Comparative effectiveness of azathioprine and mycophenolate mofetil for myasthenia gravis (PROMISE-MG): a prospective cohort study

Pathogenesis and detection methods of anti-acetylcholine receptor antibodies in myasthenia gravis

Myasthenia gravis (MG), which affects the endplate region of the postsynaptic neuromuscular junction, is the best-understood autoimmune disease. MG is driven by anti-acetylcholine receptor (AChR) or muscle-specific receptor tyrosine kinase, and 65% of MG patients have anti-AChR-positive generalized MG. Experimental autoimmune MG is a useful model to investigate the pathogenic mechanisms of anti-AChR antibodies and to evaluate the efficacy of new immunotherapies. Since long-term drug treatment is usually necessary for MG patients, the selection of immunotherapy must be chosen based on an understanding of the pathophysiology, including the roles of the thymus, T cells, B cells, autoantibodies, and neuromuscular junction. The main pathogenic mechanism of MG is the activation of the complement system caused by the attack of anti-AChR antibodies. Molecular technology using the neonatal Fc receptor (FcRn) is currently being applied to the development of new MG therapies. Many biological drugs targeting B cells, interleukin-6, FcRn and complement show promise as potential therapeutics for anti-AChR-positive generalized MG. With regard to anti-AChR antibody detection, the overall agreement rate between radioimmunoassay and enzyme linked immunosorbent assay is 91%, with positive agreement of 87% and negative agreement of 99%.

Long-term maintenance of mycophenolate mofetil in anti-NMDA receptor encephalitis (LEARN): a multicentre, open-label, blinded-endpoint, randomised controlled trial

BACKGROUND

Anti-N-methyl-D-aspartate receptor encephalitis (NMDARE) is a severe autoimmune disorder with high morbidity and mortality. Current treatments have limitations including relapse, highlighting the need for effective maintenance therapy. This study evaluates the efficacy and safety of mycophenolate mofetil (MMF) as long-term adjunctive therapy to first-line treatment in newly diagnosed patients with NMDARE.

METHODS

We conducted a prospective, randomised, open-label trial in four academic centres in China. Patients aged 14 and older with acute NMDARE, who received first-line treatments within 2 weeks of presentation to the hospital and had a modified Rankin scale (mRS) score of 2 or more, were recruited. Participants were randomly assigned to receive first-line treatment with or without MMF (0.5 g two times per day for 24 months). Primary outcomes included relapse rates and time to relapse, with secondary outcomes including cognitive deficits, treatment response (the proportion of patients with≥1 point improvement in mRS within 4 weeks) and adverse events (AEs).

RESULTS

Of 100 patients (52% female; median age 27), those in the MMF group had fewer relapses (5.9% vs 26.5%; p=0.006) and better treatment response (84.3% vs 65.3%; p=0.03). No significant difference was found in long-term functional prognosis at 12 and 24 months. However, MMF patients had less fatigue, cognitive impairment, depression and seizures. AEs were mild-to-moderate, with no deaths or anaphylactic reactions.

CONCLUSIONS

This study provides Class II evidence that long-term adjunctive treatment of MMF to first-line treatment of NMDARE resulted in a lower risk of relapse and was well tolerated beyond the 24 months of treatment.

TRIAL REGISTRATION NUMBER

ChiCTR2100044362.

New and Emerging Biological Therapies for Myasthenia Gravis: A Focussed Review for Clinical Decision-Making

Myasthenia gravis (MG) is a rare autoimmune disease characterised by exertion-induced muscle weakness that can lead to potentially life-threatening myasthenic crises. Detectable antibodies are directed against specific postsynaptic structures of the neuromuscular junction. MG is a chronic condition that can be improved through therapies, but to date, not cured. Standard treatment has been unchanged for decades and includes symptomatic treatment with acetylcholine-esterase inhibitors and disease-modifying treatment with steroids, steroid-sparing immunosuppressants and thymectomy. Overall, a relevant proportion of patients does not achieve a satisfactory clinical improvement under standard treatment. Additionally, long-term therapy with steroids can cause significant side effects and latency to clinical improvement with standard steroid-sparing immunosuppressants and after thymectomy can take months to years. In recent years, treatment of MG has changed fundamentally due to improved evidence from phase 3 trials and the regulatory approval of complement inhibitors and FcRn inhibitors as add-on treatment options. This provides new optimism for substantially more patients reaching minimal manifestation status and has led to a shift in treatment strategy with more targeted therapies being employed early in the course of the disease, especially in patients with high disease activity. In this focussed review, we provide an overview of the diagnosis, classification and standard treatment of MG, followed by data from randomised controlled trials on the modern drugs already available for therapy and those still in the final stages of clinical development. In the second part, we provide an overview of real-world data for already approved therapies and outline how the availability of new biologicals is changing both clinical decision-making and patient journey.

Outcome Predictors of Generalized Myasthenia Gravis: A Prospective Observational Study

BACKGROUND AND OBJECTIVES

There is paucity of studies on long-term remission of autoimmune generalized myasthenia gravis (MG) from Southeast Asia. We report the outcome predictors of generalized MG and also evaluate the influence of high- versus low-dose prednisolone and prednisolone with or without azathioprine (AZA).

METHODS

Fifty-seven patients with generalized MG were included, who completed 2 years of follow-up. Demographic information, comorbidities, Myasthenia Gravis Foundation of America (MGFA) class at baseline and follow-up, acetylcholine receptor (AChR) and muscle-specific kinase antibodies, decremental response, thymectomy, and treatments were recorded. Maximum doses of prednisolone, AZA, and acetylcholinesterase inhibitors were noted. The predictors of MGFA 0 at 3 and 6 months and minimal manifestation (MM) status at 2 years were evaluated.

RESULTS

MGFA 0 was achieved by 27 (47.4%) patients at 3 months, 35 (61.4%) patients at 6 months, and 46 (80.7%) patients at 12 months. At 2 years, 48 (84.2%) patients achieved the MM status and none achieved complete stable or pharmacologic remission. On multivariate analysis, AChR antibody titer (adjusted odds ratio [AOR] 1.08, 95% confidence interval [CI] 1.006-1.167; P = 0.03) and MG activity of daily living (MGADL) at 6 months (AOR 1.28, 95% CI 1.066-1.558; P = 0.01) predicted the MM status. Maximum dose of prednisolone and adjunctive AZA did not predict the MM status.

CONCLUSIONS

About 84.2% of patients with generalized MG, especially those with a low AChR antibody titer and MGADL < 4 at 6 months, achieved the MM status at 2 years.

Favorable long-term outcomes of autoimmune nodopathy with mycophenolate mofetil

Autoimmune nodopathy (AN) is a rare immune-mediated neuropathy characterized by autoantibodies against nodal or paranodal proteins. Patients with AN generally respond poorly to immunoglobulin therapy, and as a newly defined condition, there are currently no established treatment guidelines. Although rituximab shows potential as a therapeutic option, its high cost, limited availability, and the need for infusion monitoring hinder its use as a first-line treatment in many countries. In this report, we identified AN antibodies in five of 106 serum samples (4.7%) prospectively collected from patients initially diagnosed with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP): anti-neurofascin 155 (NF155) in 2 patients, anti-contactin-1 (CNTN1) in 1, anti-contactin associated protein 1 (CASPR1), and anti-NF186/140 in 1. Notably, we observed favorable long-term outcomes in these patients following treatment with mycophenolate mofetil (MMF) and corticosteroids. Given that these patients had not responded to immunoglobulin therapy and/or experienced relapses with corticosteroid monotherapy in their prior episodes, we propose MMF as a cost-effective treatment strategy for AN.

Time to response with ravulizumab, a long-acting terminal complement inhibitor, in adults with anti-acetylcholine receptor antibody-positive generalized myasthenia gravis

BACKGROUND AND PURPOSE

The efficacy and safety of ravulizumab, a terminal complement C5 inhibitor, in adults with anti-acetylcholine receptor antibody-positive (AChR Ab+) generalized myasthenia gravis (gMG) were demonstrated in the CHAMPION MG study (NCT03920293). This analysis aimed to characterize the latency to onset of a clinically meaningful therapeutic effect for ravulizumab.

METHODS

Post hoc analysis of data collected for up to 60 weeks from CHAMPION MG was performed to assess the timing of response to ravulizumab. Response was analyzed based on reductions of ≥2 and ≥3 points (minimal clinically important differences [MCIDs]) in Myasthenia Gravis-Activities of Daily Living (MG-ADL) and Quantitative Myasthenia Gravis (QMG) total scores, respectively, and on more rigorous reductions of ≥3 and ≥5 points, respectively. Time to first response was assessed using the Kaplan-Meier product-limit method.

RESULTS

The median (95% confidence interval) time to first response was 2.1 (2.1-2.6) and 4.1 (2.3-10.0) weeks for reductions of ≥2 and ≥3 points in MG-ADL total score, respectively (n = 139), and 4.1 (2.1-10.0) and 18.3 (11.0-33.4) weeks for reductions of ≥3 and ≥5 points in QMG total score, respectively (n = 134). Cumulative response rates at Week 60 (data cut-off) were 88% and 82% for ≥2- and ≥3-point MG-ADL score reductions, respectively, and 86% and 59% for ≥3- and ≥5-point QMG score reductions, respectively.

CONCLUSIONS

The median times to MCID with ravulizumab treatment in patients with AChR Ab+ gMG were ~2 weeks and ~4 weeks based on MCID MG-ADL and QMG total score reductions, respectively.

Optimal time for the addition of non-corticosteroid immunosuppressants in myasthenia gravis: a single-center retrospective study in China

Introduction

Patients with myasthenia gravis (MG) display strong treatment heterogeneity. Recent studies have indicated that low-dose steroids or immunosuppressants are effective. However, factors affecting the add-on of non-corticosteroid immunosuppressants to corticosteroids remain unknown.

Method

Consecutive patients with MG were retrospectively reviewed from May 15, 2015, to December 29, 2020. We included one group of patients with steroid treatment alone and another group who transitioned to non-steroid immunosuppressant therapy. Clinical features of the included patients were analyzed. Univariate and multivariate Cox regression models were used to identify potential influential factors.

Results

A total of 107 patients with MG were analyzed, including 66 receiving corticosteroid treatment alone and 41 who subsequently also received non-corticosteroid immunosuppressant therapy. Eight potential factors were primarily selected in univariate analysis (Ps < 0.1). Achieving minimal symptom expression (MSE) within 6 months (HR: 4.424, 95%CI: 2.102-11.865), body mass index (BMI) (HR: 0.385, 95% CI: 0.186-0.797), quantitative MG (QMG) bulbar muscle score (HR: 1.553, 95% CI: 1.140-2.118), disease duration (HR: 0.987, 95% CI: 0.977-0.997) and relapse (HR: 2.638, 95% CI: 1.031-6.750) were finally identified as potential influencing factors.

Discussion

We found multifactorial clinical factors were highly associated with the add-on of non-steroid immunosuppressants after steroid treatment in patients with MG. Achieving MSE within 6 months, BMI, QMG bulbar muscle score at baseline before steroid treatment, disease duration, and disease relapse may represent crucial influencing factors, which should be considered to improve the long-term prognosis for patients with MG in future studies and practice.

Recent advances in targeted therapy for inflammatory vascular diseases

Vascular diseases constitute a significant contributor to worldwide mortality rates, placing a substantial strain on healthcare systems and socio-economic aspects. They are closely associated with inflammatory responses, as sustained inflammation could impact endothelial function, the release of inflammatory mediators, and platelet activation, thus accelerating the progression of vascular diseases. Consequently, directing therapeutic efforts towards mitigating inflammation represents a crucial approach in the management of vascular diseases. Traditional anti-inflammatory medications may have extensive effects on multiple tissues and organs when absorbed through the bloodstream. Conversely, treatments targeting inflammatory vascular diseases, such as monoclonal antibodies, drug-eluting stents, and nano-drugs, can achieve more precise effects, including precise intervention, minimal non-specific effects, and prolonged efficacy. In addition, personalized therapy is an important development trend in targeted therapy for inflammatory vascular diseases. Leveraging advanced simulation algorithms and clinical trial data, treatment strategies are gradually being personalized based on patients' genetic, biomarker, and clinical profiles. It is expected that the application of precision medicine in the field of vascular diseases will have a broader future. In conclusion, targeting therapies offer enhanced safety and efficacy compared to conventional medications; investigating novel targeting therapies and promoting clinical transformation may be a promising direction in improving the prognosis of patients with inflammatory vascular diseases. This article reviews the pathogenesis of inflammatory vascular diseases and presents a comprehensive overview of the potential for targeted therapies in managing this condition.

Effectiveness and Safety of Mycophenolate Mophetil in Myasthenia Gravis: A Real-Life Multicenter Experience

BACKGROUND

Myasthenia gravis (MG) is an autoimmune disease characterized by fluctuating muscle weakness due to autoantibodies targeting neuromuscular junction proteins. Mycophenolate mofetil (MMF), an immunosuppressive therapy, has shown potential for managing MG with fewer side effects compared to other treatments. This study aims to evaluate the effectiveness and safety of MMF in MG patients in a real-life multicenter setting.

METHODS

A retrospective cohort study was conducted on generalized MG patients, refractory to azathioprine (AZA) and treated with MMF alone or with steroids, at three Italian centers from January 2011 to February 2024. Patients were assessed using the Myasthenia Gravis Foundation of America (MGFA) classification, MG composite score (MGCS), and MG activity of daily living (MGADL) scores at baseline, 6, 12, 18, and 24 months. Statistical analyses included the Spearman correlation, the Friedman test, and ANOVA.

RESULTS

Thirty-two patients were enrolled (13 males, mean age 66.5 ± 11.5 years). Significant improvements in MGADL and MGCS scores were observed at 6 and 12 months (p < 0.001), with continued improvement over 24 months. Side effects were reported in 12% of patients. MMF showed a faster onset of symptom control compared to azathioprine, with a significant improvement noted within 6 months.

CONCLUSIONS

A recent study found that MMF and AZA were equally effective in improving patients' quality of life, but because AZA had more serious adverse events than MMF, lower doses of AZA were therefore recommended to reduce the adverse events while maintaining efficacy. Conversely, results showed that MMF is effective and well-tolerated in the long-term management of MG, providing faster symptom control and a favorable safety profile. Future prospective studies with larger cohorts are needed to confirm these findings and explore sex differences in response to MMF treatment.