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Delshad M, Davoodi-Moghaddam Z, Pourbagheri-Sigaroodi A, Faranoush M, Abolghasemi H, Bashash D. Translating mechanisms into therapeutic strategies for immune thrombocytopenia (ITP): Lessons from clinical trials. Thromb Res 2024; 235:125-147. [PMID: 38335568 DOI: 10.1016/j.thromres.2024.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 01/30/2024] [Accepted: 02/05/2024] [Indexed: 02/12/2024]
Abstract
Immune thrombocytopenia (ITP) is an autoimmune disorder that causes a significant reduction in peripheral blood platelet count. Fortunately, due to an increased understanding of ITP, there have been significant improvements in the diagnosis and treatment of these patients. Over the past decade, there have been a variety of proven therapeutic options available for ITP patients, including intravenous immunoglobulins (IVIG), Rituximab, corticosteroids, and thrombopoietin receptor agonists (TPO-RAs). Although the effectiveness of current therapies in treating more than two-thirds of patients, still some patients do not respond well to conventional therapies or fail to achieve long-term remission. Recently, a significant advancement has been made in identifying various mechanisms involved in the pathogenesis of ITP, leading to the development of novel treatments targeting these pathways. It seems that new agents that target plasma cells, Bruton tyrosine kinase, FcRn, platelet desialylation, splenic tyrosine kinase, and classical complement pathways are opening new ways to treat ITP. In this study, we reviewed the pathophysiology of ITP and summarized updates in this population's management and treatment options. We also took a closer look at the 315 ongoing trials to investigate their progress status and compare the effectiveness of interventions. May our comprehensive view of ongoing clinical trials serve as a guiding beacon, illuminating the path towards future trials of different drugs in the treatment of ITP patients.
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Affiliation(s)
- Mahda Delshad
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Department of Laboratory Sciences, School of Allied Medical Sciences, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Zeinab Davoodi-Moghaddam
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Atieh Pourbagheri-Sigaroodi
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Faranoush
- Pediatric Growth and Development Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Hassan Abolghasemi
- Pediatric Congenital Hematologic Disorders Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Davood Bashash
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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2
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Bauer-Smith H, Sudol ASL, Beers SA, Crispin M. Serum immunoglobulin and the threshold of Fc receptor-mediated immune activation. Biochim Biophys Acta Gen Subj 2023; 1867:130448. [PMID: 37652365 PMCID: PMC11032748 DOI: 10.1016/j.bbagen.2023.130448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 08/23/2023] [Accepted: 08/23/2023] [Indexed: 09/02/2023]
Abstract
Antibodies can mediate immune recruitment or clearance of immune complexes through the interaction of their Fc domain with cellular Fc receptors. Clustering of antibodies is a key step in generating sufficient avidity for efficacious receptor recognition. However, Fc receptors may be saturated with prevailing, endogenous serum immunoglobulin and this raises the threshold by which cellular receptors can be productively engaged. Here, we review the factors controlling serum IgG levels in both healthy and disease states, and discuss how the presence of endogenous IgG is encoded into the functional activation thresholds for low- and high-affinity Fc receptors. We discuss the circumstances where antibody engineering can help overcome these physiological limitations of therapeutic antibodies. Finally, we discuss how the pharmacological control of Fc receptor saturation by endogenous IgG is emerging as a feasible mechanism for the enhancement of antibody therapeutics.
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Affiliation(s)
- Hannah Bauer-Smith
- School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK; Centre for Cancer Immunology, School of Cancer Sciences, University of Southampton Faculty of Medicine, Southampton SO16 6YD, UK
| | - Abigail S L Sudol
- School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | - Stephen A Beers
- Centre for Cancer Immunology, School of Cancer Sciences, University of Southampton Faculty of Medicine, Southampton SO16 6YD, UK.
| | - Max Crispin
- School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK.
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3
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Wang J, Brown K, Danehy C, Mérigeon E, Goralski S, Rice S, Torgbe K, Thomas F, Block D, Olsen H, Strome SE, Fitzpatrick EA. Fc multimers effectively treat murine models of multiple sclerosis. Front Immunol 2023; 14:1199747. [PMID: 37638040 PMCID: PMC10451071 DOI: 10.3389/fimmu.2023.1199747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 07/25/2023] [Indexed: 08/29/2023] Open
Abstract
Multiple Sclerosis (MS) is a chronic neurodegenerative disease with limited therapeutic options. Recombinant Fc multimers (rFc), designed to mirror many of the anti-inflammatory activities of Intravenous Immunoglobulin (IVIG), have been shown to effectively treat numerous immune-mediated diseases in rodents. In this study we used the experimental autoimmune encephalomyelitis (EAE) murine model of MS to test the efficacy of a rFc, M019, that consists of multimers of the Fc portion of IgG2, in inhibiting disease severity. We show that M019 effectively reduced clinical symptoms when given either pre- or post-symptom onset compared to vehicle treated EAE induced mice. M019 was effective in reducing symptoms in both SJL model of relapsing remitting MS as well as the B6 model of chronic disease. M019 binds to FcγR bearing-monocytes both in vivo and in vitro and prevented immune cell infiltration into the CNS of treated mice. The lack of T cell infiltration into the spinal cord was not due to a decrease in T cell priming; there was an equivalent frequency of Th17 cells in the spleens of M019 and vehicle treated EAE induced mice. Surprisingly, there was an increase in chemokines in the sera but not in the CNS of M019 treated mice compared to vehicle treated animals. We postulate that M019 interacts with a FcγR rich monocyte intermediary to prevent T cell migration into the CNS and demyelination.
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Affiliation(s)
- Jin Wang
- Dept. of Microbiology Immunology and Biochemistry, UTHSC, Memphis, TN, United States
| | - Kellie Brown
- Dept. of Microbiology Immunology and Biochemistry, UTHSC, Memphis, TN, United States
| | - Caroline Danehy
- College of Graduate Health Sciences, UTHSC, Memphis, TN, United States
| | | | | | - Samuel Rice
- College of Medicine, UTHSC, Memphis, TN, United States
| | - Kwame Torgbe
- Dept. of Pathology, UTHSC, Memphis, TN, United States
| | - Fridtjof Thomas
- Div. of Biostatistics, Dept. of Preventive Medicine, UTHSC, Memphis, TN, United States
| | | | | | - Scott E. Strome
- Dept. of Microbiology Immunology and Biochemistry, UTHSC, Memphis, TN, United States
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4
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Johnson SN, Brucks SD, Apley KD, Farrell MP, Berkland CJ. Multivalent Scaffolds to Promote B cell Tolerance. Mol Pharm 2023; 20:3741-3756. [PMID: 37410969 DOI: 10.1021/acs.molpharmaceut.3c00039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/08/2023]
Abstract
Autoimmune diseases are characterized by aberrant immune responses toward self-antigens. Current treatments lack specificity, promoting adverse effects by broadly suppressing the immune system. Therapies that specifically target the immune cells responsible for disease are a compelling strategy to mitigate adverse effects. Multivalent formats that display numerous binding epitopes off a single scaffold may enable selective immunomodulation by eliciting signals through pathways unique to the targeted immune cells. However, the architecture of multivalent immunotherapies can vary widely, and there is limited clinical data with which to evaluate their efficacy. Here, we set forth to review the architectural properties and functional mechanisms afforded by multivalent ligands and evaluate four multivalent scaffolds that address autoimmunity by altering B cell signaling pathways. First, we address both synthetic and natural polymer backbones functionalized with a variety of small molecule, peptide, and protein ligands for probing the effects of valency and costimulation. Then, we review nanoparticles composed entirely from immune signals which have been shown to be efficacious. Lastly, we outline multivalent liposomal nanoparticles capable of displaying high numbers of protein antigens. Taken together, these examples highlight the versatility and desirability of multivalent ligands for immunomodulation and illuminate strengths and weaknesses of multivalent scaffolds for treating autoimmunity.
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Affiliation(s)
- Stephanie N Johnson
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, Kansas 66047, United States
| | - Spencer D Brucks
- Department of Chemistry, Harvey Mudd College, Claremont, California 91711, United States
| | - Kyle D Apley
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, Kansas 66047, United States
| | - Mark P Farrell
- Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66047, United States
| | - Cory J Berkland
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, Kansas 66047, United States
- Department of Chemical and Petroleum Engineering, University of Kansas, Lawrence, Kansas 66045, United States
- Bioengineering Program, University of Kansas, Lawrence, Kansas 66045, United States
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5
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So EC, Zhou H, Greenwell A, Burch EE, Ji Y, Mérigeon EY, Olsen HS, Bentzen SM, Block DS, Zhang X, Strome SE. Complement component C1q is an immunological rheostat that regulates Fc:Fc[Formula: see text]R interactions. Immunogenetics 2023:10.1007/s00251-023-01311-x. [PMID: 37322230 DOI: 10.1007/s00251-023-01311-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 06/01/2023] [Indexed: 06/17/2023]
Abstract
Though binding sites for the complement factor C1q and the canonical fragment crystallizable (Fc) gamma receptors (Fc[Formula: see text]Rs) on immunoglobulin G (IgG) molecules overlap, how C1q decoration of immune complexes (ICs) influences their ability to engage Fc[Formula: see text]Rs remains unknown. In this report, we use recombinant human Fc multimers as stable IC mimics to show that C1q engagement of ICs directly and transiently inhibits their interactions with Fc[Formula: see text]RIII (CD16) on human natural killer (NK) cells. This inhibition occurs by C1q engagement alone as well as in concert with other serum factors. Furthermore, the inhibition of Fc[Formula: see text]RIII engagement mediated by avid binding of C1q to ICs is directly associated with IC size and dependent on the concentrations of both C1q and Fc multimers present. Functionally, C1q-mediated Fc blockade limits the ability of NK cells to induce the upregulation of the cosignaling molecule, 4-1BB (CD137), and to mediate antibody-dependent cell-mediated cytotoxicity (ADCC). Although C1q is traditionally viewed as a soluble effector molecule, we demonstrate that C1q may also take on the role of an "immunologic rheostat," buffering Fc[Formula: see text]R-mediated activation of immune cells by circulating ICs. These data define a novel role for C1q as a regulator of immune homeostasis and add to our growing understanding that complement factors mediate pleiotropic effects.
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Affiliation(s)
- Edward C So
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Hua Zhou
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Ariana Greenwell
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Erin E Burch
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Yaping Ji
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | | | | | - Søren M Bentzen
- Department of Epidemiology and Public Health, Division of Biostatistics and Bioinformatics, University of Maryland School of Medicine, Baltimore, MD, USA
| | | | - Xiaoyu Zhang
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Scott E Strome
- Department of Microbiology, Immunology, and Biochemistry, College of Medicine, University of Tennessee Health Science Center (UTHSC), 910 Madison Avenue, 10th floor Suite 1002, Memphis, TN, 38163, USA.
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6
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Novel Therapies to Address Unmet Needs in ITP. Pharmaceuticals (Basel) 2022; 15:ph15070779. [PMID: 35890078 PMCID: PMC9318546 DOI: 10.3390/ph15070779] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 06/16/2022] [Accepted: 06/20/2022] [Indexed: 02/04/2023] Open
Abstract
Primary immune thrombocytopenia (ITP) is an autoimmune disorder that causes low platelet counts and subsequent bleeding risk. Although current corticosteroid-based ITP therapies are able to improve platelet counts, up to 70% of subjects with an ITP diagnosis do not achieve a sustained clinical response in the absence of treatment, thus requiring a second-line therapy option as well as additional care to prevent bleeding. Less than 40% of patients treated with thrombopoietin analogs, 60% of those treated with splenectomy, and 20% or fewer of those treated with rituximab or fostamatinib reach sustained remission in the absence of treatment. Therefore, optimizing therapeutic options for ITP management is mandatory. The pathophysiology of ITP is complex and involves several mechanisms that are apparently unrelated. These include the clearance of autoantibody-coated platelets by splenic macrophages or by the complement system, hepatic desialylated platelet destruction, and the inhibition of platelet production from megakaryocytes. The number of pathways involved may challenge treatment, but, at the same time, offer the possibility of unveiling a variety of new targets as the knowledge of the involved mechanisms progresses. The aim of this work, after revising the limitations of the current treatments, is to perform a thorough review of the mechanisms of action, pharmacokinetics/pharmacodynamics, efficacy, safety, and development stage of the novel ITP therapies under investigation. Hopefully, several of the options included herein may allow us to personalize ITP management according to the needs of each patient in the near future.
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7
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Lewis BJ, Binnington B, Blacquiere M, Spirig R, Käsermann F, Branch DR. Mechanism of increased efficacy of recombinant Fc‐μTP‐L309C compared to IVIg to ameliorate mouse immune thrombocytopenia. EJHAEM 2021; 2:789-793. [PMID: 35845218 PMCID: PMC9175896 DOI: 10.1002/jha2.304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 09/06/2021] [Accepted: 09/09/2021] [Indexed: 11/06/2022]
Affiliation(s)
- Bonnie J.B. Lewis
- Donald R. Branch, BS, MT(ASCP)SBB, PhD Donald R. Branch, BS, MT(ASCP)SBB, PhD 30 Bond Street, Keenan Research Centre Toronto M5B 1W8 Canada
- Department of Laboratory Medicine and Pathobiology University of Toronto Toronto Canada
| | - Beth Binnington
- Donald R. Branch, BS, MT(ASCP)SBB, PhD Donald R. Branch, BS, MT(ASCP)SBB, PhD 30 Bond Street, Keenan Research Centre Toronto M5B 1W8 Canada
| | - Megan Blacquiere
- Donald R. Branch, BS, MT(ASCP)SBB, PhD Donald R. Branch, BS, MT(ASCP)SBB, PhD 30 Bond Street, Keenan Research Centre Toronto M5B 1W8 Canada
| | - Rolf Spirig
- Research, CSL Biologics Research Center CSL Behring AG Wankdorfstrasse 10 Bern 3010 Switzerland
| | - Fabian Käsermann
- Research, CSL Biologics Research Center CSL Behring AG Wankdorfstrasse 10 Bern 3010 Switzerland
| | - Donald R. Branch
- Donald R. Branch, BS, MT(ASCP)SBB, PhD Donald R. Branch, BS, MT(ASCP)SBB, PhD 30 Bond Street, Keenan Research Centre Toronto M5B 1W8 Canada
- Department of Medicine University of Toronto Toronto Canada
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8
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Kuter DJ. Novel therapies for immune thrombocytopenia. Br J Haematol 2021; 196:1311-1328. [PMID: 34611885 DOI: 10.1111/bjh.17872] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 09/17/2021] [Accepted: 09/19/2021] [Indexed: 01/02/2023]
Abstract
Current therapies for immune thrombocytopenia (ITP) are successful in providing a haemostatic platelet count in over two-thirds of patients. Still, some patients have an inadequate response and there is a need for other therapies. A number of novel therapies for ITP are currently being developed based upon the current pathophysiology of ITP. Many therapies are targetted at reducing platelet destruction by decreasing anti-platelet antibody production by immunosuppression with monoclonal antibodies targetted against CD40, CD38 and the immunoproteasome or physically reducing the anti-platelet antibody concentration by inhibition of the neonatal Fc receptor. Others target the phagocytic system by inhibiting FcγR function with staphylococcal protein A, hypersialylated IgG, polymeric Fc fragments, or Bruton kinase. With a recognition that platelet destruction is also mediated by complement, inhibitors of C1s are also being tested. Inhibition of platelet desialylation may also play a role. Other novel therapies promote platelet production with new oral thrombopoietin receptor agonists or the use of low-level laser light to improve mitochondrial activity and prevent megakaryocyte apoptosis. This review will focus on these novel mechanisms for treating ITP and assess the status of treatments currently under development. Successful new treatments for ITP might also provide a pathway to treat other autoimmune disorders.
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Affiliation(s)
- David J Kuter
- Hematology Division, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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9
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Baksmeier C, Blundell P, Steckel J, Schultz V, Gu Q, Da Silva Filipe A, Kohl A, Linnington C, Lu D, Dell A, Haslam S, Wang J, Czajkowsky D, Goebels N, Pleass RJ. Modified recombinant human IgG1-Fc is superior to natural intravenous immunoglobulin at inhibiting immune-mediated demyelination. Immunology 2021; 164:90-105. [PMID: 33880776 PMCID: PMC8358725 DOI: 10.1111/imm.13341] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 03/23/2021] [Accepted: 03/31/2021] [Indexed: 12/13/2022] Open
Abstract
Intravenous immunoglobulin (IVIG) is an established treatment for numerous autoimmune conditions. Although Fc fragments derived from IVIG have shown efficacy in controlling immune thrombocytopenia in children, the mechanisms of action are unclear and controversial. The aim of this study was to dissect IVIG effector mechanisms using further adapted Fc fragments on demyelination in an ex vivo model of the central nervous system-immune interface. Using organotypic cerebellar slice cultures (OSCs) from transgenic mice, we induced extensive immune-mediated demyelination and oligodendrocyte loss with an antibody specific for myelin oligodendrocyte glycoprotein (MOG) and complement. Protective effects of adapted Fc fragments were assessed by live imaging of green fluorescent protein expression, immunohistochemistry and confocal microscopy. Cysteine- and glycan-adapted Fc fragments protected OSC from demyelination in a dose-dependent manner where equimolar concentrations of either IVIG or control Fc were ineffective. The protective effects of the adapted Fc fragments are partly attributed to interference with complement-mediated oligodendroglia damage. Transcriptome analysis ruled out signatures associated with inflammatory or innate immune responses. Taken together, our findings show that recombinant biomimetics can be made that are at least two hundred-fold more effective than IVIG in controlling demyelination by anti-MOG antibodies.
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Affiliation(s)
- Christine Baksmeier
- Department of NeurologyMedical FacultyHeinrich‐Heine‐University DuesseldorfDuesseldorfGermany
| | - Pat Blundell
- Department of Tropical Disease BiologyLiverpool School of Tropical MedicineLiverpoolUK
| | - Julia Steckel
- Department of NeurologyMedical FacultyHeinrich‐Heine‐University DuesseldorfDuesseldorfGermany
| | - Verena Schultz
- Institute of Infection, Immunity and InflammationCollege of Medical Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | - Quan Gu
- Institute of Infection, Immunity and InflammationCollege of Medical Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | - Ana Da Silva Filipe
- Institute of Infection, Immunity and InflammationCollege of Medical Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | - Alain Kohl
- Institute of Infection, Immunity and InflammationCollege of Medical Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | - Chris Linnington
- Institute of Infection, Immunity and InflammationCollege of Medical Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | - Dongli Lu
- Department of Life SciencesImperial College LondonLondonUK
| | - Anne Dell
- Department of Life SciencesImperial College LondonLondonUK
| | - Stuart Haslam
- Department of Life SciencesImperial College LondonLondonUK
| | - Jiabin Wang
- Shanghai Center for Systems BiomedicineKey Laboratory of Systems Biomedicine (Ministry of Education)Shanghai Jiao Tong UniversityShanghaiChina
| | - Dan Czajkowsky
- State Key Laboratory for Oncogenes and Related Genes and Bio‐ID CenterSchool of Biomedical EngineeringShanghai Jiao Tong UniversityShanghaiChina
| | - Norbert Goebels
- Department of NeurologyMedical FacultyHeinrich‐Heine‐University DuesseldorfDuesseldorfGermany
| | - Richard J. Pleass
- Department of Tropical Disease BiologyLiverpool School of Tropical MedicineLiverpoolUK
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10
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New insights into IVIg mechanisms and alternatives in autoimmune and inflammatory diseases. Curr Opin Hematol 2021; 27:392-398. [PMID: 32868670 DOI: 10.1097/moh.0000000000000609] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE OF REVIEW Intravenous immunoglobulin (IVIg) is an effective treatment for an increasing number of autoimmune and inflammatory conditions. However, IVIg continues to be limited by problems of potential shortages and cost. A number of mechanisms have been described for IVIg, which have been captured in newly emergent IVIg mimetic and IVIg alternative therapies. This review discusses the recent developments in IVIg mimetics and alternatives. RECENT FINDINGS Newly emergent IVIg mimetics and alternatives capture major proposed mechanisms of IVIg, including FcγR blockade, FcRn inhibition, complement inhibition, immune complex mimetics and sialylated IgG. Many of these emergent therapies have promising preclinical and clinical trial results. SUMMARY Significant research has been undertaken into the mechanism of IVIg in the treatment of autoimmune and inflammatory disease. Understanding the major IVIg mechanisms has allowed for rational development of IVIg mimetics and alternatives for several IVIg-treatable diseases.
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11
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Fc-Receptor Targeted Therapies for the Treatment of Myasthenia gravis. Int J Mol Sci 2021; 22:ijms22115755. [PMID: 34071155 PMCID: PMC8198115 DOI: 10.3390/ijms22115755] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/24/2021] [Accepted: 05/25/2021] [Indexed: 12/16/2022] Open
Abstract
Myasthenia gravis (MG) is an autoimmune disease in which immunoglobulin G (IgG) antibodies (Abs) bind to acetylcholine receptors (AChR) or to functionally related molecules in the postsynaptic membrane at the neuromuscular junction. IgG crystallizable fragment (Fc)-mediated effector functions, such as antibody-dependent complement deposition, contribute to disease development and progression. Despite progress in understanding Ab-mediated disease mechanisms, immunotherapy of MG remained rather unspecific with corticosteroids and maintenance with immunosuppressants as first choice drugs for most patients. More specific therapeutic IgG Fc-based platforms that reduce serum half-life or effector functions of pathogenic MG-related Abs are currently being developed, tested in clinical trials or have recently been successfully translated into the clinic. In this review, we illustrate mechanisms of action and clinical efficacies of emerging Fc-mediated therapeutics such as neonatal Fc receptor (FcRn)-targeting agents. Furthermore, we evaluate prospects of therapies targeting classical Fc receptors that have shown promising therapeutic efficacy in other antibody-mediated conditions. Increased availability of Fc- and Fc receptor-targeting biologics might foster the development of personalized immunotherapies with the potential to induce sustained disease remission in patients with MG.
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12
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Emerging Therapies in Immune Thrombocytopenia. J Clin Med 2021; 10:jcm10051004. [PMID: 33801294 PMCID: PMC7958340 DOI: 10.3390/jcm10051004] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 02/17/2021] [Accepted: 02/18/2021] [Indexed: 12/11/2022] Open
Abstract
Immune thrombocytopenia (ITP) is a rare autoimmune disorder caused by peripheral platelet destruction and inappropriate bone marrow production. The management of ITP is based on the utilization of steroids, intravenous immunoglobulins, rituximab, thrombopoietin receptor agonists (TPO-RAs), immunosuppressants and splenectomy. Recent advances in the understanding of its pathogenesis have opened new fields of therapeutic interventions. The phagocytosis of platelets by splenic macrophages could be inhibited by spleen tyrosine kinase (Syk) or Bruton tyrosine kinase (BTK) inhibitors. The clearance of antiplatelet antibodies could be accelerated by blocking the neonatal Fc receptor (FcRn), while new strategies targeting B cells and/or plasma cells could improve the reduction of pathogenic autoantibodies. The inhibition of the classical complement pathway that participates in platelet destruction also represents a new target. Platelet desialylation has emerged as a new mechanism of platelet destruction in ITP, and the inhibition of neuraminidase could dampen this phenomenon. T cells that support the autoimmune B cell response also represent an interesting target. Beyond the inhibition of the autoimmune response, new TPO-RAs that stimulate platelet production have been developed. The upcoming challenges will be the determination of predictive factors of response to treatments at a patient scale to optimize their management.
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13
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Shock A, Humphreys D, Nimmerjahn F. Dissecting the mechanism of action of intravenous immunoglobulin in human autoimmune disease: Lessons from therapeutic modalities targeting Fcγ receptors. J Allergy Clin Immunol 2020; 146:492-500. [PMID: 32721416 DOI: 10.1016/j.jaci.2020.06.036] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 06/25/2020] [Accepted: 06/29/2020] [Indexed: 12/18/2022]
Abstract
Since the first description of the administration of high doses of pooled serum IgG, also referred to as intravenous IgG (IVIg) therapy, as being able to ameliorate various autoimmune diseases, researchers have been investigating which molecular and cellular pathways underlie IVIg activity. Apart from trying to understand the obvious conundrum that IgG can trigger both autoimmune pathology and resolution of inflammation, the rapidly expanding use of IVIg has led to a lack of availability of this primary blood product, providing a strong rationale for developing recombinant alternatives. During the last decade, a tremendous number of novel insights into IVIg activity brought the goal of replacing IVIg within reach, at least in select indications, and has led to the initiation of several clinical trials. At the forefront of this effort is the modulation of autoantibody half-life and blocking access of autoantibodies to fragment cystallizable γ receptors (Fcγ receptors). In this rostrum article, we will briefly discuss current models of IVIg activity, followed by a more specific focus on novel therapeutic avenues that are entering the clinic and may replace IVIg in the future.
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Affiliation(s)
| | | | - Falk Nimmerjahn
- Institute of Genetics, Department of Biology, Friedrich Alexander University of Erlangen-Nuremberg, Erlangen, Germany; Medical Immunology Campus Erlangen, Erlangen, Germany.
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14
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Lewis BJ, Branch DR. Mouse Models of Rheumatoid Arthritis for Studies on Immunopathogenesis and Preclinical Testing of Fc Receptor-Targeting Biologics. Pharmacology 2020; 105:618-629. [DOI: 10.1159/000508239] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 04/27/2020] [Indexed: 11/19/2022]
Abstract
<b><i>Background:</i></b> Rheumatoid arthritis (RA) is a chronic autoimmune disease that causes inflammation, swelling, and pain in the joints and involves systemic complications. Mouse models of RA have been extensively used to model the pathogenesis of RA and to develop effective therapies. Although many components of the immune system have been studied in these models, the role of crystallizable fragment (Fc) gamma receptors (FcγRs) in RA has been sorely neglected. The aim of this review was to introduce the different mouse models of RA and to describe the different drug development strategies that have been tested in these models to target FcγR function, with the focus being on drugs that have been made from the Fc of immunoglobulin G (IgG). <b><i>Summary:</i></b> Evidence suggests that FcγRs play a major role in immune complex-induced inflammation in autoimmune diseases, such as RA. However, there is limited knowledge on the importance of FcγRs in the human disease even though there has been extensive work in mouse models of RA. Numerous mouse models of RA are available, with each model depicting certain aspects of the disease. Induced models of RA have nonspecific immune activation with cartilage-directed autoimmunity, whereas spontaneous models of RA develop without immunization, which results in a more chronic form of arthritis. These models have been used to test FcγR-targeting monoclonal antibodies, intravenous immunoglobulin (IVIg), subcutaneously administered IVIg, and recombinant Fcs for their ability to interact with and modify FcγR function. Recombinant Fcs avidly bind FcγRs and exhibit enhanced therapeutic efficacy in mouse models of RA. <b><i>Key Message:</i></b> The therapeutic utility of targeting FcγRs with recombinant Fcs is great and should be explored in human clinical trials for autoimmune diseases, such as RA.
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Goldberg BS, Ackerman ME. Antibody-mediated complement activation in pathology and protection. Immunol Cell Biol 2020; 98:305-317. [PMID: 32142167 DOI: 10.1111/imcb.12324] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 02/27/2020] [Accepted: 03/03/2020] [Indexed: 01/10/2023]
Abstract
Antibody-dependent complement activity is associated not only with autoimmune morbidity, but also with antitumor efficacy. In infectious disease, both recombinant monoclonal antibodies and polyclonal antibodies generated in natural adaptive responses can mediate complement activity to protective, therapeutic or disease-enhancing effect. Recent advances have contributed to the structural resolution of molecular complexes involved in antibody-mediated complement activation, defining the avid nature of participating interactions and pointing to how antibody isotype, subclass, hinge flexibility, glycosylation state, amino acid sequence and the contextual nature of the cognate antigen/epitope are all factors that can determine complement activity through impact on antibody multimerization and subsequent recruitment of complement component 1q. Beyond the efficiency of activation, complement activation products interact with various cell types that mediate immune adherence, trafficking, immune education and innate functions. Similarly, depending on the anatomical location and extent of activation, complement can support homeostatic restoration or be leveraged by pathogens or neoplasms to enhance infection or promote tumorigenic microenvironments, respectively. Advances in means to suppress complement activation by intravenous immunoglobulin (IVIG), IVIG mimetics and complement-intervening antibodies represent proven and promising exploratory therapeutic strategies, while antibody engineering has likewise offered frameworks to enhance, eliminate or isolate complement activation to interrogate in vivo mechanisms of action. Such strategies promise to support the optimization of antibody-based drugs that are able to tackle emerging and difficult-to-treat diseases by improving our understanding of the synergistic and antagonistic relationships between antibody mechanisms mediated by Fc receptors, direct binding and the products of complement activation.
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Affiliation(s)
| | - Margaret E Ackerman
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA.,Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
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16
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Fitzpatrick EA, Wang J, Strome SE. Engineering of Fc Multimers as a Protein Therapy for Autoimmune Disease. Front Immunol 2020; 11:496. [PMID: 32269572 PMCID: PMC7109252 DOI: 10.3389/fimmu.2020.00496] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 03/04/2020] [Indexed: 02/06/2023] Open
Abstract
The success of Intravenous Immunoglobulin in treating autoimmune and inflammatory processes such as immune thrombocytopenia purpura and Kawasaki disease has led to renewed interest in developing recombinant molecules capable of recapitulating these therapeutic effects. The anti-inflammatory properties of IVIG are, in part, due to the Fc region of the IgG molecule, which interacts with activating or inhibitory Fcγ receptors (FcγRs), the neonatal Fc Receptor, non-canonical FcRs expressed by immune cells and complement proteins. In most cases, Fc interactions with these cognate receptors are dependent upon avidity—avidity which naturally occurs when polyclonal antibodies recognize unique antigens on a given target. The functional consequences of these avid interactions include antibody dependent cell-mediated cytotoxicity, antibody dependent cell phagocytosis, degranulation, direct killing, and/or complement activation—all of which are associated with long-term immunomodulatory effects. Many of these immunologic effects can be recapitulated using recombinant or non-recombinant approaches to induce Fc multimerization, affording the potential to develop a new class of therapeutics. In this review, we discuss the history of tolerance induction by immune complexes that has led to the therapeutic development of artificial Fc bearing immune aggregates and recombinant Fc multimers. The contribution of structure, aggregation and N-glycosylation to human IgG: FcγR interactions and the functional effect(s) of these interactions are reviewed. Understanding the mechanisms by which Fc multimers induce tolerance and attempts to engineer Fc multimers to target specific FcγRs and/or specific effector functions in autoimmune disorders is explored in detail.
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Affiliation(s)
- Elizabeth A Fitzpatrick
- Department of Microbiology, Immunology and Biochemistry, College of Medicine, University of Tennessee Health Science Center (UTHSC), Memphis, TN, United States
| | - Jin Wang
- College of Graduate Health Sciences, University of Tennessee Health Science Center, Memphis, TN, United States
| | - S E Strome
- Department of Microbiology, Immunology and Biochemistry, College of Medicine, University of Tennessee Health Science Center (UTHSC), Memphis, TN, United States
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17
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Lewis BJB, Ville J, Blacquiere M, Cen S, Spirig R, Zuercher AW, Käsermann F, Branch DR. Using the K/BxN mouse model of endogenous, chronic, rheumatoid arthritis for the evaluation of potential immunoglobulin-based therapeutic agents, including IVIg and Fc-μTP-L309C, a recombinant IgG1 Fc hexamer. BMC Immunol 2019; 20:44. [PMID: 31801459 PMCID: PMC6894239 DOI: 10.1186/s12865-019-0328-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Accepted: 11/21/2019] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND High-dose intravenous immunoglobulin (IVIg), and more recently, subcutaneously-delivered Ig (SCIg), are used to treat a variety of autoimmune diseases; however, there are challenges associated with product production, availability, access and efficacy. These challenges have provided incentives to develop a human recombinant Fc as a more potent alternative to IVIg and SCIg for the treatment of autoimmune diseases. Recently, a recombinant human IgG1 Fc hexamer (Fc-μTP-L309C) was shown to be more efficacious than IVIg in a variety of autoimmune mouse models. We have now examined its efficacy compared to IVIg and SCIg in the K/BxN mouse model of endogenous, chronic rheumatoid arthritis (RA). RESULT Using the serum-transfer K/BxN model and the endogenous autoimmune model, amelioration of the arthritis was achieved. Effective treatment required high and frequent doses of IVIg, SCIg and Fc-μTP-L309C. However, Fc-μTP-L309C was efficacious at 10-fold lower doses that IVIg/SCIg. Also, arthritis could be prevented when Fc-μTP-L309C was given prior to onset of the arthritis in both the endogenous model and in the serum transfer model. CONCLUSIONS Our results show that Fc-μTP-L309C is a powerful treatment for the prevention and amelioration of severe, chronic arthritis in a true autoimmune mouse model of RA. Thus, the K/BxN endogenous arthritis model should be useful for testing potential therapeutics for RA. Our findings provide rationale for further examination of the treatment efficacy of immunoglobulin-based therapeutics in rheumatoid arthritis.
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Affiliation(s)
- Bonnie J B Lewis
- Department of Laboratory Medicine and Pathobiology, University of Toronto, 67 College St., Toronto, Ontario, M5G 2M1, Canada.,Centre for Innovation, Canadian Blood Services, 67 College St., Toronto, Ontario, M5G 2M1, Canada
| | - Jade Ville
- Centre for Innovation, Canadian Blood Services, 67 College St., Toronto, Ontario, M5G 2M1, Canada.,School for Biology-Biochemistry-Biotechnology, Catholic University of Lyon, 10 place des Archives, 69288, Lyon Cedex 02, France
| | - Megan Blacquiere
- Centre for Innovation, Canadian Blood Services, 67 College St., Toronto, Ontario, M5G 2M1, Canada
| | - Selena Cen
- Centre for Innovation, Canadian Blood Services, 67 College St., Toronto, Ontario, M5G 2M1, Canada
| | - Rolf Spirig
- CSL Behring, Research, CSL Biologics Research Center, Wankdorfstrasse 10, 3010, Bern, Switzerland
| | - Adrian W Zuercher
- CSL Behring, Research, CSL Biologics Research Center, Wankdorfstrasse 10, 3010, Bern, Switzerland
| | - Fabian Käsermann
- CSL Behring, Research, CSL Biologics Research Center, Wankdorfstrasse 10, 3010, Bern, Switzerland
| | - Donald R Branch
- Department of Laboratory Medicine and Pathobiology, University of Toronto, 67 College St., Toronto, Ontario, M5G 2M1, Canada. .,Centre for Innovation, Canadian Blood Services, 67 College St., Toronto, Ontario, M5G 2M1, Canada. .,Department of Medicine, University of Toronto, 67 College St., Toronto, Ontario, M5G 2M1, Canada.
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18
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Next-generation Fc receptor–targeting biologics for autoimmune diseases. Autoimmun Rev 2019; 18:102366. [DOI: 10.1016/j.autrev.2019.102366] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Accepted: 04/11/2019] [Indexed: 01/04/2023]
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19
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NK cell expression of Tim-3: First impressions matter. Immunobiology 2019; 224:362-370. [DOI: 10.1016/j.imbio.2019.03.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 02/04/2019] [Accepted: 03/01/2019] [Indexed: 12/17/2022]
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20
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Zhang X, Owens J, Olsen HS, So E, Burch E, McCroskey MC, Li X, Weber GL, Bennett D, Rybin D, Zhou H, Hao H, Mérigeon EY, Block DS, LaRosa G, Strome SE. A recombinant human IgG1 Fc multimer designed to mimic the active fraction of IVIG in autoimmunity. JCI Insight 2019; 4:121905. [PMID: 30674715 DOI: 10.1172/jci.insight.121905] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 12/11/2018] [Indexed: 12/30/2022] Open
Abstract
The antiinflammatory effects of i.v. Ig (IVIG) in the treatment of autoimmune disease are due, in part, to the Fc fragments of Ig aggregates. In order to capitalize on the known antiinflammatory and tolerogenic properties of Ig Fc aggregates, we created a recombinant human IgG1 Fc multimer, GL-2045. In vitro, GL-2045 demonstrated high-avidity binding to Fc receptors, blocked the binding of circulating immune complexes from patients with rheumatoid arthritis to human Fcγ receptors (FcγRs), and inhibited antibody-mediated phagocytosis at log order-lower concentrations than IVIG. In vivo, administration of GL-2045 conferred partial protection against antibody-mediated platelet loss in a murine immune thrombocytopenic purpura (ITP) model. GL-2045 also suppressed disease activity in a therapeutic model of murine collagen-induced arthritis (CIA), which was associated with reduced circulating levels of IL-6. Furthermore, GL-2045 administration to nonhuman primates (NHPs) transiently increased systemic levels of the antiinflammatory cytokines IL-10 and IL-1RA, reduced the proinflammatory cytokine IL-8, and decreased surface expression of CD14 and HLA-DR on monocytes. These findings demonstrate the immunomodulatory properties of GL-2045 and suggest that it has potential as a treatment for autoimmune and inflammatory diseases, as a recombinant alternative to IVIG.
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Affiliation(s)
- Xiaoyu Zhang
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Jane Owens
- Pfizer Inc., Cambridge, Massachusetts, USA
| | | | - Edward So
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Erin Burch
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | | | | | | | | | | | - Hua Zhou
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Haiping Hao
- Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | | | | | | | - Scott E Strome
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
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Strome AL, Zhang X, Strome SE. The evolving role of immuno-oncology for the treatment of head and neck cancer. Laryngoscope Investig Otolaryngol 2019; 4:62-69. [PMID: 30828620 PMCID: PMC6383301 DOI: 10.1002/lio2.235] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 10/08/2018] [Accepted: 11/08/2018] [Indexed: 12/13/2022] Open
Abstract
Monoclonal antibodies (mAbs) that target immune co‐signaling pathways have the potential to enable immune mediated tumor eradication. While early adoption of these agents for the treatment of advanced squamous cell carcinoma of the head and neck (SCCHN) has produced some astounding clinical successes, the majority of patients fail to respond to therapy. The purpose of this review is to first provide a broad overview of the immuno‐oncology (I‐O) landscape and to then focus on the current status of mAb‐based I‐O (mAb:I‐O) for the treatment of SCCHN, with particular attention to the development of strategies for improving treatment responses.
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Affiliation(s)
| | - Xiaoyu Zhang
- Department of Otorhinolaryngology-Head and Neck Surgery University of Maryland School of Medicine Baltimore Maryland
| | - Scott E Strome
- Department of Otorhinolaryngology-Head and Neck Surgery University of Maryland School of Medicine Baltimore Maryland.,College of Medicine University of Tennessee Health Science Center Memphis Tennessee
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22
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Spirig R, Campbell IK, Koernig S, Chen CG, Lewis BJB, Butcher R, Muir I, Taylor S, Chia J, Leong D, Simmonds J, Scotney P, Schmidt P, Fabri L, Hofmann A, Jordi M, Spycher MO, Cattepoel S, Brasseit J, Panousis C, Rowe T, Branch DR, Baz Morelli A, Käsermann F, Zuercher AW. rIgG1 Fc Hexamer Inhibits Antibody-Mediated Autoimmune Disease via Effects on Complement and FcγRs. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2018; 200:2542-2553. [PMID: 29531170 PMCID: PMC5890536 DOI: 10.4049/jimmunol.1701171] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 02/13/2018] [Indexed: 12/27/2022]
Abstract
Activation of Fc receptors and complement by immune complexes is a common important pathogenic trigger in many autoimmune diseases and so blockade of these innate immune pathways may be an attractive target for treatment of immune complex-mediated pathomechanisms. High-dose IVIG is used to treat autoimmune and inflammatory diseases, and several studies demonstrate that the therapeutic effects of IVIG can be recapitulated with the Fc portion. Further, recent data indicate that recombinant multimerized Fc molecules exhibit potent anti-inflammatory properties. In this study, we investigated the biochemical and biological properties of an rFc hexamer (termed Fc-μTP-L309C) generated by fusion of the IgM μ-tailpiece to the C terminus of human IgG1 Fc. Fc-μTP-L309C bound FcγRs with high avidity and inhibited FcγR-mediated effector functions (Ab-dependent cell-mediated cytotoxicity, phagocytosis, respiratory burst) in vitro. In addition, Fc-μTP-L309C prevented full activation of the classical complement pathway by blocking C2 cleavage, avoiding generation of inflammatory downstream products (C5a or sC5b-9). In vivo, Fc-μTP-L309C suppressed inflammatory arthritis in mice when given therapeutically at approximately a 10-fold lower dose than IVIG, which was associated with reduced inflammatory cytokine production and complement activation. Likewise, administration of Fc-μTP-L309C restored platelet counts in a mouse model of immune thrombocytopenia. Our data demonstrate a potent anti-inflammatory effect of Fc-μTP-L309C in vitro and in vivo, likely mediated by blockade of FcγRs and its unique inhibition of complement activation.
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Affiliation(s)
| | - Ian K Campbell
- CSL Ltd., Bio21 Institute, Parkville, Victoria 3010, Australia
| | - Sandra Koernig
- CSL Ltd., Bio21 Institute, Parkville, Victoria 3010, Australia
| | - Chao-Guang Chen
- CSL Ltd., Bio21 Institute, Parkville, Victoria 3010, Australia
| | - Bonnie J B Lewis
- Centre for Innovation Canadian Blood Services, Toronto, Ontario K1G 4J5, Canada; and
- Department of Medicine, University of Toronto, Toronto, Ontario M5G 2M1, Canada
| | - Rebecca Butcher
- CSL Ltd., Bio21 Institute, Parkville, Victoria 3010, Australia
| | - Ineke Muir
- CSL Ltd., Bio21 Institute, Parkville, Victoria 3010, Australia
| | - Shirley Taylor
- CSL Ltd., Bio21 Institute, Parkville, Victoria 3010, Australia
| | - Jenny Chia
- CSL Ltd., Bio21 Institute, Parkville, Victoria 3010, Australia
| | - David Leong
- CSL Ltd., Bio21 Institute, Parkville, Victoria 3010, Australia
| | - Jason Simmonds
- CSL Ltd., Bio21 Institute, Parkville, Victoria 3010, Australia
| | - Pierre Scotney
- CSL Ltd., Bio21 Institute, Parkville, Victoria 3010, Australia
| | - Peter Schmidt
- CSL Ltd., Bio21 Institute, Parkville, Victoria 3010, Australia
| | - Louis Fabri
- CSL Ltd., Bio21 Institute, Parkville, Victoria 3010, Australia
| | | | | | | | | | | | - Con Panousis
- CSL Ltd., Bio21 Institute, Parkville, Victoria 3010, Australia
| | - Tony Rowe
- CSL Ltd., Bio21 Institute, Parkville, Victoria 3010, Australia
| | - Donald R Branch
- Centre for Innovation Canadian Blood Services, Toronto, Ontario K1G 4J5, Canada; and
- Department of Medicine, University of Toronto, Toronto, Ontario M5G 2M1, Canada
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23
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Kühne T. Advances in chemical pharmacotherapy for the treatment of pediatric immune thrombocytopenia. Expert Opin Pharmacother 2018; 19:667-676. [PMID: 29589486 DOI: 10.1080/14656566.2018.1458091] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
INTRODUCTION Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder of heterogeneous pathophysiological mechanisms. Treatment endpoints include elevation of platelets and reduction of bleeding risk, elevation of quality of life, reduction of concomitant therapies and prevention from bleeding. Persistent and chronic ITP is more common in adults but occurs in children. Standard therapies include corticosteroids and immunoglobulins, both associated with side effects. There are new treatments, such as thrombopoietin-receptor agonists and promising investigational drugs. AREAS COVERED Experience from the management of adults is valuable for children with persistent and chronic symptomatic ITP. In this review first- and second-line therapies, but also investigational drugs for children with ITP are discussed. EXPERT OPINION Although time-consuming and based on experience, children with no or mild bleeding can be safely managed with a watch and wait strategy. Chronic symptomatic immune thrombocytopenia is an area of second-line treatments based on a highly individualized approach. Furthermore, there are investigational drugs, which may also be of benefit for children with chronic symptomatic ITP.
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Affiliation(s)
- Thomas Kühne
- a Division of Oncology/Hematology , University Children's Hospital , Basel , Switzerland
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Recombinant human IgG1 based Fc multimers, with limited FcR binding capacity, can effectively inhibit complement-mediated disease. J Autoimmun 2017; 84:97-108. [PMID: 28830653 DOI: 10.1016/j.jaut.2017.08.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 08/09/2017] [Accepted: 08/10/2017] [Indexed: 12/13/2022]
Abstract
There is a lack of effective targeted therapies for the treatment of complement dependent diseases. We developed two recombinant Fc multimers, G207 and G211, with limited ability to interact with low/moderate affinity FcγRs, but with high avidity for C1q. These drugs effectively inhibited complement dependent cytotoxicity (CDC) in vitro, and prevented the deposition of C1q, C3b and MAC, on the surface of Ab-opsonized cells. Importantly, these inhibitory effects were both C1q dependent and independent. In order to determine the biologic relevance of our findings, we evaluated the clinical efficacy of these drugs in three different animal models, acute RBC hemolysis, anti-Thy-1 nephritis and passive Heymann's nephropathy (PHN), in which disease pathophysiology relies preferentially on complement activation. While G207 was protective in the anti-Thy-1 nephritis and PHN models, G211 was protective in all of the models tested and could effectively treat PHN. In the anti-Thy-1 nephritis model, G211 prevented the characteristic histologic changes associated with the disease and limited glomerular deposition of C3. Collectively, these data suggest that "complement preferential" Fc multimers offer a novel approach to the treatment of complement mediated diseases.
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