Modified radioimmunoassay versus ELISA to quantify anti-acetylcholine receptor antibodies in a mouse model of myasthenia gravis.

In mouse models of myasthenia gravis (MG), anti-acetylcholine receptor (AChR) antibodies can be quantified to monitor disease progression and treatment response. In mice, enzyme-linked immunosorbent assay (ELISA) is the gold standard to quantify these antibodies. However, this method requires antigen purification, which is both time-consuming and expensive. In humans, radioimmunoassay (RIA)-which is more sensitive than ELISA-is commonly used to quantify AChR antibodies. At present, however, no commercial RIA kits are available to quantify these antibodies in mice. The aim of this study was to compare a modified commercial human RIA kit to two ELISA methods to detect AChR antibodies in an experimental autoimmune mouse model of MG (EAMG). C57BL/6 J mice were immunized with purified AChR from Tetronarce californica (T-AChR). Serum samples were analyzed by RIA and two ELISAs (T-AChR and purified mouse AChR peptide [m-AChR]). The modified RIA showed excellent sensitivity (84.1 %) and specificity (100 %) for the detection of AChR antibodies. RIA showed a good agreement with T-AChR ELISA (κ = 0.69) but only moderate agreement with m-AChR ELISA (κ = 0.49). These results demonstrate the feasibility of modifying a commercially-available RIA kit to quantify AChR antibodies in EAMG. The advantage of this technique is that it eliminates the need to develop the entire methodology in-house and reduces inter and intra-laboratory variability.

Maintenance of zilucoplan efficacy in patients with generalised myasthenia gravis up to 24 weeks: a model-informed analysis.

Background: Clinical efficacy of zilucoplan has been demonstrated in a 12-week, placebo-controlled, phase III study in patients with acetylcholine receptor autoantibody-positive generalised myasthenia gravis (gMG). However, placebo-controlled zilucoplan data past 12 weeks are not available. Objectives: Predict the treatment effect of zilucoplan versus control (placebo or standard of care) in patients with gMG up to 24 weeks. Design: A model-informed analysis (MIA) within a Bayesian framework. Methods: Part 1 of the MIA comprised a control meta-regression using aggregate data on control response over time from randomised studies and a national myasthenia gravis (MG) registry. In Part 2, a combined Bayesian analysis of individual patient-level data from the phase II (NCT03315130), RAISE (NCT04115293) and RAISE-XT (NCT04225871) studies of zilucoplan was conducted using posterior distributions from Part 1 as informative priors. Population mean treatment effect in the change from baseline (CFB) at week 24 in MG-Activities of Daily Living (MG-ADL) and quantitative MG (QMG) scores for zilucoplan versus control were assessed. Results: At week 24, the predicted mean CFB in MG-ADL score was -4.55 (95% credible interval: -6.04, -3.13) with zilucoplan versus -2.00 (-3.35, -0.64) with control (difference: -2.55 [-3.76, -1.40]). The probability of a favourable treatment effect as measured by MG-ADL score at week 24 with zilucoplan versus control was >99.9%. There was an 82.8% probability that the difference in the predicted mean CFB in MG-ADL score at week 24 was greater than the clinically meaningful threshold (⩾2.0-point improvement). Comparable results were observed with QMG. Conclusion: This MIA demonstrates the maintenance of efficacy with zilucoplan versus control up to 24 weeks. Through combining real-world evidence with data from randomised studies, this novel method to estimate long-term treatment efficacy facilitated reduced exposure to placebo in the phase III RAISE study. This methodology could be used to reduce the length of future placebo-controlled studies.

Seronegative Myasthenia Gravis: A Rare Disease Triggered by SARS-CoV-2 or a Coincidence?

Myasthenia gravis (MG) results from the production of autoantibodies against the neuromuscular junction, leading to muscle weakness. Although the exact cause is not fully understood, it is known that the onset and exacerbations of MG can occur after viral infections. We present the case of a patient with no prior history of MG with new-onset proximal muscle weakness and ptosis, following SARS-CoV-2 infection, This case underscores the potential for autoimmune diseases to be triggered by SARS-CoV-2.

Case report: Multi-antibody-positive myasthenia gravis concomitant myositis associated with thymoma.

Myasthenia gravis (MG) and idiopathic inflammatory myopathy (IIM) are autoimmune diseases of the nervous system, and their main clinical manifestation is muscle weakness. The concurrent presence of both conditions in the same patient is clinically rare and easily missed. Here, we report the case of a 74-year-old woman who went to the doctor with fluctuating weakness of the limbs and muscle pain. By analyzing the patient's history and the results of repeated frequency electrical stimulation, chest computed tomography, thigh muscle magnetic resonance imaging, serum antibody detection, lymph node biopsy, etc., she was finally diagnosed with MG-concomitant IIM with squamous cell carcinoma of the thymus. Acetylcholine receptor antibody, titin antibody, ryanodine receptor antibody, anti-JO-1 antibody, and Ro-52 antibody tests were positive. MG-concomitant IIM is often associated with thymoma. The immunopathology mechanism may be different from that of pure MG or IIM, which needs further research.

Clinical features of COVID-19 infection in patients with myasthenia gravis: a real-world retrospective study.

Objective: We investigated the risk factors associated with severe or critical Coronavirus disease 2019 (COVID-19) infection due to the Omicron variant in patients with myasthenia gravis (MG) and determined the potential effect of COVID-19 on myasthenic exacerbation during the Omicron pandemic. Methods: This retrospective study included 287 patients with MG in Tianjin, China. Clinical data of the patients were collected using electronic questionnaires, databases, and clinical records. Results: The overall infection rate was 84.7%. Advanced age, comorbidities, generalized phenotype, and MG instability were drivers of COVID-19 severity, and post-COVID-19 myasthenic exacerbation. The concurrent use of a steroid-sparing agent did not affect COVID-19 susceptibility or severity. It did lower the risk of myasthenic exacerbation after COVID-19 infection. Patients with severe COVID-19 experienced myasthenic exacerbation earlier than patients with non-severe infection (p < 0.001). The severity of COVID-19 (Hazards Ratio = 3.04, 95% CI: 1.41-6.54, p = 0.004) and the clinical phenotype (Hazards Ratio = 3.29, 95% CI: 1.63-6.63, p < 0.001) emerged as independent risk factors for early MG exacerbation. Conclusion: Generally, patients with MG appear to be susceptible to the Omicron strains. Immunotherapy for MG did not increase COVID-19 susceptibility or severity. We do not advocate an immediate cessation of ongoing immunosuppressive treatments once a COVID-19 infection is diagnosed. Instead, a judicious evaluation of the risks and benefits, tailored to each individual, is recommended.

Evaluation of Clinical Effects of COVID-19 Infection and Vaccines on Myasthenia Gravis.

Introduction: In this study, we aimed to investigate the clinical effects of COVID-19 infection and vaccines on Myasthenia gravis (MG) during the pandemic. Methods: A total of 141 MG patients between April 2020 and December 2021 were retrospectively analyzed. Data including demographic and clinical characteristics of patients, COVID-19 test results, and vaccine types (mRNA-BNT162b2 and/or inactivated-CoronaVac) were recorded. All patients were followed by face-to-face interviews and/or phone calls. Worsening MG symptoms after COVID-19 infection or vaccines were noted. Results: A total of 60 patients were diagnosed with COVID-19, and reverse transcriptase-polymerase chain reaction test results were COVID-19 positive in 54 (90%) patients. Twenty-eight (46.7%) patients had lung involvement, while 20(33.3%) patients were followed in the ward. Twelve (20%) patients were followed in the intensive care unit, and two of them (3.3%) died. Both deceased patients were unvaccinated. The most common symptoms were fatigue (78.3%), and 13(21.7%) patients were asymptomatic. Of the patients, 96(68%) received at least one dose BNT162b2 or CoronaVac, while 30.4% of the patients received ≥3 doses of vaccines. The local skin irritation and fatigue rate was significantly higher with BNT162b2 vaccine than CoronaVac (p<0.001 and p=0.004, respectively). No serious side effect was observed with either vaccine. Five patients had worsening MG symptoms after vaccination during a six-week follow-up. None of the patients experienced myasthenic crises. Conclusion: Our study results suggest that COVID-19 infection affects MG similar to the general population and does not lead to worsening MG symptoms. Both mRNA and inactivated vaccines with proven efficacy can be used safely in MG patients.

Elevated C1s/C1-INH in serum and plasma of myasthenia gravis patients.

Myasthenia Gravis (MG) is an autoimmune neuromuscular disorder where acetylcholine receptor (AChR) antibodies induce membrane attack complex formation at the muscle membrane. The C1-inhibitor (C1-INH) regulates the classical pathway and is a promising marker in other autoimmune disorders. Treatment options for AChR antibody MG include complement inhibitors; nevertheless, the early pathway activation in MG remains unclear. Serum and plasma C1s-C1-INH levels were higher in MG patients than in matched healthy controls, supporting early classical pathway activation in most MG patients. These findings allow prospective validation studies of activated C1s as a putative treatment target and potential accompanying biomarker in MG.

Aquaporin4-IgG seropositivity significantly increases the risk of comorbid autoimmune diseases in NMOSD patients: population-based registry data.

BACKGROUND: The aim of our study was to estimate the frequency of autoimmune comorbidities, in NMOSD patients from the national Serbian NMOSD Registry. METHODS: Our study comprises 136 patients with NMOSD, diagnosed according to the NMOSD criteria 2015. At the time of the study, in the Registry were collected demographic and clinical data, including those related to the coexisting comorbidities and pathogenic autoantibodies. Not all patients were tested for all autoimmune antibodies. None of the seronegative aquaporin4-IgG (AQP4-IgG) NMOSD patients, included in the Registry, were positive for the myelin oligodendrocyte glycoprotein IgG. RESULTS: Among 136 NMOSD patients, 50 (36.8%) had at least one associated autoimmune disorder. AQP4-IgG was present in the sera from 106 patients (77.9%), the proportion of NMOSD patients with autoimmune comorbidities being significantly higher in the AQP4-IgG positive subgroup in comparison to the AQP4-IgG negative (p = 0.002). AQP4-IgG seropositive NMOSD patients had 5.2-fold higher risk of comorbid autoimmune diseases (OR = 5.2, 95% CI 1.4-18.5, p = 0.012). The most frequently reported diseases were autoimmune thyroid disease (15.4%), Sjogren's syndrome (11.0%), systemic lupus erythematosus (5.1%), myasthenia gravis (4.4%), and primary antiphospholipid antibody syndrome (2.9%). Antinuclear antibodies (ANAs) were frequently detected in the subgroup of NMOSD patients tested for this antibody (50/92; 54.3%). The higher frequency of ANAs and anti-extractable nuclear antigen autoantibodies, in the subgroups of AQP4-IgG-positive patients compared to the AQP4-IgG negative, tested for these antibodies, was statistically significant (p = 0.009, and p = 0.015, respectively). CONCLUSION: In conclusion, based on our results, in a defined cohort with European ethnical background, a wide spectrum of autoimmune diseases is frequently associated with AQP4-IgG seropositive NMOSD patients.

Type 2 hypersensitivity disorders, including systemic lupus erythematosus, Sjögren's syndrome, Graves' disease, myasthenia gravis, immune thrombocytopenia, autoimmune hemolytic anemia, dermatomyositis, and graft-versus-host disease, are THαß-dominant autoimmune diseases.

The THαß host immunological pathway contributes to the response to infectious particles (viruses and prions). Furthermore, there is increasing evidence for associations between autoimmune diseases, and particularly type 2 hypersensitivity disorders, and the THαß immune response. For example, patients with systemic lupus erythematosus often produce anti-double stranded DNA antibodies and anti-nuclear antibodies and show elevated levels of type 1 interferons, type 3 interferons, interleukin-10, IgG1, and IgA1 throughout the disease course. These cytokines and antibody isotypes are associated with the THαß host immunological pathway. Similarly, the type 2 hypersensitivity disorders myasthenia gravis, Graves' disease, graft-versus-host disease, autoimmune hemolytic anemia, immune thrombocytopenia, dermatomyositis, and Sjögren's syndrome have also been linked to the THαß pathway. Considering the potential associations between these diseases and dysregulated THαß immune responses, therapeutic strategies such as anti-interleukin-10 or anti-interferon α/ß could be explored for effective management.

Myasthenia gravis and myocarditis induced by chemoimmunotherapy in locally advanced gastric cancer: A case report.

The treatment strategy of patients with locally advanced gastric cancer has undergone notable changes since immune checkpoint inhibitors (ICIs) were developed. Although ICIs are generally well-tolerated, they can also cause serious adverse events, such as autoimmune diseases. In patients with gastric cancer and without a history of immune disease, the incidence of myasthenia gravis combined with myocarditis caused by ICI treatment is rare. Furthermore, cases of gastric cancer with ocular myasthenia gravis, without limb weakness or severe dyspnea, although with urination difficulties and symptoms of third-degree atrioventricular block have not been previously reported, to the best of our knowledge. The present study describes the case of a 72-year-old male patient with locally advanced gastric cancer that was treated with chemoimmunotherapy with oxaliplatin + tigio + sintilimab. At 19 days following only one cycle of therapy, the patient developed a left eyelid weakness and difficulty in urinating, as well as diplopia. At 5 days after the symptom of eyelid weakness, a third-degree atrioventricular block occurred. Hormone therapy, a temporary pacemaker and gamma-globulin therapy were administered, and the patient was discharged 1 month later with the resolution of myasthenia gravis and the atrioventricular block. At the final follow-up (1 month after discharge), the patient had a full recovery from myasthenia gravis and arrhythmias. Although some similar cases have been previously reported, the majority of patients with limb weakness and have eventually succumbed; moreover, clinical symptoms were identified at a late stage, and the disease evolution records were not detailed. Therefore, the present study describes the case of the patient and treatment strategy, also providing detailed laboratory indicators and clinical symptom evolution. This was performed with the aim to aid future research and the treatment of immune-related diseases.

Long-Term Bone Density Changes and Fracture Risk in Myasthenia Gravis: Implications for FRAX® Tool Application.

Myasthenia gravis (MG) patients often require long-term glucocorticoid therapy, which may affect bone health. This study aimed to assess long-term changes in bone mineral density (BMD), evaluate osteoporotic fracture incidence, and examine the relationship between MG-specific factors and bone health outcomes over a 10-year period. This single-center, prospective cohort study included 28 MG patients. BMD, T-scores, Z-scores, and bone turnover markers were measured at baseline. FRAX® scores were calculated and adjusted for glucocorticoid dose. Fracture occurrence was monitored for over 10 years. Five (17.9%) patients experienced major osteoporotic fractures during follow-up. The fracture group had significantly lower baseline BMD and T-scores than the no-fracture group. Baseline FRAX® scores for major osteoporotic fracture risk were significantly higher in the fracture group (median 19.0% vs. 5.7%, p = 0.001). The fracture group progressed from osteopenia at baseline to osteoporosis by the end of this study. This study highlights the importance of early and regular bone health assessments in MG patients, particularly those receiving long-term glucocorticoid therapy. The FRAX® tool may be valuable for fracture risk stratification in this population. These findings can inform clinical practice and improve long-term management strategies for MG patients who are at risk of osteoporotic fractures.

An extremely rare case of thymic squamous cell carcinoma complicated with B3 thymoma and myasthenia gravis: a case report.

BACKGROUND: Thymomas complicated with myasthenia gravis are conventionally treated during thoracic surgery. Particularly, invasive thymomas are resected alongside the surrounding organs. Here, we present a case where surgical and perioperative management was performed under the presumption of thymoma with myasthenia gravis. However, definitive pathology revealed the co-occurrence of B3 thymoma and thymic squamous cell carcinoma. This case highlights the unique presentation and exceptional rarity of thymomas that are complicated by myasthenia gravis and thymic carcinoma. CASE PRESENTATION: A 65-year-old female presented with eyelid ptosis at our hospital. Following a comprehensive examination, the patient was diagnosed with myasthenia gravis. Her computed tomography (CT) scan revealed an anterior mediastinal tumor suggestive of a thymoma, prompting a referral to the Department of Thoracic Surgery. Moreover, preoperative assessment could not definitively exclude pericardial invasion. She subsequently underwent an extended thymectomy via a longitudinal sternal incision. The tumor exhibited partial invasion of the pericardium, necessitating resection and reconstruction. Definitive pathological examination confirmed the co-occurrence of B3 thymoma and thymic squamous cell carcinoma. Positive lymph node metastasis classified the patient as stage IVa according to the Union for International Cancer Control (UICC) TNM Classification of Malignant Tumors, 8th Edition, and she was started on adjuvant radiotherapy postoperatively. Currently, the patient remains under observation, with follow-up CT scans showing no signs of recurrence. CONCLUSIONS: This report describes an extremely rare case of thymoma complicated with myasthenia gravis and thymic squamous cell carcinoma.

Correlation Between the Prevalence of Myasthenia Gravis and the Frequency of Class II Human Leucocyte Antigen Alleles in Various Geographical Locations Around the World.

Myasthenia gravis (MG) is an autoimmune condition characterised by muscle weakness due to antibodies produced against post-synaptic receptors. The impact of MG can be significant, especially with an ageing population. Human leukocyte antigens (HLA) are polymorphic genes associated with autoimmune conditions. Establishing the HLA alleles associated with MG may aid in the diagnosis, screening and early management of individuals at risk of MG. This research aims to establish the class II HLA alleles associated with the prevalence of MG in various regions of the world and identify the alleles that could predispose to the condition. A Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flow chart and various databases including, Scopus and PubMed as well as other sources were used to find appropriate papers on HLA class II alleles associated with MG and the prevalence of MG in various countries. The frequency of selected HLA alleles in selected regions were obtained from the website, allelefrequencies.net. From this, a correlation coefficient and p-value were calculated to investigate whether the frequency of MG and the prevalence of HLA alleles had a significant association.  The results highlighted two HLA alleles, DRB1*04:04 and DRB1*03, to have a significant positive association with the prevalence of MG. The frequency of the alleles showed regional variation, with European countries, particularly Northern Europe, exhibiting the highest frequencies. A significant positive correlation between HLA-DRB1*04:04 and DRB1*03 showed with the prevalence of MG, highlighting these alleles as a possible cause of the disease. Screening for these alleles, particularly in Northern Europe, may help identify individuals susceptible to MG.

Cushing's syndrome developing myasthenia gravis with takotsubo cardiomyopathy after adrenalectomy: a case report.

BACKGROUND: Several cases of autoimmune disease onset after treatment for Cushing's syndrome have been reported. CASE PRESENTATION: Herein, we report a case of myasthenia gravis crisis in a 51-year-old woman 2 months after adrenalectomy for adrenal Cushing's syndrome accompanied by takotsubo cardiomyopathy. The resolution of excessive endogenous cortisol after adrenalectomy may have triggered the onset of previously latent myasthenia gravis. CONCLUSIONS: Observing the similarities in symptoms between myasthenia gravis and adrenal crisis, which can sometimes be challenging to differentiate, is essential. Moreover, the presence of takotsubo cardiomyopathy as a non-motor manifestation of myasthenic crisis must be noted.

Sero-Positive Isolated Ocular Myasthenia Gravis.

Ocular myasthenia gravis (OMG) is a neuromuscular disease characterized by the production of autoantibodies against post-synaptic proteins at the neuromuscular junction (NMJ). An 18-year-old male who had symptoms of drooping eyelids and double vision was diagnosed with ocular myasthenia gravis on investigations and examinations. Treatment was initiated with a tablet of pyridostigmine 60 mg twice daily per oral for two weeks, followed by three times daily for four weeks. The patient demonstrated significant improvement in ptosis and diplopia. There are still a considerable number of challenges in the diagnosis and treatment of ocular myasthenia gravis, with the typical treatment involving acetylcholinesterase inhibitors and immunosuppressants.

Association between baseline lipid profile and risk of worsening in patients with myasthenia gravis: A retrospective cohort study.

Background: Dyslipidemia has been implicated in autoimmunity; however, its association with myasthenia gravis (MG) prognosis is unclear. We aimed to investigate the correlation between baseline lipid profiles and risk of MG worsening. Methods: This 7-year retrospective cohort study conducted at a Chinese hospital included 264 adult patients with MG. Data on baseline lipids, 1-year worsening, and covariates, including demographics, MG characteristics, comorbidities, and treatments were extracted. Results: Univariate and multivariate logistic regression analyses failed to show a significant association between the risk of 1-year MG worsening and any of the seven blood lipid-related indicators. However, the subsequent non-linear analysis revealed an inflection point in the risk curve of ln[lipoprotein(a)], at 4.06 (58 nmol/L). The lipoprotein(a) levels on the left side of the inflection point presented a positive significant correlation with the risk of MG worsening (relative risk [RR]: 6.06, 95 % confidence interval [CI]: 1.00-38.57), whereas those on the right side of the inflection point demonstrated no significant correlation (RR: 0.86, 95 % CI: 0.55-1.34). Conclusions: Except for lipoprotein(a) levels being associated with worsening of myasthenia gravis, most lipid parameters were not associated with changes in the clinical course and severity of myasthenia gravis.we observed that lower levels of lipoprotein(a) were associated with a better prognosis in the interval 7-58 nml/L, whereas beyond this interval this was not observed, suggesting dyslipidemia may impact MG prognosis. Further studies are required to validate these findings.

Cardiac implications in myasthenia gravis.

This editorial aimed to consolidate the current evidence in literature on the association between myasthenia gravis (MG) and cardiac involvement, focusing on the impact of thymoma, antistriational antibodies, and late-onset MG. Additionally, the study aimed to explore the influence of genetic differences among populations on the association with cardiac disease. We conducted a review of existing literature in PubMed and Google Scholar to find relevant studies on cardiac involvement in MG. We created search criteria using a combination of free text words, including MG, antistriational antibodies, thymectomy, cardiomyopathy, myocarditis, arrhythmias, autonomic dysfunction. Relevant articles published in English language were analyzed and incorporated. The findings indicate a strong association between thymoma, myasthenic crisis, antistriational antibodies, and late-onset MG with cardiac involvement. The study also revealed that genetic differences among populations influence the risk of cardiac disease and electrocardiography (ECG) abnormalities in MG patients. Autonomic dysfunctions altered cardiac autonomic response and increased susceptibility to arrhythmias and sudden cardiac death in MG patients. The study supports the significance of thymoma, antistriational antibodies, and late-onset MG as key factors associated with cardiac involvement in MG patients. It emphasizes the importance of ECG as the initial test in managing MG patients, particularly in the perioperative period, to identify and genetic testing if needed to address their cardiac risk effectively.

Agonist antibody to MuSK protects mice from MuSK myasthenia gravis.

Myasthenia gravis (MG) is a chronic and severe disease of the skeletal neuromuscular junction (NMJ) in which the effects of neurotransmitters are attenuated, leading to muscle weakness. In the most common forms of autoimmune MG, antibodies attack components of the postsynaptic membrane, including the acetylcholine receptor (AChR) or muscle-specific kinase (MuSK). MuSK, a master regulator of NMJ development, associates with the low-density lipoprotein-related receptor 4 (Lrp4) to form the signaling receptor for neuronal Agrin, a nerve-derived synaptic organizer. Pathogenic antibodies to MuSK interfere with binding between MuSK and Lrp4, inhibiting the differentiation and maintenance of the NMJ. MuSK MG can be debilitating and refractory to treatments that are effective for AChR MG. We show here that recombinant antibodies, derived from MuSK MG patients, cause severe neuromuscular disease in mice. The disease can be prevented by a MuSK agonist antibody, presented either prophylactically or after disease onset. These findings suggest a therapeutic alternative to generalized immunosuppression for treating MuSK MG by selectively and directly targeting the disease mechanism.

Patient and care partner perspectives and preferences related to myasthenia gravis treatment: A qualitative study.

Background and Aims: Due to the high symptom and treatment burden in myasthenia gravis (MG), understanding patient and care partner perspectives and preferences is crucial. Methods: This study used voice analysis and virtual focus groups to understand patient and care partner experiences with MG-related symptoms, treatments, and preferences. The voice analysis via social media listening used artificial intelligence-powered tools to gather and structure public digital conversations on MG. Focus groups included people living with MG and care partners who completed a questionnaire and participated in a 1-h virtual session facilitated using a semi-structured interview guide. Qualitative data were aggregated, transcribed, and thematically analyzed. Results: The voice analysis examined 11,554 posts from 8321 individuals, discussing MG symptoms, treatments, and burden. Of 7563 symptom-related posts, 5902 (78%) conveyed negative, 1427 (19%) neutral, and 234 (3%) positive sentiment. The most frequently mentioned symptoms were categorized as dysarthria, muscle weakness, and dysphagia. MG treatment sentiment analysis identified 6667 posts (67%) as neutral, 2887 (29%) as negative, and 350 (4%) as positive. For the focus groups, 15 individuals (12 patients and 3 care partners) completed the questionnaire and 14 participated in the virtual focus group sessions. The 15 participants who completed the questionnaire prioritized treatment convenience, symptom control for improved quality of life, and preventing potential MG crises in their current treatment. New treatment expectations included increased effectiveness, less frequent dosing, faster onset, and fewer side effects. Participants were also receptive to wearable medication delivery systems placed on the body and valued direct involvement in treatment decisions. Conclusion: Patients and care partners are often negatively impacted by MG symptoms and value convenient and fast-acting treatments that control symptoms with minimal side effects. Considering patient preferences may help optimize treatment decisions and improve patients' overall well-being and satisfaction in their care.

Efficacy and safety of rozanolixizumab in patients with muscle-specific tyrosine kinase autoantibody-positive generalised myasthenia gravis: a subgroup analysis of the randomised, double-blind, placebo-controlled, adaptive phase III MycarinG study.

Background: Muscle-specific tyrosine kinase (MuSK) autoantibody-positive (Ab+) generalised myasthenia gravis (gMG) is a rare and frequently severe subtype of gMG. Objectives: To assess the efficacy and safety of rozanolixizumab in the subgroup of patients with MuSK Ab+ gMG in the MycarinG study. Design: A randomised, double-blind, placebo-controlled phase III study. Methods: Patients with acetylcholine receptor (AChR) Ab+ or MuSK Ab+ gMG (aged ⩾18 years, Myasthenia Gravis Foundation of America Disease Class II-IVa, Myasthenia Gravis Activities of Daily Living [MG-|ADL] score ⩾3.0 [non-ocular symptoms], Quantitative Myasthenia Gravis score ⩾11.0) were randomly assigned (1:1:1) to receive once-weekly subcutaneous infusions of rozanolixizumab 7 mg/kg, rozanolixizumab 10 mg/kg or placebo for 6 weeks, followed by an 8-week observation period. Randomisation was stratified by AChR and MuSK autoantibody status. The primary study endpoint was change from baseline to Day 43 in MG-ADL score. Treatment-emergent adverse events (TEAEs) were also assessed. Results: Overall, 200 patients were randomised, of whom 21 had MuSK Ab+ gMG and received rozanolixizumab 7 mg/kg (n = 5), 10 mg/kg (n = 8) or placebo (n = 8). In patients with MuSK Ab+ gMG, reductions from baseline to Day 43 in MG-ADL scores were observed: rozanolixizumab 7 mg/kg least squares mean (LSM) change (standard error), -7.28 (1.94); 10 mg/kg, -4.16 (1.78); and placebo, 2.28 (1.95). Rozanolixizumab 7 mg/kg LSM difference from placebo was -9.56 (97.5% confidence interval: -15.25, -3.87); 10 mg/kg, -6.45 (-11.03, -1.86). TEAEs were experienced by four (80.0%), five (62.5%) and three (37.5%) patients with MuSK Ab+ gMG receiving rozanolixizumab 7 mg/kg, 10 mg/kg and placebo, respectively. No patients experienced serious TEAEs. No deaths occurred. Conclusion: This subgroup analysis of adult patients with MuSK Ab+ gMG enrolled in the MycarinG study supports the use of rozanolixizumab as an effective treatment option for patients with gMG who have MuSK autoantibodies. Trial registration: ClinicalTrials.gov: NCT03971422 (https://clinicaltrials.gov/study/NCT03971422); EU Clinical Trials Register: EudraCT 2019-000968-18 (https://www.clinicaltrials|register.eu/ctr-search/trial/2019-000968-18/GB).

Rozanolixizumab improved symptoms in people with anti-muscle-specific tyrosine kinase antibody-positive generalised myasthenia gravis in the MycarinG clinical study Myasthenia gravis is a rare, chronic autoimmune disease affecting the communication between nerves and muscles. People with the disease experience fluctuating muscle weakness and fatigue, leading to problems with mobility, speaking, swallowing and breathing. The disease is called generalised when muscles other than those that move the eyes and eyelids are affected. It is caused by antibodies that attack a person's own cells. Most people with the disease have antibodies against acetylcholine receptors (AChRs). However, some have antibodies against the muscle-specific tyrosine kinase (MuSK) protein and can experience more severe symptoms compared with people who have anti-AChR antibodies. Standard treatments for myasthenia gravis do not always work for people with anti-MuSK antibodies. The MycarinG study looked at whether rozanolixizumab was better than a placebo at treating the symptoms of adults with generalised myasthenia gravis and anti-AChR or anti-MuSK antibodies. Assessments measured disease severity and myasthenia gravis symptoms, such as physical fatigue, and how they affected daily activities. The study also looked at whether people receiving rozanolixizumab had any side effects. Here, we look at the group of people with anti-MuSK antibodies who took part in the MycarinG study. In total, 21 of the 200 people in the study had anti-MuSK antibodies. The symptoms of myasthenia gravis improved more in people with anti-MuSK antibodies who received rozanolixizumab than in those who received placebo. Common side effects with rozanolixizumab included headache, diarrhoea and feeling sick. No serious side effects were seen, and no patients died. The results show that rozanolixizumab is an effective treatment for people with generalised myasthenia gravis who have anti-MuSK antibodies. The results in this group of people are consistent with those seen in all people who took part in the study (with either antibody type).