutant allele burdens and modifiers of signaling by driver mutants, clonal architecture and the order of mutation acquisition, signaling events that occur downstream of a driver mutation, the presence of specific germ-line variants, the interaction of the neoplastic clone with bone marrow microenvironment and chronic inflammation, all can modulate the disease phenotype, influence the MPN clinical course and therefore, might be useful therapeutic targets.
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Affiliation(s)
- Gabriel Levy
- Ludwig Institute for Cancer Research, Brussels, Belgium; SIGN Unit, de Duve Institute, Université Catholique de Louvain, Brussels, Belgium; Department of Pediatric Hematology and Oncology, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Brussels, Belgium
| | - Cristina Mambet
- Department of Cellular and Molecular Pathology, Stefan S. Nicolau Institute of Virology, Bucharest, Romania; Department of Hematology, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
| | - Christian Pecquet
- Ludwig Institute for Cancer Research, Brussels, Belgium; SIGN Unit, de Duve Institute, Université Catholique de Louvain, Brussels, Belgium; WELBIO (Walloon Excellence in Life Sciences and Biotechnology), Brussels, Belgium
| | - Sarah Bailly
- Ludwig Institute for Cancer Research, Brussels, Belgium; SIGN Unit, de Duve Institute, Université Catholique de Louvain, Brussels, Belgium; Department of Hematology, Cliniques Universitaires Saint Luc, Université Catholique de Louvain, Brussels, Belgium
| | - Violaine Havelange
- SIGN Unit, de Duve Institute, Université Catholique de Louvain, Brussels, Belgium; Department of Hematology, Cliniques Universitaires Saint Luc, Université Catholique de Louvain, Brussels, Belgium
| | - Carmen C Diaconu
- Department of Cellular and Molecular Pathology, Stefan S. Nicolau Institute of Virology, Bucharest, Romania
| | - Stefan N Constantinescu
- Ludwig Institute for Cancer Research, Brussels, Belgium; SIGN Unit, de Duve Institute, Université Catholique de Louvain, Brussels, Belgium; WELBIO (Walloon Excellence in Life Sciences and Biotechnology), Brussels, Belgium; Ludwig Institute for Cancer Research, Nuffield Department of Medicine, Oxford University, Oxford, United Kingdom.
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8
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Tremblay D, Mascarenhas J. Next Generation Therapeutics for the Treatment of Myelofibrosis. Cells 2021; 10:cells10051034. [PMID: 33925695 PMCID: PMC8146033 DOI: 10.3390/cells10051034] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 04/24/2021] [Accepted: 04/27/2021] [Indexed: 01/02/2023] Open
Abstract
Myelofibrosis is a myeloproliferative neoplasm characterized by splenomegaly, constitutional symptoms, bone marrow fibrosis, and a propensity towards transformation to acute leukemia. JAK inhibitors are the only approved therapy for myelofibrosis and have been successful in reducing spleen and symptom burden. However, they do not significantly impact disease progression and many patients are ineligible due to coexisting cytopenias. Patients who are refractory to JAK inhibition also have a dismal survival. Therefore, non-JAK inhibitor-based therapies are being explored in pre-clinical and clinical settings. In this review, we discuss novel treatments in development for myelofibrosis with targets outside of the JAK-STAT pathway. We focus on the mechanism, preclinical rationale, and available clinical efficacy and safety information of relevant agents including those that target apoptosis (navitoclax, KRT-232, LCL-161, imetelstat), epigenetic modulation (CPI-0610, bomedemstat), the bone marrow microenvironment (PRM-151, AVID-200, alisertib), signal transduction pathways (parsaclisib), and miscellaneous agents (tagraxofusp. luspatercept). We also provide commentary on the future of therapeutic development in myelofibrosis.
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Abstract
INTRODUCTION The outlook for patients with myeloproliferative neoplasms, particularly myelofibrosis, has improved in recent years, with greater understanding of the pathogenesis and the subsequent development of a plethora of new agents. Areas covered: This article will discuss some of the advances in the field in recent years and explore in greater detail some of the most advanced emerging agents as well as those with greatest potential. An extensive literature review has been performed to identify recent clinical trials and any relevant pre-clinical work. Expert commentary: Important discoveries regarding molecular pathogenesis have led to advances in diagnostic algorithms, prognosis and ultimately also treatment strategies. However, the therapeutic armamentarium for MPN is still largely inadequate to cope with significant challenges including normalization of life span, reduction of cardiovascular complications, prevention of hematological progression and improved quality of life. Sadly, no currently available drugs have shown clear evidence of disease-modifying activity and results of early phase I and II clinical trials have been quite disappointing to date, with toxicities sometimes limiting and a lack of meaningful biological surrogate end points.
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Affiliation(s)
- Patrick M Harrington
- a Department of Haematology , Guys and St Thomas' NHS Foundation Trust , London , UK
| | - Claire N Harrison
- a Department of Haematology , Guys and St Thomas' NHS Foundation Trust , London , UK
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10
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Zhao B, Mei Y, Cao L, Zhang J, Sumagin R, Yang J, Gao J, Schipma MJ, Wang Y, Thorsheim C, Zhao L, Stalker T, Stein B, Wen QJ, Crispino JD, Abrams CS, Ji P. Loss of pleckstrin-2 reverts lethality and vascular occlusions in JAK2V617F-positive myeloproliferative neoplasms. J Clin Invest 2017; 128:125-140. [PMID: 29202466 DOI: 10.1172/jci94518] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 10/17/2017] [Indexed: 12/19/2022] Open
Abstract
V617F driver mutation of JAK2 is the leading cause of the Philadelphia-chromosome-negative myeloproliferative neoplasms (MPNs). Although thrombosis is a leading cause of mortality and morbidity in MPNs, the mechanisms underlying their pathogenesis are unclear. Here, we identified pleckstrin-2 (Plek2) as a downstream target of the JAK2/STAT5 pathway in erythroid and myeloid cells, and showed that it is upregulated in a JAK2V617F-positive MPN mouse model and in patients with MPNs. Loss of Plek2 ameliorated JAK2V617F-induced myeloproliferative phenotypes including erythrocytosis, neutrophilia, thrombocytosis, and splenomegaly, thereby reverting the widespread vascular occlusions and lethality in JAK2V617F-knockin mice. Additionally, we demonstrated that a reduction in red blood cell mass was the main contributing factor in the reversion of vascular occlusions. Thus, our study identifies Plek2 as an effector of the JAK2/STAT5 pathway and a key factor in the pathogenesis of JAK2V617F-induced MPNs, pointing to Plek2 as a viable target for the treatment of MPNs.
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Affiliation(s)
- Baobing Zhao
- Department of Pathology, Feinberg School of Medicine, and.,The Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, Illinois, USA
| | - Yang Mei
- Department of Pathology, Feinberg School of Medicine, and.,The Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, Illinois, USA
| | - Lan Cao
- Department of Pathology, Feinberg School of Medicine, and.,Department of Hematology and Oncology, Children's Hospital of Soochow University, Suzhou, China
| | - Jingxin Zhang
- Department of Pathology, Feinberg School of Medicine, and.,The Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, Illinois, USA
| | - Ronen Sumagin
- Department of Pathology, Feinberg School of Medicine, and.,The Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, Illinois, USA
| | - Jing Yang
- Department of Pathology, Feinberg School of Medicine, and.,The Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, Illinois, USA
| | - Juehua Gao
- Department of Pathology, Feinberg School of Medicine, and.,The Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, Illinois, USA
| | - Matthew J Schipma
- Center for Genetic Medicine, Northwestern University, Chicago, Illinois, USA
| | - Yanfeng Wang
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Chelsea Thorsheim
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Liang Zhao
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Timothy Stalker
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Brady Stein
- The Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, Illinois, USA.,Division of Hematology and Oncology, Department of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Qiang Jeremy Wen
- The Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, Illinois, USA.,Division of Hematology and Oncology, Department of Medicine, Northwestern University, Chicago, Illinois, USA
| | - John D Crispino
- The Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, Illinois, USA.,Division of Hematology and Oncology, Department of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Charles S Abrams
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Peng Ji
- Department of Pathology, Feinberg School of Medicine, and.,The Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, Illinois, USA
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11
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Bose P, Verstovsek S. Developmental Therapeutics in Myeloproliferative Neoplasms. CLINICAL LYMPHOMA, MYELOMA & LEUKEMIA 2017; 17S:S43-S52. [PMID: 28760302 PMCID: PMC5540010 DOI: 10.1016/j.clml.2017.02.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 02/28/2017] [Indexed: 12/12/2022]
Abstract
The unprecedented success of the Janus kinase (JAK) 1/2 inhibitor ruxolitinib in myelofibrosis (MF) provided much-needed impetus for clinical drug development for the Philadelphia chromosome-negative myeloproliferative neoplasms. The survival benefit conferred by this agent, along with its marked efficacy with regard to spleen volume and symptom reduction, have made ruxolitinib the cornerstone of drug therapy in MF. However, there remain significant unmet needs in the treatment of patients with MF, and many novel classes of agents continue to be investigated in efforts to build on the progress made with ruxolitinib. These include inhibitors of histone deacetylases (HDACs) and DNA methyltransferases, phosphatidylinositol-3-kinase isoforms, heat shock protein 90, cyclin-dependent kinases 4/6, and Hedgehog signaling, among others. In parallel, other JAK inhibitors with potential for less myelosuppression or even improvement of anemia, greater selectivity for JAK1 or JAK2, and the ability to overcome JAK inhibitor persistence are in various stages of development. First-in-class agents such as the activin receptor IIA ligand trap sotatercept (for anemia of MF), the telomerase inhibitor imetelstat, and the antifibrotic agent PRM-151 (recombinant human pentraxin-2) are also in clinical trials. In polycythemia vera, a novel interferon administered every 2 weeks is being developed for front-line therapy in high-risk individuals, and inhibitors of human double minute 2 (HDM2) have shown promise in preclinical studies, as have HDAC inhibitors such as givinostat (both in the laboratory and in the clinic). Ruxolitinib is approved for second-line therapy of polycythemia vera and is being developed for essential thrombocythemia.
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Affiliation(s)
- Prithviraj Bose
- Department of Leukemia, University of Texas MD Anderson Cancer Center, Houston, TX.
| | - Srdan Verstovsek
- Department of Leukemia, University of Texas MD Anderson Cancer Center, Houston, TX
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12
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Cao WJ, Wu K, Wang C, Wan DM. Polydatin-induced cell apoptosis and cell cycle arrest are potentiated by Janus kinase 2 inhibition in leukemia cells. Mol Med Rep 2016; 13:3297-302. [PMID: 26934953 DOI: 10.3892/mmr.2016.4909] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2015] [Accepted: 11/10/2015] [Indexed: 11/05/2022] Open
Abstract
Polydatin (PD), a natural precursor of resveratrol, has a variety of biological activities, including anti‑tumor effects. However, the underlying molecular mechanisms of the anti-cancer activity of PD has not been fully elucidated. The present study demonstrated that PD significantly inhibited the proliferation of the MOLT-4 leukemia cell line in a dose‑ and time-dependent manner by using Cell Counting Kit‑8 assay. PD also dose-dependently increased the apoptotic rate and caused cell cycle arrest in S phase in MOLT‑4 cells, as revealed by flow cytometry. In addition, PD dose-dependently decreased the mitochondrial membrane potential and led to the generation of reactive oxygen species in MOLT-4 cells. Western blot analysis revealed that the expression of anti‑apoptotic protein B-cell lymphoma 2 (Bcl-2) was decreased, whereas that of pro‑apoptotic protein Bcl‑2‑associated X was increased by PD. Furthermore, the expression of two cell cycle regulatory proteins, cyclin D1 and cyclin B1, was suppressed by PD. Of note, the pro‑apoptotic and cell cycle‑inhibitory effects of PD were potentiated by Janus kinase 2 (JAK2) inhibition. In conclusion, the results of the present study strongly suggested that PD is a promising therapeutic compound for the treatment of leukemia, particularly in combination with JAK inhibitors.
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Affiliation(s)
- Wei-Jie Cao
- Department of Hematology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
| | - Ke Wu
- Department of Endodontics, The Fourth Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
| | - Chong Wang
- Department of Hematology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
| | - Ding-Ming Wan
- Department of Hematology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
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13
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Matatall KA, Shen CC, Challen GA, King KY. Type II interferon promotes differentiation of myeloid-biased hematopoietic stem cells. Stem Cells 2015; 32:3023-30. [PMID: 25078851 DOI: 10.1002/stem.1799] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Revised: 06/05/2014] [Accepted: 06/19/2014] [Indexed: 12/21/2022]
Abstract
Interferon gamma (IFNγ) promotes cell division of hematopoietic stem cells (HSCs) without affecting the total HSC number. We postulated that IFNγ stimulates differentiation of HSCs as part of the innate immune response. Here, we report that type II interferon signaling is required, both at baseline and during an animal model of LCMV infection, to maintain normal myeloid development. By separately evaluating myeloid-biased and lymphoid-biased HSC subtypes, we found that myeloid-biased HSCs express higher levels of IFNγ receptor and are specifically activated to divide after recombinant IFNγ exposure in vivo. While both HSC subtypes show increased expression of the transcription factor C/EBPβ after infection, only the myeloid-biased HSCs are transiently depleted from the marrow during the type II interferon-mediated immune response to Mycobacterium avium infection, as measured both functionally and phenotypically. These findings indicate that IFNγ selectively permits differentiation of myeloid-biased HSCs during an innate immune response to infection. This represents the first report of a context and a mechanism for discriminate utilization of the alternate HSC subtypes. Terminal differentiation, at the expense of self-renewal, may compromise HSC populations during states of chronic inflammation.
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Affiliation(s)
- Katie A Matatall
- Section of Pediatric Infectious Diseases and the Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, Texas, USA
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14
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Myeloproliferative Neoplasms: JAK2 Signaling Pathway as a Central Target for Therapy. CLINICAL LYMPHOMA MYELOMA & LEUKEMIA 2014; 14 Suppl:S23-35. [DOI: 10.1016/j.clml.2014.06.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 06/04/2014] [Indexed: 12/16/2022]
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15
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The orally bioavailable MDM2 antagonist RG7112 and pegylated interferon α 2a target JAK2V617F-positive progenitor and stem cells. Blood 2014; 124:771-9. [PMID: 24869939 DOI: 10.1182/blood-2013-11-536854] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The Philadelphia chromosomal-negative chronic myeloproliferative neoplasms (MPNs) originate at the level of the hematopoietic stem cell (HSC). The protracted clinical course of the MPNs has limited the use of potentially toxic treatment modalities, which may eliminate the responsible malignant clone. Treatment with low doses of RG7112, an orally available small-molecule inhibitor of p53-MDM2, both alone and combined with pegylated interferon α 2a (Peg-IFNα 2a), significantly decreased MPN colony-forming unit-granulocyte macrophage and burst-forming unit-erythroid numbers and preferentially eliminated the total number of JAKV617F(+) MPN hematopoietic progenitor cells. The effects of RG7112 and Peg-IFNα 2a on MPN progenitor cells were dependent on blocking p53-MDM2 interactions and activating the p53 pathway, thereby increasing MPN CD34(+) cell apoptosis. Treatment of polycythemia vera (PV) and primary myelofibrosis (PMF) CD34(+) cells with low doses of RG7112 and Peg-IFNα 2a before their transplantation into immune-deficient mice decreased the degree of donor-derived chimerism as well as the JAK2V617F allele burden, indicating that these drugs can each alone or in combination deplete MPN HSCs. These results provide a rationale for the use of combinations of low doses of RG7112 and Peg-IFNα 2a for the treatment of PV or PMF patients with the intent of altering their natural history.
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16
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Harrison C, Vannucchi AM. Ruxolitinib: a potent and selective Janus kinase 1 and 2 inhibitor in patients with myelofibrosis. An update for clinicians. Ther Adv Hematol 2012; 3:341-54. [PMID: 23606937 PMCID: PMC3627327 DOI: 10.1177/2040620712459746] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Ruxolitinib became the first US Food and Drug Administration approved therapy for myelofibrosis in 2011 and EU approval is anticipated in summer 2012. Two large phase III trials (known as the COMFORT studies) were the basis for this approval and were published recently. In this review article we discuss the challenges in managing myelofibrosis, the information to date about ruxolitinib and speculate as to the future direction with this and similar agents.
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Affiliation(s)
- Claire Harrison
- Guy's and St Thomas's NHS Foundation Trust, Guy's Hospital, Great Maze Pond, London SE1 9RT, UK
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17
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Ng AP. Hematopoietic stem cells, progenitor cells and leukemic stem cells in adult myeloproliferative neoplasms. Leuk Lymphoma 2012; 54:922-33. [PMID: 23013358 DOI: 10.3109/10428194.2012.734615] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The understanding of myeloproliferative neoplasms has changed dramatically since Dameshek proposed his classification over 50 years ago. Our knowledge of the types of cells which constitute the hematopoietic system and of how they are regulated has also appreciated significantly over this time. This review relates what is currently known about the acquired genetic mutations associated with adult myeloproliferative neoplasms to how they lead to the hematopoietic perturbations of myeloproliferative disease. There is a particular focus on how stem and progenitor cell compartments are affected by BCR-ABL1 and JAK2V617F mutations, and the particular issue of resistance of leukemic stem cells to conventional and targeted therapies.
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Affiliation(s)
- Ashley P Ng
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.
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18
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Skov V, Thomassen M, Riley CH, Jensen MK, Bjerrum OW, Kruse TA, Hasselbalch HC, Larsen TS. Gene expression profiling with principal component analysis depicts the biological continuum from essential thrombocythemia over polycythemia vera to myelofibrosis. Exp Hematol 2012; 40:771-780.e19. [DOI: 10.1016/j.exphem.2012.05.011] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Revised: 05/21/2012] [Accepted: 05/23/2012] [Indexed: 01/23/2023]
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19
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20
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Busca A, Saxena M, Kumar A. Critical role for antiapoptotic Bcl-xL and Mcl-1 in human macrophage survival and cellular IAP1/2 (cIAP1/2) in resistance to HIV-Vpr-induced apoptosis. J Biol Chem 2012; 287:15118-33. [PMID: 22403404 DOI: 10.1074/jbc.m111.312660] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Macrophages are resistant to HIV cytopathic effects, which contributes to viral persistence and reservoir formation. HIV viral protein R (Vpr) is a potent apoptosis-inducing agent for primary monocytes. Because the biologically active Vpr is found in serum and cerebrospinal fluid of HIV-infected patients, we investigated the apoptotic effect of Vpr on monocyte-derived macrophages and phorbol 12-myristate 13-acetate-activated THP1 macrophages. Our results show that primary monocytes and THP1 cells develop resistance to Vpr-induced apoptosis following differentiation into macrophages. To determine the effect of Vpr on the expression of antiapoptotic proteins, we show that in contrast to the undifferentiated cells, Vpr did not down-regulate the expression of antiapoptotic inhibitors of apoptosis (IAPs) and Bcl2 family members in macrophages, suggesting their involvement in resistance to Vpr-induced apoptosis. However, knocking down Bcl-xL and Mcl-1 proteins induced spontaneous apoptosis with no impact on susceptibility to Vpr-induced apoptosis. In contrast, down-regulation of cellular IAP1 (cIAP1) and cIAP2 by using siRNAs and SMAC (second mitochondria-derived activator of caspases) mimetic sensitized macrophages to Vpr-induced apoptosis. Overall, our results suggest that resistance to Vpr-induced apoptosis is specifically mediated by cIAP1/2 genes independent of Bcl-xL and Mcl-1, which play a key role in maintaining cell viability. Moreover, IAP modulation may be a potential strategy to eliminate HIV persistence in macrophages.
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Affiliation(s)
- Aurelia Busca
- Department of Biochemistry, Microbiology and Immunology, Research Institute, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada
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21
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Donato NJ, Peterson LF. Chronic myeloid leukemia stem cells and developing therapies. Leuk Lymphoma 2011; 52 Suppl 1:60-80. [PMID: 21299460 DOI: 10.3109/10428194.2010.546921] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Chronic myeloid leukemia therapy has remarkably improved with the use of frontline BCR-ABL kinase inhibitors such that newly diagnosed patients have minimal disease manifestations or progression. Effective control of disease may also set the stage for eventual 'cure' of this leukemia. However, the existence of Philadelphia chromosome-positive leukemic cells that are unaffected by BCR-ABL inhibition represents a major barrier that may delay or prevent curative therapy with the current approaches. The most commonly reported mechanism of resistance to tyrosine kinase inhibitor-based therapies involves BCR-ABL gene mutations and amplification, but these changes may not be solely responsible for disease relapse when inhibitor-based therapies are curtailed. Therefore new targets may need to be defined before significant advancement in curative therapies is possible. Emerging evidence suggests that persistence of chronic myeloid leukemia stem cells or acquisition of stem cell-like characteristics prevents complete elimination of chronic myeloid leukemia by tyrosine kinase inhibition alone. This review focuses on several recently emerging concepts regarding the existence and characteristics of chronic myeloid leukemia stem cells. Definitions based on human primary cells and animal model studies are highlighted as are the potential signaling pathways associated with disease repopulating cells. Finally, several recently defined therapeutic targets and active compounds that have emerged from stem cell studies are described. Our goal is to provide an unbiased report on the current state of discovery within the chronic myeloid leukemia stem cell field and to orient the reader to emerging therapeutic targets and strategies that may lead to elimination of this leukemia.
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Affiliation(s)
- Nicholas J Donato
- University of Michigan Comprehensive Cancer Center, Ann Arbor, MI 48109, USA.
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22
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Vannucchi AM. Management of myelofibrosis. HEMATOLOGY. AMERICAN SOCIETY OF HEMATOLOGY. EDUCATION PROGRAM 2011; 2011:222-230. [PMID: 22160038 DOI: 10.1182/asheducation-2011.1.222] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Myelofibrosis (MF), either primary or arising from previous polycythemia vera (PV) or essential thrombocythemia (ET), is the worst among the chronic myeloproliferative neoplasms in terms of survival and quality of life. Patients with MF have to face several clinical issues that, because of the poor effectiveness of medical therapy, surgery or radiotherapy, represent largely unmet clinical needs. Powerful risk stratification systems, applicable either at diagnosis using the International Prognostic Scoring System (IPSS) or during the variable course of illness using the Dynamic International Prognostic Scoring System (DIPSS) and DIPSS Plus, allow recognition of categories of patients with survival times ranging from decades to < 2 years. These scores are especially important for therapeutic decisions that include allogeneic stem cell transplantation (allogeneic SCT), the only curative approach that still carries a nonnegligible risk of morbidity and mortality even with newest reduced intensity conditioning (RIC) regimens. Discovery of JAK2V617F mutation prompted the development of clinical trials using JAK2 inhibitors; these agents overall have resulted in meaningful symptomatic improvement and reduction of splenomegaly that were otherwise not achievable with conventional therapy. Intriguing differences in the efficacy and tolerability of JAK2 inhibitors are being recognized, which could lead to a nonoverlapping spectrum of activity/safety. Other agents that do not directly target JAK2 and have shown symptomatic efficacy in MF are represented by inhibitors of the mammalian target of rapamycin (mTOR) and histone deacetylases (HDACs). Pomalidomide appears to be particularly active against MF-associated anemia. However, because these agents are all poorly effective in reducing the burden of mutated cells, further advancements are needed to move from enhancing our ability to palliate the disease to arriving at an actual cure for MF.
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Affiliation(s)
- Alessandro M Vannucchi
- Section of Hematology, Department of Critical Care, University of Florence, Florence, Italy.
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