Risk-Benefit Analysis of Novel Treatments for Patients with Generalized Myasthenia Gravis.

INTRODUCTION: This study used network meta-analysis (NMA) to inform and compare the number needed to treat (NNT), number needed to harm (NNH), and cost per improved outcome (CPIO) associated with more recently approved treatments for anti-acetylcholine receptor antibody-positive (anti-AChR Ab+) generalized myasthenia gravis (gMG). METHODS: Clinical trials of neonatal Fc receptor (FcRn) inhibitors, efgartigimod intravenous (IV) and rozanolixizumab, and complement inhibitors, ravulizumab and zilucoplan, versus placebo (with background conventional treatment) were included in the primary NMA to compare efficacy and safety outcomes. The outputs from the NMAs were used to estimate NNT and NNH of each treatment versus placebo. CPIO (2024 USD) was estimated for a ≥ 3- or ≥ 5-point reduction from baseline in Quantitative Myasthenia Gravis (QMG) and Myasthenia Gravis-Activities of Daily Living (MG-ADL) scores. Sensitivity analyses were performed adding efgartigimod PH20 subcutaneous (SC) and eculizumab to the NMA. RESULTS: Efgartigimod IV had the lowest NNT versus placebo for achieving a ≥ 3- and ≥ 5-point reduction in QMG, as well as a ≥ 5-point reduction in MG-ADL, whereas rozanolixizumab had the lowest NNT for a ≥ 3-point reduction in MG-ADL. The NNH versus placebo was similar across comparator treatments. Efgartigimod IV had the lowest CPIO among all treatments for all assessed efficacy outcomes. Sensitivity analyses yielded results consistent with primary analysis and indicated that efgartigimod PH20 SC had comparable NNT and CPIO values to efgartigimod IV, whereas eculizumab had comparable NNT and higher CPIO values compared to other complement inhibitors. CONCLUSIONS: FcRn inhibitors and complement inhibitors assessed in this study all demonstrated clinical benefit in terms of NNT as well as an acceptable safety profile in terms of NNH. Within the limitations of this meta-analysis, efgartigimod was associated with a favorable benefit-risk profile as well as a better economic value compared to ravulizumab, rozanolixizumab, and zilucoplan as treatments for anti-AChR Ab+ gMG.

Myasthenia gravis.

Myasthenia gravis (MG) is a rare neuromuscular junction disorder that is characterized by fatigable weakness of muscles. People with MG experience various clinical manifestations based on the muscles involved. MG can be autoimmune, paraneoplastic, congenital, medication-related, or transient in the neonatal period due to the passive placental transfer of antibodies from mothers with MG. Acetylcholine receptor antibodies are seen in the majority of patients with MG. However, other antibodies have been discovered in the last 20 years, including muscle-specific tyrosine kinase (MuSK) and lipoprotein-related peptide 4 (LRP4), and are now available through commercial testing. More recently, a handful of other antibodies have been associated with MG; however, they are not presently available for routine testing. A disease classification system has been developed by the Myasthenia Gravis Foundation of America (MGFA) and is commonly used worldwide. A number of objective and subjective outcome measures have been developed and validated over the years and have been proven useful for both clinical and research purposes, serving as primary and secondary outcome measures in most clinical trials. A growing number of therapies are available for both acute and chronic management of MG, with several new mechanistic approaches under investigation. An international consensus guidance for the management of MG was first published in 2016 and updated in 2020.

Psychometric properties of MG-ADL items and MG-ADL score: An assessment of distributional characteristics, validity and factor structure in two large datasets.

BACKGROUND: The Myasthenia Gravis-Activities of Daily Living scale (MG-ADL) is an 8-item outcome measure to assess symptoms and functional limitations in myasthenia gravis (MG) patients. The MG-ADL score is an equally weighted level sum score that is used as primary outcome measures in clinical trials, in clinical practice, and as an end-point in health economic evaluation. This data analysis aims to obtain detailed knowledge of measurement properties of MG-ADL items and the MG-ADL score. METHODS: Cross-sectional data from a real-world prospective study (MRW) were combined with longitudinal data from the ADAPT trial. Outcome measures included were MG-ADL, Quantitative Myasthenia Gravis score (QMG), MG 15-item Quality of Life (MG-QOL15r) and EQ-5D-5L. Patients were categorized by their Myasthenia Gravis Foundation of America (MGFA) clinical classification. The following measurement properties were assessed: distributional characteristics, inter-item correlation, convergent, known groups and construct validity and internal factor structure. RESULTS: Correlations of items within MG-ADL dimensions were moderate, while MG-ADL correlations between comparable MG-QOL15r and QMG items were mixed. Known groups validity for the MG-ADL score was demonstrated for MGFA class. Mean MG-ADL item level scores by MGFA class demonstrated construct validity. PCA, including all four outcome measures, resulted in a nine factor solution. DISCUSSION: Psychometric properties of individual MG-ADL items were moderate to good. This study showed that the MG-ADL adequately captures the multidimensional heterogeneous nature of MG. This is, however, accompanied by mixed psychometric performance of the MG-ADL score, which may complicate health economic modelling. REGISTRATION: MyRealWorld-MG was registered on November 25, 2019, with registration numberNCT04176211. The ADAPT randomized clinical trial is registered atClinicalTrials.gov(NCT03669588).

Trends and Disparities in the Utilization of Thymectomy for Myasthenia Gravis in the United States.

Background and Objectives: In 2016, a randomized controlled trial demonstrated the clinical efficacy of trans-sternal thymectomy for patients with non-thymomatous myasthenia gravis (MG). Whether large-scale changes occurred in clinical practice after this trial is unknown. Methods: We performed a retrospective longitudinal cross-sectional analysis using National Inpatient Sample (NIS) data from 2012 to 2019. Our study included hospitalized adults at least 18 years of age diagnosed with MG without an associated thymoma. We used joinpoint regression to analyze annual trends in thymectomy volume and surgical approach (minimally invasive vs trans-sternal) from 2012 to 2019. Using logistic regression models, we examined patient and hospital-level factors that may have influenced whether thymectomy was performed, such as age, sex, race, insurance payor, hospital size and teaching status, and Elixhauser Comorbidity Index. Sampling weights were applied to account for the complex survey design of NIS. Results: The total number of thymectomy procedures increased by 69.8% per year (95% CI 40.1-105.8) between 2012 and 2019. Trans-sternal thymectomies increased by 62.8% per year (95% CI 35.8-95.2) and minimally invasive thymectomies by 83.7% per year (95% CI 38.1-144.3). Thymectomies were significantly more likely to occur in 2017-2019 compared with 2012-2016 (OR 1.93, 95% CI 1.62-2.31). In a multivariable regression model, several factors decreased the odds of patients with MG having a thymectomy: older age, Black race (OR 0.62, 95% CI 0.49-0.77), female (OR 0.73, 95% CI 0.63-0.86), and higher Elixhauser Comorbidity Index. Patients in medium (OR 1.82, 95% CI 1.30-2.55) or large (OR 2.81, 95% CI 2.07-3.82) size and urban teaching hospitals (OR 6.09, 95% CI 2.65-13.97) were more likely to undergo thymectomy. Discussion: Thymectomy is being performed more frequently for non-thymomatous MG, especially after 2016 after publication of a positive phase III clinical trial. There are several disparities in thymectomy utilization that warrant further attention.

Does Surgical Removal of the Thymus Have Deleterious Consequences?

The role of immunosenescence, particularly the natural process of thymic involution during aging, is increasingly acknowledged as a factor contributing to the development of autoimmune diseases and cancer. Recently, a concern has been raised about deleterious consequences of the surgical removal of thymic tissue, including for patients who undergo thymectomy for myasthenia gravis (MG) or resection of a thymoma. This review adopts a multidisciplinary approach to scrutinize the evidence concerning the long-term risks of cancer and autoimmunity postthymectomy. We conclude that for patients with acetylcholine receptor antibody-positive MG and those diagnosed with thymoma, the removal of the thymus offers prominent benefits that well outweigh the potential risks. However, incidental removal of thymic tissue during other thoracic surgeries should be minimized whenever feasible.

Effect of Lower Extremity Nerve Decompression in Patients With Painful Diabetic Peripheral Neuropathy: The Diabetic Neuropathy Nerve Decompression Randomized, Observation Group and Placebo Surgery-Controlled Clinical Trial.

OBJECTIVE: To evaluate the effect of nerve decompression on pain in patients with lower extremity painful diabetic peripheral neuropathy (DPN). BACKGROUND: Currently, no treatment provides lasting relief for patients with DPN. The benefits of nerve decompression remain inconclusive. METHODS: This double-blinded, observation and same-patient sham surgery-controlled randomized trial enrolled patients aged 18 to 80 years with lower extremity painful DPN who failed 1 year of medical treatment. Patients were randomized to nerve decompression or observation group (2:1). Decompression-group patients were further randomized and blinded to nerve decompression in either the right or left leg and sham surgery in the opposite leg. Pain (11-point Likert score) was compared between decompression and observation groups and between decompressed versus sham legs at 12 and 56 months. RESULTS: Of 2987 screened patients, 78 were randomized. At 12 months, compared with controls (n=37), both the right-decompression group (n=22) and left-decompression group (n=18) reported lower pain (mean difference for both: -4.46; 95% CI: -6.34 to -2.58 and -6.48 to -2.45, respectively; P < 0.0001). Decompressed and sham legs equally improved. At 56 months, compared with controls (n=m 14), pain was lower in both the right-decompression group (n=20; mean difference: -7.65; 95% CI: -9.87 to -5.44; P < 0.0001) and left-decompression group (n=16; mean difference: -7.26; 95% CI: -9.60 to -4.91; P < 0.0001). The mean pain score was lower in decompressed versus sham legs (mean difference: 1.57 95% CI: 0.46 to 2.67; P =0.0002). CONCLUSIONS: Although nerve decompression was associated with reduced pain, the benefit of surgical decompression needs further investigation as a placebo effect may be responsible for part or all of these effects.

Serum metabolomics of treatment response in myasthenia gravis.

OBJECTIVE: High-dose prednisone use, lasting several months or longer, is the primary initial therapy for myasthenia gravis (MG). Upwards of a third of patients do not respond to treatment. Currently no biomarkers can predict clinical responsiveness to corticosteroid treatment. We conducted a discovery-based study to identify treatment responsive biomarkers in MG using sera obtained at study entry to the thymectomy clinical trial (MGTX), an NIH-sponsored randomized, controlled study of thymectomy plus prednisone versus prednisone alone. METHODS: We applied ultra-performance liquid chromatography coupled with electro-spray quadrupole time of flight mass spectrometry to obtain comparative serum metabolomic and lipidomic profiles at study entry to correlate with treatment response at 6 months. Treatment response was assessed using validated outcome measures of minimal manifestation status (MMS), MG-Activities of Daily Living (MG-ADL), Quantitative MG (QMG) score, or a strictly defined composite measure of response. RESULTS: Increased serum levels of phospholipids were associated with treatment response as assessed by QMG, MMS, and the Responders classification, but all measures showed limited overlap in metabolomic profiles, in particular the MG-ADL. A panel including histidine, free fatty acid (13:0), γ-cholestenol and guanosine was highly predictive of the strictly defined treatment response measure. The AUC in Responders' prediction for these markers was 0.90 irrespective of gender, age, thymectomy or baseline prednisone use. Pathway analysis suggests that xenobiotic metabolism could play a major role in treatment resistance. There was no association with outcome and gender, age, thymectomy or baseline prednisone use. INTERPRETATION: We have defined a metabolomic and lipidomic profile that can now undergo validation as a treatment predictive marker for MG patients undergoing corticosteroid therapy. Metabolomic profiles of outcome measures had limited overlap consistent with their assessing distinct aspects of treatment response and supporting unique biological underpinning for each outcome measure. Interindividual variation in prednisone metabolism may be a determinate of how well patients respond to treatment.

Attitudes and Beliefs Toward Thymectomy in the Myasthenia Gravis Patient Registry.

OBJECTIVES: To evaluate patient attitudes and beliefs toward thymectomy for myasthenia gravis (MG). METHODS: The Myasthenia Gravis Foundation of America administered a questionnaire to the MG Patient Registry, an ongoing longitudinal survey of adult MG patients. Questions assessed reasons for or against thymectomy and how hypothetical scenarios would have affected their decision. RESULTS: Of 621 respondents, 190 (31%) reported a history of thymectomy. Of those who underwent thymectomy for nonthymomatous MG, 97 (51.6%) ranked symptom improvement as most important and 100 (53.2%) ranked reducing medication as least important. Among 431 nonthymectomy patients, the most frequent reason for not undergoing thymectomy was that their doctor did not discuss it (152 of 431 = 35.2%) and 235 (56.8%) said that they would have considered it more strongly if their doctor spent more time discussing it. CONCLUSIONS: Thymectomies are motivated more by symptoms than by medication, and a lack of neurologist discussion is the most common barrier to thymectomy.

Phase 2 trial in acetylcholine receptor antibody-positive myasthenia gravis of transition from intravenous to subcutaneous immunoglobulin: The MGSCIg study.

BACKGROUND AND PURPOSE: Data on maintenance therapy with subcutaneous immunoglobulin (SCIg) in myasthenia gravis (MG) are limited. We report on transitioning acetylcholine receptor (AChR) antibody-positive (Ab+) MG patients on stable intravenous immunoglobulin (IVIg) regimens as part of routine clinical care to SCIg 1:1.2. METHODS: This multicenter North American open-label prospective investigator-initiated study had two components: the IVIg Stabilization Period (ISP) enrolling patients already on IVIg as part of routine clinical care (Weeks -10 to -1), followed by transition of stable MG subjects to SCIg in the Experimental Treatment Period (ETP; Weeks 0 to 12). We hypothesized that >65% of patients entering the ETP would have a stable Quantitative Myasthenia Gravis (QMG) score from Week 0 to Week 12. Secondary outcome measures included other efficacy measures, safety, tolerability, IgG levels, and treatment satisfaction. RESULTS: We recruited 23 patients in the ISP, and 22 entered the ETP. A total of 12 subjects (54.5%) were female, and 18 (81.8%) were White, with mean age 51.4 ± 17 years. We obtained Week 12 ETP QMG data on 19 of 22; one subject withdrew from ETP owing to clinical deterioration, and two subjects withdrew due to dislike of needles. On primary analysis, 19 of 22 participants (86.4%, 95% confidence interval = 0.72-1.00) were treatment successes using last observation carried forward (p = 0.018). Secondary efficacy measures supported MG stability. SCIg was safe and well tolerated, and IgG levels were stable. Treatment satisfaction was comparable between ISP and ETP. CONCLUSIONS: MG patients on IVIg as part of their routine clinical care remained stable on monthly IVIg dosage, and most maintained similar disease stability on SCIg.

Phase 2 Trial of Rituximab in Acetylcholine Receptor Antibody-Positive Generalized Myasthenia Gravis: The BeatMG Study.

OBJECTIVE: To determine whether rituximab is safe and potentially beneficial, warranting further investigation in an efficacy trial for acetylcholine receptor antibody-positive generalized MG (AChR-Ab+ gMG). METHODS: The B-Cell Targeted Treatment in MG (BeatMG) study was a randomized, double-blind, placebo-controlled, multicenter phase-2 trial that utilized a futility design. Individuals 21-90 years of age, with AChR-Ab+ gMG (MG Foundation of America Class II-IV) and receiving prednisone ≥15 mg/day were eligible. The primary outcome was a measure of steroid-sparing effect, defined as the proportion achieving ≥75% reduction in mean daily prednisone dose in the 4-weeks prior to week 52 and with clinical improvement or no significant worsening as compared to the 4-week period prior to randomization. The co-primary outcome was safety. Secondary outcomes included MG-specific clinical assessments. Fifty-two individuals were randomized (1:1) to either a two-cycle rituximab/placebo regimen, with follow-up through 52-weeks. RESULTS: Of the 52 participants included, mean (±SD) age at enrollment was 55.1 (±17.1) years; 23 (44.2%) were female, and 31 (59.6%) were MGFA Class II. The mean (±SD) baseline prednisone dose was 22.1 (±9.7) mg/day. The primary steroid-sparing outcome was achieved in 60% of those on rituximab vs. 56% on placebo. The study reached its futility endpoint (p=0.03) suggesting that the pre-defined clinically meaningful improvement of 30% due to rituximab over placebo was unlikely to be achieved in a subsequent, larger trial. No safety issues identified. CONCLUSIONS: While rituximab was safe and well-tolerated, these results suggest that there is a low probability of observing the defined clinically meaningful steroid-sparing effect over a 12-month period in a phase-3 trial of mild-moderately symptomatic AChR-Ab+ gMG. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that for mild-to-moderate AChR-Ab+ gMG, compared with placebo, rituximab is safe but unlikely to reduce steroid use by an absolute difference of at least 30% at 1 year. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02110706.

IgG regulation through FcRn blocking: A novel mechanism for the treatment of myasthenia gravis.

The neonatal Fc receptor (FcRn) is an MHC class I-like molecule that is widely distributed in mammalian organs, tissues, and cells. FcRn is critical to maintaining immunoglobulin G (IgG) and albumin levels through rescuing these molecules from lysosomal degradation. IgG autoantibodies are associated with many autoimmune diseases, including myasthenia gravis (MG), a rare neuromuscular autoimmune disease that causes debilitating and, in its generalized form (gMG), potentially life-threatening muscle weakness. IgG autoantibodies are directly pathogenic in MG and target neuromuscular junction proteins, causing neuromuscular transmission failure. Treatment approaches that reduce autoantibody levels, such as therapeutic plasma exchange and intravenous immunoglobulin, have been shown to be effective for gMG patients but are not indicated as ongoing maintenance therapies and can be associated with burdensome side effects. Agents that block FcRn-mediated recycling of IgG represent a rational and promising approach for the treatment of gMG. Blocking FcRn allows targeted reduction of all IgG subtypes without decreasing concentrations of other Ig isotypes; therefore, FcRn blocking could be a safe and effective treatment strategy for a broad population of gMG patients. Several FcRn-blocking antibodies and one antibody Fc fragment have been developed and are currently in various stages of clinical development. This article describes the mechanism of FcRn blockade as a novel approach for IgG-mediated disease therapy and reviews promising clinical data using such FcRn blockers for the treatment of gMG.

Validation of Spanish version of 15-item myasthenia gravis quality-of-life questionnaire.

OBJECTIVES: The aim of this study was to achieve the translation and cross-cultural adaptation of the MG-QOL15R questionnaire into Spanish and the analysis of its psychometric properties. MATERIALS AND METHODS: We recruited patients with MG, ≥18 years old, whose mother tongue was Spanish. After the translation and cross-cultural adaptation of the MG-QOL15-R, the following tests were performed: internal consistency using the Cronbach-α coefficient and corrected item-total correlations; reproducibility with a test-retest analysis using intraclass correlation coefficients; and concurrent validity using Spearman's correlation coefficient of the Spanish language MG-QOL15R-S, Myasthenia Gravis Activity of Daily Living (MG-ADL) and Quantitative Myasthenia Gravis (QMG) scores. As an approximation to construct validity, the nonparametric Mann-Whitney U test was performed between MG-QOL15R-S scores according to the Myasthenia Gravis Foundation of America classification. RESULTS: A total of 83 MG patients were enrolled, mean age 48.19 ± 17.25 years; 58 (69.9%) were women. The mean MG-QOL15R-S score was 11.3 ± 7.1. Cronbach-α coefficient was 0.92. Item-total correlation ranged between 0.43 and 0.75. Intraclass correlation coefficient was 0.80. The Spearman correlation coefficient was 0.637 (p-value < .001) for MG-ADL and 0.487 (p-value < .001) for QMG. Mann-Whitney U tests of the mean MG-QOL15R-S scores were significantly different according to the clinical severity (p-value < .001). CONCLUSIONS: The Spanish version of the MG-QOL15R is a valid and reliable instrument and potentially useful for measuring health-related quality of life in Spanish-speaking MG patients.

What Is in the Neuromuscular Junction Literature?

ABSTRACT: This update covers recommendations for myasthenia gravis (MG) in patients with coronavirus 2019 disease as well as reports of the clinical features of patients with MG and coronavirus 2019. Updated advisory committee recommendations for the use of thymectomy in generalized MG are also provided. Other MG topics include lipoprotein receptor-4 and agrin antibody associations, factors influencing conversion of ocular to generalized MG, the use of rituximab for more recent onset disease, immunoglobulins for maintenance therapy, and fatigue and depression.

Ocular myasthenia gravis - How effective is low dose prednisone long term?

INTRODUCTION: Controversy persists on the best treatment to control ocular myasthenia gravis (OMG) and reduce conversion to generalized myasthenia gravis (GMG). We hypothesized that low dose prednisone could accomplish both in a cohort of OMG patients followed after three years. METHODS: We reviewed the records of 168 patients who presented with OMG. Our study included 103 of the OMG patients who met inclusion criteria, requiring follow up for a minimum of 3 years without disease generalization. Low dose prednisone was defined as ≤7.5 mg per day. The main outcome was having single vision without ptosis blocking vision, measured by binocular single vision (BSV) and upper lid position. We also analyzed late progression to GMG. RESULTS: Of 87 patients treated with prednisone, chronic low dose prednisone alone restored BSV in 47 patients (46% of all patients) without GMG. Pyridostigmine monotherapy restored BSV in 11/14 patients (11% of all patients). Other immunomodulatory therapy (OIT) was needed in 38 patients (37%). Medical therapy maintained BSV at last evaluation (mean follow up 8.2 ± 5.0 years) in 93 patients (90%). GMG developed in 10 patients (10%) during the follow-up period. CONCLUSION: In OMG patients who do not generalize before 3 years, chronic long term prednisone at lower doses is moderately effective in maintaining optimum BSV. However, OIT are commonly required in these patients. In these OMG patients receiving prednisone and/or OIT, conversion to GMG after three years of disease is uncommon.

Post-intervention Status in Patients With Refractory Myasthenia Gravis Treated With Eculizumab During REGAIN and Its Open-Label Extension.

OBJECTIVE: To evaluate whether eculizumab helps patients with anti-acetylcholine receptor-positive (AChR+) refractory generalized myasthenia gravis (gMG) achieve the Myasthenia Gravis Foundation of America (MGFA) post-intervention status of minimal manifestations (MM), we assessed patients' status throughout REGAIN (Safety and Efficacy of Eculizumab in AChR+ Refractory Generalized Myasthenia Gravis) and its open-label extension. METHODS: Patients who completed the REGAIN randomized controlled trial and continued into the open-label extension were included in this tertiary endpoint analysis. Patients were assessed for the MGFA post-intervention status of improved, unchanged, worse, MM, and pharmacologic remission at defined time points during REGAIN and through week 130 of the open-label study. RESULTS: A total of 117 patients completed REGAIN and continued into the open-label study (eculizumab/eculizumab: 56; placebo/eculizumab: 61). At week 26 of REGAIN, more eculizumab-treated patients than placebo-treated patients achieved a status of improved (60.7% vs 41.7%) or MM (25.0% vs 13.3%; common OR: 2.3; 95% CI: 1.1-4.5). After 130 weeks of eculizumab treatment, 88.0% of patients achieved improved status and 57.3% of patients achieved MM status. The safety profile of eculizumab was consistent with its known profile and no new safety signals were detected. CONCLUSION: Eculizumab led to rapid and sustained achievement of MM in patients with AChR+ refractory gMG. These findings support the use of eculizumab in this previously difficult-to-treat patient population. CLINICALTRIALSGOV IDENTIFIER: REGAIN, NCT01997229; REGAIN open-label extension, NCT02301624. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that, after 26 weeks of eculizumab treatment, 25.0% of adults with AChR+ refractory gMG achieved MM, compared with 13.3% who received placebo.

Epidemiological evidence for a hereditary contribution to myasthenia gravis: a retrospective cohort study of patients from North America.

OBJECTIVES: To approximate the rate of familial myasthenia gravis and the coexistence of other autoimmune disorders in the patients and their families. DESIGN: Retrospective cohort study. SETTING: Clinics across North America. PARTICIPANTS: The study included 1032 patients diagnosed with acetylcholine receptor antibody (AChR)-positive myasthenia gravis. METHODS: Phenotype information of 1032 patients diagnosed with AChR-positive myasthenia gravis was obtained from clinics at 14 centres across North America between January 2010 and January 2011. A critical review of the epidemiological literature on the familial rate of myasthenia gravis was also performed. RESULTS: Among 1032 patients, 58 (5.6%) reported a family history of myasthenia gravis. A history of autoimmune diseases was present in 26.6% of patients and in 28.4% of their family members. DISCUSSION: The familial rate of myasthenia gravis was higher than would be expected for a sporadic disease. Furthermore, a high proportion of patients had a personal or family history of autoimmune disease. Taken together, these findings suggest a genetic contribution to the pathogenesis of myasthenia gravis.

Minimal manifestation status and prednisone withdrawal in the MGTX trial.

OBJECTIVE: To examine whether sustained minimal manifestation status (MMS) with complete withdrawal of prednisone is better achieved in thymectomized patients with myasthenia gravis (MG). METHODS: This study is a post hoc analysis of data from a randomized trial of thymectomy in MG (Thymectomy Trial in Non-Thymomatous Myasthenia Gravis Patients Receiving Prednisone Therapy [MGTX]). MGTX was a multicenter, randomized, rater-blinded 3-year trial that was followed by a voluntary 2-year extension for patients with acetylcholine receptor (AChR) antibody-positive MG without thymoma. Patients were randomized 1:1 to thymectomy plus prednisone vs prednisone alone. Participants were age 18-65 years at enrollment with disease duration less than 5 years. All patients received oral prednisone titrated up to 100 mg on alternate days until they achieved MMS, which prompted a standardized prednisone taper as long as MMS was maintained. The achievement rate of sustained MMS (no symptoms of MG for 6 months) with complete withdrawal of prednisone was compared between the thymectomy plus prednisone and prednisone alone groups. RESULTS: Patients with MG in the thymectomy plus prednisone group achieved sustained MMS with complete withdrawal of prednisone more frequently (64% vs 38%) and quickly compared to the prednisone alone group (median time 30 months vs no median time achieved, p < 0.001) over the 5-year study period. Prednisone-associated adverse symptoms were more frequent in the prednisone alone group and distress level increased with higher doses of prednisone. CONCLUSIONS: Thymectomy benefits patients with MG by increasing the likelihood of achieving sustained MMS with complete withdrawal of prednisone. CLINICALTRIALSGOV IDENTIFIER: NCT00294658. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that for patients with generalized MG with AChR antibody, those receiving thymectomy plus prednisone are more likely to attain sustained MMS and complete prednisone withdrawal than those on prednisone alone.

Correlation of Quantitative Myasthenia Gravis and Myasthenia Gravis Activities of Daily Living scales in the MGTX study.

INTRODUCTION: Quantitative Myasthenia Gravis (QMG) and Myasthenia Gravis Activities of Daily Living (MG-ADL) scales were compared using the data from the Thymectomy Trial in Non-Thymomatous Myasthenia Gravis Patients Receiving Prednisone Therapy (MGTX) study. METHODS: Correlation between QMG and MG-ADL raw and change-from-baseline scores was calculated every 3 months for 60 months based on treatment groups and minimal manifestation status (MMS). RESULTS: QMG and MG-ADL change-from-baseline scores correlated significantly, with increasing strength of correlation over time, in both treatment groups. QMG and MG-ADL raw scores correlated significantly in both treatment groups, with increasing correlation only in the prednisone-alone group. Correlation between raw scores was weaker in patients who were in MMS, demonstrating a "floor effect" on the MG-ADL scale. Raw QMG scores could be modeled assuming a normal distribution, whereas raw MG-ADL scores could not be modeled this way. DISCUSSION: The floor effect and skewed distribution of the MG-ADL measure should be taken into account in the design of myasthenia gravis clinical trials.

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.