Efgartigimod improved health-related quality of life in generalized myasthenia gravis: results from a randomized, double-blind, placebo-controlled, phase 3 study (ADAPT)

Assessing the symptom control provided by ravulizumab or efgartigimod in myasthenia gravis: an evaluation of the patient experience of two different treatment approaches

OBJECTIVE

To introduce patient-centric perspectives of symptom control using a novel modeling approach to estimate time spent in health states for the generalized myasthenia gravis (gMG) therapies ravulizumab (terminal complement inhibitor) and efgartigimod (neonatal Fc receptor antagonist).

METHODS

Myasthenia Gravis Activities of Daily Living (MG-ADL), Quantitative Myasthenia Gravis (QMG), and Myasthenia Gravis Quality of Life 15-item revised (MG-QOL15r) scores were extracted from the phase 3 CHAMPION MG (ravulizumab; seven time points) and ADAPT (efgartigimod; nine time points) trials and compared with the preceding score to define health states of improving, stable, or worsening, with extrapolation to 1 year. Stable state was evaluated across threshold ranges of 0.2-1.0-point change between observations. The proportion of time spent across health states was calculated for each stability threshold and then averaged for an overall summary across the range of cut points.

RESULTS

When extrapolated to 1 year, patients receiving ravulizumab spent more time with stable symptoms compared with patients on efgartigimod as measured by MG-ADL, QMG, and MG-QOL15r across stability thresholds. On average, patients receiving ravulizumab spent more time in stable or improving health states combined according to MG-ADL, QMG, MG-QOL15r (100%, 91%, and 79% of the year, respectively) compared to worsening states (0%, 9%, 21%). Patients receiving efgartigimod also spent more time, on average, stable or improving (83%, 75%, 77%) than worsening (17%, 25%, 23%). Variation in symptom control was smaller with ravulizumab than with efgartigimod.

CONCLUSIONS

In this analysis, fixed-dose ravulizumab treatment was associated with stable symptom control in patients with gMG, whereas treatment with variable-dose efgartigimod resulted in initial improvement but more variable symptom control over time. Patients' personal goals and quality-of-life should be considered when choosing a gMG therapy.

Efgartigimod as a fast-acting treatment in generalized very-late-onset myasthenia gravis

Objective

Efgartigimod (EFG), a neonatal Fc receptor antagonist that facilitates the degradation of pathogenic immunoglobulin G, is approved for the treatment of generalized myasthenia gravis (MG). This study aims to evaluate the efficacy and safety of EFG in patients with very-late-onset myasthenia gravis (VLOMG).

Methods

This study enrolled 15 consecutive patients diagnosed with VLOMG who received EFG treatment. Baseline demographic and clinical characteristics, as well as dynamic changes in the MG-specific activities of daily living (MG-ADL) score and quantitative MG (QMG) score, were systematically recorded.

Results

Patients were stratified into two groups: a worse group (n = 8) and a new-diagnosed group (n = 7), the latter of which included 5 patients who had received monotherapy with pyridostigmine (Py) prior to EFG. At week 5, the mean changes in MG-ADL scores were -4.9 ± 3.3 in the overall VLOMG cohort, -6.1 ± 3.1 in the new-diagnosed group, -6.6 ± 3.6 in the mono-Py subgroup, and -3.8 ± 3.2 in the worse group. The clinical meaningful improvement (CMI) rate was 86.7% (13/15) in the overall cohort, 75.0% (6/8) in the worse group, and 100.0% (7/7) in the new-diagnosed group. During a mean follow-up time of 39.2 ± 16.2 weeks, symptoms remained stable in responsive patients, with various treatment strategies implemented following the fast-acting treatment of EFG. No adverse drug reactions were reported in this cohort.

Conclusion

This study demonstrates that EFG is an effective and safe treatment for patients with VLOMG. EFG exhibits potential as an early, fast-acting treatment and may confer sustained clinical benefits in this patient population.

Assessing the effectiveness of measurement scales in evaluating the health-related quality of life in rare disease patients after treatment: a systematic review

BACKGROUND

Rare diseases often entail significant challenges in clinical management and health-related quality of life (HRQoL) assessment. HRQoL assessment tools for rare diseases show substantial variability in outcomes, influenced by disease heterogeneity, intervention types, and scale characteristics. The variability in reported quality of life (QoL) improvements following interventions reflects a need to evaluate the effectiveness of HRQoL assessment tools and understand their suitability across diverse contexts.

OBJECTIVE

This systematic review aims to analyse the effectiveness of various assessment scales in evaluating QoL and explores the general trends observed in the studies using the same and different assessment scales on rare diseases.

METHODS

A comprehensive literature search was conducted across various databases to identify studies that reported QoL outcomes related to interventions for rare diseases. Search terms included various synonyms, and both the generic and specific terms related to rare diseases and QoL. Key variables, including intervention types, patient demographics, study design, and geographical factors, were analysed to determine their role in influencing the reported HRQoL outcomes. The findings were then compared with existing literature to identify consistent patterns and discrepancies.

RESULTS

A total of 39 studies were included, comprising randomised controlled trials, observational studies, and cohort studies, with 4737 participants. Significant variations were observed in QoL improvements across studies, even when using the same assessment scales. These differences were primarily attributed to the heterogeneity in disease severity, intervention types, and patient characteristics. Studies employing disease-specific scales reported more nuanced outcomes than generic ones. Additionally, methodological differences, including study design and intervention type, contributed to variations in results and geographical factors influencing patients' perceptions of health and well-being.

CONCLUSION

The reported differences in QoL outcomes across studies can be explained by a combination of factors, including disease heterogeneity, treatment modalities, patient demographics, and assessment scale characteristics. These findings underscore the importance of selecting appropriate HRQoL assessment tools based on the research context and patient population. For more accurate comparisons across studies, it is crucial to consider these factors alongside consistent methodology and cultural adaptability of scales. Future research should focus on developing standardised guidelines for QoL assessments that accommodate the diverse needs of patients with rare diseases.

Pharmacokinetics, Pharmacodynamics, and Safety of Intravenous Efgartigimod and Subcutaneous Efgartigimod PH20 in Healthy Chinese Participants

BACKGROUND

Efgartigimod, a human immunoglobulin G (IgG)1-derived Fc fragment targeting the neonatal Fc receptor, has been developed into intravenous (IV) and subcutaneous (SC) formulations for treating generalized myasthenia gravis (gMG) and other autoimmune diseases. Data in the Chinese population were not available to date, and while both formulations have been approved in the USA, the EU, Japan and China for the treatment of gMG.

OBJECTIVE

We present the pharmacokinetic, pharmacodynamic, and safety of IV and SC PH20 efgartigimod in healthy Chinese participants.

METHODS

In two independent, double-blinded, placebo-controlled, phase I studies of the IV and SC formulations of efgartigimod, healthy Chinese adults were randomized 3:1 to receive active treatment or matching placebo once every 7 days for four doses. Primary endpoints were pharmacokinetic parameters.

RESULTS

After the fourth IV infusion, a mean maximum observed concentration (Cmax) of 194 µg/mL was reached at the end of the 1 h infusion; the mean area under concentration-time curve from time zero to 168 h (AUC0-168h) was 5300 µg × h/mL. After the fourth SC injection, a mean Cmax of 42.1 µg/mL was achieved with a median Tmax of 47.74 h; the mean AUC0-168h was 4790 µg × h/mL. Maximal mean reductions from baseline in total IgG levels were reached approximately 24 days after the first dose (60.7%, IV formulation; 66.4%, SC formulation). Treatment-related adverse events (TRAEs) were reported in seven (58.3%) participants receiving SC efgartigimod, mostly injection-site reactions. No TRAEs or AEs of special interest were reported in the IV study.

CONCLUSIONS

The efgartigimod IV and SC pharmacokinetic, pharmacodynamic, and safety profiles in Chinese participants were similar to the known profiles in non-Chinese participants. Both formulations effectively reduced total IgG levels by a similar percentage.

CLINICAL TRIAL REGISTRATION

CTR20211952 and CTR20211805.

Case report: Rapid clinical improvement of anti-HMGCR immune-mediated necrotizing myopathy treated with efgartigimod

Immune-mediated necrotizing myopathy (IMNM) with anti-HMGCR antibody positivity is characterized by proximal extremity weakness, increased creatine kinase, and extensive muscle edema. There is an urgent need to find more appropriate treatment options for anti-HMGCR IMNM patients who do not respond well to conventional therapy in the acute phase. With the advent of targeted biologics, new treatment options are available. We report on a 66-year-old anti-HMGCR IMNM patient who initially presented with a 1-month history of progressive proximal extremity weakness and dysphagia with markedly elevated creatine kinase. The patient did not respond to conventional high-dose glucocorticoid and intravenous immunoglobulin therapy, and his symptoms rapidly deteriorated over the 2 weeks after this treatment, with worsening limb weakness that prevented walking, marked proximal muscle atrophy, and weight loss. After one cycle (four infusions) of efgartigimod, the patient's symptoms improved markedly and he has since (for several months) remained in a good clinical state.

Efgartigimod: A Review in Generalised Myasthenia Gravis

Efgartigimod (Vyvgart®; Vyvgart® Hytrulo) is a neonatal fragment crystallizable receptor (FcRn) antagonist indicated for the treatment of generalised myasthenia gravis (gMG) in adults who are acetylcholine receptor (AChR) antibody positive (Ab+). Efgartigimod is approved for both intravenous (IV) and subcutaneous (SC) use. In a pivotal phase III trial, IV efgartigimod was associated with significant and clinically meaningful improvements in myasthenia gravis symptoms and reductions in disease burden. The beneficial effects of IV efgartigimod were reproducible, durable and maintained over the long term. IV efgartigimod also improved health-related quality of life (HRQOL). In another phase III trial, SC efgartigimod PH20 was noninferior to IV efgartigimod in reducing total immunoglobulin G levels. Clinical improvement with SC efgartigimod PH20 was consistent with that of IV efgartigimod and was reproducible over the long term. Efgartigimod was generally well tolerated; the most common adverse events were headache and infections (with IV efgartigimod) and injection-site reactions (with SC efgartigimod PH20). Although further long-term data are required, IV and SC formulations of efgartigimod provide effective, generally well-tolerated and flexible treatment options for adults with AChR Ab+ gMG.

Food and Drug Administration (FDA) Approvals of Biological Drugs in 2023

An increase in total drug (small molecules and biologics) approvals by the Food and Drug Administration (FDA) was seen in 2023 compared with the previous year. Cancer remained the disease most targeted by monoclonal antibodies (mAbs), followed by autoimmune conditions. Our data reveal the prevalence of approvals for biologics even during years when the total number of authorizations was low, such as in 2022. Over half the drugs that received the green light in 2023 benefited from expedited programs, as the incidence of many diseases increased. In addition, over half of the biologics approved received Orphan Drug Designation from the FDA. This narrative review delves into details of the most significant approvals in 2023, including mAbs, enzymes, and proteins, explaining their mechanisms of action, differences from previous drugs, placebo, and standards of care, and outcomes in clinical trials. Given the varying number of drugs authorized annually by the U.S. health authority, this review also examines the limits of external influences over the FDA's decisions and independence regarding drug approvals and withdrawals.

A multicenter, randomized, open-label, phase 2 clinical study of telitacicept in adult patients with generalized myasthenia gravis

BACKGROUND AND PURPOSE

This study aimed to investigate the clinical efficacy and safety of telitacicept in patients with generalized myasthenia gravis (gMG) who tested positive for acetylcholine receptor antibodies or muscle-specific kinase antibodies and were receiving standard-of-care therapy.

METHODS

Patients meeting the eligibility criteria were randomly assigned to receive telitacicept subcutaneously once a week for 24 weeks in addition to standard-of-care treatment. The primary efficacy endpoint was the mean change in the quantitative myasthenia gravis (QMG) score from baseline to week 24. Secondary efficacy endpoints included mean change in QMG score from baseline to week 12 and gMG clinical absolute score from baseline to week 24. Additionally, safety, tolerability and pharmacodynamics were assessed.

RESULTS

Twenty-nine of the 41 patients screened were randomly selected and enrolled. The mean (± standard deviation [SD]) reduction in QMG score from baseline to week 24 was 7.7 (± 5.34) and 9.6 (± 4.29) in the 160 mg and 240 mg groups, respectively. At week 12, mean reductions in QMG scores for these two groups were 5.8 (± 5.85) and 9.5 (± 5.03), respectively, indicating rapid clinical improvement. Safety analysis revealed no adverse events leading to discontinuation or mortalities. All patients showed consistent reductions in serum immunoglobulin (Ig) A, IgG and IgM levels throughout the study.

CONCLUSION

Telitacicept demonstrated safety, good tolerability and reduced clinical severity throughout the study period. Further validation of the clinical efficacy of telitacicept in gMG will be conducted in an upcoming phase 3 clinical trial.

Overcoming therapeutic challenges: Successful management of a supposedly triple seronegative, refractory generalized myasthenia gravis patient with efgartigimod

BACKGROUND AND PURPOSE

This study was undertaken to highlight neonatal Fc receptor inhibition (efgartigimod) as a valuable therapeutic option for patients with refractory seronegative myasthenia gravis (MG) and to emphasize the concept that seronegative MG is greatly constrained by the limitations of currently available diagnostic methods and therapeutic measures.

METHODS

We describe the first refractory, generalized MG (gMG) patient successfully treated with efgartigimod after testing negative on standard autoantibody detection tests.

RESULTS

Our patient presented with severe fluctuating bulbar and generalized weakness, resulting in multiple myasthenic crises requiring intubation. After a 28-year medical history of multiple failed lines of treatment, our patient was started on efgartigimod. Over five treatment cycles, a definite improvement in her clinical condition was observed (Myasthenia Gravis Foundation of America class: IIIb to IIb; MG-Activities of Daily Living score: 11 to 0; MG-Quality of Life 15 score: 30 to 0; Quantitative MG score: 28 to 6). Standard autoantibody detection tests failed to detect known pathogenic autoantibodies, but cell-based assay (CBA) identified autoantibodies against clustered adult acetylcholine receptor (AChR).

CONCLUSIONS

In light of recent approvals of efgartigimod by the European Medicines Agency and US Food and Drug Administration exclusively for AChR-positive gMG forms, our case highlights evidence suggesting that such an approach might be shortsighted and could limit therapeutic options for patients with refractory seronegative gMG. Additionally, introducing more sensitive analytical techniques, exemplified by CBA, may help bridge the gap between seronegative and seropositive patients. This represents an urgent unmet need for gMG patients, as the antibody profile dramatically influences the therapeutic approach.

Expert consensus recommendations for improving and standardising the assessment of patients with generalised myasthenia gravis

BACKGROUND

Regular and consistent disease assessment could provide a clearer picture of burden in generalised myasthenia gravis (gMG) and improve patient care; however, the use of assessment tools in practice lacks standardisation. This modified Delphi approach was taken to review current evidence on assessment tool use in gMG and develop expert-derived consensus recommendations for good practice.

METHODS

A European expert panel of 15 experienced gMG neurologists contributed to development of this consensus, four of whom formed a lead Sub-committee. The PICO (Population, Intervention, Control, Outcomes) framework was used to define six clinical questions on gMG assessment tools, a systematic literature review was conducted, and evidence-based statements were developed. According to a modified Delphi voting process, consensus was reached when ≥70% of the experts rated agreement with a statement as ≥8 on a scale of 1-10.

RESULTS

Eighteen expert- and evidence-based consensus statements based on six themes were developed. Key recommendations include: consistent use of the Myasthenia Gravis Activities of Daily Living score (MG-ADL) across clinical settings, followed by a simple question (e.g., Patient Acceptable Symptom State [PASS]) or scale to determine patient satisfaction in clinical practice; use of a Quantitative Myasthenia Gravis [QMG] or quality of life [QoL] assessment when the MG-ADL indicates disease worsening; and consideration of symptom state to determine the timing and frequency of recommended assessments. Expert panel consensus was reached on all 18 statements after two voting rounds.

CONCLUSIONS

This process provided evidence- and expert consensus-based recommendations for the use of objective and subjective assessment tools across gMG research and care to improve management and outcomes for patients.

Case report: Rapid clinical improvement in acute exacerbation of MuSK-MG with efgartigimod

Myasthenia gravis with positive MuSK antibody often involves the bulbar muscles and is usually refractory to acetylcholinesterase inhibitors. For MuSK-MG patients who experience acute exacerbations and do not respond to conventional treatments, there is an urgent need to find more suitable treatment options. With the advent of biologic agents, efgartigimod has shown promising results in the treatment of MG. We report a 65-year-old MuSK-MG patient who presented with impaired eye movements initially, and the symptoms rapidly worsened within a week, affecting the limbs and neck muscles, and had difficulties in chewing and swallowing. Lymphoplasmapheresis did not achieve satisfactory results, but after a cycle of efgartigimod treatment, the patient's symptoms gradually improved and remained in a good clinical state for several months.

B cell-targeting chimeric antigen receptor T cells as an emerging therapy in neuroimmunological diseases

BACKGROUND

Neuroimmunology research and development has been marked by substantial advances, particularly in the treatment of neuroimmunological diseases, such as multiple sclerosis, myasthenia gravis, neuromyelitis optica spectrum disorders, and myelin oligodendrocyte glycoprotein antibody disease. With more than 20 drugs approved for multiple sclerosis alone, treatment has become more personalised. The approval of disease-modifying therapies, particularly those targeting B cells, has highlighted the role of immunotherapeutic interventions in the management of these diseases. Despite these successes, challenges remain, particularly for patients who do not respond to conventional therapies, underscoring the need for innovative approaches.

RECENT DEVELOPMENTS

The approval of monoclonal antibodies, such as ocrelizumab and ofatumumab, which target CD20, and inebilizumab, which targets CD19, for the treatment of various neuroimmunological diseases reflects progress in the understanding and management of B-cell activity. However, the limitations of these therapies in halting disease progression or activity in patients with multiple sclerosis or neuromyelitis optica spectrum disorders have prompted the exploration of cell-based therapies, particularly chimeric antigen receptor (CAR) T cells. Initially successful in the treatment of B cell-derived malignancies, CAR T cells offer a novel therapeutic mechanism by directly targeting and eliminating B cells, potentially overcoming the shortcomings of antibody-mediated B cell depletion. WHERE NEXT?: The use of CAR T cells in autoimmune diseases and B cell-driven neuroimmunological diseases shows promise as a targeted and durable option. CAR T cells act autonomously, penetrating deep tissue and effectively depleting B cells, especially in the CNS. Although the therapeutic potential of CAR T cells is substantial, their application faces hurdles such as complex logistics and management of therapy-associated toxic effects. Ongoing and upcoming clinical trials will be crucial in determining the safety, efficacy, and applicability of CAR T cells. As research progresses, CAR T cell therapy has the potential to transform treatment for patients with neuroimmunological diseases. It could offer extended periods of remission and a new standard in the management of autoimmune and neuroimmunological disorders.

FcRn Inhibitor Therapies in Neurologic Diseases

In the last decade, the landscape of treating autoimmune diseases has evolved with the emergence and approval of novel targeted therapies. Several new biological agents offer selective and target-specific immunotherapy and therefore fewer side effects, such as neonatal Fc receptor (FcRn)-targeting therapy. Neonatal Fc receptor-targeted therapies are engineered to selectively target FcRn through various methods, such as Fc fragments or monoclonal anti-FcRn antibodies. These approaches enhance the breakdown of autoantibodies by blocking the immunoglobulin G recycling pathway. This mechanism reduces overall plasma immunoglobulin levels, including the levels of pathogenic autoantibodies, without affecting the other immunoglobulin class immunoglobulin A, immunoglobulin E, immunoglobulin M, and immunoglobulin D levels. Drugs that inhibit FcRn include efgartigimod, rozanolixizumab, batoclimab, and nipocalimab. These medications can be administered either intravenously or subcutaneously. Numerous clinical trials are currently underway to investigate their effectiveness, safety, and tolerability in various neurological conditions, including myasthenia gravis and other neurological disorders such as chronic inflammatory demyelinating polyneuropathy, myositis, neuromyelitis optica, and myelin oligodendrocyte glycoprotein antibody disease. Positive results from clinical trials of efgartigimod and rozanolixizumab led to their approval for the treatment of generalized myasthenia gravis. Additional clinical trials are still ongoing. Neonatal Fc receptor inhibitor agents seem to be well tolerated. Reported adverse events include headache (most commonly observed with efgartigimod and rozanolixizumab), upper respiratory tract infection, urinary tract infection, diarrhea, pyrexia, and nausea. Additionally, some of these agents may cause transient hypoalbuminemia and hypercholesterolemia notably reported with batoclimab and nipocalimab. In this review, we discuss the available clinical data for FcRN inhibitor agents in treating different neurological autoimmune diseases.

Efgartigimod in generalized myasthenia gravis: A real-life experience at a national reference center

BACKGROUND AND PURPOSE

Inhibition of the neonatal Fc receptor (FcRn) for IgG is a promising new therapeutic strategy for antibody-mediated disorders. We report our real-life experience with efgartigimod (EFG) in 19 patients with generalized myasthenia gravis (gMG) along a clinical follow-up of 14 months.

METHODS

EFG was administered according to the GENERATIVE protocol (consisting of a Fixed period of two treatment cycles [given 1 month apart] of four infusions at weekly intervals, followed by a Flexible period of re-cycling in case of worsening). Eight patients were positive for acetylcholine receptor antibody, four for muscle-specific tyrosine kinase antibody, and two for lipoprotein-related protein 4 antibody, and five were classified as triple negative. Efficacy of EFG was assessed by the Myasthenia Gravis Activities of Daily Living, Myasthenia Gravis Composite, and Quantitative Myasthenia Gravis scales.

RESULTS

Fifty-three percent of patients needed three treatment cycles, 26% needed four, and 21% needed five along the 14-month clinical follow-up. Meaningful improvement was observed at the end of each cycle with the clinical scores adopted. EFG had a dramatic effect on disease course, as during the year before treatment eight of 19 patients (42%) were hospitalized, and 15 of 19 (79%) needed treatment with plasma exchange or immunoglobulins; three of 19 (16%) were admitted to the intensive care unit. During EFG, none of the patients was hospitalized and only one patient required plasma exchange and intravenous immunoglobulins. No major side effects or infusion-related reactions occurred.

CONCLUSIONS

We observed that EFG was safe and modified significantly the course of the disease along a 14-month follow-up. Our experience strengthens the role of FcRn inhibition as an effective new tool for long-term treatment of gMG.

Registered trials on novel therapies for myasthenia gravis: a cross-sectional study on ClinicalTrials.gov

Novel biologics in MG therapy research is on the rise. This research aimed to investigate the characteristics of registered trials on novel therapies for myasthenia gravis on ClinicalTrials.gov. This cross-sectional study used a descriptive approach to assess the features of the included trials on ClinicalTrials.gov. We found 62 registered trials from 2007 to 2023 on ClinicalTrials.gov. The results showed a yearly rise in the number of registered trials (r = 0.76, p < 0.001). Following 2017, more industry-sponsored trials were conducted (91.5% [43] vs. 60% [9], p = 0.009), fewer results were released (10.6% [5] vs. 60% [9], p = 0.001), and more trials entered phase 3 (67.4% [31] vs. 20% [2], p = 0.001). The most researched novel medications were neonatal Fc receptor inhibitors (51.2% [21]), complement inhibitors (39.0% [16]), and B cell depletors (14.6% [6]). According to the website's data, the neonatal Fc receptor inhibitors and complement inhibitors were effective in treating myasthenia gravis patients in three trials (NCT03315130, NCT03669588, and NCT00727194). This study provides valuable insights into the profile of registered trials on novel therapies for myasthenia gravis. More clinical studies are needed in the future to prove the value of its application.

Therapeutic Plasma Exchange Versus FcRn Inhibition in Autoimmune Disease

Therapeutic plasma exchange (TPE or PLEX) is used in a broad range of autoimmune diseases, with the goal of removing autoantibodies from the circulation. A newer approach for the selective removal of immunoglobulin G (IgG) antibodies is the use of therapeutic molecules targeting the neonatal Fc receptor (FcRn). FcRn regulates IgG recycling, and its inhibition results in a marked decrease in circulating autoantibodies of the IgG subtype. The difference between FcRn inhibition and PLEX is often questioned. With anti-FcRn monoclonal antibodies (mAbs) and fragments only recently entering this space, limited data are available regarding long-term efficacy and safety. However, the biology of FcRn is well understood, and mounting evidence regarding the efficacy, safety, and potential differences among compounds in development is available, allowing us to compare against nonselective plasma protein depletion methods such as PLEX. FcRn inhibitors may have distinct advantages and disadvantages over PLEX in certain scenarios. Use of PLEX is preferred over FcRn inhibition where removal of antibodies other than IgG or when concomitant repletion of missing plasma proteins is needed for therapeutic benefit. Also, FcRn targeting has not yet been studied for use in acute flares or crisis states of IgG-mediated diseases. Compared with PLEX, FcRn inhibition is associated with less invasive access requirements, more specific removal of IgG versus other immunoglobulins without a broad impact on circulating proteins, and any impacts on other therapeutic drug levels are restricted to other mAbs. In addition, the degree of IgG reduction is similar with FcRn inhibitors compared with that afforded by PLEX. Here we describe the scientific literature regarding the use of PLEX and FcRn inhibitors in autoimmune diseases and provide an expert discussion around the potential benefits of these options in varying clinical conditions and scenarios.

What Is in the Neuromuscular Junction Literature?

ABSTRACT

This update covers several articles on diagnosis and misdiagnosis of myasthenia gravis (MG), the role of complement in MG, and then an impressive number of recent treatment trials. There is a negative study on any corticosteroid-sparing effect of intravenous immunoglobulin. A number of positive studies are reviewed. Open-label extension studies of phase 3 trials showed benefit regarding quality of life with efgartigimod and in functional measures with ravulizumab. The phase 3 RAISE trial of zilucoplan, a self-administered complement C5 inhibitor, is covered as well as the MyCarinG trial of rozanolixizumab. The notion of using fast-acting therapies early in the course of MG is addressed. The last sections center on MG and Lambert-Eaton myasthenic syndrome as a consequence of immune checkpoint inhibitor therapy.

Plasma Exchange versus Intravenous Immunoglobulin in Worsening Myasthenia Gravis: A Systematic Review and Meta-Analysis with Special Attention to Faster Relapse Control

Currently used rescue interventions to prevent rapid myasthenic deterioration are plasma exchange (PLEX) and intravenous immunoglobulin (IVIG). We investigated the evidence to determine whether the two methods were interchangeable or whether one was superior to the other. This review was registered on PROSPERO (CRD42021285985). Only randomized controlled trials (RCTs) comparing the efficacy and safety of PLEX and IVIG in patients with moderate-to-severe myasthenia gravis (MG) were included. Five major databases were systematically searched (PubMed, CENTRAL, Embase, Scopus, and Web of Science). Odds ratios (OR) with 95% confidence intervals (CI) were calculated for adverse events and mean differences (MD) for changes in quantitative myasthenia gravis scores (QMG). Three RCTs met the inclusion criteria. Two investigating 114 patients in total were eligible for meta-analysis to analyze efficacy and safety. For the change in QMG score, the MD was -2.8 (95% CI: -5.614-0.113), with PLEX performing better. For adverse events, an OR of 1.04 was found (95% CI: 0.25-4.27). This study demonstrated a low risk of bias in evaluating treatment efficacy but indicated a high risk of bias in assessing procedural safety outcomes. Although the results did not show any significant difference, there was a tendency indicating faster efficacy of PLEX in the first two weeks of treatment. In such a critical clinical condition, this tendency may be clinically meaningful, but further studies should clarify this benefit.

People Diagnosed with Myasthenia Gravis have Lower health-related quality of life and Need More Medical and Caregiver Help in Comparison to the General Population: Analysis of Two Observational Studies

INTRODUCTION

Myasthenia gravis (MG) is a neuromuscular disease causing extreme muscular fatigue, triggering problems with vision, swallowing, speech, mobility, dexterity, and breathing. This analysis intended to estimate the health-related quality-of-life impact, the medical burden, and the need for caregiver help of people diagnosed with MG.

METHODS

MyRealWorld-MG (MRW) is an observational study among adults diagnosed with MG in 9 countries. The General Population Norms (POPUP) observational study enrolled representative members of the general population in 8 countries. In both digital studies, respondents entered personal characteristics and provided data on medical conditions, EQ-5D-5L, HUI3, MG-Activities of Daily Living (MG-ADL), sick leave, caregiver help, and medical care utilization.

RESULTS

In MRW (n = 1859), 58.4% of respondents had moderate-to-severe MG. Average utility values were lower in MRW versus POPUP (0.739 vs. 0.843 for EQ-5D-5L; 0.493 vs. 0.746 for HUI3), and declined with more severe disease (0.872, 0.707, 0.511 EQ-5D-5L utilities and 0.695, 0.443, 0.168 HUI3 utilities for mild, moderate, and severe MG, respectively). Taking sick leave in the past month was 2.6 times more frequent among people diagnosed with MG compared to the general population (34.4% vs. 13.2%) and four times more people diagnosed with MG reported needing help from a caregiver (34.8% vs. 8.3%). Use of medical care was twice as likely in MRW in comparison with POPUP (51.9% vs. 24.6%).

CONCLUSION

This direct comparison of people diagnosed with MG and the general population using two large international studies revealed significant negative impact of MG. Results were consistent across all outcomes, in all countries.

Evaluation of the Quality of Life of Patients with Myasthenia Gravis in Greece

Myasthenia Gravis (MG) patients often report an affected quality of life (QoL). The aim of the current study was to evaluate the QoL of patients with MG in Greece using a specific tool. A cross-sectional online survey was performed. Adult patients were invited to participate. A questionnaire incorporating the MG-QOL15r scale was distributed, following its translation and cultural adaptation into Greek. Overall, 99 valid responses were submitted. The median age (interquartile range) of the participants was 48.50 (13.50) years and 76.80% were females. One third of the patients mentioned that they could not work/changed jobs after their diagnosis (28.30%) and that they face severe restriction of their everyday activities (26.30%). The mean MG-QOL15r score was 13.50 ± 7.70. Patients with important restriction of everyday activities (p < 0.01), patients with more pronounced need of emotional support (p < 0.01), patients with generalized MG (p < 0.01) and patients with myasthenic crises (p < 0.01) reported lower QoL. This study is the first to report on the affected QoL of the Greek population with MG using the MG-QoL15r scale. Further work should be done to incorporate the routine evaluation of QoL in the care of patients with MG.

Fighting Post-COVID and ME/CFS - development of curative therapies

The sequela of COVID-19 include a broad spectrum of symptoms that fall under the umbrella term post-COVID-19 condition or syndrome (PCS). Immune dysregulation, autoimmunity, endothelial dysfunction, viral persistence, and viral reactivation have been identified as potential mechanisms. However, there is heterogeneity in expression of biomarkers, and it is unknown yet whether these distinguish different clinical subgroups of PCS. There is an overlap of symptoms and pathomechanisms of PCS with postinfectious myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). No curative therapies are available for ME/CFS or PCS. The mechanisms identified so far provide targets for therapeutic interventions. To accelerate the development of therapies, we propose evaluating drugs targeting different mechanisms in clinical trial networks using harmonized diagnostic and outcome criteria and subgrouping patients based on a thorough clinical profiling including a comprehensive diagnostic and biomarker phenotyping.

Immune-Mediated Neuropathies: Pathophysiology and Management

Dysfunction of the immune system can result in damage of the peripheral nervous system. The immunological mechanisms, which include macrophage infiltration, inflammation and proliferation of Schwann cells, result in variable degrees of demyelination and axonal degeneration. Aetiology is diverse and, in some cases, may be precipitated by infection. Various animal models have contributed and helped to elucidate the pathophysiological mechanisms in acute and chronic inflammatory polyradiculoneuropathies (Guillain-Barre Syndrome and chronic inflammatory demyelinating polyradiculoneuropathy, respectively). The presence of specific anti-glycoconjugate antibodies indicates an underlying process of molecular mimicry and sometimes assists in the classification of these disorders, which often merely supports the clinical diagnosis. Now, the electrophysiological presence of conduction blocks is another important factor in characterizing another subgroup of treatable motor neuropathies (multifocal motor neuropathy with conduction block), which is distinct from Lewis-Sumner syndrome (multifocal acquired demyelinating sensory and motor neuropathy) in its response to treatment modalities as well as electrophysiological features. Furthermore, paraneoplastic neuropathies are also immune-mediated and are the result of an immune reaction to tumour cells that express onconeural antigens and mimic molecules expressed on the surface of neurons. The detection of specific paraneoplastic antibodies often assists the clinician in the investigation of an underlying, sometimes specific, malignancy. This review aims to discuss the immunological and pathophysiological mechanisms that are thought to be crucial in the aetiology of dysimmune neuropathies as well as their individual electrophysiological characteristics, their laboratory features and existing treatment options. Here, we aim to present a balance of discussion from these diverse angles that may be helpful in categorizing disease and establishing prognosis.