A randomized controlled trial of methotrexate for patients with generalized myasthenia gravis

Efficacy and safety of immunosuppressants and monoclonal antibodies in adults with myasthenia gravis: a systematic review and network meta-analysis

Numerous clinical trials for myasthenia gravis (MG) treatment have been conducted recently, with satisfactory cognitive and clinical results. However, due to the limited evidence for direct comparison of the safety and effectiveness of various drugs, there is a need for further exploration of the advantages and disadvantages of different monoclonal antibodies and immunosuppressants. Thus, in the present network meta-analysis (NMA), we aimed to compare the efficacy and safety of immunosuppressants and monoclonal antibodies in treating MG. We systematically searched for randomized controlled trials published in PubMed, Embase, Web of Science, and the Cochrane Library between January 1, 2000 and March 6, 2024. Statistical analyses were performed using R software (version 4.2.3), JAGS, and STATA (version 15.0). The surface under the cumulative ranking curve (SUCRA) value was calculated to assess the potential efficacy of each drug and the likelihood of adverse events (AEs), with higher SUCRA values indicating better efficacy or a lower likelihood of AEs. This NMA included 21 randomized controlled trials involving 13 drugs and 1,657 patients. Based on changes in Quantitative MG and MG Composite scores, batoclimab was most likely to exert the best therapeutic effects, with SUCRA values of 99% and 92%, respectively. Rozanolixzumab performed better than the other drugs in terms of the MG Activities of Daily Living score (85%). Eculizumab exhibited the highest potential in reducing the 15-item revised version of the MG Quality of Life score (96%). Regarding safety, belimumab had the highest SUCRA value (85%), demonstrating the lowest likelihood of AEs. In conclusion, all immunosuppressants and monoclonal antibodies analyzed in this study were more effective than the placebo in treating MG, with rozanolixzumab and batoclimab potentially being the most effective. Regarding safety, rozanolixzumab exhibited a higher likelihood of AEs than did placebo. The conclusions guide the clinical selection of effective drugs and offer insights for future drug experiments.

Clinical features of double seronegative ocular myasthenia gravis

PURPOSE

To clarify the clinical features of patients with Double seronegative (DS) ocular myasthenia gravis (OMG).

METHODS

Sixty-one patients diagnosed with DS OMG at the Department of Ophthalmology, Hyogo Medical University Hospital over a 5-year period from 2017 were included. Patients were classified into three groups based on the initial examination findings: group P (ptosis alone), group M (ocular motility disorder alone), and group PM (combination of both). We retrospectively reviewed the patients and clarified their clinical features.

RESULTS

There were 32 males and 29 females, with a mean age of 49.8 ± 20.9:1-82 years. Twenty-one patients (34.4%) were in group P, 23 (37.7%) in group M, and 17 (27.8%) in group PM. The proportion of males (73.9%) was significantly higher in group M compared with the other two groups. The diagnosis was proven by detection of neuromuscular junction (NMJ) disorder in 73.8%, oral pyridostigmine trial test in 13.1%, and eight patients (13.1%) in group M were diagnosed after surgical treatment. The clinical symptoms were resolved by oral pyridostigmine treatment in 54.1% of cases.

CONCLUSION

About 30% of patients with DS OMG had no obvious NMJ disorder, and an oral pyridostigmine trial test was necessary to diagnose these patients. Although DS OMG is often considered as the mildest form of MG, its prognosis is not optimistic and it requires aggressive therapeutic intervention.

TRIAL REGISTRATION

Trial registration number: 202104-750, "2016/4/18," retrospectively registered.

Immune mediated myasthenia gravis in children, current concepts and new treatments: A narrative review article

Myasthenia gravis (MG) is the most frequent transmission disease in the neuromuscular junction. Juvenile myasthenia gravis (JMG) is an autoimmune antibody-mediated disease of postsynaptic endplate defined as MG presentation in patients before the age of 18 years old. While many clinical features of JMG are identical to the adults, there are some significant differences between them regarding presentation, clinical course, antibody level, and thymus histopathology. In JMG, ocular symptoms are more frequent, the clinical course is comparably benign, and the outcome is better than adult MG. Antibodies attack the muscle endplate proteins in the postsynaptic membrane and interfere with transmission. These antibodies in most patients are against the acetylcholine receptors, but they may also be directed toward muscle-specific kinase, lipoprotein-related protein 4, and agrin. Findings show racial influences and genetic effects on the occurrence of JMG. The essential clinical symptom is fatigable weakness of muscles that can be in the form of isolated ocular type or more disseminated weakness. The diagnosis of JMG is essentially clinical, with fluctuating patterns of weakness and easy fatigability, but a series of diagnostic evaluations can confirm the diagnosis. Precise diagnostic evaluation and distinction from congenital myasthenic syndromes is critical. The treatment plan is conducted according to the clinical course (ocular or generalized), antibody type, and disease severity. The mainstay of treatment includes symptomatic therapy, long-lasting immunosuppressive treatment and treatment of myasthenic crisis. Novel medications are introduced and conducted to the specific pathophysiologic mechanisms of the disease, and they are used primarily in the refractory MG.

Generalized myasthenia gravis with acetylcholine receptor antibodies: A guidance for treatment

BACKGROUND

Generalized myasthenia gravis (MG) with antibodies against the acetylcholine receptor is a chronic disease causing muscle weakness. Access to novel treatments warrants authoritative treatment recommendations. The Nordic countries have similar, comprehensive health systems, mandatory health registers, and extensive MG research.

METHODS

MG experts and patient representatives from the five Nordic countries formed a working group to prepare treatment guidance for MG based on a systematic literature search and consensus meetings.

RESULTS

Pyridostigmine represents the first-line symptomatic treatment, while ambenonium and beta adrenergic agonists are second-line options. Early thymectomy should be undertaken if a thymoma, and in non-thymoma patients up to the age of 50-65 years if not obtaining remission on symptomatic treatment. Most patients need immunosuppressive drug treatment. Combining corticosteroids at the lowest possible dose with azathioprine is recommended, rituximab being an alternative first-line option. Mycophenolate, methotrexate, and tacrolimus represent second-line immunosuppression. Plasma exchange and intravenous immunoglobulin are used for myasthenic crises and acute exacerbations. Novel complement inhibitors and FcRn blockers are effective and fast-acting treatments with promising safety profiles. Their use depends on local availability, refunding policies, and cost-benefit analyses. Adapted physical training is recommended. Planning of pregnancies with optimal treatment, information, and awareness of neonatal MG is necessary. Social support and adaptation of work and daily life activities are recommended.

CONCLUSIONS

Successful treatment of MG rests on timely combination of different interventions. Due to spontaneous disease fluctuations, comorbidities, and changes in life conditions, regular long-term specialized follow-up is needed. Most patients do reasonably well but there is room for further improvement. Novel treatments are promising, though subject to restricted access due to costs.

Myasthenia gravis-Pathophysiology, diagnosis, and treatment

Myasthenia gravis (MG) is an autoimmune disease characterized by dysfunction of the neuromuscular junction resulting in skeletal muscle weakness. It is equally prevalent in males and females, but debuts at a younger age in females and at an older age in males. Ptosis, diplopia, facial bulbar weakness, and limb weakness are the most common symptoms. MG can be classified based on the presence of serum autoantibodies. Acetylcholine receptor (AChR) antibodies are found in 80%-85% of patients, muscle-specific kinase (MuSK) antibodies in 5%-8%, and <1% may have low-density lipoprotein receptor-related protein 4 (Lrp4) antibodies. Approximately 10% of patients are seronegative for antibodies binding the known disease-related antigens. In patients with AChR MG, 10%-20% have a thymoma, which is usually detected at the onset of the disease. Important differences between clinical presentation, treatment responsiveness, and disease mechanisms have been observed between these different serologic MG classes. Besides the typical clinical features and serologic testing, the diagnosis can be established with additional tests, including repetitive nerve stimulation, single fiber EMG, and the ice pack test. Treatment options for MG consist of symptomatic treatment (such as pyridostigmine), immunosuppressive treatment, or thymectomy. Despite the treatment with symptomatic drugs, steroid-sparing immunosuppressants, intravenous immunoglobulins, plasmapheresis, and thymectomy, a large proportion of patients remain chronically dependent on corticosteroids (CS). In the past decade, the number of treatment options for MG has considerably increased. Advances in the understanding of the pathophysiology have led to new treatment options targeting B or T cells, the complement cascade, the neonatal Fc receptor or cytokines. In the future, these new treatments are likely to reduce the chronic use of CS, diminish side effects, and decrease the number of patients with refractory disease.

Single institution experience with efgartigimod in patients with myasthenia gravis: Patient selection, dosing schedules, treatment response, and adverse events

INTRODUCTION/AIMS

Efgartigimod is a neonatal Fc receptor blocker and was the first approved medication in its class for the treatment of generalized myasthenia gravis (gMG). As a novel therapy, little is known about the use of efgartigimod in clinical practice. This study aims to describe how efgartigimod is being incorporated into the current therapeutic landscape of MG.

METHODS

We reviewed the charts of 17 patients with gMG treated with efgartigimod at the University of Pennsylvania between January 2022 and June 2023.

RESULTS

Efgartigimod was selected mainly for patients who were treatment refractory, had side effects to other treatments, and/or required quick improvement in their symptoms. All patients had been previously treated with at least one medication for MG and had an average baseline Myasthenia Gravis Activities of Daily Living (MG-ADL) score of 9.1. The patients treated with efgartigimod improved their MG-ADL score by an average of 5.5 points at 3 months (p < .001) and 7.1 points by 6 months (p < .001). Forty percent of patients achieved minimal symptom expression. Adverse events (AEs) were reported in 43.7% of patients on efgartigimod, the most common being mild infection (urinary tract infection and thrush). There were no serious AEs.

DISCUSSION

This study found efgartigimod to be efficacious, well tolerated, and safe in patients with MG. Efgartigimod should be considered as an add-on therapy, a bridge therapy, or as a monotherapy if patients have difficulty tolerating other treatments.

Guideline for the management of myasthenic syndromes

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.

Case Report: Telitacicept in severe myasthenia gravis: a case study with multiple autoantibodies

Multi-antibody-positive myasthenia gravis (MG) presentations are relatively rare, often found in older patients, and generally predict a poor prognosis. We report a case of a female patient with generalized MG, testing positive for Titin antibodies (Titin-Ab), ryanodine receptor antibodies (RyR-Ab), and acetylcholine receptor antibodies (AChR-Ab), and resistant to acetylcholinesterase inhibitors. Following unsuccessful traditional therapies, she received Telitacicept, leading to significant improvements. This case underscores Telitacicept's potential efficacy for similar patients and offers insights into the clinical characteristics of multi-antibody MG.

Myasthenia gravis: Molecular mechanisms and promising therapeutic strategies

Myasthenia gravis (MG) is a type of autoimmune disease caused by the blockage of neuromuscular junction transmission owing to the attack of autoantibodies on transmission-related proteins. Related antibodies, such as anti-AChR, anti-MuSK and anti-LRP4 antibodies, can be detected in most patients with MG. Although traditional therapies can control most symptoms, several challenges remain to be addressed, necessitating the development of more effective and safe treatment strategies for MG. With the in-depth exploration on the mechanism and immune targets of MG, effective therapies, especially therapies using biologicals, have been reported recently. Given the important roles of immune cells, cytokines and intercellular interactions in the pathological process of MG, B-cell targeted therapy, T-cell targeted therapy, proteasome inhibitors targeting plasma cell, complement inhibitors, FcRn inhibitors have been developed for the treatment of MG. Although these novel therapies exert good therapeutic effects, they may weaken the immunity and increase the risk of infection in MG patients. This review elaborates on the pathogenesis of MG and discusses the advantages and disadvantages of the strategies of traditional treatment and biologicals. In addition, this review emphasises that combined therapy may have better therapeutic effects and reducing the risk of side effects of treatments, which has great prospects for the treatment of MG. With the deepening of research on immunotherapy targets in MG, novel opportunities and challenges in the treatment of MG will be introduced.

Unlocking the Complexity of Neuromuscular Diseases: Insights from Human Pluripotent Stem Cell-Derived Neuromuscular Junctions

Over the past 20 years, the use of pluripotent stem cells to mimic the complexities of the human neuromuscular junction has received much attention. Deciphering the key mechanisms underlying the establishment and maturation of this complex synapse has been driven by the dual goals of addressing developmental questions and gaining insight into neuromuscular disorders. This review aims to summarise the evolution and sophistication of in vitro neuromuscular junction models developed from the first differentiation of human embryonic stem cells into motor neurons to recent neuromuscular organoids. We also discuss the potential offered by these models to decipher different neuromuscular diseases characterised by defects in the presynaptic compartment, the neuromuscular junction, and the postsynaptic compartment. Finally, we discuss the emerging field that considers the use of these techniques in drug screening assay and the challenges they will face in the future.

Methotrexate in generalized myasthenia gravis: a systematic review

Current myasthenia gravis guidelines recommend the use of azathioprine as first-line steroid sparing agent. However, due to its high cost, compliance to azathioprine is low in developing countries. To determine the efficacy and safety of the cheaper methotrexate as an alternative immunosuppressant, Medline/Pubmed, Embase and Cochrane databases and references were searched for clinical trials and observational studies using the search terms: "Myasthenia OR Myasthenia Gravis OR anti AchR antibody positive Myasthenia Gravis OR anti-MuSK antibody Myasthenia Gravis OR MG" AND "Methotrexate". Of 78 possible articles, only 4 were selected using the following eligibility criteria: population: generalized MG patients; intervention: methotrexate; and outcome: effectiveness, steroid sparing efficacy and adverse effects. Two clinical trials and one observational study noted improvement in different MG outcomes in patients given methotrexate. While one randomized controlled clinical trial concluded that methotrexate has no steroid sparing benefit, a single blinded clinical trial established that methotrexate was a better steroid sparing agent than azathioprine starting at 10th month of use. Adverse effects were rare with non-specific pain and elevated transaminases as the most common complaints. Based on available evidence, MTX may be a safe and effective alternative to AZA as steroid sparing agent in developing countries.

Randomized Double-Blind Placebo-Controlled Trial of the Corticosteroid-Sparing Effects of Immunoglobulin in Myasthenia Gravis

BACKGROUND AND OBJECTIVES

Myasthenia gravis (MG) is an autoimmune disease characterized by dysfunction at the neuromuscular junction. Treatment frequently includes corticosteroids (CSs) and IV immunoglobulin (IVIG). This study was conducted to determine whether immune globulin (human), 10% caprylate/chromatography purified (IGIV-C) could facilitate CS dose reduction in CS-dependent patients with MG.

METHODS

In this randomized double-blind placebo-controlled trial, CS-dependent patients with MG (Myasthenia Gravis Foundation of America Class II-Iva; AChR+) received a loading dose of 2 g/kg IGIV-C over 2 days (maximum 80 g/d) or placebo at week 0 (baseline). Maintenance doses (1 g/kg IGIV-C or placebo) were administered every 3 weeks through week 36. Tapering of CS was initiated at week 9 and continued through week 36 unless the patient worsened (quantitative MG score ≥4 points from baseline). CS doses were increased (based on the current CS dose) in patients who worsened. Patients were withdrawn if worsening failed to improve within 6 weeks or if a second CS increase was required. The primary efficacy end point (at week 39) was a ≥50% reduction in CS dose. Secondary and safety end points were assessed throughout the study and follow-up (weeks 42 and 45). The study results and full protocol are available at clinicaltrials.gov/ct2/show/NCT02473965.

RESULTS

The primary end point (≥50% reduction in CS dose) showed no significant difference between the IGIV-C treatment (60.0% of patients) and placebo (63.3%). There were no significant differences for secondary end points. Safety data indicated that IGIV-C was well tolerated.

DISCUSSION

In this study, IGIV-C was not more effective than placebo in reducing daily CS dose. These results suggest that the effects of IGIV-C and CS are not synergistic and may be mechanistically different.

TRIAL REGISTRATION INFORMATION

The trial was registered on clinicaltrialsregister.eu (EudraCT #: 2013-005099-17) and clinicaltrials.gov (identifier NCT02473965).

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that IVIG infusions in adult patients with MG do not increase the percentage of patients achieving a ≥50% reduction in corticosteroid dose compared with placebo.

Comparative the efficacy and acceptability of immunosuppressive agents for myasthenia gravis: A protocol for systematic review and network meta-analysis

BACKGROUND

Immunosuppressive drugs are routinely used to treat myasthenia gravis (MG). However, current recommendations provide limited evidence to support treatment options, leading to considerable variation in practice among healthcare specialists. Hence, we present a protocol for a systematic review and network meta-analysis (NMA) to update the evidence by comparing the efficacy and acceptability of oral immunosuppressive drugs for the treatment of MG.

METHODS

We will conduct a systematic review and NMA of all randomized controlled trials evaluating the following oral immunosuppressive drugs for the treatment of MG. Published studies will be searched using the following databases from inception to November 23, 2021: CENTRAL, the CINAHL, MEDLINE, Embase, PsycINFO, Web of Science, and 3 Chinese databases (Chinese Biomedical Literatures Database, CNKI, and Wan Fang database). Assessment of study eligibility and data extraction will be conducted independently by 2 reviewers. The main outcome will be a quantitative MG scoring system. We will conduct Bayesian NMA to synthesize all evidence for each outcome and obtain a comprehensive ranking of all treatments. The quality of the evidence will be evaluated using the Grading of Recommendations, Assessment, Development, and Evaluations framework.

RESULTS

The objective of this study was to assess the relative clinical efficacy and acceptability of first-line immunosuppressants for the treatment of MG, using a systematic review and NMA approach.

CONCLUSION

In the absence of head-to-head trials comparing therapies, evidence from this NMA of available clinical trials will inform clinicians, patients, and families the risk-benefit profiles of different treatment options.

Efficacy and Safety of Rituximab for New-Onset Generalized Myasthenia Gravis: The RINOMAX Randomized Clinical Trial

Importance

Rituximab is a third-line option for refractory generalized myasthenia gravis (MG) based on empirical evidence, but its effect in new-onset disease is unknown.

Objective

To investigate the efficacy and safety of rituximab compared with placebo as an add-on to standard of care for MG.

Design, Setting, and Participants

This randomized, double-blind, placebo-controlled study took place throughout 48 weeks at 7 regional clinics in Sweden. Key inclusion criteria were age older than 18 years, onset of generalized symptoms within 12 months or less, and a Quantitative Myasthenia Gravis (QMG) score of 6 or more. Patients were screened from October 20, 2016, to March 2, 2020. Key exclusion criteria included pure ocular MG, suspected thymoma, previous thymectomy, and prior noncorticosteroid immunosuppressants or high doses of corticosteroids.

Interventions

Participants were randomized 1:1 without stratification to a single intravenous infusion of 500 mg of rituximab or matching placebo.

Main Outcomes and Measures

Minimal disease manifestations at 16 weeks defined as a QMG score of 4 or less with prednisolone, 10 mg or less daily, and no rescue treatment.

Results

Of 87 potentially eligible patients, 25 were randomized to rituximab (mean [SD] age, 67.4 [13.4] years; 7 [28%] female) and 22 to placebo (mean [SD] age, 58 [18.6] years; 7 [32%] female). Compared with placebo, a greater proportion with rituximab met the primary end point; 71% (17 of 24) in the rituximab group vs 29% (6 of 21) in the placebo group (Fisher exact test P = .007; probability ratio, 2.48 [95% CI, 1.20-5.11]). Secondary end points, comparing changes in Myasthenia Gravis Activities of Daily Living and Myasthenia Gravis Quality of Life at 16 weeks with QMG at 24 weeks did not differ between groups with censoring for rescue treatment (per-protocol analysis) but were in favor of active treatment when rescue treatment was taken into account by worst rank imputation (post hoc analysis). Rescue treatments were also more frequent in the placebo arm (rituximab: 1 [4%]; placebo, 8 [36%]). One patient in the placebo arm had a myocardial infarction with cardiac arrest and 1 patient in the active arm experienced a fatal cardiac event.

Conclusions and Relevance

A single dose of 500 mg of rituximab was associated with greater probability of minimal MG manifestations and reduced need of rescue medications compared with placebo. Further studies are needed to address long-term benefit-risk balance with this treatment.

Trial Registration

ClinicalTrials.gov Identifier: NCT02950155.

Long-Term Efficacy of Non-steroid Immunosuppressive Agents in Anti-Muscle-Specific Kinase Positive Myasthenia Gravis Patients: A Prospective Study

Background and Purpose

Anti-muscle-specific kinase (MuSK) positive myasthenia gravis (MG) is characterized by a high relapsing rate, thus, choosing the appropriate oral drug regimen is a challenge. This study aimed to evaluate the efficacy of oral immunosuppressants (IS) in preventing relapse in MuSK-MG.

Methods

This prospective cohort observational study included patients with MuSK-MG at Peking Union Medical College Hospital between January 1, 2018, and November 15, 2021. The patients were divided into 2 groups: those with (IS+) or without (IS-) non-steroid immunosuppressive agents. The primary outcome was relapsed at follow-up, and the log-rank test was used to compare the proportion of maintenance-free relapse between the groups; hazard ratio (HR) was calculated using the Cox proportional hazards models.

Results

Fifty-three of 59 patients with MuSK-MG were included in the cohort, 14 were in the IS+ group, and 39 were in the IS- group. Twenty-four cases in the cohort experienced relapse at least once; the relapse rate was 2/14 (14.3%) in the IS+ group and 22/39 (56.4%) in the IS- group. At the end of follow-up, the proportion of maintenance-free relapse was significantly different between the two groups (log-rank χ2 = 4.94, P = 0.02). Of all the potential confounders, only the use of IS was associated with a reduced risk of relapse. The HR for relapse among patients in the IS+ group was 0.21 (95%CI 0.05-0.58) and was 0.23 (95%CI 0.05-0.93) in a model adjusted for age, sex, relapse history, highest Myasthenia Gravis Foundation of America (MGFA), and accumulated time of steroid therapy.

Conclusions

This study provides evidence that oral non-steroid immunosuppressive agents may be beneficial in reducing relapse in patients with MuSK-MG.

Pharmacotherapy of Generalized Myasthenia Gravis with Special Emphasis on Newer Biologicals

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.

Corticosteroid Treatment-Resistance in Myasthenia Gravis

Chronic, high-dose, oral prednisone has been the mainstay of myasthenia gravis treatment for decades and has proven to be highly beneficial in many, toxic in some way to all, and not effective in a significant minority. No patient characteristics or biomarkers are predictive of treatment response leading to many patients suffering adverse effects with no benefit. Presently, measurements of treatment response, whether taken from clinician or patient perspective, are appreciated to be limited by lack of good correlation, which then complicates correlation to biological measures. Treatment response may be limited because disease mechanisms are not influenced by corticosteroids, limits on dosage because of adverse effects, or individual differences in corticosteroids. This review evaluates potential mechanisms that underlie lack of response to glucocorticoids in patients with myasthenia gravis.

Novel treatment strategies for acetylcholine receptor antibody-positive myasthenia gravis and related disorders

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.

A Randomized Open-Labeled Trial of Methotrexate as a Steroid-Sparing Agent for Patients With Generalized Myasthenia Gravis

Background and Purpose

Two clinical trials assessing the steroid-sparing effect of methotrexate (MTX) yielded conflicting results. Our objective was to investigate whether MTX would show a steroid-sparing effect in the treatment of generalized myasthenia gravis (MG) patients who fitted Myasthenia Gravis Foundation of America (MGFA) Class II and Class III.

Methods

We performed an 18-month prospective, randomized, open-labeled trial of prednisone combined with MTX 10 mg orally every week versus prednisone alone in 40 recently diagnosed MG patients of MGFA Class II and Class III between July 2014 and July 2018. The primary endpoint was the prednisone area under the dose–time curve (AUDTC) from months 3 to 18. Secondary endpoints included changes of the Quantitative Myasthenia Gravis Score (QMG), the Myasthenia Gravis Activity of Daily Living Score (MG-ADL), initial time of prednisone reduction, the median prednisone daily dose in each month, adverse events, and treatment failures in each group.

Results

Forty participants were included; among those, 5 individuals withdrew. A total of 35 participants completed 18 months of follow-up (18 in prednisone+MTX, 17 in prednisone group). Combined use of MTX reduced the month 3–18 prednisone AUDTC (prednisone+MTX 5,663.44 ± 1,678.08 mg, prednisone 6,683.94 ± 678.08 mg, p = 0.03, 95% confidence interval -1916.01 to -124.98). The initial times of prednisone reduction were 4.34 ± 1.44 months in the prednisone+MTX group and 5.56 ± 2.05 months in the prednisone group (p = 0.04, 95% CI -2.41 to -0.03). The median daily prednisone dose was significantly lower in the prednisone+MTX group at month 6 and months 9–18. No significant differences were found in QMG and MG-ADL scores between the two groups. No serious drug-related adverse events were observed in both groups.

Conclusions

This study provides evidence that MTX has the steroid-sparing ability in generalized MG patients of MGFA Class II and Class III.

Clinical Trial Registration

http://www.chictr.org.cn/showproj.aspx?proj=10563 identifier ChiCTR-IPR-15006081.

Current Treatment of Myasthenia Gravis

Myasthenia gravis (MG) is the most extensively studied antibody-mediated disease in humans. Substantial progress has been made in the treatment of MG in the last century, resulting in a change of its natural course from a disease with poor prognosis with a high mortality rate in the early 20th century to a treatable condition with a large proportion of patients attaining very good disease control. This review summarizes the current treatment options for MG, including non-immunosuppressive and immunosuppressive treatments, as well as thymectomy and targeted immunomodulatory drugs.

Long-Term Improvement in a Chinese Cohort of Glucocorticoid-Resistant Childhood-Onset Myasthenia Gravis Patients Treated With Tacrolimus

Objectives

To evaluate the long-term outcome of tacrolimus for childhood-onset myasthenia gravis (CMG) with an inadequate response to glucocorticoids, and investigate factors associated with favorable outcomes following tacrolimus treatment.

Methods

A retrospective, observational cohort study was performed for CMG patients who had not improved satisfactorily after sufficient prednisone therapy for at least 8 weeks. All patients were given tacrolimus in doses of 2–3 mg for more than 6 months. The primary efficacy outcome was assessed using the prednisone dose, quantitative MG (QMG), and MG-activity of daily living (ADL) scores. The participants were divided into improved and unimproved groups based on changes in QMG scores to investigate the risk factors that affected tacrolimus efficacy.

Results

A total of 149 glucocorticoid resistant CMG patients were finally enrolled in our study, with 113 (75.8%) responding well to tacrolimus (defined as minimal manifestation status or better). One month after initiating tacrolimus, there was a noticeable improvement in prednisone dose, QMG, and ADL scores, which continued to improve throughout the study. More importantly, the prednisone was eventually stopped in 89 of the patients (78.8%). Thymus type [odds ratio (OR) = 3.156, 95% confidence interval (CI) 1.427–6.978; P = 0.005] and pre-intervention status (OR = 0.284, 95%CI 0.109–0.741; P = 0.010) were independent predictors of tacrolimus efficacy after controlling for confounding factors in multiple logistic regression.

Conclusion

The majority of glucocorticoid-resistant CMG patients have a good long-term prognosis after adding tacrolimus. Thymus type and pre-intervention status can serve as potential predictors affecting the efficacy of tacrolimus.

TREATMENT OF MYASTHENIA GRAVIS PATIENTS WITH COVID-19: REVIEW OF THE LITERATURE

Coronavirus disease 2019 (COVID-19), caused by the late 2019 outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), causes a respiratory disease which could put myasthenia gravis (MG) patients at a greater risk of developing severe disease course, since infections and some drugs are a well-recognized trigger of symptom exacerbation in MG patients. Out of ten most commonly used past and present drugs used in COVID-19 treatment, two (quinolone derivatives and azithromycin) are known to worsen MG symptoms, whereas another two (tocilizumab and eculizumab) might have positive effect on MG symptoms. Colchicine, remdesivir, lopinavir, ritonavir and favipiravir seem to be safe to use, while data are insufficient for bamlanivimab, although it is also probably safe to use. Considering MG treatment options in patients infected with SARS-CoV-2, acetylcholine esterase inhibitors are generally safe to use with some preliminary studies even demonstrating therapeutic properties in regard to COVID-19. Corticosteroids are in general safe to use, even recommended in specific circumstances, whereas other immunosuppressive medications (mycophenolate mofetil, azathioprine, cyclosporine, methotrexate) are probably safe to use. The only exception is rituximab since the resulting B cell depletion can lead to more severe COVID-19 disease. Concerning plasmapheresis and intravenous immunoglobulins, both can be used in COVID-19 while taking into consideration thromboembolic properties of the former and hemodynamic disturbances of the latter. As current data suggest, all known COVID-19 vaccines are safe to use in MG patients.

Drug-refractory myasthenia gravis: Clinical characteristics, treatments, and outcome

Objective

To describe the clinical characteristics and outcomes in patients with refractory myasthenia gravis (MG) and to determine the effectiveness and side effects of the drugs used for their treatment.

Methods

This observational retrospective cross‐sectional multicenter study was based on data from the Spanish MG Registry (NMD‐ES). Patients were considered refractory when their MG Foundation of America post‐interventional status (MGFA‐PIS) was unchanged or worse after corticosteroids and two or more other immunosuppressive agents. Clinical and immunologic characteristics of drug‐refractory patients, efficiency and toxicity of drugs used, and outcome (MGFA‐PIS) at end of follow‐up were studied.

Results

We included 990 patients from 15 hospitals. Eighty‐four patients (68 of 842 anti‐acetylcholine receptor [AChR], 5 of 26 anti‐muscle‐specific tyrosine kinase [MusK], 10 of 120 seronegative, and 1 of 2 double‐seropositive patients) were drug refractory. Drug‐refractory patients were more frequently women (p < 0.0001), younger at onset (p < 0.0001), and anti‐MuSK positive (p = 0.037). Moreover, they more frequently presented a generalized form of the disease, bulbar symptoms, and life‐threatening events (p < 0.0001; p = 0.018; and p = 0.002, respectively) than non‐drug‐refractory patients. Mean follow‐up was 9.8 years (SD 4.5). Twenty‐four (50%) refractory patients had side effects to one or more of the drugs. At the end of follow‐up, 42.9% of drug‐refractory patients (42.6% of anti‐AChR, 100% of anti‐MuSK, and 10% of seronegative patients) and 79.8% of non‐drug‐refractory patients (p < 0.0001) achieved remission or had minimal manifestations. Eighty percent of drug‐refractory‐seronegative patients did not respond to any drug tested.

Interpretation

In this study, 8.5% of MG patients were drug‐refractory. New more specific drugs are needed to treat drug‐refractory MG patients.

Rheumatoid arthritis and myasthenia gravis: a case-based review of the therapeutic options

Introduction

Myasthenia gravis is an autoimmune disease affecting the neuromuscular junction, often associated with other autoimmune diseases, including rheumatoid arthritis. Patients with rheumatoid arthritis present an increased prevalence of myasthenia gravis compared to the general population. While these two diseases share some therapeutic options, such as glucocorticoids, methotrexate, and rituximab, there are no guidelines for treating concomitant disease. We aim to review the available evidence and to discuss the efficacy and safety of the therapeutic options in patients with rheumatoid arthritis associated with myasthenia gravis.

Method

We described three patients with rheumatoid arthritis associated with myasthenia gravis and we performed a systematic review of the associated literature.

Results

A 48-year-old man and two women (48 and 55 years old) with concomitant diagnoses of active rheumatoid arthritis and well-controlled myasthenia gravis are described. They were treated with methotrexate, leflunomide, upadacitinib, and adalimumab. None of them experienced changes in their myasthenic symptoms. We found 9 additional cases from our literature review. Methotrexate, rituximab, upadacitinib, diphenyl sulfone, auranofin, and loxoprofen sodium did not show an impact on the seven patients with previously well-controlled myasthenia. Glucocorticoids, methotrexate, and rituximab proved effective in active myasthenia gravis and arthritis. Conflicting data emerged for Tumor-necrosis factor inhibitors.

Conclusions

Although the available evidence remains scarce, we consider glucocorticoids, methotrexate, and rituximab as safe and effective options. The role of tumor-necrosis factor inhibitors remains uncertain. Eventually, Janus Kinase inhibitors are a novel interesting option for these patients.

Key Points • To date, the only evidence on the treatment of patients with rheumatoid arthritis and concomitant myasthenia gravis derives from case reports. • Based on the review of the available case reports and on the cases we described, we consider glucocorticoids, methotrexate, and rituximab as safe and effective options, while the role of Tumor-necrosis factor inhibitors remains uncertain. • Based on the cases we described, Janus Kinase inhibitors are a novel interesting option for patients with concomitant rheumatoid arthritis and myasthenia gravis.

Utilization of MG-ADL in myasthenia gravis clinical research and care

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.

Ocular Myasthenia: Clinical Course and the Diagnostic Utility of Assaying Acetylcholine Receptor Antibodies

Myasthenia gravis (MG) is an autoimmune disease that causes neuromuscular junction transmission defect and has a predilection for the with neuromuscular junction transmission defect and predilection for extra-ocular and eyelid muscles. Most cases of ocular MG (OMG) convert later to generalised MG (GMG). Assaying acetylcholine receptor antibodies (AchRA) has been used to diagnose MG, but the reported sensitivity in OMG is lower (50%) than in GMG. We report the clinical course and the diagnostic yield of assaying AchRA in a Kuwaiti cohort of patients with OMG. We carried out a retrospective review of 47 patients diagnosed with OMG who were tested for AchRA. Ancillary tests included the ice test, single-fibre electromyography (SFMEG), and repetitive nerve stimulation electromyography (RNS). Progression to GMG occurred in 51% of OMG patients with a mean time to progression of 12.1 months (range 4 to 20 months). AchRAs were positive in 46 of 47 cases (98%), while SFEMG was positive in 31 of 34 cases (91.1%). Older age (44.25 years versus 38 years, p < .05) and higher AchRA titre (2.0 nmol/L versus 1.27 nmol/L, p < .05) were significantly associated with conversion to GMG. We have found a high rate of AchRA seropositivity in relatively younger subjects of OMG. Higher AchRA titres and older age were associated with conversion to GMG, usually within the first 2 years.

Myasthenia Gravis and Lambert-Eaton Myasthenic Syndrome: New Developments in Diagnosis and Treatment

"Myasthenia Gravis is, like it or not, the neurologist's disease!" (Thomas Richards Johns II, MD Seminars in Neurology 1982). The most common disorders in clinical practice involving defective neuromuscular transmission are myasthenia gravis (MG) and Lambert-Eaton myasthenic syndrome (LEMS). The hallmark of weakness related to malfunction of the neuromuscular junction (NMJ) is variability in severity of symptoms from minute to minute and hour to hour. Fatigable weakness and fluctuation in symptoms are common in patients whether the etiology is autoimmune, paraneoplastic, genetic, or toxic. Autoimmune MG is the most common disorder of neuromuscular transmission affecting adults with an estimated prevalence of 1 in 10,000. While LEMS is comparatively rare, the unique clinical presentation, the association with cancer, and evolving treatment strategies require the neurologist to be familiar with its presentation, diagnosis, and management. In this paper we provide a summary of the meaningful recent clinical developments in the diagnosis and treatment of both MG and LEMS.

Methotrexate as a Steroid-Sparing Agent in Myasthenia Gravis: A Preliminary Retrospective Study

OBJECTIVES

Treatment approach of myasthenia gravis (MG) is still debated; corticosteroids alone or in combination with immunosuppressive agents are the most used drugs. Azathioprine (AZA) has been shown to be effective for MG with a significant steroid-sparing activity, although burdened by side effects. Few studies on methotrexate (MTX) administration showed controversial results. In this cohort, we evaluated the role of MTX as a effective steroid-sparing agent.

METHODS

Fifteen MG patients treated with MTX, previously treated with AZA for at least 12 months, with poor benefits and uncomfortable side effects AZA related, have been selected. Each patient was evaluated through MG-Activity of Daily Living and Quantitative MG scores 5 times/yr.

RESULTS

Patients treated with MTX had a significant improvement of MG-Activity of Daily Living and Quantitative MG scores. Furthermore, all patients reduced prednisone dosage, and none complained of side effects.

CONCLUSIONS

We suggest MTX is effective and well tolerated and could be considered as a steroid-sparing agent in MG treatment.

Adverse Side Effects Associated with Corticosteroid Therapy: A Study in 39 Patients with Generalized Myasthenia Gravis

Background

The tolerability of high-dose oral corticosteroids in patients with generalized myasthenia gravis (gMG) has not been systematically assessed. We evaluated adverse side effects (ASEs) of corticosteroid treatment in patients with gMG.

Material/Methods

Retrospective analysis was conducted of ASEs reported as being related to corticosteroid treatment in 39 patients with gMG who were treated with oral corticosteroids for ≥1 year.

Results

Median (interquartile range [IQR]) age was 60 (21) years, 53.8% of patients were women, and 66.7% were aged ≤65 years. Median (IQR) prednisone treatment duration was 14 (2) months; median (IQR) daily dose was 40 (15) mg. The median number of ASEs reported as corticosteroid-related was 2/patient (IQR, 1). Pre-diabetes and weight gain were most common (each 43.6% of patients). Bruising, insomnia, and osteoporosis were more prevalent in patients aged >65 years, while irritability, osteopenia, and pre-diabetes were more common in patients aged ≤65 years, although differences were not statistically significant. Irritability and weight gain were more prevalent in women (P=0.010 for irritability); osteoporosis and pre-diabetes more common in men (P=0.015 for osteoporosis). ASEs were generally more common in the high-dose prednisone group (>30 mg/day), but were only statistically significant for irritability (P=0.001).

Conclusions

Corticosteroid-related ASEs were common in patients with gMG. Some of these ASEs can have serious medical consequences, and certain ASEs appeared to be associated with specific patient characteristics. Demographics and comorbidities of patients with gMG must be carefully considered before corticosteroid initiation. Potential ASEs, such as unanticipated osteoporosis in men, require extra vigilance.

Comparison of Corticosteroid Tapering Regimens in Myasthenia Gravis: A Randomized Clinical Trial

Importance

The tapering of prednisone therapy in generalized myasthenia gravis (MG) presents a therapeutic dilemma; however, the recommended regimen has not yet been validated.

Objective

To compare the efficacy of the standard slow-tapering regimen of prednisone therapy with a rapid-tapering regimen.

Design

From June 1, 2009, to July 31, 2013, a multicenter, parallel, single-blind randomized trial was conducted to compare 2 regimens of prednisone tapering. Data analysis was conducted from February 18, 2019, to January 23, 2020. A total of 2291 adults with a confirmed diagnosis of moderate to severe generalized MG at 7 specialized centers in France were assessed for eligibility.

Interventions

The slow-tapering arm included a gradual increase of the prednisone dose to 1.5 mg/kg every other day and a slow decrease once minimal manifestation status of MG was attained. The rapid-tapering arm consisted of immediate high-dose daily administration of prednisone, 0.75 mg/kg, followed by an earlier and rapid decrease once improved MG status was attained. Azathioprine, up to a maximum dose of 3 mg/kg/d, was prescribed for all participants.

Main Outcomes and Measures

The primary outcome was attainment of minimal manifestation status of MG without prednisone at 12 months and without clinical relapse at 15 months. Intention-to-treat analysis was conducted.

Results

Of the 2291 patients assessed, 2086 did not fulfill the inclusion criteria, 87 declined to participate, and 1 patient registered after trial closure. A total of 117 patients (58 in the slow-tapering arm and 59 in the rapid-tapering arm) were selected for inclusion by MG specialists and were randomized. The population included 62 men (53%); median age was 65 years (interquartile range, 35-69 years). The proportion of patients having met the primary outcome was higher in the rapid- vs slow-tapering arm (23 [39%] vs 5 [9%]), with a risk ratio of 3.61 (95% CI, 1.64-7.97; P < .001) after adjusting for center and thymectomy. The rapid-tapering regimen allowed sparing of a mean of 1898 mg (95% CI, -3121 to -461 mg) of prednisone over 1 year (ie, 5.3 mg/d per patient, P = .03). The number of serious adverse events did not differ significantly between the slow- vs rapid-tapering group (13 [22%] vs 21 [36%], P = .15).

Conclusions and Relevance

In patients with moderate to severe generalized MG who require high-dose prednisone with azathioprine therapy, rapid tapering of prednisone appears to be feasible, well tolerated, and associated with a good outcome.

Trial Registration

ClinicalTrials.gov Identifier: NCT00987116.

Seven-Year Experience From the National Institute of Neurological Disorders and Stroke-Supported Network for Excellence in Neuroscience Clinical Trials

Importance

One major advantage of developing large, federally funded networks for clinical research in neurology is the ability to have a trial-ready network that can efficiently conduct scientifically rigorous projects to improve the health of people with neurologic disorders.

Observations

National Institute of Neurological Disorders and Stroke Network for Excellence in Neuroscience Clinical Trials (NeuroNEXT) was established in 2011 and renewed in 2018 with the goal of being an efficient network to test between 5 and 7 promising new agents in phase II clinical trials. A clinical coordinating center, data coordinating center, and 25 sites were competitively chosen. Common infrastructure was developed to accelerate timelines for clinical trials, including central institutional review board (a first for the National Institute of Neurological Disorders and Stroke), master clinical trial agreements, the use of common data elements, and experienced research sites and coordination centers. During the first 7 years, the network exceeded the goal of conducting 5 to 7 studies, with 9 funded. High interest was evident by receipt of 148 initial applications for potential studies in various neurologic disorders. Across the first 8 studies (the ninth study was funded at end of initial funding period), the central institutional review board approved the initial protocol in a mean (SD) of 59 (21) days, and additional sites were added a mean (SD) of 22 (18) days after submission. The median time from central institutional review board approval to first site activation was 47.5 days (mean, 102.1; range, 1-282) and from first site activation to first participant consent was 27 days (mean, 37.5; range, 0-96). The median time for database readiness was 3.5 months (mean, 4.0; range, 0-8) from funding receipt. In the 4 completed studies, enrollment met or exceeded expectations with 96% overall data accuracy across all sites. Nine peer-reviewed manuscripts were published, and 22 oral presentations or posters and 9 invited presentations were given at regional, national, and international meetings.

Conclusions and Relevance

NeuroNEXT initiated 8 studies, successfully enrolled participants at or ahead of schedule, collected high-quality data, published primary results in high-impact journals, and provided mentorship, expert statistical, and trial management support to several new investigators. Partnerships were successfully created between government, academia, industry, foundations, and patient advocacy groups. Clinical trial consortia can efficiently and successfully address a range of important neurologic research and therapeutic questions.

VNTR2/VNTR3 genotype in the FCGRT gene is associated with reduced effectiveness of intravenous immunoglobulin in patients with myasthenia gravis

Background:

Intravenous immunoglobulin (IVIG) has been commonly used to treat myasthenia gravis exacerbation, but is still ineffective in nearly 30% of patients. A variable number of tandem repeat (VNTR) polymorphism in the FCGRT gene has been found to reduce the efficiency of IgG biologics. However, whether the polymorphism influences the efficacy of IVIG in generalized myasthenia gravis (MG) patients with exacerbations remains unknown.

Methods:

The distribution of VNTR genotypes was analyzed in 334 patients with MG. Varied VNTR alleles were determined by capillary electrophoresis and confirmed by Sanger sequencing. Information of endogenous IgG levels were collected in patients without previous immunotherapy (n = 26). Medical records of patients who received IVIG therapy were retrospectively analyzed for therapeutic outcomes of IVIG treatment (n = 61). Patients whose Activities of Daily Living scores decreased by 2 or more points on day 14 were considered responders to the treatment.

Results:

The VNTR3/3 and VNTR2/3 genotypes were detected in 96.7% (323/334) and 3.4% (11/334) patients, respectively. Patients with VNTR2/3 heterozygosity had lower endogenous IgG levels than those with VNTR3/3 homozygosity (9.81 ± 2.61 g/L versus 12.41 ± 2.45g/L, p = 0.016). The response rate of IVIG therapy was 78.7% (48/61). All responders and nine non-responders were VNTR3/3 homozygotes, whereas all the patients with VNTR2/3 genotypes were non-responders (n = 4). In patients who took IVIG treatments, endogenous IgG levels were significantly lower in non-responders compared with responders (12.93 ± 2.24 g/L versus 8.85 ± 2.69 g/L, p = 0.006), especially in VNTR2/3 heterozygotes (7.86 ± 1.78 g/L, p = 0.001).

Conclusion:

The VNTR2/3 genotype could influence endogenous IgG levels and serve as a predictive marker for poor responses to IVIG in MG patients.

Outcome Measures in Clinical Trials of Patients With Myasthenia Gravis

Myasthenia gravis (MG) is a heterogeneous disorder whose clinical presentation ranges from mild ocular deficits to severe widespread weakness. This variance poses a challenge when quantifying clinical deficits. Deficits and symptoms are quantified using standardized clinical scales and questionnaires which are often used as outcome measures. The past decades have seen the development of several validated outcome measures in MG, which are used in clinical trials to obtain regulatory approval. In recent years, emphasis has moved from objective assessments to patient-reported outcomes. Despite a growing body of literature on the validity of the MG-specific outcome measures, several unresolved factors remain. As several novel therapeutics are currently in clinical development, knowledge about capabilities and limitations of outcome measures is needed. In the present paper, we describe the most widely used clinical classifications and scales in MG. We highlight the choice of outcome measures in published and ongoing trials, and we denote whether trial efficacy was reached on these outcomes. We discuss advantages and limitations of the individual scales, and discuss some of the unresolved factors relating to outcome assessments in MG.

Update in immunosuppressive therapy of myasthenia gravis

Myasthenia gravis (MG) is an autoimmune disease of the neuromuscular junction. Immunosuppressive treatments are part of the therapeutic armamentarium in MG. Long-term systemic steroid administration carry considerable risks and adverse events. Consequently, steroid-free immunosuppressive therapy is necessary to reduce the dose or discontinue steroids. First immunosuppressive drug trials in MG were performed in the mid-60s using standard and nonspecific immunosuppression. Since then, only few randomized controlled clinical trials were conducted in MG and assesed drug efficacy in terms of its steroid-sparing capacity and the ability to reduce myasthenic signs and symptoms. Treatment strategy in MG is quite challenging, mainly due to the disease heterogeneity in terms of clinical presentation, immunopathogenesis and drug response. To solve this dilemma, emerging treatment are based on biological drugs and use new targets of the immune pathway.

Update in the Management of Myasthenia Gravis and Lambert-Eaton Myasthenic Syndrome

Myasthenia gravis (MG) and Lambert-Eaton myasthenic syndrome (LEMS) are the most common disorders of neuromuscular transmission in clinical practice. Disorders of the neuromuscular junction (NMJ) are characterized by fluctuating and fatigable weakness and include autoimmune, toxic, and genetic conditions. Adults with NMJ disorders are most often antibody mediated, with MG being the most common, having a prevalence of approximately 1 in 10,000, and with women being affected about twice as often as men. This article focuses on advances in management of autoimmune MG and LEMS.

History of Myasthenia Gravis Revisited

The first description of myasthenia gravis (MG) was given by Thomas Willis in 1672. MG was the focus of attention after mid-nineteenth century and a great amount of information has been accumulated in a span of 150 years. The aim of this review is to convey this information according to a particular systematic and to briefly relate the experience of Istanbul University. MG history was examined in four periods: 1868-1930, 1930-1960, 1960-1990, and 1990-2020. In the first period (1868-1930), all the clinical characteristics of MG were defined. Physiological/pharmacological studies on the transmission at the neuromuscular junction were initiated, and the concept of repetitive nerve stimulation emerged. A toxic agent was believed to be the cause of MG which appeared to resemble curare intoxication. Association of MG with thymus was noticed. No noteworthy progress was made in its treatment. In the second period (1930-1960), acetylcholine was discovered to be the transmitter at the neuromuscular junction. Repetitive nerve stimulation was used as a diagnostic test. The autoimmune nature of MG was suspected and experiments to this end started to give results. The hallmark of this period was the use of anticholinesterases and thymectomy in the treatment of MG. The third period (1960-1990) can probably be considered a revolutionary era for MG. Important immunological mechanisms (acetylcholine receptor isolation, discovery of anti-acetylcholine receptor antibodies) were clarified and the autoimmune nature of MG was demonstrated. Treatment modalities which completely changed the prognosis of MG, including positive pressure mechanic ventilation and corticosteroids as well as plasma exchange/IVIg and azathioprine, were put to use. In the fourth period (1990-2020), more immunological progress, including the discovery of anti-MuSK antibodies, was achieved. Videothoracoscopic thymectomy reduced the morbidity and mortality rate associated with surgery. New drugs emerged and clinical trials were performed. Valuable guidelines were published. In the last part of the review, the experience in MG of Istanbul University, a pioneer in Turkey, is related.

International Consensus Guidance for Management of Myasthenia Gravis: 2020 Update

Objective

To update the 2016 formal consensus-based guidance for the management of myasthenia gravis (MG) based on the latest evidence in the literature.

Methods

In October 2013, the Myasthenia Gravis Foundation of America appointed a Task Force to develop treatment guidance for MG, and a panel of 15 international experts was convened. The RAND/UCLA appropriateness method was used to develop consensus recommendations pertaining to 7 treatment topics. In February 2019, the international panel was reconvened with the addition of one member to represent South America. All previous recommendations were reviewed for currency, and new consensus recommendations were developed on topics that required inclusion or updates based on the recent literature. Up to 3 rounds of anonymous e-mail votes were used to reach consensus, with modifications to recommendations between rounds based on the panel input. A simple majority vote (80% of panel members voting “yes”) was used to approve minor changes in grammar and syntax to improve clarity.

Results

The previous recommendations for thymectomy were updated. New recommendations were developed for the use of rituximab, eculizumab, and methotrexate as well as for the following topics: early immunosuppression in ocular MG and MG associated with immune checkpoint inhibitor treatment.

Conclusion

This updated formal consensus guidance of international MG experts, based on new evidence, provides recommendations to clinicians caring for patients with MG worldwide.

Reappraisal of Oral Steroid Therapy for Myasthenia Gravis

Treatment with oral corticosteroids at high doses with an escalation and de-escalation schedule is effective against myasthena gravis (MG). In fact, the use of corticosteroids has led to a reduction in mortality to below 10% after the 1960s. However, long-term use of oral steroids above a certain dosage level is known to cause a number of problems. In 2014, the Japanese clinical guidelines for MG proposed that the first goal in MG treatment (treatment target) should be set at minimal manifestations (MM) with oral prednisolone (PSL) 5 mg/day or below, and that treatment strategies should strive to attain this level as rapidly as possible. In 2015, a multicenter, cross-sectional study revealed that higher PSL dose and longer PSL treatment do not ensure better outcome. In the absence of good response, the PSL dose should be decreased by combining with modalities such as plasma exchange/plasmapheresis and intravenous immunoglobulin (fast-acting treatments). In 2018, we conducted a multicenter, cross-sectional study in a large population of Japanese patients with generalized MG, aiming to elucidate the correlation between oral PSL regimens and achievement of treatment goals. The ORs for low vs. high dose to achieve treatment goals at 1, 2, and 3 years were 10.4, 2.75, and 1.86, respectively, whereas the corresponding ORs for low vs. medium dose were 13.4, 3.99, and 4.92. Early combination with fast-acting therapy (OR 2.19 at 2 years, 2.11 at 3 years) or combination with calcineurin inhibitors (OR 2.09 at 2 years, 2.36 at 3 years) were also positively associated with achieving treatment goals. These results indicate that early combination of low-dose PSL regimens with other therapies is the key for early achievement of treatment goals in generalized MG. However, even with this regimen, ~35% of patients did not achieve the treatment target after 3 years. These results suggest the limitation of the current oral corticosteroid therapy. We need to develop new treatment options to increase the rate of satisfactory outcome.

Management of Juvenile Myasthenia Gravis

Juvenile Myasthenia Gravis (JMG) is a rare disorder, defined as myasthenia gravis in children younger than 18 years of age. While clinical phenotypes are similar to adults, there are a number of caveats that influence management: broader differential diagnoses; higher rates of spontaneous remission; and the need to initiate appropriate treatment early, to avoid the long-term physical and psychosocial morbidity. Current practice is taken from treatment guidelines for adult MG or individual experience, with considerable variability seen across centers. We discuss our approach to treating JMG, in a large specialist JMG service, and review currently available evidence and highlight potential areas for future research. First-line treatment of generalized JMG is symptomatic management with pyridostigmine, but early use of immunosuppression, where good control is not achieved is important. Oral prednisolone is used as first-line immunosuppression with appropriate prevention and monitoring of side effects. Second-line therapies including azathioprine and mycophenolate may be considered where there is: no response to steroids, inability to wean to a reasonable minimum effective dose or if side-effects are intolerable. Management of ocular JMG is similar, but requires close involvement of ophthalmology in young children to prevent amblyopia. Muscle-specific tyrosine kinase (MuSK)-JMG show a poorer response to pyridostigmine and anecdotal evidence suggests that rituximab should be considered as second-line immunosuppression. Thymectomy is indicated in any patient with a thymoma, and consideration should be given in acetylcholine receptor (AChR) positive JMG allowing time for spontaneous remission. The benefit is less clear in ocular JMG and is not advised in MuSK-JMG. Children experiencing a myasthenic crisis require urgent hospital admission with access to the intensive care unit. PLEX is preferred over IVIG due to rapid onset of action, but this needs to be balanced with feasibility in very young children. Key questions remain in the management of JMG: when to initiate both first- and second-line treatments, choosing between steroid-sparing agents, and determining the optimal dose and treatment duration. We feel that given the rarity of this disease, the establishment of national registries and collaboration across groups will be needed to address these issues and facilitate future drug trials in JMG.

A Practical Approach to Managing Patients With Myasthenia Gravis-Opinions and a Review of the Literature

When the diagnosis of myasthenia gravis (MG) has been secured, the aim of management should be prompt symptom control and the induction of remission or minimal manifestations. Symptom control, with acetylcholinesterase inhibitors such as pyridostigmine, is commonly employed. This may be sufficient in mild disease. There is no single universally accepted treatment regimen. Corticosteroids are the mainstay of immunosuppressive treatment in patients with more than mild MG to induce remission. Immunosuppressive therapies, such as azathioprine are prescribed in addition to but sometimes instead of corticosteroids when background comorbidities preclude or restrict the use of steroids. Rituximab has a role in refractory MG, while plasmapheresis and immunoglobulin therapy are commonly prescribed to treat MG crisis and in some cases of refractory MG. Data from the MGTX trial showed clear evidence that thymectomy is beneficial in patients with acetylcholine receptor (AChR) antibody positive generalized MG, up to the age of 65 years. Minimally invasive thymectomy surgery including robotic-assisted thymectomy surgery has further revolutionized thymectomy and the management of MG. Ocular MG is not life-threatening but can be significantly disabling when diplopia is persistent. There is evidence to support early treatment with corticosteroids when ocular motility is abnormal and fails to respond to symptomatic treatment. Treatment needs to be individualized in the older age-group depending on specific comorbidities. In the younger age-groups, particularly in women, consideration must be given to the potential teratogenicity of certain therapies. Novel therapies are being developed and trialed, including ones that inhibit complement-induced immunological pathways or interfere with antibody-recycling pathways. Fatigue is common in MG and should be duly identified from fatigable weakness and managed with a combination of physical therapy with or without psychological support. MG patients may also develop dysfunctional breathing and the necessary respiratory physiotherapy techniques need to be implemented to alleviate the patient's symptoms of dyspnoea. In this review, we discuss various facets of myasthenia management in adults with ocular and generalized disease, including some practical approaches and our personal opinions based on our experience.

Infection risk of dermatologic therapeutics during the COVID-19 pandemic: an evidence-based recalibration

Recommendations were made recently to limit or stop the use of oral and systemic immunotherapies for skin diseases due to potential risks to the patients during the current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) COVID-19 pandemic. Herein, we attempt to identify potentially safe immunotherapies that may be used in the treatment of cutaneous diseases during the current COVID-19 pandemic. We performed a literature review to approximate the risk of SARS-CoV-2 infection, including available data on the roles of relevant cytokines, cell subsets, and their mediators in eliciting an optimal immune response against respiratory viruses in murine gene deletion models and humans with congenital deficiencies were reviewed for viral infections risk and if possible coronaviruses specifically. Furthermore, reported risk of infections of biologic and non-biologic therapeutics for skin diseases from clinical trials and drug data registries were evaluated. Many of the immunotherapies used in dermatology have data to support their safe use during the COVID-19 pandemic including the biologics that target IgE, IL-4/13, TNF-α, IL-17, IL-12, and IL-23. Furthermore, we provide evidence to show that oral immunosuppressive medications such as methotrexate and cyclosporine do not significantly increase the risk to patients. Most biologic and conventional immunotherapies, based on doses and indications in dermatology, do not appear to increase risk of viral susceptibility and are most likely safe for use during the COVID-19 pandemic. The limitation of this study is availability of data on COVID-19.

Update on immune-mediated therapies for myasthenia gravis

With the exception of thymectomy, immune modulatory treatment strategies and clinical trials in myasthenia gravis over the past 50 y were mainly borrowed from experience in other nonneurologic autoimmune disorders. The current experimental therapy paradigm has significantly changed such that treatments directed against the pathological mechanisms specific to myasthenia gravis are being tested, in some cases as the initial disease indication. Key advances have been made in three areas: (i) the expanded role and long-term benefits of thymectomy, (ii) complement inhibition to prevent antibody-mediated postsynaptic membrane damage, and (iii) neonatal Fc receptor (FcRn) inhibition as in vivo apheresis, removing pathogenic antibodies. Herein, we discuss these advances and the potential for these newer therapies to significantly influence the current treatment paradigms. While these therapies provide exciting new options with rapid efficacy, there are anticipated challenges to their use, especially in terms of a dramatic increase in cost of care for some patients with myasthenia gravis.

Overview of Dual-Acting Drug Methotrexate in Different Neurological Diseases, Autoimmune Pathologies and Cancers

Methotrexate, a structural analogue of folic acid, is one of the most effective and extensively used drugs for treating many kinds of cancer or severe and resistant forms of autoimmune diseases. In this paper, we take an overview of the present state of knowledge with regards to complex mechanisms of methotrexate action and its applications as immunosuppressive drug or chemotherapeutic agent in oncological combination therapy. In addition, the issue of the potential benefits of methotrexate in the development of neurological disorders in Alzheimer’s disease or myasthenia gravis will be discussed.

Methotrexate Polyglutamation in a Myasthenia Gravis Clinical Trial

INTRODUCTION

Methotrexate (MTX) is an immunosuppressive and anti-inflammatory drug used to treat rheumatoid arthritis (RA) and other autoimmune conditions. MTX is transported into cells, where glutamate moieties are added and is retained as methotrexate polyglutamates (MTXPGs). In the RA literature, it has been reported that the degree of polyglutamation correlates with the anti-inflammatory effect of MTX in RA. There are no prior studies evaluating the relationship between MTXPGs and myasthenia gravis (MG) outcome measures. The objective of this study was to assess the correlation between methotrexate (MTX) polyglutamates (MTXPGs) with Myasthenia Gravis (MG) outcome measures.

METHODS

An analysis was done of blood drawn from patients enrolled in the 12-month randomized, placebo-controlled study of MTX in MG study. Red blood cell MTXPGs were measured via ultra-performance liquid chromatography and tandem mass spectrometry. MTXPG was correlated to MG outcome measures using Spearman Correlation Coefficient. A two-group t-test was used to determine the difference in MTXPG based on clinical outcome responder definitions.

RESULTS

Twenty-one polyglutamate samples were analyzed of subjects on MTX while eight samples were analyzed from subjects on placebo. Pentaglutamate had the strongest correlation with the MG-ADL (0.99), while tetraglutamate had the strongest correlation with the QMG (0.54). Triglutamate had the strongest correlation with MGC (0.76).

CONCLUSION

There were variable correlations between MTXPG_1-5 and MG outcomes (rho range: 0.08 to 0.99). There are strong correlations between MTXPG and the MG-ADL, QMG, and MGC. Long chain methotrexate polyglutamates correlate better with MG outcomes.