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Bouwman HB, Guchelaar HJ. The efficacy and safety of eculizumab in patients and the role of C5 polymorphisms. Drug Discov Today 2024; 29:104134. [PMID: 39111540 DOI: 10.1016/j.drudis.2024.104134] [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: 03/14/2024] [Revised: 07/11/2024] [Accepted: 07/31/2024] [Indexed: 08/13/2024]
Abstract
Eculizumab is an orphan drug with indications for extremely rare autoimmune disorders. It is primarily prescribed for use in patients with paroxysmal nocturnal hemoglobinuria and atypical hemolytic uremic syndrome; but is also highly effective in the treatment of myasthenia gravis, among others. By binding to the C5 protein in the complement system, eculizumab effectively inhibits cellular hemolysis and autoimmune reactions. Despite this effective treatment, some patients reported no improvement in symptoms. Genetic sequencing revealed three distinct C5 mutations in the non-responders and these polymorphisms appeared to be most prevalent among Japanese, Korean and African populations. Here, we present an overview of the current and potential future applications of eculizumab, as well as the disadvantages of eculizumab treatment in patients with C5 polymorphisms.
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Affiliation(s)
| | - Henk-Jan Guchelaar
- Clinical Pharmacy and Toxicology, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, the Netherlands.
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2
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Ryder S. Integrated Applied Clinical Pharmacology in the Advancement of Rare and Ultra-Rare Disease Therapeutics. Clin Pharmacol Ther 2024. [PMID: 39034754 DOI: 10.1002/cpt.3382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Accepted: 06/29/2024] [Indexed: 07/23/2024]
Abstract
The introduction of safe and effective rare/ultra-rare disease treatments is a focus of many biotherapeutic enterprises. Despite this increased activity, a significant unmet need remains, and the responsibility to meet this need is augmented by enhanced genomic, biologic, medical, analytical, and informatic tools. It is recognized that the development of an effective and safe rare/ultra-rare disease therapeutic faces a number of challenges with an important role noted for clinical pharmacology. Clinical pharmacology is foundationally an integrative discipline which must be embedded in and is interdependent upon understanding the pathogenic biology, clinical presentation, disease progression, and end-point assessment of the disease under study. This manuscript presents an overview and two case examples of this integrative approach, the development of C5-targeted therapeutics for the treatment of generalized myasthenia gravis and asfotase alpha for the treatment of hypophosphatasia. The two presented case examples show the usefulness of understanding the biological drivers and clinical course of a rare disease, having relevant animal models, procuring informative natural history data, importing assessment tools from relevant alternative areas, and using integrated applied clinical pharmacology to inform target engagement, dose, and the cascade of pharmacodynamic and clinical effects that follow. Learnings from these programs include the importance of assuring cross-validation of assays throughout a development program and continued commitment to understanding the relationship among the array of Pd end points and clinical outcomes. Using an integrative approach, substantive work remains to be done to meet the unmet needs of patients with rare/ultra-rare disease.
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Gutschmidt K, Schoser B. [Myasthenia Gravis - Update]. FORTSCHRITTE DER NEUROLOGIE-PSYCHIATRIE 2024; 92:139-156. [PMID: 38636491 DOI: 10.1055/a-2238-7784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/20/2024]
Abstract
Myasthenia gravis - still a challenge for sufferers and doctors in 2023. But which therapy is best suited? Our clinically experienced experts have summarized the current guidelines for diagnosis and treatment in order to provide optimal support for those affected. Find out how you can carry out a quick and targeted diagnosis and which treatment options are available to alleviate the course of the disease.
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Uysal SP, Morren JA. Promising therapies for the treatment of myasthenia gravis. Expert Opin Pharmacother 2024; 25:395-408. [PMID: 38523508 DOI: 10.1080/14656566.2024.2332610] [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: 01/13/2024] [Accepted: 03/14/2024] [Indexed: 03/26/2024]
Abstract
INTRODUCTION Myasthenia gravis (MG) is an autoimmune condition targeting the neuromuscular junction, which manifests with neuromuscular symptoms of varying severity and significant morbidity. The mainstay of treatment in MG is mitigation of the immune cascade with steroids and non-steroidal immunosuppressive therapies. The therapeutic strategies in MG are transitioning from broad and indiscriminate immunosuppression to novel agents targeting key steps in MG pathogenesis, including T cell activation, B cell proliferation, complement activation, maintenance of pathogenic antibody production, and proinflammatory cytokine production. AREAS COVERED In this review, an overview of the pathogenesis of MG and traditional MG therapies is presented, followed by a discussion of the novel MG drugs that have been evaluated in phase 3 clinical trials with an emphasis on those which have received regulatory approval. EXPERT OPINION Novel MG therapeutics belonging to the classes of complement inhibitors, neonatal Fc receptor (FcRn) inhibitors and B cell depletors, as well as the other emerging MG drugs in the pipeline constitute promising treatment strategies with potentially better efficacy and safety compared to the conventional MG treatments. However, further long-term research is needed in order to optimize the implementation of these new treatment options for the appropriate patient populations.
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Affiliation(s)
- Sanem Pinar Uysal
- Department of Neurology, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA
| | - John A Morren
- Neuromuscular Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA
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Ma Y, Nie X, Zhu G, Qi W, Hao L, Guo X. The Efficacy and Safety of Different Targeted Drugs for the Treatment of Generalized Myasthenia Gravis: A Systematic Review and Bayesian Network Meta-analysis. CNS Drugs 2024; 38:93-104. [PMID: 38300476 DOI: 10.1007/s40263-024-01062-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/08/2024] [Indexed: 02/02/2024]
Abstract
BACKGROUND The treatment of generalized myasthenia gravis (gMG) has been transformed by the development and approval of new targeted therapies. This analysis aimed to rank and compare the new therapies for gMG using efficacy and safety data from randomized controlled trials (RCTs). METHODS We searched PubMed, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), and ClinicalTrials.gov (up to November 2022) for RCTs of targeted drugs for gMG. We used a Bayesian random-effects network meta-analysis (NMA) model and a Markov chain Monte Carlo (MCMC) model for statistical analysis. The primary outcome was the change in quantitative myasthenia gravis score (QMGS) from baseline, while the secondary outcome was the risk ratio (RR) of adverse events (AEs) during treatment. The surface under the cumulative ranking curve (SUCRA) was used to rank these targeted drugs, with higher SUCRA values indicating better efficacy or lower likelihood of AEs. RESULTS In total, 13 studies (872 subjects) were included in this analysis evaluating 10 targeted drugs (batoclimab, belimumab, CFZ533, eculizumab, efgartigimod, nipocalimab, rituximab, ravulizumab, rozanolixizumab, and zilucoplan). With regards to the primary outcome, batoclimab [standardized mean difference (SMD), - 1.61; 95% credible interval (CrI), - 2.78, - 0.43] significantly reduced QMGS in patients with gMG when compared with placebo and was ranked as the most efficacious drug. Ranked second and third were eculizumab (SMD, - 0.67; 95% CrI, 1.43, 0.01) and zilucoplan (SMD, - 0.54; 95% CrI, - 1.56, 0.46), respectively. Nipoclimab (SMD, - 0.02; 95% CrI, - 1.04, 1.00) had the worst efficacy and ranked last among all targeted drugs. In our study, except for batoclimab, there was no statistically significant difference in the reduction of patient QMGS for the remaining targeted agents compared with placebo. With regards to the secondary outcomes, only batoclimab (RR, 0.19; 95% CrI, 0, 0.97) led to a significant reduction in the incidence of AEs when compared with the placebo. Belimumab (RR, 0.85; 95% CrI, 0.57, 1.19), CFZ533 (RR, 0.95; 95% CrI, 0.72, 1.25), eculizumab (RR, 0.99; 95% CrI, 0.85, 1.21), and efgartigimod (RR, 0.93; 95% CrI, 0.76, 1.15) also led to a lower incidence of AEs, although these effects were not significantly different from the placebo. CONCLUSIONS Batoclimab had the best efficacy and safety for the treatment of gMG and was ranked first out of the 10 targeted drugs included in this study. Eculizumab was ranked second, and nipocalimab had the worst efficacy. With the exception of batoclimab, the incidence of AEs for the remaining drugs was not statistically significantly different from placebo. We note, however, that wide CrIs reflect the uncertainty in this analysis owing to the small number of available studies and low numbers of study participants; moreover, batoclimab had the widest CrI of all drugs in this analysis. More well-designed studies with long-term follow-up are needed to further evaluate and compare the efficacy and safety of these drugs in the future.
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Affiliation(s)
- Yongbo Ma
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, 1 Youyi Road, Yuzhong District, Chongqing, 400016, China
| | - Xiangtao Nie
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, 1 Youyi Road, Yuzhong District, Chongqing, 400016, China
| | - Geke Zhu
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, 1 Youyi Road, Yuzhong District, Chongqing, 400016, China
| | - Wenjing Qi
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, 1 Youyi Road, Yuzhong District, Chongqing, 400016, China
| | - Lei Hao
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, 1 Youyi Road, Yuzhong District, Chongqing, 400016, China.
| | - Xiuming Guo
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, 1 Youyi Road, Yuzhong District, Chongqing, 400016, China.
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Crisafulli S, Boccanegra B, Carollo M, Bottani E, Mantuano P, Trifirò G, De Luca A. Myasthenia Gravis Treatment: From Old Drugs to Innovative Therapies with a Glimpse into the Future. CNS Drugs 2024; 38:15-32. [PMID: 38212553 DOI: 10.1007/s40263-023-01059-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/11/2023] [Indexed: 01/13/2024]
Abstract
Myasthenia gravis (MG) is a rare autoimmune disease that causes debilitating muscle weakness due to impaired neuromuscular transmission. Since most (about 80-90%) MG patients present autoantibodies against the acetylcholine receptor, standard medical therapy consists of symptomatic treatment with acetylcholinesterase inhibitors (e.g., pyridostigmine). In addition, considering the autoimmune basis of MG, standard therapy includes immunomodulating agents, such as corticosteroids, azathioprine, cyclosporine A, and cyclophosphamide. New strategies have been proposed for the treatment of MG and include complement blockade (i.e., eculizumab, ravulizumab, and zilucoplan) and neonatal Fc receptor antagonism (i.e., efgartigimod and rozanolixizumab). The aim of this review is to provide a detailed overview of the pre- and post-marketing evidence on the five pharmacological treatments most recently approved for the treatment of MG, by identifying both preclinical and clinical studies registered in clinicaltrials.gov. A description of the molecules currently under evaluation for the treatment of MG is also provided.
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Affiliation(s)
| | - Brigida Boccanegra
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Bari, Italy
| | - Massimo Carollo
- Department of Diagnostics and Public Health, University of Verona, P.le L.A. Scuro 10, 37124, Verona, Italy
| | - Emanuela Bottani
- Department of Diagnostics and Public Health, University of Verona, P.le L.A. Scuro 10, 37124, Verona, Italy
| | - Paola Mantuano
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Bari, Italy
| | - Gianluca Trifirò
- Department of Diagnostics and Public Health, University of Verona, P.le L.A. Scuro 10, 37124, Verona, Italy.
| | - Annamaria De Luca
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Bari, Italy
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Zhou A, Ho S, Vickers A. Eculizumab in myasthenia gravis: A review. Saudi J Ophthalmol 2024; 38:34-40. [PMID: 38628404 PMCID: PMC11016999 DOI: 10.4103/sjopt.sjopt_74_23] [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: 03/31/2023] [Revised: 10/09/2023] [Accepted: 10/10/2023] [Indexed: 04/19/2024] Open
Abstract
Eculizumab, a monoclonal antibody against complement C5, is a novel therapy to treat refractory myasthenia gravis (MG). The present review was undertaken to study the role of eculizumab in MG. This includes the drug's mechanism, pharmacokinetics, clinical trial findings, tolerability, side effects, safety, dosage, administration, and cost. An English-language search for relevant items was undertaken using Embase and PubMed from 1946 to present. Clinical trial registries/databases and websites were also searched for relevant data. Keywords were eculizumab and MG. The present review found 103 articles after initial screening. Current data support eculizumab as an effective, safe, and tolerable drug in cases of refractory MG. However, its cost can prevent it from being widely accessible to a majority of the general population.
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Affiliation(s)
- Avery Zhou
- Kirk Kerkorian School of Medicine, Las Vegas, NV, USA
| | - Sabrina Ho
- Kirk Kerkorian School of Medicine, Las Vegas, NV, USA
| | - Aroucha Vickers
- Department of Neurology, Valley Hospital Medical Center, Las Vegas, NV, USA
- Department of Neuro-Ophthalmology, Las Vegas Neurology Center, Las Vegas, NV, USA
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8
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Wiendl H, Abicht A, Chan A, Della Marina A, Hagenacker T, Hekmat K, Hoffmann S, Hoffmann HS, Jander S, Keller C, Marx A, Melms A, Melzer N, Müller-Felber W, Pawlitzki M, Rückert JC, Schneider-Gold C, Schoser B, Schreiner B, Schroeter M, Schubert B, Sieb JP, Zimprich F, Meisel A. Guideline for the management of myasthenic syndromes. Ther Adv Neurol Disord 2023; 16:17562864231213240. [PMID: 38152089 PMCID: PMC10752078 DOI: 10.1177/17562864231213240] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 10/23/2023] [Indexed: 12/29/2023] Open
Abstract
Myasthenia gravis (MG), Lambert-Eaton myasthenic syndrome (LEMS), and congenital myasthenic syndromes (CMS) represent an etiologically heterogeneous group of (very) rare chronic diseases. MG and LEMS have an autoimmune-mediated etiology, while CMS are genetic disorders. A (strain dependent) muscle weakness due to neuromuscular transmission disorder is a common feature. Generalized MG requires increasingly differentiated therapeutic strategies that consider the enormous therapeutic developments of recent years. To include the newest therapy recommendations, a comprehensive update of the available German-language guideline 'Diagnostics and therapy of myasthenic syndromes' has been published by the German Neurological society with the aid of an interdisciplinary expert panel. This paper is an adapted translation of the updated and partly newly developed treatment guideline. It defines the rapid achievement of complete disease control in myasthenic patients as a central treatment goal. The use of standard therapies, as well as modern immunotherapeutics, is subject to a staged regimen that takes into account autoantibody status and disease activity. With the advent of modern, fast-acting immunomodulators, disease activity assessment has become pivotal and requires evaluation of the clinical course, including severity and required therapies. Applying MG-specific scores and classifications such as Myasthenia Gravis Activities of Daily Living, Quantitative Myasthenia Gravis, and Myasthenia Gravis Foundation of America allows differentiation between mild/moderate and (highly) active (including refractory) disease. Therapy decisions must consider age, thymic pathology, antibody status, and disease activity. Glucocorticosteroids and the classical immunosuppressants (primarily azathioprine) are the basic immunotherapeutics to treat mild/moderate to (highly) active generalized MG/young MG and ocular MG. Thymectomy is indicated as a treatment for thymoma-associated MG and generalized MG with acetylcholine receptor antibody (AChR-Ab)-positive status. In (highly) active generalized MG, complement inhibitors (currently eculizumab and ravulizumab) or neonatal Fc receptor modulators (currently efgartigimod) are recommended for AChR-Ab-positive status and rituximab for muscle-specific receptor tyrosine kinase (MuSK)-Ab-positive status. Specific treatment for myasthenic crises requires plasmapheresis, immunoadsorption, or IVIG. Specific aspects of ocular, juvenile, and congenital myasthenia are highlighted. The guideline will be further developed based on new study results for other immunomodulators and biomarkers that aid the accurate measurement of disease activity.
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Affiliation(s)
- Heinz Wiendl
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Albert-Schweitzer-Campus 1, Building A1, Münster 48149, Germany
| | - Angela Abicht
- Friedrich-Baur-Institut an der Neurologischen Klinik und Poliklinik, LMU Munich, Munich, Germany
| | - Andrew Chan
- Universitätsklinik für Neurologie, Inselspital Bern, Bern, Switzerland
| | - Adela Della Marina
- Klinik für Kinderheilkunde I, Universitätsklinikum Essen, Essen, Germany
| | - Tim Hagenacker
- Klinik für Neurologie, Universitätsklinikum Essen, Essen, Germany
| | | | - Sarah Hoffmann
- Charité – Universitätsmedizin Berlin, Klinik für Neurologie mit Experimenteller Neurologie, Berlin, Germany
| | | | - Sebastian Jander
- Klinik für Neurologie, Marien Hospital Düsseldorf, Düsseldorf, Germany
| | - Christian Keller
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Münster, Germany
| | - Alexander Marx
- Pathologisches Institut, Universitätsklinikum Mannheim, Mannheim, Germany
| | - Arthur Melms
- Facharztpraxis für Neurologie und Psychiatrie, Stuttgart, Germany
| | - Nico Melzer
- Klinik für Neurologie, Universitätsklinikum Düsseldorf, Düsseldorf, Germany
| | - Wolfgang Müller-Felber
- Kinderklinik und Kinderpoliklinik im Dr. von Haunerschen Kinderspital, LMU Munich, Munich, Germany
| | - Marc Pawlitzki
- Klinik für Neurologie, Universitätsklinikum Düsseldorf, Düsseldorf, Germany
| | | | | | - Benedikt Schoser
- Friedrich-Baur-Institut an der Neurologischen Klinik und Poliklinik, LMU Munich, Munich, Germany
| | - Bettina Schreiner
- Klinik für Neurologie, Universitätsspital Zürich, Zürich, Switzerland
| | - Michael Schroeter
- Klinik und Poliklinik für Neurologie, Uniklinik Cologne, Cologne, Germany
| | | | | | - Fritz Zimprich
- Universitätsklinik für Neurologie, AKH-Wien, Wien, Austria
| | - Andreas Meisel
- Charité – Universitätsmedizin Berlin, Klinik für Neurologie mit Experimenteller Neurologie, Berlin, Germany
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Vu T, Wiendl H, Katsuno M, Reddel SW, Howard JF. Ravulizumab in Myasthenia Gravis: A Review of the Current Evidence. Neuropsychiatr Dis Treat 2023; 19:2639-2655. [PMID: 38059203 PMCID: PMC10697093 DOI: 10.2147/ndt.s374694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 10/17/2023] [Indexed: 12/08/2023] Open
Abstract
The terminal complement C5 inhibitor ravulizumab was engineered from the humanized monoclonal antibody eculizumab to have an extended half-life and duration of action. It binds to human terminal complement protein C5, inhibiting its cleavage into C5a and C5b, thus preventing the cascade of events that lead to architectural destruction of the postsynaptic neuromuscular junction membrane by the membrane attack complex, and consequent muscle weakness in patients with anti-acetylcholine receptor (AChR) antibody-positive generalized myasthenia gravis (gMG). The 26-week randomized, placebo-controlled period (RCP) of the phase 3 CHAMPION MG study demonstrated the rapid efficacy of ravulizumab in reducing MG symptoms. Weight-based dosing of ravulizumab every 8 weeks provided sustained efficacy, in terms of patient-reported (Myasthenia Gravis-Activities of Daily Living) and clinician-reported (Quantitative Myasthenia Gravis) endpoints in patients with anti-AChR antibody-positive gMG. Pharmacokinetic and pharmacodynamic analyses showed therapeutic serum ravulizumab concentrations (>175 µg/mL) were achieved immediately after the first dose and were maintained throughout 26 weeks, irrespective of patient body weight; inhibition of serum free C5 was immediate, complete (<0.5 μg/mL), and sustained in all patients. Interim results from the open-label extension (OLE) showed that after 60 weeks, efficacy was maintained in patients continuing on ravulizumab. Rapid and sustained improvements in efficacy, similar to those seen in patients initiating ravulizumab in the RCP, were observed after initiation of ravulizumab treatment in patients who switched from placebo in the RCP to ravulizumab in the OLE. The findings from the RCP and OLE support ravulizumab's favorable safety profile. In conclusion, ravulizumab has a simple weight-based administration and long dosing interval. Its targeted mechanism of action without generalized immunosuppression is reflected in its rapid onset of symptom improvement, sustained efficacy and good safety profile in the treatment of patients with anti-AChR antibody-positive gMG.
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Affiliation(s)
- Tuan Vu
- Department of Neurology, University of South Florida Morsani College of Medicine, Tampa, FL, USA
| | - Heinz Wiendl
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Münster, Germany
| | - Masahisa Katsuno
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Stephen W Reddel
- Department of Neurology, Concord Hospital, University of Sydney, Sydney, NSW, Australia
| | - James F Howard
- Department of Neurology, The University of North Carolina, Chapel Hill, NC, USA
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10
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Koopman I, Tack RWP, Wunderink HF, Bruns AHW, van der Schaaf IC, Cianci D, Gelderman KA, van de Ridder IM, Hol EM, Rinkel GJE, Vergouwen MDI. Safety and pharmacodynamic efficacy of eculizumab in aneurysmal subarachnoid hemorrhage (CLASH): A phase 2a randomized clinical trial. Eur Stroke J 2023; 8:1097-1106. [PMID: 37606053 PMCID: PMC10683736 DOI: 10.1177/23969873231194123] [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: 05/15/2023] [Accepted: 07/25/2023] [Indexed: 08/23/2023] Open
Abstract
INTRODUCTION Complement C5 antibodies reduce brain injury after experimental subarachnoid hemorrhage. PATIENTS AND METHODS In this randomized, controlled, open-label, phase 2a clinical trial with blinded-outcome assessment, we included adult aneurysmal subarachnoid hemorrhage (aSAH) patients admitted to a tertiary referral center ⩽11 h after ictus. Patients were randomized (1:1) to eculizumab plus care as usual or to care as usual. Eculizumab (1200 mg) was administered <12 h, and on days 3 and 7 after ictus. In the intervention group, all patients received prophylactic antibiotics and, after a protocol amendment, fluconazole if indicated. Primary outcome was C5a concentration in cerebrospinal fluid (CSF) on day 3 after ictus. Safety was monitored during 4 weeks. In each group, 13 patients with CSF assessments were needed to detect a 55% reduction in CSF C5a concentration. RESULTS From October 2018 to May 2021, we enrolled 31 patients of whom 26 with CSF samples, 13 per group. Median C5a concentration in CSF on day 3 was 251 pg/ml [IQR: 103-402] in the intervention group and 371 pg/ml [IQR: 131-534] in the control group (p = 0.29). Infections occurred in two patients in the intervention group and four patients in the control group. One patient in the intervention group developed a C. albicans meningitis prior to the protocol amendment. DISCUSSION AND CONCLUSION One dose of eculizumab did not result in a ⩾ 55% decrease in C5a concentration in CSF on day 3 after aSAH. The study did not reveal new safety concerns, except for a C. albicans drain-related infection prior to antifungal monitoring and treatment. TRIAL REGISTRATION EudraCT 2017-004307-51, https://www.clinicaltrialsregister.eu/.
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Affiliation(s)
- Inez Koopman
- Department of Neurology and Neurosurgery, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Reinier WP Tack
- Department of Neurology and Neurosurgery, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Herman F Wunderink
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Anke HW Bruns
- Department of Internal Medicine and Infectious Diseases, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Irene C van der Schaaf
- Department of Radiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Daniela Cianci
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | | | - Inge M van de Ridder
- Department of Intensive Care Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Elly M Hol
- Department of Translational Neuroscience, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Gabriel JE Rinkel
- Department of Neurology and Neurosurgery, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Mervyn DI Vergouwen
- Department of Neurology and Neurosurgery, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
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11
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Golfinopoulou R, Giudicelli V, Manso T, Kossida S. Delving into Molecular Pathways: Analyzing the Mechanisms of Action of Monoclonal Antibodies Integrated in IMGT/mAb-DB for Myasthenia Gravis. Vaccines (Basel) 2023; 11:1756. [PMID: 38140161 PMCID: PMC10747390 DOI: 10.3390/vaccines11121756] [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: 09/30/2023] [Revised: 11/20/2023] [Accepted: 11/22/2023] [Indexed: 12/24/2023] Open
Abstract
BACKGROUND Myasthenia Gravis (MG) is a rare autoimmune disease presenting with auto-antibodies that affect the neuromuscular junction. In addition to symptomatic treatment options, novel therapeutics include monoclonal antibodies (mAbs). IMGT®, the international ImMunoGeneTics information system®, extends the characterization of therapeutic antibodies with a systematic description of their mechanisms of action (MOA) and makes them available through its database for mAbs and fusion proteins, IMGT/mAb-DB. METHODS Using available literature data combined with amino acid sequence analyses from mAbs managed in IMGT/2Dstructure-DB, the IMGT® protein database, biocuration allowed us to define in a standardized way descriptions of MOAs of mAbs that target molecules towards MG treatment. RESULTS New therapeutic targets include FcRn and molecules such as CD38, CD40, CD19, MS4A1, and interleukin-6 receptor. A standardized graphical representation of the MOAs of selected mAbs was created and integrated within IMGT/mAb-DB. The main mechanisms involved in these mAbs are either blocking or neutralizing. Therapies directed to B cell depletion and plasma cells have a blocking MOA with an immunosuppressant effect along with Fc-effector function (MS4A1, CD38) or FcγRIIb engager effect (CD19). Monoclonal antibodies targeting the complement also have a blocking MOA with a complement inhibitor effect, and treatments targeting T cells have a blocking MOA with an immunosuppressant effect (CD40) and Fc-effector function (IL6R). On the other hand, FcRn antagonists present a neutralizing MOA with an FcRn inhibitor effect. CONCLUSION The MOA of each new mAb needs to be considered in association with the immunopathogenesis of each of the subtypes of MG in order to integrate the new mAbs as a viable and safe option in the therapy decision process. In IMGT/mAb-DB, mAbs for MG are characterized by their sequence, domains, and chains, and their MOA is described.
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Affiliation(s)
- Rebecca Golfinopoulou
- IMGT, The International ImMunoGeneTics Information System, National Center for Scientific Research (CNRS), Institute of Human Genetics (IGH), University of Montpellier (UM), 34090 Montpellier, France; (R.G.); (V.G.)
- Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 11855 Athens, Greece
| | - Véronique Giudicelli
- IMGT, The International ImMunoGeneTics Information System, National Center for Scientific Research (CNRS), Institute of Human Genetics (IGH), University of Montpellier (UM), 34090 Montpellier, France; (R.G.); (V.G.)
| | - Taciana Manso
- IMGT, The International ImMunoGeneTics Information System, National Center for Scientific Research (CNRS), Institute of Human Genetics (IGH), University of Montpellier (UM), 34090 Montpellier, France; (R.G.); (V.G.)
| | - Sofia Kossida
- IMGT, The International ImMunoGeneTics Information System, National Center for Scientific Research (CNRS), Institute of Human Genetics (IGH), University of Montpellier (UM), 34090 Montpellier, France; (R.G.); (V.G.)
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Katyal N, Halldorsdottir K, Govindarajan R, Shieh P, Muley S, Reyes P, Leung KK, Mullen J, Milani-Nejad S, Korb M, Goyal NA, Mozaffar T, Goyal N, Habib AA, Muppidi S. Safety and outcomes with efgartigimod use for acetylcholine receptor-positive generalized myasthenia gravis in clinical practice. Muscle Nerve 2023; 68:762-766. [PMID: 37695277 DOI: 10.1002/mus.27974] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 08/22/2023] [Accepted: 08/23/2023] [Indexed: 09/12/2023]
Abstract
INTRODUCTION/AIMS Multiple novel therapies have been approved for patients with myasthenia gravis. Our aim is to describe the early experience of efgartigimod use in acetylcholine receptor antibody-positive generalized myasthenia gravis (AChR+ve gMG). METHODS This multicenter retrospective study included AChR+ve gMG patients from five major neuromuscular centers who were treated with efgartigimod and had both pre- and post-efgartigimod myasthenia gravis activities of daily living (MG-ADL) scores. Information regarding MG history, concomitant treatment(s), MG-ADL and other MG-specific measures, laboratory data, and adverse events were recorded. RESULTS A total of 37 patients (M:23, F:14) with a mean age of 65.56 (±14.74) y were included in this cohort. A total of 36/37 patients completed at least one cycle and 28 patients completed at least two cycles of efgartigimod. A total of 72% (26/36) of patients had a clinically meaningful reduction (≥2 point change) in MG-ADL after the completion of the first cycle of efgartigimod (mean pre-efgartigimod 8.02) (±3.09) versus post-efgartigimod 4.33 (±3.62). Twenty-five percent (9/36) achieved minimal symptom expression status after one cycle and 25% (7/28) after the second cycle. Treatment benefit was sustained after cycle 2. Three out of four patients with thymoma in this cohort had clinically significant reductions in MG-ADL scores. Immunoglobulin G (IgG) levels decreased by about 60% (n = 10). One patient had a relapse of Clostridium difficile infection resulting in the discontinuation of therapy. Four patients had mild side effects. DISCUSSION Efgartigimod led to clinically meaningful improvement in MG-ADL in diverse AChR+ve gMG patients but treatment frequency to achieve optimal symptom control needs to be explored.
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Affiliation(s)
- Nakul Katyal
- Department of Neurology and Neurosciences, Stanford University, Stanford, California, USA
| | | | | | - Perry Shieh
- Department of Neurology, University of California, Los Angeles, Los Angeles, California, USA
| | - Suraj Muley
- Bob Bove Neuroscience Institute at HonorHealth, Scottsdale, Arizona, USA
| | - Phoebedel Reyes
- Department of Neurology, University of California, Los Angeles, Los Angeles, California, USA
| | - Kenneth K Leung
- Department of Neurology and Neurosciences, Stanford University, Stanford, California, USA
| | - Jeffrey Mullen
- Departments of Neurology, University of California, Irvine, California, USA
| | - Shadi Milani-Nejad
- Departments of Neurology, University of California, Irvine, California, USA
| | - Manisha Korb
- Departments of Neurology, University of California, Irvine, California, USA
| | - Namita A Goyal
- Departments of Neurology, University of California, Irvine, California, USA
| | - Tahseen Mozaffar
- Departments of Neurology, University of California, Irvine, California, USA
- Department of Pathology and Laboratory Medicine, University of California, Irvine, California, USA
| | - Neelam Goyal
- Department of Neurology and Neurosciences, Stanford University, Stanford, California, USA
| | - Ali A Habib
- Departments of Neurology, University of California, Irvine, California, USA
| | - Srikanth Muppidi
- Department of Neurology and Neurosciences, Stanford University, Stanford, California, USA
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13
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San PP, Jacob S. Role of complement in myasthenia gravis. Front Neurol 2023; 14:1277596. [PMID: 37869140 PMCID: PMC10585143 DOI: 10.3389/fneur.2023.1277596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 09/18/2023] [Indexed: 10/24/2023] Open
Abstract
Myasthenia gravis is a prototypic neuroimmune disorder with autoantibodies targeting the acetylcholine receptor complex at the neuromuscular junction. Patients present with mainly ocular muscle weakness and tend to have a generalized muscle weakness later in the clinical course. The weakness can be severe and fatal when bulbar muscles are heavily involved. Acetylcholine receptor antibodies are present in the majority of patients and are of IgG1 and IgG3 subtypes which can activate the complement system. The complement involvement plays a major role in the neuromuscular junction damage and the supporting evidence in the literature is described in this article. Complement therapies were initially studied and approved for paroxysmal nocturnal hemoglobinuria and in the past decade, those have also been studied in myasthenia gravis. The currently available randomized control trial and real-world data on the efficacy and safety of the approved and investigational complement therapies are summarized in this review.
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Affiliation(s)
- Pyae Phyo San
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Saiju Jacob
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
- Department of Neurology, Queen Elizabeth Hospital Birmingham, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
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14
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Ren J, Wang J, Liu R, Jin Y, Guo J, Yao Y, Luo J, Hao H, Gao F. Long-Term Efficacy and Safety of Low-Dose Rituximab in Patients with Refractory Myasthenia Gravis. Eur Neurol 2023; 86:387-394. [PMID: 37778340 DOI: 10.1159/000534336] [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: 04/20/2023] [Accepted: 09/26/2023] [Indexed: 10/03/2023]
Abstract
INTRODUCTION Rituximab is a monoclonal chimeric antibody against CD20+ B cells. We aimed to assess the long-term efficacy and safety of CD20+ B cell-guided treatment with low-dose rituximab in refractory myasthenia gravis patients. METHODS Patients with refractory myasthenia gravis treated with rituximab for more than 2 years were included. Rituximab was administered when CD20+ B cells were greater than 1%. We analysed the efficacy of rituximab, treatment interval, side effects, prognosis, and treatment course. RESULTS A total of 22 patients were included. All patients received 2-12 doses of rituximab, and the median follow-up time was 48.5 months. The scores of the Myasthenia Gravis Activities of Daily Living and Myasthenia Gravis Composite were significantly lower than those at baseline (p < 0.05). MGFA-PIS was significantly improved in 21 (95.45%) patients and 14 (63.64%) patients have reached MGFA-PIS minimal manifestations. The average daily dose of prednisone and pyridostigmine bromide and the proportion of immunosuppressants were significantly lower (p < 0.05). Seven patients suffered from 14 worsenings. Eight patients terminated rituximab due to good efficacy. Most patients tolerated rituximab well, although 1 patient had opportunistic infection and hypogammaglobulinemia, 1 patient had an intracranial mass. CONCLUSION Long-term CD20+ B-cell-guided low-dose rituximab showed good efficacy and tolerance in patients with refractory myasthenia gravis.
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Affiliation(s)
- Jingru Ren
- Department of Neurology, Peking University First Hospital, Beijing, China,
| | - Jianchun Wang
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Ran Liu
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Yunyi Jin
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Jing Guo
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Yan Yao
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Jingjing Luo
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Hongjun Hao
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Feng Gao
- Department of Neurology, Peking University First Hospital, Beijing, China
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15
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Emine Rabia K, Ömer Faruk T, Furkan S, Lazrak ES, Ozen PA, Tuncer A. Probable eculizumab-associated hepatotoxicity in a patient with neuromyelitis optica: a case report. Int J Neurosci 2023:1-5. [PMID: 37632449 DOI: 10.1080/00207454.2023.2253361] [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: 12/12/2022] [Revised: 07/06/2023] [Accepted: 08/21/2023] [Indexed: 08/28/2023]
Abstract
OBJECTIVES Neuromyelitis optica (NMO) is an inflammatory, autoimmune and demyelinating disease of the central nervous system and is often characterized by attacks of severe optic neuritis and long segment myelitis. Identifying the disease-specific pathogenic anti-AQP4 autoantibody in NMOSD has allowed the development of highly effective disease-modifying drugs in the treatment phase. Eculizumab is a humanized antibody that binds to complement C5 and inhibits the formation of the C5b-induced membrane attack complex. It is approved for treating many diseases in which tissue damage is accompanied by complement (such as neuromyelitis optica, myasthenia gravis, autoimmune hemolytic anemia and paroxysmal hemoglobinuria). METHODS We present a patient diagnosed with NMO who developed possible drug-induced liver injury three months after the start of eculizumab treatment. RESULT After discontinuing eculizumab treatment, liver function tests gradually regressed in a month. CONCLUSIONS Eculizumab-associated hepatotoxicity is a previously unreported adverse event in NMOSD patients. Therefore, patients should be monitored for liver function tests during eculizumab treatment, and care should be taken for hepatotoxicity. If hepatotoxicity is detected while under eculizumab treatment, patients should be investigated for other drug use, complementary food supplementation, or possible autoimmune hepatitis, and other potential causes should be excluded.
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Affiliation(s)
- Koc Emine Rabia
- Department of Neurology, Faculty of Medicine, Uludag University, Bursa, Turkey
| | - Turan Ömer Faruk
- Department of Neurology, Faculty of Medicine, Uludag University, Bursa, Turkey
| | - Saridas Furkan
- Department of Neurology, Faculty of Medicine, Uludag University, Bursa, Turkey
| | | | - Pinar Acar Ozen
- Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Aslı Tuncer
- Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
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16
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Aggelina A, Karampli E, Mavrovounis G, Boutsikos I, Pantazopoulos I, Kakavas S, Pavi E, Athanasakis K. Evaluation of the Quality of Life of Patients with Myasthenia Gravis in Greece. J Pers Med 2023; 13:1130. [PMID: 37511743 PMCID: PMC10381620 DOI: 10.3390/jpm13071130] [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: 06/27/2023] [Revised: 07/07/2023] [Accepted: 07/11/2023] [Indexed: 07/30/2023] Open
Abstract
Myasthenia Gravis (MG) patients often report an affected quality of life (QoL). The aim of the current study was to evaluate the QoL of patients with MG in Greece using a specific tool. A cross-sectional online survey was performed. Adult patients were invited to participate. A questionnaire incorporating the MG-QOL15r scale was distributed, following its translation and cultural adaptation into Greek. Overall, 99 valid responses were submitted. The median age (interquartile range) of the participants was 48.50 (13.50) years and 76.80% were females. One third of the patients mentioned that they could not work/changed jobs after their diagnosis (28.30%) and that they face severe restriction of their everyday activities (26.30%). The mean MG-QOL15r score was 13.50 ± 7.70. Patients with important restriction of everyday activities (p < 0.01), patients with more pronounced need of emotional support (p < 0.01), patients with generalized MG (p < 0.01) and patients with myasthenic crises (p < 0.01) reported lower QoL. This study is the first to report on the affected QoL of the Greek population with MG using the MG-QoL15r scale. Further work should be done to incorporate the routine evaluation of QoL in the care of patients with MG.
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Affiliation(s)
- Afrodite Aggelina
- Department of Public Health Policy, University of West Attica Athens, 115 21 Athens, Greece
| | - Eleftheria Karampli
- Laboratory for Health Technology Assessment, Department of Public Health Policy, School of Public Health, University of West Attica, 115 21 Athens, Greece
| | - Georgios Mavrovounis
- Department of Emergency Medicine, Faculty of Medicine, University of Thessaly, 415 00 Larissa, Greece
| | - Ioannis Boutsikos
- Department of Emergency Medicine, Faculty of Medicine, University of Thessaly, 415 00 Larissa, Greece
| | - Ioannis Pantazopoulos
- Department of Emergency Medicine, Faculty of Medicine, University of Thessaly, 415 00 Larissa, Greece
| | | | - Elpida Pavi
- Laboratory for Health Technology Assessment, Department of Public Health Policy, School of Public Health, University of West Attica, 115 21 Athens, Greece
| | - Kostas Athanasakis
- Laboratory for Health Technology Assessment, Department of Public Health Policy, School of Public Health, University of West Attica, 115 21 Athens, Greece
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17
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Dhamne MC. Clinical Outcomes in AchR Antibody-Positive Myasthenia Gravis: Where Does Rituximab Stand in the Current Times? Ann Indian Acad Neurol 2023; 26:313-314. [PMID: 37970317 PMCID: PMC10645217 DOI: 10.4103/aian.aian_516_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Accepted: 06/23/2023] [Indexed: 11/17/2023] Open
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18
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Nair SS, Jacob S. Novel Immunotherapies for Myasthenia Gravis. Immunotargets Ther 2023; 12:25-45. [PMID: 37038596 PMCID: PMC10082579 DOI: 10.2147/itt.s377056] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Accepted: 03/03/2023] [Indexed: 04/07/2023] Open
Abstract
Myasthenia gravis (MG), a prototype autoimmune neurological disease, had its therapy centred on corticosteroids, non-steroidal broad-spectrum immunotherapy and cholinesterase inhibitors for several decades. Treatment-refractory MG and long-term toxicities of the medications have been major concerns with the conventional therapies. Advances in the immunology and pathogenesis of MG have ushered in an era of newer therapies which are more specific and efficacious. Complement inhibitors and neonatal Fc receptor blockers target disease-specific pathogenic mechanisms linked to myasthenia and have proven their efficacy in pivotal clinical studies. B cell-depleting agents, specifically rituximab, have also emerged as useful for the treatment of severe MG. Many more biologicals are in the pipeline and in diverse stages of development. This review discusses the evidence for the novel therapies and the specific issues related to their clinical use.
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Affiliation(s)
- Sruthi S Nair
- Department of Neurology, University Hospitals Birmingham, Birmingham, B15 2TH, UK
- Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India
| | - Saiju Jacob
- Department of Neurology, University Hospitals Birmingham, Birmingham, B15 2TH, UK
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, B15 2TT, UK
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Younger DS. Critical illness-associated weakness and related motor disorders. HANDBOOK OF CLINICAL NEUROLOGY 2023; 195:707-777. [PMID: 37562893 DOI: 10.1016/b978-0-323-98818-6.00031-5] [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: 08/12/2023]
Abstract
Weakness of limb and respiratory muscles that occurs in the course of critical illness has become an increasingly common and serious complication of adult and pediatric intensive care unit patients and a cause of prolonged ventilatory support, morbidity, and prolonged hospitalization. Two motor disorders that occur singly or together, namely critical illness polyneuropathy and critical illness myopathy, cause weakness of limb and of breathing muscles, making it difficult to be weaned from ventilatory support, commencing rehabilitation, and extending the length of stay in the intensive care unit, with higher rates of morbidity and mortality. Recovery can take weeks or months and in severe cases, and may be incomplete or absent. Recent findings suggest an improved prognosis of critical illness myopathy compared to polyneuropathy. Prevention and treatment are therefore very important. Its management requires an integrated team approach commencing with neurologic consultation, creatine kinase (CK) measurement, detailed electrodiagnostic, respiratory and neuroimaging studies, and potentially muscle biopsy to elucidate the etiopathogenesis of the weakness in the peripheral and/or central nervous system, for which there may be a variety of causes. These tenets of care are being applied to new cases and survivors of the coronavirus-2 disease pandemic of 2019. This chapter provides an update to the understanding and approach to critical illness motor disorders.
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Affiliation(s)
- David S Younger
- Department of Clinical Medicine and Neuroscience, CUNY School of Medicine, New York, NY, United States; Department of Medicine, Section of Internal Medicine and Neurology, White Plains Hospital, White Plains, NY, United States.
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20
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Younger DS. On the path to evidence-based therapy in neuromuscular disorders. HANDBOOK OF CLINICAL NEUROLOGY 2023; 195:315-358. [PMID: 37562877 DOI: 10.1016/b978-0-323-98818-6.00007-8] [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: 08/12/2023]
Abstract
Neuromuscular disorders encompass a diverse group of acquired and genetic diseases characterized by loss of motor functionality. Although cure is the goal, many therapeutic strategies have been envisioned and are being studied in randomized clinical trials and entered clinical practice. As in all scientific endeavors, the successful clinical translation depends on the quality and translatability of preclinical findings and on the predictive value and feasibility of the clinical models. This chapter focuses on five exemplary diseases: childhood spinal muscular atrophy (SMA), Charcot-Marie-Tooth (CMT) disorders, chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), acquired autoimmune myasthenia gravis (MG), and Duchenne muscular dystrophy (DMD), to illustrate the progress made on the path to evidenced-based therapy.
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Affiliation(s)
- David S Younger
- Department of Clinical Medicine and Neuroscience, CUNY School of Medicine, New York, NY, United States; Department of Medicine, Section of Internal Medicine and Neurology, White Plains Hospital, White Plains, NY, United States.
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Ren J, Wang J, Liu R, Guo J, Yao Y, Luo J, Hao H, Gao F. Case report: Persistent hypogammaglobulinemia in thymoma-associated myasthenia gravis: the impact of rituximab or Good's syndrome? Front Neurol 2023; 14:1152992. [PMID: 37213908 PMCID: PMC10196171 DOI: 10.3389/fneur.2023.1152992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 04/12/2023] [Indexed: 05/23/2023] Open
Abstract
Introduction Rituximab (RTX) showed good efficacy and safety for patients with myasthenia gravis. However, the percentage of peripheral CD20+ B cell may be absent for years after low dose of RTX treatment. Persistent hypogammaglobulinemia and opportunistic infection may occur in patients under treatment of RTX with thymoma relapse. Case representation We report a case of refractory myasthenia gravis. After two doses of 100 mg rituximab, the patient developed transient neutropenia. The peripheral blood CD20+ B cell percentage was 0 more than 3 years. Eighteen months later, the patient's symptoms relapsed with thymoma recurred. She had persistent hypogammaglobulinemia and multiple opportunistic infections. Conclusion In MG patient under B cell depletion therapy had thymoma relapse, Good's syndrome may induce prolonged B cell depletion, hypogammaglobulinemia and opportunistic infections.
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22
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Schmidt CQ, Smith RJH. Protein therapeutics and their lessons: Expect the unexpected when inhibiting the multi-protein cascade of the complement system. Immunol Rev 2023; 313:376-401. [PMID: 36398537 PMCID: PMC9852015 DOI: 10.1111/imr.13164] [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] [Indexed: 11/19/2022]
Abstract
Over a century after the discovery of the complement system, the first complement therapeutic was approved for the treatment of paroxysmal nocturnal hemoglobinuria (PNH). It was a long-acting monoclonal antibody (aka 5G1-1, 5G1.1, h5G1.1, and now known as eculizumab) that targets C5, specifically preventing the generation of C5a, a potent anaphylatoxin, and C5b, the first step in the eventual formation of membrane attack complex. The enormous clinical and financial success of eculizumab across four diseases (PNH, atypical hemolytic uremic syndrome (aHUS), myasthenia gravis (MG), and anti-aquaporin-4 (AQP4) antibody-positive neuromyelitis optica spectrum disorder (NMOSD)) has fueled a surge in complement therapeutics, especially targeting diseases with an underlying complement pathophysiology for which anti-C5 therapy is ineffective. Intensive research has also uncovered challenges that arise from C5 blockade. For example, PNH patients can still face extravascular hemolysis or pharmacodynamic breakthrough of complement suppression during complement-amplifying conditions. These "side" effects of a stoichiometric inhibitor like eculizumab were unexpected and are incompatible with some of our accepted knowledge of the complement cascade. And they are not unique to C5 inhibition. Indeed, "exceptions" to the rules of complement biology abound and have led to unprecedented and surprising insights. In this review, we will describe initial, present and future aspects of protein inhibitors of the complement cascade, highlighting unexpected findings that are redefining some of the mechanistic foundations upon which the complement cascade is organized.
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Affiliation(s)
- Christoph Q. Schmidt
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, Ulm, Germany
| | - Richard J. H. Smith
- Departments of Internal Medicine and Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
- Molecular Otolaryngology and Renal Research Laboratories, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
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23
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Su Y, Ruan Z, Wang R, Hao S, Tang Y, Huang X, Gao T, Li Z, Chang T. Knowledge mapping of targeted immunotherapy for myasthenia gravis from 1998 to 2022: A bibliometric analysis. Front Immunol 2022; 13:998217. [PMID: 36248874 PMCID: PMC9557176 DOI: 10.3389/fimmu.2022.998217] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 09/06/2022] [Indexed: 11/13/2022] Open
Abstract
BackgroundThe treatment of myasthenia gravis (MG) has advanced from steroids and traditional immunosuppressants to targeted immunotherapy. Targeted immunotherapy has been successfully employed in clinical practice in recent years. This study aimed to explore the emerging trend of targeted immunotherapy in MG and summarize the knowledge structure through bibliometric methods.MethodsThe Web of Science Core Collection database (WoSCC) was chosen to retrieve the literature on targeted immunotherapy for MG. Two bibliometric analysis software, VOSviewer and CiteSpace, and bibliometric online platform were mainly used to evaluate the contributions from countries/regions, institutions, journals, and authors through the construction and visualization of bibliometric networks. By systematically reviewing a knowledge domain, future research developments were determined. The R version 4.1.2 and Microsoft Excel 365 were used for statistical analysis.ResultsA total of 562 original articles and 262 reviews relevant to MG targeted immunotherapy were included. The number of publications on targeted immunotherapy for MG exhibited a two-phase advancement. The first stage showed a steady growth trend from 1998 to 2016, with an annual number of no more than 35 publications. The second stage revealed an explosive growth trend from 2017, reaching a peak number of publications in 2020. The United States ranked first in the number of publications, citations, and h-index. The author with the highest citation and h-index was Vincent A. And 28.03% of the articles were published in the top 10 journals. In addition to “myasthenia gravis”, the keyword with the highest consideration was “rituximab”, followed by “double-blind”, which indicate research hotspots gradually from basic research to clinical research over time, especially in the field of targeted immunotherapy. The MG treatment has entered a personalized precision treatment phase. Exploration into new target molecules and conducting high-quality randomized controlled trials on existing biological agents are the further research direction.ConclusionThe current study summarized the global research trends concerning targeted immunotherapy for MG. Research interests gradually advanced from basic research to clinical research. MG treatment has entered a personalized precision treatment phase. Further investigations into new target molecules and high-quality randomized controlled trials on existing biological agents are required urgently to direct future immunotherapy research.
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Affiliation(s)
- Yue Su
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi’an, China
| | - Zhe Ruan
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi’an, China
| | - Rui Wang
- Medical Department of Tangdu Hospital, The Fourth Military Medical University, Xi’an, China
| | - Sijia Hao
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi’an, China
| | - Yonglan Tang
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi’an, China
| | - Xiaoxi Huang
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi’an, China
| | - Ting Gao
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi’an, China
| | - Zhuyi Li
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi’an, China
| | - Ting Chang
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi’an, China
- *Correspondence: Ting Chang,
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Lekova E, Zelek WM, Gower D, Spitzfaden C, Osuch IH, John-Morris E, Stach L, Gormley D, Sanderson A, Bridges A, Wear ER, Petit-Frere S, Burden MN, Priest R, Wattam T, Kitchen SJ, Feeney M, Davis S, Morgan BP, Nichols EM. Discovery of functionally distinct anti-C7 monoclonal antibodies and stratification of anti-nicotinic AChR positive Myasthenia Gravis patients. Front Immunol 2022; 13:968206. [PMID: 36148231 PMCID: PMC9486540 DOI: 10.3389/fimmu.2022.968206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 07/19/2022] [Indexed: 11/13/2022] Open
Abstract
Myasthenia Gravis (MG) is mediated by autoantibodies against acetylcholine receptors that cause loss of the receptors in the neuromuscular junction. Eculizumab, a C5-inhibitor, is the only approved treatment for MG that mechanistically addresses complement-mediated loss of nicotinic acetylcholine receptors. It is an expensive drug and was approved despite missing the primary efficacy endpoint in the Phase 3 REGAIN study. There are two observations to highlight. Firstly, further C5 inhibitors are in clinical development, but other terminal pathway proteins, such as C7, have been relatively understudied as therapeutic targets, despite the potential for lower and less frequent dosing. Secondly, given the known heterogenous mechanisms of action of autoantibodies in MG, effective patient stratification in the REGAIN trial may have provided more favorable efficacy readouts. We investigated C7 as a target and assessed the in vitro function, binding epitopes and mechanism of action of three mAbs against C7. We found the mAbs were human, cynomolgus monkey and/or rat cross-reactive and each had a distinct, novel mechanism of C7 inhibition. TPP1820 was effective in preventing experimental MG in rats in both prophylactic and therapeutic dosing regimens. To enable identification of MG patients that are likely to respond to C7 inhibition, we developed a patient stratification assay and showed in a small cohort of MG patients (n=19) that 63% had significant complement activation and C7-dependent loss of AChRs in this in vitro set up. This study provides validation of C7 as a target for treatment of MG and provides a means of identifying patients likely to respond to anti-C7 therapy based on complement-activating properties of patient autoantibodies.
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Affiliation(s)
- Eleonora Lekova
- Immunology Research Unit, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Wioleta M. Zelek
- Division of Infection and Immunity and Dementia Research Institute, Systems Immunity Research Institute, School of Medicine, Cardiff University, Wales, United Kingdom
| | - David Gower
- Medicinal Science and Technology, Biopharm Discovery, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Claus Spitzfaden
- Medicines, Science and Technology, Protein Cellular and Structural Sciences (PCSS) Structural and Biophysical Sciences, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Isabelle H. Osuch
- Immunology Research Unit, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Elen John-Morris
- Immunology Research Unit, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Lasse Stach
- Medicinal Science and Technology, Biopharm Discovery, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Darren Gormley
- Immunology Research Unit, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Andrew Sanderson
- Medicines, Science and Technology, Protein Cellular and Structural Sciences (PCSS) Protein and Cellular Sciences, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Angela Bridges
- Medicines, Science and Technology, Protein Cellular and Structural Sciences (PCSS) Protein and Cellular Sciences, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Elizabeth R. Wear
- Immunology Research Unit, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Sebastien Petit-Frere
- Immunology Research Unit, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Michael N. Burden
- Medicinal Science and Technology, Biopharm Discovery, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Richard Priest
- Medicinal Science and Technology, Biopharm Discovery, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Trevor Wattam
- Medicinal Science and Technology, Biopharm Discovery, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Semra J. Kitchen
- Immunology Research Unit, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Maria Feeney
- Immunology Research Unit, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - Susannah Davis
- Medicinal Science and Technology, Biopharm Discovery, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
| | - B. Paul Morgan
- Division of Infection and Immunity and Dementia Research Institute, Systems Immunity Research Institute, School of Medicine, Cardiff University, Wales, United Kingdom
| | - Eva-Maria Nichols
- Immunology Research Unit, GlaxoSmithKline Research & Development (GSK R&D), Stevenage, United Kingdom
- *Correspondence: Eva-Maria Nichols,
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Stathopoulos P, Dalakas MC. The role of complement and complement therapeutics in neuromyelitis optica spectrum disorders. Expert Rev Clin Immunol 2022; 18:933-945. [PMID: 35899480 DOI: 10.1080/1744666x.2022.2105205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Neuromyelitis optica spectrum disorders (NMOSD) are characterized in the majority of cases by the presence of IgG1 autoantibodies against aquaporin 4 (AQP4) and myelin-oligodendrocyte glycoprotein (MOG), both capable of activating complement. AREAS COVERED We review evidence of complement involvement in NMOSD pathophysiology from pathological, in vitro, in vivo, human studies, and clinical trials. EXPERT OPINION In AQP4 NMOSD, complement deposition is a prominent pathological feature, while in vitro and in vivo studies have demonstrated complement-dependent pathogenicity of AQP4 antibodies. Consistent with these studies, the anti-C5 monoclonal antibody eculizumab was remarkably effective and safe in a phase 2/3 trial of AQP4-NMOSD patents leading to FDA-approved indication. Several other anti-complement agents, either approved or in trials for other neuro-autoimmunities, like myasthenia, CIDP, and GBS, are also relevant to NMOSD generating an exciting group of evolving immunotherapies. Limited but compelling in vivo and in vitro data suggest that anti-complement therapeutics may be also applicable to a subset of MOG NMOSD patients with severe disease. Overall, anticomplement agents, along with the already approved anti-IL6 and anti-CD19 monoclonal antibodies sartralizumab and inebilizumab, are rapidly changing the therapeutic algorithm in NMOSD, a previously difficult-to-treat autoimmune neurological disorder.
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Affiliation(s)
- Panos Stathopoulos
- Department of Neurology, National and Kapodistrian University of Athens, Athens, Greece
| | - Marinos C Dalakas
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA, USA.,Neuroimmunology Unit, National and Kapodistrian University of Athens, Athens, Greece
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Waheed W, Newman E, Aboukhatwa M, Moin M, Tandan R. Practical Management for Use of Eculizumab in the Treatment of Severe, Refractory, Non-Thymomatous, AChR + Generalized Myasthenia Gravis: A Systematic Review. Ther Clin Risk Manag 2022; 18:699-719. [PMID: 35855752 PMCID: PMC9288180 DOI: 10.2147/tcrm.s266031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Accepted: 07/04/2022] [Indexed: 11/28/2022] Open
Abstract
Myasthenia gravis (MG) is a rare autoimmune disorder caused by specific autoantibodies at the neuromuscular junction. MG is classified by the antigen specificity of these antibodies. Acetylcholine receptor (AChR) antibodies are the most common type (74–88%), followed by anti-muscle specific kinase (MuSK) and other antibodies. While all these antibodies lead to neuromuscular transmission failure, the immuno-pathogenic mechanisms are distinct. Complement activation is a primary driver of AChR antibody-positive MG (AChR+ MG) pathogenesis. This leads to the formation of the membrane attack complex and destruction of AChR receptors and the postsynaptic membrane resulting in impaired neurotransmission and muscle weakness characteristic of MG. Broad-based immune-suppressants like corticosteroids are effective in controlling MG; however, their long-term use can be associated with significant adverse effects. Advances in translational research have led to the development of more directed therapeutic agents that are likely to alter the future of MG treatment. Eculizumab is a humanized monoclonal antibody that inhibits the cleavage of complement protein C5 and is approved for use in generalized MG. In this review, we discuss the pathophysiology of MG; the therapeutic efficacy and tolerability of eculizumab, as well as the practical guidelines for its use in MG; future studies exploring the role of eculizumab in different stages and subtypes of MG subtypes; the optimal duration of therapy and its discontinuation; the characterization of non-responder patients; and the use of biomarkers for monitoring therapy are highlighted. Based on the pathophysiologic mechanisms, emerging therapies and new therapeutic targets are also reviewed.
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Affiliation(s)
- Waqar Waheed
- Department of Neurological Sciences, The University of Vermont and the University of Vermont Medical Center, Burlington, VT, USA
| | - Eric Newman
- Department of Neurological Sciences, The University of Vermont and the University of Vermont Medical Center, Burlington, VT, USA
| | - Marwa Aboukhatwa
- Pharmacotherapy Department, University of Vermont Medical Center, Burlington, VT, USA
| | - Maryam Moin
- Department of Neurology, University of Illinois College of Medicine, Peoria, IL, USA
| | - Rup Tandan
- Department of Neurological Sciences, The University of Vermont and the University of Vermont Medical Center, Burlington, VT, USA
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Obaid AH, Zografou C, Vadysirisack DD, Munro-Sheldon B, Fichtner ML, Roy B, Philbrick WM, Bennett JL, Nowak RJ, O'Connor KC. Heterogeneity of Acetylcholine Receptor Autoantibody-Mediated Complement Activity in Patients With Myasthenia Gravis. NEUROLOGY(R) NEUROIMMUNOLOGY & NEUROINFLAMMATION 2022; 9:9/4/e1169. [PMID: 35473886 PMCID: PMC9128035 DOI: 10.1212/nxi.0000000000001169] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 03/08/2022] [Indexed: 11/24/2022]
Abstract
BACKGROUND AND OBJECTIVES Autoantibodies targeting the acetylcholine receptor (AChR), found in patients with myasthenia gravis (MG), mediate pathology through 3 mechanisms: complement-directed tissue damage, blocking of the acetylcholine binding site, and internalization of the AChR. Clinical assays, used to diagnose and monitor patients, measure only autoantibody binding. Consequently, they are limited in providing association with disease burden, understanding of mechanistic heterogeneity, and monitoring therapeutic response. The objective of this study was to develop a cell-based assay that measures AChR autoantibody-mediated complement membrane attack complex (MAC) formation. METHODS An HEK293T cell line-modified using CRISPR/Cas9 genome editing to disrupt expression of the complement regulator genes (CD46, CD55, and CD59)-was used to measure AChR autoantibody-mediated MAC formation through flow cytometry. RESULTS Serum samples (n = 155) from 96 clinically confirmed AChR MG patients, representing a wide range of disease burden and autoantibody titer, were tested along with 32 healthy donor (HD) samples. AChR autoantibodies were detected in 139 of the 155 (89.7%) MG samples through a cell-based assay. Of the 139 AChR-positive samples, autoantibody-mediated MAC formation was detected in 83 (59.7%), whereas MAC formation was undetectable in the HD group or AChR-positive samples with low autoantibody levels. MAC formation was positively associated with autoantibody binding in most patient samples; ratios (mean fluorescence intensity) of MAC formation to AChR autoantibody binding ranged between 0.27 and 48, with a median of 0.79 and an interquartile range of 0.43 (0.58-1.1). However, the distribution of ratios was asymmetric and included extreme values; 16 samples were beyond the 10-90 percentile, with high MAC to low AChR autoantibody binding ratio or the reverse. Correlation between MAC formation and clinical disease scores suggested a modest positive association (rho = 0.34, p = 0.0023), which included a subset of outliers that did not follow this pattern. MAC formation did not associate with exposure to immunotherapy, thymectomy, or MG subtypes defined by age-of-onset. DISCUSSION A novel assay for evaluating AChR autoantibody-mediated complement activity was developed. A subset of patients that lacks association between MAC formation and autoantibody binding or disease burden was identified. The assay may provide a better understanding of the heterogeneous autoantibody molecular pathology and identify patients expected to benefit from complement inhibitor therapy.
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Complement Activation Profile in Myasthenia Gravis Patients: Perspectives for Tailoring Anti-Complement Therapy. Biomedicines 2022; 10:biomedicines10061360. [PMID: 35740382 PMCID: PMC9220000 DOI: 10.3390/biomedicines10061360] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 06/01/2022] [Accepted: 06/06/2022] [Indexed: 12/03/2022] Open
Abstract
The complement system plays a key role in myasthenia gravis (MG). Anti-complement drugs are emerging as effective therapies to treat anti-acetylcholine receptor (AChR) antibody-positive MG patients, though their usage is still limited by the high costs. Here, we searched for plasma complement proteins as indicators of complement activation status in AChR-MG patients, and potential biomarkers for tailoring anti-complement therapy in MG. Plasma was collected from AChR-MG and MuSK-MG patients, and healthy controls. Multiplex immunoassays and ELISA were used to quantify a panel of complement components (C1Q, C2, C3, C4, C5, Factor B, Factor H, MBL, and properdin) and activation products (C4b, C3b, C5a, and C5b-9), of classical, alternative and lectin pathways. C2 and C5 levels were significantly reduced, and C3, C3b, and C5a increased, in plasma of AChR-MG, but not MuSK-MG, patients compared to controls. This protein profile was indicative of complement activation. We obtained sensitivity and specificity performance results suggesting plasma C2, C3, C3b, and C5 as biomarkers for AChR-MG. Our findings reveal a plasma complement “C2, C3, C5, C3b, and C5a” profile associated with AChR-MG to be further investigated as a biomarker of complement activation status in AChR-MG patients, opening new perspectives for tailoring of anti-complement therapies to improve the disease treatment.
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Menon D, Bril V. Pharmacotherapy of Generalized Myasthenia Gravis with Special Emphasis on Newer Biologicals. Drugs 2022; 82:865-887. [PMID: 35639288 PMCID: PMC9152838 DOI: 10.1007/s40265-022-01726-y] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/25/2022] [Indexed: 11/20/2022]
Abstract
Myasthenia gravis (MG) is a chronic, fluctuating, antibody-mediated autoimmune disorder directed against the post-synaptic neuromuscular junctions of skeletal muscles, resulting in a wide spectrum of manifestations ranging from mild to potentially fatal. Given its unique natural course, designing an ideal trial design for MG has been wrought with difficulties and evidence in favour of several of the conventional agents is weak as per current standards. Despite this, acetylcholinesterases and corticosteroids have remained the cornerstones of treatment for several decades with intravenous immunoglobulins (IVIG) and therapeutic plasma exchange (PLEX) offering rapid treatment response, especially in crises. However, the treatment of MG entails long-term immunosuppression and conventional agents are viable options but take longer to act and have a number of class-specific adverse effects. Advances in immunology, translational medicine and drug development have seen the emergence of several newer biological agents which offer selective, target-specific immunotherapy with fewer side effects and rapid onset of action. Eculizumab is one of the newer agents that belong to the class of complement inhibitors and has been approved for the treatment of refractory general MG. Zilucoplan and ravulizumab are other agents in this group in clinical trials. Neisseria meningitis is a concern with all complement inhibitors, mandating vaccination. Neonatal Fc receptor (FcRn) inhibitors prevent immunoglobulin recycling and cause rapid reduction in antibody levels. Efgartigimod is an FcRn inhibitor recently approved for MG treatment, and rozanolixizumab, nipocalimab and batoclimab are other agents in clinical trial development. Although lacking high quality evidence from randomized clinical trials, clinical experience with the use of anti-CD20 rituximab has led to its use in refractory MG. Among novel targets, interleukin 6 (IL6) inhibitors such as satralizumab are promising and currently undergoing evaluation. Cutting-edge therapies include genetically modifying T cells to recognise chimeric antigen receptors (CAR) and chimeric autoantibody receptors (CAAR). These may offer sustained and long-term remissions, but are still in very early stages of evaluation. Hematopoietic stem cell transplantation (HSCT) allows immune resetting and offers sustained remission, but the induction regimens often involve serious systemic toxicity. While MG treatment is moving beyond conventional agents towards target-specific biologicals, lack of knowledge as to the initiation, maintenance, switching, tapering and long-term safety profile necessitates further research. These concerns and the high financial burden of novel agents may hamper widespread clinical use in the near future.
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Affiliation(s)
- Deepak Menon
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore, India
| | - Vera Bril
- Ellen and Martin Prosserman Centre for Neuromuscular Diseases, University Health Network, 5EC-309, Toronto General Hospital, University of Toronto, 200 Elizabeth St, Toronto, M5G 2C4, Canada.
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Novel treatment strategies for acetylcholine receptor antibody-positive myasthenia gravis and related disorders. Autoimmun Rev 2022; 21:103104. [PMID: 35452851 DOI: 10.1016/j.autrev.2022.103104] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 04/18/2022] [Indexed: 11/21/2022]
Abstract
The presence of autoantibodies directed against the muscle nicotinic acetylcholine receptor (AChR) is the most common cause of myasthenia gravis (MG). These antibodies damage the postsynaptic membrane of the neuromuscular junction and cause muscle weakness by depleting AChRs and thus impairing synaptic transmission. As one of the best-characterized antibody-mediated autoimmune diseases, AChR-MG has often served as a reference model for other autoimmune disorders. Classical pharmacological treatments, including broad-spectrum immunosuppressive drugs, are effective in many patients. However, complete remission cannot be achieved in all patients, and 10% of patients do not respond to currently used therapies. This may be attributed to production of autoantibodies by long-lived plasma cells which are resistant to conventional immunosuppressive drugs. Hence, novel therapies specifically targeting plasma cells might be a suitable therapeutic approach for selected patients. Additionally, in order to reduce side effects of broad-spectrum immunosuppression, targeted immunotherapies and symptomatic treatments will be required. This review presents established therapies as well as novel therapeutic approaches for MG and related conditions, with a focus on AChR-MG.
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McCombe JA, Pittock SJ. Anti-complement Agents for Autoimmune Neurological Disease. Neurotherapeutics 2022; 19:711-728. [PMID: 35553024 PMCID: PMC9294087 DOI: 10.1007/s13311-022-01223-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/14/2022] [Indexed: 01/06/2023] Open
Abstract
In recent years, there has been increasing recognition of the diversity of autoimmune neurological diseases affecting all levels of the nervous system. A growing understanding of disease pathogenesis has enabled us to better target specific elements of the immune system responsible for the cell dysfunction and cell destruction seen in these diseases. This is no better demonstrated than in the development of complement directed therapies for the treatment of complement mediated autoimmune neurological conditions. Herein, we describe the basic elements of the complement cascade, provide an overview of select autoimmune neurological diseases whose pathogenesis is mediated by complement, the effector system of autoantigen bound autoantibodies, and discuss the complement directed therapies trialed in the treatment of these diseases. Several complement-directed therapies have demonstrated benefit in the treatment of autoimmune neurological diseases; we also review the trials resulting in the approval of these therapies for the treatment of AChR Ab-positive myasthenia gravis (MG) and neuromyelitis spectrum disorder. Finally, on the heels of the recent successes described, we discuss possibilities for the future, including additional targeted therapies with greater ease of administration, improved risk profiles, and other possible uses for therapeutics targeting elements of the complement cascade.
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Affiliation(s)
- Jennifer A McCombe
- Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
- Division of Neurology, Department of Medicine, University of Alberta, Edmonton, AB, Canada
| | - Sean J Pittock
- Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.
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Gelinas D, Parvin-Nejad S, Phillips G, Cole C, Hughes T, Silvestri N, Govindarajan R, Jefferson M, Campbell J, Burnett H. The humanistic burden of myasthenia gravis: A systematic literature review. J Neurol Sci 2022; 437:120268. [DOI: 10.1016/j.jns.2022.120268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 04/14/2022] [Accepted: 04/16/2022] [Indexed: 11/25/2022]
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Abdulrazaq A, Smith R, Digala LP, Govindarajan R. Minimal Manifestations With Eculizumab Therapy in a Patient With Refractory Generalized Seropositive Myasthenia Gravis. J Clin Neuromuscul Dis 2022; 23:170-173. [PMID: 35188923 DOI: 10.1097/cnd.0000000000000388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
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Song Z, Zhang J, Meng J, Jiang G, Yan Z, Yang Y, Chen Z, You W, Wang Z, Chen G. Different Monoclonal Antibodies in Myasthenia Gravis: A Bayesian Network Meta-Analysis. Front Pharmacol 2022; 12:790834. [PMID: 35115936 PMCID: PMC8804097 DOI: 10.3389/fphar.2021.790834] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 12/10/2021] [Indexed: 11/13/2022] Open
Abstract
Background: Myasthenia gravis (MG) is a common autoimmune disease with acquired neuromuscular transmission disorders. Recently, monoclonal antibodies have been shown to successfully treat a variety of diseases. Methods: In this meta-analysis, an appropriate search strategy was used to search eligible randomized controlled trials (RCTs) on different monoclonal antibodies to treat patients with MG published up to September 2021 from the embase, PubMed, and Cochrane Library. We assessed the average difference or odds ratio between each drug and placebo and summarized them as the average and 95% confidence interval (CI), respectively. Results: In indicators of efficacy, patients receiving eculizumab (MD, −1.9; 95% CI, −3.2–0.76) had decreases in MG-ADL scores compared to placebo. In addition, only eculizumab (MD, −3.1; 95% CI, −4.7–1.5) and efgartigimod (MD, −1.4; 95% CI, −2.1–0.68) showed a significant difference from placebo in the amount of reduction in QMG scores, while neither of the other two monoclonal antibodies was statistically significant. With regard to the safety of monoclonal antibody therapy, there was no significant difference in the probability of AE in subjects treated with any of the four monoclonal antibodies compared to placebo. Conclusions: eculizumab was effective in reducing MG-ADL scores and QMG scores in myasthenia gravis. Meanwhile, eculizumab also caused fewer AE. As an emerging therapy, monoclonal antibodies are prospective in the treatment of MG. However, more researches are required to be invested in the future as the results obtained from small sample sizes are not reliable enough.
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Affiliation(s)
- Zhaoming Song
- Department of Neurosurgery and Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Jie Zhang
- Department of Neurosurgery and Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Jiahao Meng
- Department of Neurosurgery and Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Guannan Jiang
- Department of Neurosurgery and Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Zeya Yan
- Department of Neurosurgery and Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Yanbo Yang
- Department of Neurosurgery, China-Japan Friendship Hospital, Beijing, China
| | - Zhouqing Chen
- Department of Neurosurgery and Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Wanchun You
- Department of Neurosurgery and Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, China
- *Correspondence: Wanchun You, ; Zhong Wang,
| | - Zhong Wang
- Department of Neurosurgery and Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, China
- *Correspondence: Wanchun You, ; Zhong Wang,
| | - Gang Chen
- Department of Neurosurgery and Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, China
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Jiao L, Li H, Guo S. Eculizumab treatment for myasthenia gravis subgroups: 2021 update. J Neuroimmunol 2022; 362:577767. [PMID: 34823117 DOI: 10.1016/j.jneuroim.2021.577767] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 11/01/2021] [Accepted: 11/13/2021] [Indexed: 01/21/2023]
Abstract
Eculizumab is a recombinant humanized monoclonal antibody that targets the complement protein C5, inhibiting its cleavage into C5a and C5b and ultimately preventing the formation of C5b-9 membrane attack complex (MACs), thereby protecting the neuromuscular junction from the damage of complement activation. In 2017, eculizumab became the second FDA-approved medication for AchR-positive generalized myasthenia gravis (gMG) patients based on the successful results of a randomized, double-blinded, placebo-controlled, phase 2, phase 3 study (the REGAIN trial) and its open-label extension study. Despite the efficacy of eculizumab in treating AchR antibody-positive refractory gMG was demonstrated in the REGAIN study, there is few information on its efficacy in other subgroup of MG patients including seronegative MG, thymoma-associated MG and MG crisis. This narrative review summarizes current clinical studies of eculizumab in these refractory gMG patients, with a focus on the therapeutic efficacy and tolerability in different subgroup of MG.
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Affiliation(s)
- Li Jiao
- Department of Neurology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jing Wu Road, Huaiyin District, Jinan 250021, Shandong, China
| | - Honghao Li
- Department of Neurology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jing Wu Road, Huaiyin District, Jinan 250021, Shandong, China
| | - Shougang Guo
- Department of Neurology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jing Wu Road, Huaiyin District, Jinan 250021, Shandong, China.
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Muppidi S, Silvestri NJ, Tan R, Riggs K, Leighton T, Phillips GA. Utilization of MG-ADL in myasthenia gravis clinical research and care. Muscle Nerve 2022; 65:630-639. [PMID: 34989427 PMCID: PMC9302997 DOI: 10.1002/mus.27476] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 12/15/2021] [Accepted: 12/15/2021] [Indexed: 11/17/2022]
Abstract
The Myasthenia Gravis Activities of Living (MG‐ADL) scale is an 8‐item patient‐reported scale that measures myasthenia gravis (MG) symptoms and functional status. The objective of the current review is to summarize the psychometric properties of the MG‐ADL and published evidence of MG‐ADL use. A targeted literature review for published studies of the MG‐ADL was conducted using a database and gray literature search. A total of 48 publications and 35 clinical trials were included. Studies indicated that the MG‐ADL is a reliable and valid measure that has been used as an outcome in clinical trials and observational studies to measure MG symptoms and response to treatment. While most often used as a secondary endpoint in clinical trials, its use as a primary endpoint has increased in recent years. The most common MG‐ADL endpoint is change in MG‐ADL score from baseline, although there has been an increase in the analysis of a responder threshold using the MG‐ADL. A new concept of minimal symptom expression (MSE) has emerged more recently. Duration of treatment effect is another important construct that is being increasingly evaluated using the MG‐ADL. The use of the MG‐ADL as a primary endpoint in clinical trials and in responder threshold analyses to indicate treatment improvement has increased in recent years. MSE using the MG‐ADL shows promise in helping to determine success of treatment and may be the aspirational goal of MG treatment for the future once validated, particularly given the evolving treatment landscape in MG.
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Affiliation(s)
- Srikanth Muppidi
- Neurology & Neurological Sciences, Stanford University School of Medicine, Stanford, California, USA
| | - Nicholas J Silvestri
- Department of Neurology, State University of New York, Buffalo Jacobs School of Medicine and Biomedical Sciences, Buffalo, New York, USA
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37
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Treatment and Management of Disorders of the Neuromuscular Junction. Neuromuscul Disord 2022. [DOI: 10.1016/b978-0-323-71317-7.00019-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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38
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El-Abassi RN, Soliman M, Levy MH, England JD. Treatment and Management of Autoimmune Neuropathies. Neuromuscul Disord 2022. [DOI: 10.1016/b978-0-323-71317-7.00015-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Feng X, Song Z, Wu M, Liu Y, Luo S, Zhao C, Zhang W. Efficacy and Safety of Immunotherapies in Refractory Myasthenia Gravis: A Systematic Review and Meta-Analysis. Front Neurol 2021; 12:725700. [PMID: 34925206 PMCID: PMC8672452 DOI: 10.3389/fneur.2021.725700] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 10/25/2021] [Indexed: 01/21/2023] Open
Abstract
Introduction: Approximately 10–20% of patients WITH myasthenia gravis (MG) are refractory to conventional immunotherapies. The purpose of this study was to conduct a systematic review and meta-analysis to explore the optimal therapies for refractory MG. Method: Correlative studies were performed through a search in PubMed, Cochrane Library, and Embase databases. The primary outcome was defined by changes in the quantitative myasthenia gravis score (QMG). Secondary outcomes were defined by the Myasthenia Gravis Activities of Daily Living Scale (MG-ADL), Myasthenia Gravis Foundation of America (MGFA) post intervention status, adverse events, and disease exacerbation after treatment. Result: A total of 16 studies were included with 403 patients with refractory MG on therapies with rituximab, eculizumab, tacrolimus, and cladribine. Therapeutic efficacy of rituximab and eculizumab was identified with an estimated reduction in QMG score (4.158 vs. 6.928) and MG-ADL (4.400 vs. 4.344), respectively. No significant changes were revealed in efficacy or exacerbation density between the two independent therapeutic cohorts. The estimated adverse event density of eculizumab was more significant than that in the rituximab group (1.195 vs. 0.134 per patient-year), while the estimated serious event density was similar. Conclusion: The efficacy and safety of rituximab and eculizumab have been approved in patients with refractory MG. Rituximab had a superior safety profile than eculizumab with a lower incidence of adverse events. Systematic Review Registration:https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021236818, identifier CRD42021236818.
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Affiliation(s)
- Xuelin Feng
- Department of Neurology, East Hospital, Tongji University School of Medicine, Shanghai, China.,Department of Neurology, National Key Clinical Department and Key Discipline of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Zubiao Song
- Department of Neurology, National Key Clinical Department and Key Discipline of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Mengli Wu
- Department of Neurology, National Key Clinical Department and Key Discipline of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Yanmei Liu
- Department of Neurology, National Key Clinical Department and Key Discipline of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Sushan Luo
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Chongbo Zhao
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Weixi Zhang
- Department of Neurology, National Key Clinical Department and Key Discipline of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
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40
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Monteleone JPR, Gao X, Kleijn HJ, Bellanti F, Pelto R. Eculizumab Pharmacokinetics and Pharmacodynamics in Patients With Generalized Myasthenia Gravis. Front Neurol 2021; 12:696385. [PMID: 34795626 PMCID: PMC8594444 DOI: 10.3389/fneur.2021.696385] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 08/20/2021] [Indexed: 11/17/2022] Open
Abstract
Objective: To investigate the pharmacokinetics, pharmacodynamics, and exposure-response of the approved 900/1,200 mg dosing regimen for the terminal complement component 5 (C5) inhibitor eculizumab in patients with generalized myasthenia gravis (gMG). Methods: The analysis used data from 62 patients aged ≥ 18 years with anti-acetylcholine receptor (AChR) antibody-positive refractory gMG who received eculizumab during the REGAIN study (ClinicalTrials.gov: NCT01997229). One- and two-compartment population-pharmacokinetic models were evaluated, and the impact of covariates on pharmacokinetic parameters was assessed. Relationships between eculizumab exposure and free C5 concentration, in vitro hemolytic activity, clinical response, and tolerability were characterized. Results: Steady-state serum eculizumab concentrations were achieved by Week 4 and were sustained throughout the 26-week treatment period. The eculizumab pharmacokinetic data were well-described by a two-compartment model with first-order elimination, including effects of body weight on pharmacokinetic parameters and plasma-exchange events on clearance. Complete inhibition of terminal complement was achieved in nearly all patients at the time of trough and peak eculizumab concentrations at all post-dose timepoints assessed (free C5 < 0.5 μg/ml in 92% of patients; in vitro hemolysis < 20% in 87% of patients). Serum eculizumab concentrations of ≥116 μg/ml achieved free C5 concentrations of < 0.5 μg/ml. Clinical efficacy and tolerability were consistent across the eculizumab exposure range. Conclusions: Rigorous, quantitative, model-based exposure-response analysis of serum eculizumab concentration and response data demonstrated that the approved eculizumab dosing (900/1,200 mg) for adults with anti-AChR antibody-positive refractory gMG rapidly achieved complete inhibition of terminal complement activation and provided sustained clinical efficacy across the eculizumab exposure range.
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Affiliation(s)
- Jonathan P. R. Monteleone
- Department of Pharmacometrics, PK/PD M&S, Clinical Development and Translational Sciences, Alexion Pharmaceuticals Inc., Boston, MA, United States
| | - Xiang Gao
- Department of Pharmacometrics, PK/PD M&S, Clinical Development and Translational Sciences, Alexion Pharmaceuticals Inc., Boston, MA, United States
| | | | | | - Ryan Pelto
- Department of Pharmacometrics, PK/PD M&S, Clinical Development and Translational Sciences, Alexion Pharmaceuticals Inc., Boston, MA, United States
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41
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Lee JD, Woodruff TM. The emerging role of complement in neuromuscular disorders. Semin Immunopathol 2021; 43:817-828. [PMID: 34705082 DOI: 10.1007/s00281-021-00895-4] [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] [Received: 08/17/2021] [Accepted: 09/22/2021] [Indexed: 12/14/2022]
Abstract
The complement cascade is a key arm of the immune system that protects the host from exogenous and endogenous toxic stimuli through its ability to potently regulate inflammation, phagocytosis, and cell lysis. Due to recent clinical trial successes and drug approvals for complement inhibitors, there is a resurgence in targeting complement as a therapeutic approach to prevent ongoing tissue destruction in several diseases. In particular, neuromuscular diseases are undergoing a recent focus, with demonstrated links between complement activation and disease pathology. This review aims to provide a comprehensive overview of complement activation and its role during the initiation and progression of neuromuscular disorders including myasthenia gravis, amyotrophic lateral sclerosis, and Duchenne muscular dystrophy. We will review the preclinical and clinical evidence for complement in these diseases, with an emphasis on the complement-targeting drugs in clinical trials for these indications.
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Affiliation(s)
- John D Lee
- School of Biomedical Sciences, The University of Queensland, St Lucia, Brisbane, QLD, 4072, Australia.
| | - Trent M Woodruff
- School of Biomedical Sciences, The University of Queensland, St Lucia, Brisbane, QLD, 4072, Australia.,Queensland Brain Institute, The University of Queensland, St Lucia, Brisbane, QLD, 4072, Australia
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42
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Jeong S, Noh Y, Oh IS, Hong YH, Shin JY. Survival, Prognosis, and Clinical Feature of Refractory Myasthenia Gravis: a 15-year Nationwide Cohort Study. J Korean Med Sci 2021; 36:e242. [PMID: 34636500 PMCID: PMC8506414 DOI: 10.3346/jkms.2021.36.e242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 08/11/2021] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Myasthenia gravis (MG) is a rare classic autoimmune disease where immunosuppressant therapies have been successful to reduce MG attributable mortality fairly well. However, patients with refractory MG (rMG) among the actively treated MG (aMG) are nonresponsive to conventional therapy and display high disease severity, which calls for further research. We aimed to determine survival, prognosis, and clinical feature of patients with rMG compared to non-rMG. METHODS Retrospective nationwide cohort study using Korea's healthcare database between 2002 and 2017 was conducted. Patients with rMG (n = 47) and non-rMG (n = 4,251) who were aged > 18 years, followed-up for ≥ 1 year, and prescribed immunosuppressants within 2 years after incident MG diagnosis were included. Patients with rMG were defined as administered plasma exchange or intravenous immunoglobulin at least 3 times per year after receiving ≥ 2 immunosuppressants. All-cause mortality, myasthenic crisis, hospitalization, pneumonia/sepsis, and emergency department (ED) visits were measured using Cox proportional hazard models and pharmacotherapy patterns for rMG were assessed. RESULTS The rMG cohort included a preponderance of younger patients and women. The adjusted hazard ratio was 2.49 (95% confidence interval, 1.26-4.94) for mortality, 3.14 (2.25-4.38) for myasthenic crisis, 1.54 (1.15-2.06) for hospitalization, 2.69 (1.74-4.15) for pneumonia/sepsis, and 1.81 (1.28-2.56) for ED visits for rMG versus non-rMG. The immunosuppressant prescriptions were more prevalent in patients with rMG, while the difference was more remarkable before rMG onset rather than after rMG onset. CONCLUSION Despite the severe prognosis of rMG, the strategies for pharmacotherapeutic regimens were similar in those two groups, suggesting that intensive monitoring and introduction of timely treatment options in the early phase of MG are required.
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Affiliation(s)
- Sohyun Jeong
- Department of Pharmacy, School of Pharmacy, Sungkyunkwan University, Suwon, Korea
- Marcus Institute for Aging Research, Hebrew SeniorLife and Harvard Medical School, Boston, MA, USA
| | - Yunha Noh
- Department of Pharmacy, School of Pharmacy, Sungkyunkwan University, Suwon, Korea
| | - In-Sun Oh
- Department of Pharmacy, School of Pharmacy, Sungkyunkwan University, Suwon, Korea
| | - Yoon-Ho Hong
- Department of Neurology, Neuroscience Research Institute, Seoul National University Medical Research Council, Seoul Metropolitan Boramae Medical Center, Seoul National University College of Medicine, Seoul, Korea
| | - Ju-Young Shin
- Department of Pharmacy, School of Pharmacy, Sungkyunkwan University, Suwon, Korea
- Department of Clinical Research Design & Evaluation, SAIHST, Sungkyunkwan University, Seoul, Korea.
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43
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Allinovi M, Bellinvia A, Pesce F, Milan Manani S, Razzolini L, Brezzi B, Protopapa P, Mantero V, Caroti L, Cirami CL, Amato MP, Del Vecchio L. Safety and Efficacy of Eculizumab Therapy in Multiple Sclerosis: A Case Series. Brain Sci 2021; 11:1341. [PMID: 34679405 PMCID: PMC8533854 DOI: 10.3390/brainsci11101341] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 10/01/2021] [Accepted: 10/05/2021] [Indexed: 11/16/2022] Open
Abstract
(1) Background: Complement system activation has been proposed as one of the different factors that contribute to Multiple Sclerosis (MS) pathogenesis. In this study, we aimed to describe the potential effects of eculizumab, an anticomplement therapy, on MS disease activity in a cohort of relapsing-remitting (RR) MS patients who discontinued IFN-β therapy due to IFN-β-related thrombotic microangiopathy (TMA) onset. (2) Methods: In this retrospective observational multicentric study, we searched for all patients with MS treated by eculizumab with a survey of several nephrological and neurological centers (over 45 centers). (3) Results: Nine patients were included. The mean follow-up time under eculizumab was 3.72 ± 2.58 years. There were no significant differences in disease activity (EDSS, relapses, new T2, and/or Gd-enhancing lesions at MRI) considering the two years before and after eculizumab therapy. No adverse events potentially related to eculizumab therapy were reported during follow-up. (4) Conclusions: In this preliminary study, we described a good safety profile for eculizumab therapy in MS. However, the available data are not sufficient to make firm conclusions about the possible efficacy of eculizumab as a disease-modifying therapy for MS patients.
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Affiliation(s)
- Marco Allinovi
- Nephrology, Dialysis and Transplantation Unit, Careggi University Hospital, 50139 Florence, Italy; (L.C.); (C.L.C.)
| | - Angelo Bellinvia
- NEUROFARBA Department, University of Florence, 50139 Florence, Italy; (A.B.); (L.R.); (M.P.A.)
| | - Francesco Pesce
- Nephrology, Dialysis and Transplantation Unit, Department of Emergency and Organ Transplantation (DETO), University of Bari, 70121 Bari, Italy; (F.P.); (P.P.)
| | - Sabrina Milan Manani
- Department of Nephrology, Dialysis and Transplant, San Bortolo Hospital, 36100 Vicenza, Italy;
| | - Lorenzo Razzolini
- NEUROFARBA Department, University of Florence, 50139 Florence, Italy; (A.B.); (L.R.); (M.P.A.)
| | - Brigida Brezzi
- Division of Nephrology and Dialysis, SS Antonio e Biagio e C. Arrigo Hospital, 15121 Alessandria, Italy;
| | - Paolo Protopapa
- Nephrology, Dialysis and Transplantation Unit, Department of Emergency and Organ Transplantation (DETO), University of Bari, 70121 Bari, Italy; (F.P.); (P.P.)
| | - Vittorio Mantero
- MS Center, Department of Neurology, ASST Lecco, 23900 Lecco, Italy;
| | - Leonardo Caroti
- Nephrology, Dialysis and Transplantation Unit, Careggi University Hospital, 50139 Florence, Italy; (L.C.); (C.L.C.)
| | - Calogero Lino Cirami
- Nephrology, Dialysis and Transplantation Unit, Careggi University Hospital, 50139 Florence, Italy; (L.C.); (C.L.C.)
| | - Maria Pia Amato
- NEUROFARBA Department, University of Florence, 50139 Florence, Italy; (A.B.); (L.R.); (M.P.A.)
- IRCCS Don Carlo Gnocchi, 50143 Florence, Italy
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Li Y, Yi JS, Howard JF, Chopra M, Russo MA, Guptill JT. Cellular changes in eculizumab early responders with generalized myasthenia gravis. Clin Immunol 2021; 231:108830. [PMID: 34450290 DOI: 10.1016/j.clim.2021.108830] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 08/19/2021] [Accepted: 08/19/2021] [Indexed: 11/19/2022]
Abstract
Eculizumab (ECU), a C5 complement inhibitor, is approved to treat acetylcholine receptor autoantibody positive generalized myasthenia gravis (AChR MG). The clinical effect of ECU relies on inhibition of the terminal complement complex; however, the effect of ECU on lymphocytes is largely unknown. We evaluated innate and adaptive immunity among AChR MG patients (N = 3) before ECU and ≥3 months later while on stable therapy, and found reduced activation markers in memory CD4+ T cell subsets, increased regulatory T cell populations, and reduced frequencies of CXCR5+HLA-DR+CCR7+ Tfh subsets and CD11b+ migratory memory B cells. We observed increases within CD8+ T cell subsets that were terminally differentiated and senescent. Our data suggest complement inhibition with ECU modulates the adaptive immunity in patients with MG, consistent with preclinical data showing changes in complement-mediated signaling by T- and antigen-presenting cells. These findings extend our understanding of ECU's mechanism of action when treating patients with MG.
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Affiliation(s)
- Yingkai Li
- Department of Neurology, Duke University Medical Center, Durham, NC, USA
| | - John S Yi
- Department of Surgery, Duke University Medical Center, Durham, NC, USA
| | - James F Howard
- Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Manisha Chopra
- Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Melissa A Russo
- Department of Neurology, Duke University Medical Center, Durham, NC, USA
| | - Jeffrey T Guptill
- Department of Neurology, Duke University Medical Center, Durham, NC, USA; Duke Clinical Research Institute, Durham, NC, USA.
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45
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Xiao H, Wu K, Liang X, Li R, Lai KP. Clinical Efficacy and Safety of Eculizumab for Treating Myasthenia Gravis. Front Immunol 2021; 12:715036. [PMID: 34456922 PMCID: PMC8384962 DOI: 10.3389/fimmu.2021.715036] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 07/26/2021] [Indexed: 12/18/2022] Open
Abstract
Myasthenia gravis (MG) is an autoimmune disease primarily mediated by acetylcholine receptor antibodies (AChR-Ab), cellular immune dependence, and complement system involvement. Since the AChR on the postsynaptic membrane is destroyed by an immune attack, sufficient endplate potential cannot be generated, resulting in the development of a synaptic transmission disorder at the neuromuscular junction and in muscle weakness. The role of the complement system in MG has been demonstrated in animal models and clinical tests, and it has been determined that complement inhibition in patients with MG can prevent disease induction and reverse its progression. Eculizumab is a humanized monoclonal antibody that inhibits the cleavage of complement protein C5 and prevents autoimmune damage; additionally, it has received subsequent approval by the Federal Drug Administration of the United States for MG treatment. However, various concerns regarding the use of eculizumab persist. In this review, we have discussed the treatment time, cost effectiveness, long-term efficacy, and tolerability of eculizumab for MG treatment. We have also summarized historical information and have presented perspectives on this new therapeutic modality.
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Affiliation(s)
- Hai Xiao
- Department of Neurology, Guigang City People’s Hospital, The Eighth Affiliated Hospital of Guangxi Medical University, Guigang, China
| | - Ka Wu
- Department of Pharmacy, The Second People’s Hospital of Nanning City, The Third Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Xiaoliu Liang
- College of Pharmacy, Guangxi Medical University, Nanning, China
| | - Rong Li
- Laboratory of Environmental Pollution and Integrative Omics, Guilin Medical University, Guilin, China
| | - Keng Po Lai
- Laboratory of Environmental Pollution and Integrative Omics, Guilin Medical University, Guilin, China
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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: 6] [Impact Index Per Article: 2.0] [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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Dalakas MC. Progress in the therapy of myasthenia gravis: getting closer to effective targeted immunotherapies. Curr Opin Neurol 2021; 33:545-552. [PMID: 32833750 DOI: 10.1097/wco.0000000000000858] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW To provide an update on immunomodulating and immunosuppressive therapies in myasthenia gravis and highlight newly approved, or pending approval, therapies with new biologics. RECENT FINDINGS Preoperative IVIg is not needed to prevent myasthenic crisis in stable myasthenia gravis patients scheduled for surgery under general anesthesia, based on controlled data. Rituximab, if initiated early in new-onset myasthenia gravis, can lead to faster and more sustained remission even without immunotherapies in 35% of patients at 2 years. Biomarkers determining the timing for follow-up infusions in Rituximab-responding AChR-positive patients are discussed. Most patients with MuSK-positive myasthenia gravis treated with Rituximab have sustained long-term remission with persistent reduction of IgG4 anti-MuSK antibodies. Eculizumb in the extension REGAIN study showed sustained long-term pharmacological remissions and reduced exacerbations. Three new biologic agents showed promising results in phase-II controlled myasthenia gravis trials: Zilucoplan, a subcutaneous macrocyclic peptide inhibiting complement C5; Efgartigimod, an IgG1-derived Fc fragment binding to neonatal FcRn receptor; and Rozanolixizumab, a high-affinity anti-FcRn monoclonal antibody. Finally, the safety of ongoing myasthenia gravis immunotherapies during COVID19 pandemic is discussed. SUMMARY New biologics against B cells, complement and FcRn receptor, are bringing us closer to successful targeted immunotherapies in the chronic management of myasthenia gravis promising an exciting future for antibody-mediated neurological diseases.
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Affiliation(s)
- Marinos C Dalakas
- Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.,Neuroimmunology Unit, National and Kapodistrian University of Athens Medical School, Athens, Greece
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48
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Howard JF, Vissing J, Gilhus NE, Leite MI, Utsugisawa K, Duda PW, Farzaneh-Far R, Murai H, Wiendl H. Zilucoplan: An Investigational Complement C5 Inhibitor for the Treatment of Acetylcholine Receptor Autoantibody-Positive Generalized Myasthenia Gravis. Expert Opin Investig Drugs 2021; 30:483-493. [PMID: 33792453 DOI: 10.1080/13543784.2021.1897567] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Generalized myasthenia gravis (gMG) is an autoimmune disorder in which pathogenic autoantibodies damage the neuromuscular junction, causing disabling or life-threatening muscle weakness. Most treatments nonspecifically inhibit aspects of the immune system, do not directly address the causal mechanisms of tissue damage, and often have side-effect profiles that negatively impact patients. Understanding of the central pathogenic role of the complement cascade in gMG is advancing, and a new complement-targeting treatment is under investigation. AREAS COVERED We provide an overview of gMG etiology, the complement cascade, current treatments, and the investigational gMG therapy zilucoplan. Zilucoplan is a small, subcutaneously administered, macrocyclic peptide that inhibits cleavage of complement component C5 and the subsequent formation of the membrane attack complex. EXPERT OPINION In a randomized, double-blind, placebo-controlled, phase 2 clinical trial, zilucoplan demonstrated clinically meaningful complement inhibition in patients with acetylcholine receptor-positive gMG. Zilucoplan, a first-of-its-kind cyclic peptide targeting C5, appears to be a therapeutic option for the treatment of gMG based on available pharmacokinetic/pharmacodynamic data and phase 1 and 2 efficacy, safety, and tolerability data with limited long-term follow-up. Zilucoplan use earlier in the treatment paradigm would be suitable in this population should phase 3 efficacy and safety data be equally favorable.
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Affiliation(s)
- James F Howard
- Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - John Vissing
- Department of Clinical Medicine, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Nils E Gilhus
- Department of Clinical Medicine, University of Bergen and Haukeland University Hospital, Bergen, Norway
| | - M Isabel Leite
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Kimiaki Utsugisawa
- Department of Neurology, Hanamaki General Hospital, Hanamaki, Iwate, Japan
| | | | | | - Hiroyuki Murai
- Department of Neurology, International University of Health and Welfare, Narita, Chiba, Japan
| | - Heinz Wiendl
- Department of Neurology, Institute of Translational Neurology, University of Münster, Münster, Germany
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49
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Zhao R, Luo S, Zhao C. The role of innate immunity in myasthenia gravis. Autoimmun Rev 2021; 20:102800. [PMID: 33722749 DOI: 10.1016/j.autrev.2021.102800] [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] [Received: 01/12/2021] [Accepted: 01/22/2021] [Indexed: 12/19/2022]
Abstract
Myasthenia gravis (MG) is a T cell-driven, B cell-mediated and autoantibody-dependent autoimmune disorder against neuromuscular junctions (NMJ). Accumulated evidence has emerged regarding the role of innate immunity in the pathogenesis of MG. In this review, we proposed two hypothesis underlying the pathological mechanism. In the context of gene predisposition, on the one hand, Toll-like receptors (TLRs) pathways were initiated by viral infection in the thymus with MG to generate chemokines and pro-inflammatory cytokines such as Type I interferon (IFN), which facilitate the thymus to function as a tertiary lymphoid organ (TLO). On the another hand, the antibodies against acetylcholine receptors (AChR) generated by thymus then activated the classical pathways on thymus and neuromuscular junction (NMJ). Futher, we also highlight the role of innate immune cells in the pathogenic response. Finally, we provide some future perspectives in developing new therapeutic approaches particularly targeting the innate immunity for MG.
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Affiliation(s)
- Rui Zhao
- Department of Neurology, Huashan hospital Fudan University, 200040 Shanghai, China
| | - Sushan Luo
- Department of Neurology, Huashan hospital Fudan University, 200040 Shanghai, China
| | - Chongbo Zhao
- Department of Neurology, Huashan hospital Fudan University, 200040 Shanghai, China.
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Katyal N, Narula N, Govindarajan R. Clinical Experience with Eculizumab in Treatment-Refractory Acetylcholine Receptor Antibody-Positive Generalized Myasthenia Gravis. J Neuromuscul Dis 2021; 8:287-294. [PMID: 33325394 PMCID: PMC8075396 DOI: 10.3233/jnd-200584] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Background: Although established therapies are effective in most patients with generalized myasthenia gravis (gMG), some patients do not respond or they experience intolerable adverse events, highlighting the need for better tolerated, targeted therapies for treatment-refractory gMG. Objective: To describe real-world experience with eculizumab in patients with treatment-refractory acetylcholine receptor antibody-positive (AChR+) gMG. Methods: Retrospective chart review of 15 patients with treatment-refractory AChR+ gMG treated for 12 months with eculizumab (900 mg/week for 4 weeks then 1200 mg every 2 weeks). Outcome measures were Myasthenia Gravis–Activities of Daily Living (MG-ADL) scores, number of exacerbations, single-breath count test (SBCT) score, medication changes, selected Quantitative Myasthenia Gravis (QMG) evaluations, and adverse events. Data collected at 3-monthly intervals for 12 months before and after eculizumab initiation were analyzed. Results: Clinically meaningful reductions in total MG-ADL scores were observed at 3 months following eculizumab initiation and maintained up to 12 months in all patients. After 12 months’ eculizumab treatment, there was a significant reduction in the number of acute exacerbations; mean (SD) SBCT score improved from 28.13 (0.33) to 50.26 (2.86); all patients achieved a ‘none’ or ‘mild’ rating for QMG evaluations; all patients reduced their daily prednisone dose; and nine patients had discontinued pyridostigmine. At the end of treatment, intravenous immunoglobulin was discontinued in all six patients receiving this therapy at eculizumab initiation. Eculizumab was well tolerated. Conclusions: This real-world study demonstrated improvement in outcome measures and decreased concomitant drug requirement within 12 months of eculizumab initiation in patients with treatment-refractory AChR+ gMG.
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Affiliation(s)
- Nakul Katyal
- University of Missouri Health Care, Columbia, Missouri, USA
| | - Naureen Narula
- University of Missouri Health Care, Columbia, Missouri, USA
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