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Yang Y, Shen Z, Shi F, Wang F, Wen N. Efgartigimod as a novel FcRn inhibitor for autoimmune disease. Neurol Sci 2024:10.1007/s10072-024-07460-5. [PMID: 38644454 DOI: 10.1007/s10072-024-07460-5] [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: 11/13/2023] [Accepted: 03/11/2024] [Indexed: 04/23/2024]
Abstract
Immunoglobulin G (IgG) autoantibodies can lead to the formation of autoimmune diseases through Fab and/or Fc-mediated interactions with host molecules as well as activated T cells. The neonatal Fc receptor (FcRn) binds at acidic pH IgG and albumin, and the mechanism for prolonging serum IgG half-life is making IgG re-entry into circulation by prompting it not to be degraded by lysosomes and back to the cell surface. Given the FcRn receptor's essential role in IgG homeostasis, one of the strategies to promote the quick degradation of endogenous IgG is to suppress the function of FcRn, which is beneficial to the treatment of IgG-driven autoimmune disorders like myasthenia gravis (MG), chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), stiff person syndrome, and immune thrombocytopenia (ITP). We elaborately read the literature about efgartigimod and systematically reviewed the research progress and clinical application of this novel FcRn inhibitor in autoimmune diseases. Efgartigimod is the firstly FcRn antagonist developed and was approved on 17 December 2021 by the United States for the therapy of acetylcholine receptor-positive MG. In January 2022, efgartigimod received its second regulatory approval in Japan. In addition, the market authorization application in Europe was submitted and validated in August 2021. China's National Medical Products Administration officially accepted the marketing application of efgartigimod on July 13, 2022. To suppress the function of FcRn, which is beneficial to the treatment of IgG-driven autoimmune disorders like MG, CIDP, ITP, and stiff person syndrome. We review the rationale, clinical evidence, and future perspectives of efgartigimod for the treatment of autoimmune disease.
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Affiliation(s)
- Yun Yang
- Department of Stomatology, Yantai Yuhuangding Hospital, Yantai, Shandong, 264000, China
| | - Zhengxuan Shen
- Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, Zhejiang, 310000, China
| | - Fan Shi
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Center for Oral Diseases, Shaanxi Clinical Research Center for Oral Diseases, Department of Oral and Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University, Shan'xi, Xi'an, 710000, China
| | - Fei Wang
- Department of Pharmacy, Yantai Yuhuangding Hospital, Yantai, Shandong, 264000, China.
| | - Ning Wen
- Department of Orthodontics, Hangzhou Dental Hospital, Hangzhou, Zhejiang, 310003, People's Republic of China.
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Mehrabyan A, Traub RE. Retrospective review of patients with myasthenia gravis switched from plasma exchange therapy to efgartigimod treatment. Muscle Nerve 2024; 69:467-471. [PMID: 38284651 DOI: 10.1002/mus.28042] [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: 03/17/2023] [Revised: 01/12/2024] [Accepted: 01/14/2024] [Indexed: 01/30/2024]
Abstract
INTRODUCTION/AIMS Therapeutic plasma exchange (TPE) is sometimes used as maintenance therapy for the treatment of myasthenia gravis (MG). Efgartigimod is a newly approved monoclonal antibody targeting the neonatal Fc receptor, effectively reducing immunoglobulin G levels in the treatment of MG. The aim of this study was to describe the clinical experience of switching patients from maintenance TPE treatment to efgartigimod infusions. METHODS A retrospective review of medical records was performed on patients previously treated with maintenance TPE for the diagnosis of MG and subsequently switched to efgartigimod infusions. Clinical characteristics and response to treatment switch were described. RESULTS Five of seven patients demonstrated improvement on Myasthenia Gravis Foundation of America-post intervention status, one was unchanged and one was in pharmacological remission. This was reflected in pre- and postswitch MG activities of daily living and MG manual muscle testing scores. All patients have continued on efgartigimod therapy. The duration of treatment with efgartigimod at the time of this review ranged from 1 to 13 months. Recurrent uncomplicated infections were noted in two patients on efgartigimod therapy. Maintenance dosing regimens of efgartigimod varied based on clinical response to treatment and side effects. DISCUSSION In this series, efgartigimod appeared effective and well tolerated in patients switched from TPE.
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Affiliation(s)
| | - Rebecca E Traub
- University of North Carolina, Chapel Hill, North Carolina, USA
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Hawkes MA, Wijdicks EFM. Improving Outcome in Severe Myasthenia Gravis and Guillain-Barré Syndrome. Semin Neurol 2024. [PMID: 38560985 DOI: 10.1055/s-0044-1785509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
When progressive and severe, myasthenia gravis and Guillain-Barré syndrome may have the potential for fatal and unfavorable clinical outcomes. Regardless of important differences in their clinical course, the development of weakness of oropharyngeal muscles and respiratory failure with requirement of mechanical ventilation is the main driver of poor prognosis in both conditions. The need for prolonged mechanical ventilation is particularly relevant because it immobilizes the patient and care becomes extraordinarily complex due to daily risks of systemic complications. Additionally, patients with myasthenia gravis often require long-term immunosuppressive treatments with associated toxicity and infectious risks. Unlike myasthenia gravis, the recovery period is prolonged in Guillain-Barré syndrome, but often favorable, even in the more severely affected patients. Outcome, for a large part, is determined by expert neurocritical care.
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Affiliation(s)
- Maximiliano A Hawkes
- Department of Neurology, Neurocritical Care Services, Mayo Clinic, Rochester, Minnesota
| | - Eelco F M Wijdicks
- Department of Neurology, Neurocritical Care Services, Mayo Clinic, Rochester, Minnesota
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Sneed SL, Reese BB, Laureano AF, Ratnapriya S, Fraschilla I, Jeffrey KL, Coffey GP, Conley PB, Anthony RM. An engineered immunomodulatory IgG1 Fc suppresses autoimmune inflammation through pathways shared with i.v. immunoglobulin. J Clin Invest 2024; 134:e172980. [PMID: 38357917 PMCID: PMC10866649 DOI: 10.1172/jci172980] [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: 06/09/2023] [Accepted: 12/27/2023] [Indexed: 02/16/2024] Open
Abstract
Immunoglobulin G (IgG) antibodies in the form of high-dose intravenous immunoglobulin (IVIG) exert immunomodulatory activity and are used in this capacity to treat inflammatory and autoimmune diseases. Reductionist approaches have revealed that terminal sialylation of the single asparagine-linked (N-linked) glycan at position 297 of the IgG1 Fc bestows antiinflammatory activity, which can be recapitulated by introduction of an F241A point mutation in the IgG1 Fc (FcF241A). Here, we examined the antiinflammatory activity of CHO-K1 cell-produced FcF241A in vivo in models of autoimmune inflammation and found it to be independent of sialylation. Intriguingly, sialylation markedly improved the half-life and bioavailability of FcF241A via impaired interaction with the asialoglycoprotein receptor ASGPR. Further, FcF241A suppressed inflammation through the same molecular pathways as IVIG and sialylated IgG1 Fc and required the C-type lectin SIGN-R1 in vivo. This contrasted with FcAbdeg (efgartigimod), an engineered IgG1 Fc with enhanced neonatal Fc receptor (FcRn) binding, which reduced total serum IgG concentrations, independent of SIGN-R1. When coadministered, FcF241A and FcAbdeg exhibited combinatorial antiinflammatory activity. Together, these results demonstrated that the antiinflammatory activity of FcF241A requires SIGN-R1, similarly to that of high-dose IVIG and sialylated IgG1, and can be used in combination with other antiinflammatory therapeutics that rely on divergent pathways, including FcAbdeg.
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Affiliation(s)
- Sunny L. Sneed
- Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Harvard Medical School, and
| | - Brian B. Reese
- Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Harvard Medical School, and
| | - Ana F.S. Laureano
- Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Harvard Medical School, and
| | - Sneha Ratnapriya
- Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Harvard Medical School, and
| | - Isabella Fraschilla
- Center for the Study of Inflammatory Bowel Disease, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Kate L. Jeffrey
- Center for the Study of Inflammatory Bowel Disease, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | | | | | - Robert M. Anthony
- Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Harvard Medical School, and
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Harrison A, Mudhar O, Yoo J, Rampal M. Diplopia in a patient presenting with "blurred vision": a case report. J Med Case Rep 2023; 17:402. [PMID: 37679826 PMCID: PMC10485954 DOI: 10.1186/s13256-023-04089-4] [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: 05/30/2023] [Accepted: 07/18/2023] [Indexed: 09/09/2023] Open
Abstract
BACKGROUND Myasthenia gravis is an autoimmune condition affecting the neuromuscular junction and causing muscle weakness along with fatigue (myasthenia). When the clinical manifestations of myasthenia gravis are isolated to the eye muscles, only causing weak eye movements, it is referred to as ocular myasthenia gravis, which can mimic a 1 and ½ syndrome. CASE PRESENTATION An African-American female in her fifties with past medical history of hypertension presented to our outpatient clinic with complaints of blurred vision for two weeks. Her symptoms were associated with facial discomfort and a generalized headache. On physical examination upon her initial presentation, there was demonstratable swelling of the left upper eyelid with drooping. Her extraocular movements revealed defects with the abduction and adduction of the right eye, and the left eye would not adduct, although the outward movement was normal. The left eye failed to lift/elevate completely when looking upwards, a pseudo 1 and ½ syndrome. A positive Cogan lid twitch was also noticed. Imaging of the brain and orbit ruled out central causes. Diagnosis of ocular myasthenia gravis was made in accordance with positive anti-acetylcholine receptor antibodies. With 120 mg pyridostigmine oral dose, the patient experienced improvement subjectively and objectively, and the patient was discharged on oral pyridostigmine and prednisone. Six months later, with prednisone having been tapered off, the patient developed a myasthenic crisis and was treated with plasmapheresis and intravenous immunoglobulins. After recovering from the myasthenic crisis, efgartigimod infusions were instituted, which helped our patient restore normal life. CONCLUSION Our patient who presented with "blurred vision" was discovered to have binocular diplopia due to significant dysconjugate eye movements. After diligently ruling out central etiologies, we concluded that her presentation was due to a peripheral etiology. Her serologies and her presentation helped confirm a diagnosis of ocular myasthenia gravis. Also, as in most cases, our patient also progressed to develop generalized myasthenia gravis while on pyridostigmine. Efgartigimod infusions instituted after our patient recovered from a myasthenic crisis have helped her restore a normal life.
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Affiliation(s)
- Anil Harrison
- Department of Internal Medicine, UCF/HCA, Pensacola, FL, USA
| | - Onkar Mudhar
- Internal Medicine Resident, Department of Internal Medicine, Touro University, Stockton, CA, USA
| | - Jun Yoo
- Department of Internal Medicine, UCF/HCA, Pensacola, FL, USA.
| | - Mayank Rampal
- Department of Internal Medicine, UCF/HCA, Pensacola, FL, USA
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Dos Santos JBR, Gomes RM, da Silva MRR. Abdeg technology for the treatment of myasthenia gravis: efgartigimod drug experience. Expert Rev Clin Immunol 2022; 18:879-888. [PMID: 35892247 DOI: 10.1080/1744666x.2022.2106972] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Myasthenia gravis is characterized by fluctuating muscle weakness that improves with rest and worsens with effort or throughout the day. AREAS COVERED Efgartigimod is a human IgG1-derived Fc fragment modified at five residues to increase its affinity for the neonatal Fc receptor by Abdeg technology. Thus, efgartigimod binds to the neonatal Fc receptor and decreases the levels of IgG, including autoantibodies of this isotype. For acetylcholine receptor (AChR) antibody-positive patients, efgartigimod had a higher proportion of MG-ADL responders than placebo in the first treatment cycle. The mean changes of multiple outcomes from baseline were better for efgartigimod than placebo from weeks 1 to 7 in the first treatment cycle. The decrease of IgG and AChR autoantibodies was 61.3% and 57.6% one week after the first treatment cycle ends, respectively. The most common adverse events were headache, nasopharyngitis, nausea, and diarrhea, which occurred in the same proportion in the efgartigimod and placebo groups. Urinary and upper respiratory tract infections were twice as frequent in efgartigimod-treated patients. EXPERT OPINION Efgartigimod was efficacious and safe for generalized myasthenia patients with AChR antibody-positive patients. These findings need to be confirmed in AChR antibody-negative patients, and long-term safety studies are currently ongoing.
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Affiliation(s)
- Jéssica Barreto Ribeiro Dos Santos
- Health Economics and Technology Assessment Group; Center for Exact, Natural and Health Sciences; Federal University of Espírito Santo, Alto Universitário S/N, Guararema, Alegre, Espírito Santo, 29500-000, Brazil
| | - Rosângela Maria Gomes
- Department of Management and Incorporation of Technologies and Innovation in Health; Secretariat of Science, Technology and Strategic Inputs; Ministry of Health of Brazil, Brasilia, Federal District, 70058-900, Brazil
| | - Michael Ruberson Ribeiro da Silva
- Health Economics and Technology Assessment Group; Center for Exact, Natural and Health Sciences; Federal University of Espírito Santo, Alto Universitário S/N, Guararema, Alegre, Espírito Santo, 29500-000, Brazil
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Beladakere Ramaswamy S, Singh S, Hooshmand S, Junsang C, Sweeney M, Govindarajan R. Current and Upcoming Treatment Modalities in Myasthenia Gravis. J Clin Neuromuscul Dis 2021; 23:75-99. [PMID: 34808650 DOI: 10.1097/cnd.0000000000000377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
ABSTRACT Myasthenia gravis (MG) is one of the extensively studied autoimmune disorder. There has been a dramatic increase in research to further understand molecular pathogenesis of MG and clinical trials for new drugs in MG treatment in the past decade. This review article is to consolidate the available information in simple terms with students, residents, and fellows as target audience for easy learning and help application of this knowledge to clinical practice.
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Menon D, Urra Pincheira A, Bril V. Emerging drugs for the treatment of myasthenia gravis. Expert Opin Emerg Drugs 2021; 26:259-270. [PMID: 34228579 DOI: 10.1080/14728214.2021.1952982] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Introduction: Advances in understanding the immune pathomechanisms in myasthenia gravis (MG) allow for the development of novel targeted immune therapies. By working at specific points in the immunopathogenesis, these agents have the potential to provide rapid and efficacious responses compared to conventional immunosuppressive therapy (IST), addressing unmet needs and consequently are a research priority.Areas covered: This paper reviews the advances in MG treatment modalities with their scientific rationale. A search of clinicaltrials.gov and a literature search of PubMed from January 2015 to the end of June 2021 was done using the search terms: MG, treatment, immune targets to obtain information on recent developments of complement inhibitors, FcRn receptor inhibitors, direct and indirect B cell inhibitors, CAR and CAAR- T cell therapy, and hematopoietic stem cell transplantation. Specific agents in various phases of clinical development, evidence from ongoing trials and potential roadblocks are examined.Expert opinion: Despite several promising novel agents, existing data as to the timing of initiation and duration of treatment, long-term safety profile and utility in certain patient subsets are limited and require further research. Despite these considerations, the future of MG treatment is transitioning from broad-spectrum IST toward precise, target-driven and personalized immunotherapy.
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Affiliation(s)
- Deepak Menon
- Department of Medicine, Ellen & Martin Prosserman Centre for Neuromuscular Diseases, University Health Network, University of Toronto, Toronto, Canada
| | - Alejandra Urra Pincheira
- Department of Medicine, Ellen & Martin Prosserman Centre for Neuromuscular Diseases, University Health Network, University of Toronto, Toronto, Canada
| | - Vera Bril
- Department of Medicine, Ellen & Martin Prosserman Centre for Neuromuscular Diseases, University Health Network, University of Toronto, Toronto, Canada
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Menon D, Barnett C, Bril V. Novel Treatments in Myasthenia Gravis. Front Neurol 2020; 11:538. [PMID: 32714266 PMCID: PMC7344308 DOI: 10.3389/fneur.2020.00538] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 05/14/2020] [Indexed: 01/08/2023] Open
Abstract
Myasthenia gravis (MG) is the prototypical autoimmune disorder caused by specific autoantibodies at the neuromuscular junction. Broad-based immunotherapies, such as corticosteroids, azathioprine, mycophenolate, tacrolimus, and cyclosporine, have been effective in controlling symptoms of myasthenia. While being effective in a majority of MG patients many of these immunosuppressive agents are associated with long-term side effects, often intolerable for patients, and take several months to be effective. With advances in translational research and drug development capabilities, more directed therapeutic agents that can alter the future of MG treatment have been developed. This review focuses on the aberrant immunological processes in MG, the novel agents that target them along with the clinical evidence for efficacy and safety. These agents include terminal complement C5 inhibitors, Fc receptor inhibitors, B cell depleting agents (anti CD 19 and 20 and B cell activating factor [BAFF)]inhibitors), proteosome inhibitors, T cells and cytokine based therapies (chimeric antigen receptor T [CART-T] cell therapy), autologous stem cell transplantation, and subcutaneous immunoglobulin (SCIG). Most of these new agents have advantages over conventional immunosuppressive treatment (IST) for MG therapy in terms of faster onset of action, favourable side effect profile and the potential for a sustained and long-term remission.
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Affiliation(s)
| | | | - Vera Bril
- Ellen & Martin Prosserman Centre for Neuromuscular Diseases, University Health Network, University of Toronto, Toronto, ON, Canada
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Huda R. New Approaches to Targeting B Cells for Myasthenia Gravis Therapy. Front Immunol 2020; 11:240. [PMID: 32153573 PMCID: PMC7047318 DOI: 10.3389/fimmu.2020.00240] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 01/29/2020] [Indexed: 01/06/2023] Open
Abstract
Current therapies for myasthenia gravis (MG) are limited, and many investigations have recently focused on target-specific therapies. B cell-targeting monoclonal antibody (mAb) therapies for MG are increasingly attractive due to their specificity and efficacy. The targeted B cell biomarkers are mainly the cluster of differentiation (CD) proteins that mediate maturation, differentiation, or survival of pathogenic B cells. Additional B cell-directed therapies include non-specific peptide inhibitors that preferentially target specific B cell subsets. The primary goals of such therapies are to intercept autoantibodies and prevent the generation of an inflammatory response that contributes to the pathogenesis of MG. Treatment of patients with MG using B cell-directed mAbs, antibody fragments, or selective inhibitors have exhibited moderate to high efficacy in early studies, and some of these therapies appear to be highly promising for further drug development. Numerous other biologics targeting various B cell surface molecules have been approved for the treatment of other conditions or are either in clinical trials or preclinical development stages. These approaches remain to be tested in patients with MG or animal models of the disease. This review article provides an overview of B cell-targeted treatments for MG, including those already available and those still in preclinical and clinical development. We also discuss the potential benefits as well as the shortcomings of these approaches to development of new therapies for MG and future directions in the field.
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Affiliation(s)
- Ruksana Huda
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
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