Real world study on prevalence, treatment and economic burden of myasthenia gravis in Italy

278th ENMC International Workshop: European standards for harmonization of myasthenia gravis registries and emerging digital solutions. 20th-21st September 2024, Hoofddorp, The Netherlands

The European Neuromuscular Centre workshop convened a diverse array of key stakeholders dedicated to the European standards for harmonization of national Myasthenia Gravis registries and emerging digital solutions. Participants included representatives from the pharmaceutical industry, patient advocacy organizations, clinicians with expertise in Myasthenia Gravis, and members of the European Reference Network for Rare Neuromuscular Diseases. This multidisciplinary composition, as well as preliminary activities, fostered robust discussions and facilitated the identification of shared objectives for future endeavors to allow collaboration at European level among national Myasthenia Gravis registries. Throughout the workshop sessions, relevant topics emerged, highlighting both the challenges and strengths towards harmonizing data on myasthenia gravis in national registries and improving outcomes for patients with myasthenia.

The economic burden of Myasthenia gravis from the patient´s perspective and reflected in German claims data

Myasthenia gravis (MG) is a neuromuscular disorder resulting in exertion-dependent muscle fatigability. Affecting all age groups MG is a chronic disease with unpredictable fluctuations and a range of symptom expression which can require costly immunosuppressive therapy and intensive care critically influencing economic burden. Here we aim to elucidate both the personal and societal economic burden of MG. Data were used from two sources: (1) a cross sectional study of MG patients registered in the German Myasthenia Society (DMG) collected by a survey in 2019 (n = 1660), and (2) from a dataset provided by a German health insurance company covering the period from 01/01/2014 to 31/12/2019 (n = 750) and categorized to similar subgroups for comparison. Individual and societal economic burden was highest in patients with intensified medical treatment. Absence days from work per patient year in the first year after index in claims data were 67.1 days (95% CI 66.1-68.2) (referring to n = 260 non-retired patients). Of 686 patients with early onset (< 50 years) MG 260 (41.2%) reported loss of income due to MG in DMG data. Average inpatient costs from claims data in patients with intensified treatment (38,669€; 95% CI 38,627-38,712€) were particularly high compared with standard treatment (2980€; 95% CI 2975-2986€) and to no MG-related treatment (887€; 95% CI 877-886€). MG represents a major economic burden for the individual and the health care system. The costs are positively associated with the severity of disease. The economic burden is particularly high for working patients. UCB Pharma provided financial support for the subanalysis, but was not involved in the design of the study.Trial registration: clinicaltrials.gov, NCT03979521, submitted: June 7, 2019, first patient enrolled: May 1, 2019, https://clinicaltrials.gov/ct2/show/NCT03979521 .

Persistent symptoms, exacerbations and drug side effects despite treatment in myasthenia gravis

BACKGROUND

Generalized myasthenia gravis (gMG) is characterized by fluctuating muscle weakness. Exacerbation frequency, adverse events (AEs) related to immunosuppressant therapy and healthcare resource utilization (HCRU) are not well understood. Our study aimed to describe long-term clinical outcomes, drug-related AEs and estimated HCRU in gMG patients.

METHODS

This was a retrospective cohort analysis of clinical data from patients with gMG followed-up over eight consecutive years in a Spanish referral unit. Myasthenia Gravis Foundation of America (MGFA) clinical classification, MGFA post-interventional status (MGFA-PIS), Myasthenia Gravis Activities of Daily Living (MG-ADL) score, exacerbations, MG crises, therapies, AEs reported, specialist consultations and emergency room visits were studied biannually. An estimation of HRCU was made based on these data.

RESULTS

Some 220 patients newly diagnosed with gMG were included. Ninety percent were seropositive (84.5% anti-acetylcholine receptor [AChR], 5.9% anti-muscle-specific kinase [MuSK]). Baseline mean MG-ADL score was 5.04 points (SD 3.17), improving to 0.7 points (SD 1.40) after 8 years. Exacerbations were more frequent in years 1-2 (30.1%) but still occurred in years 7-8 (20.2%). Myasthenic crisis frequency remained 1% in years 7-8. Eighty-nine percent achieved MGFA-PIS minimal manifestations or better at 8 years. Fifty-one percent of patients reported at least one AE during the study period, leading to drug withdrawal in approximately 20% of cases. HCRU decreased between years 1-2 to years 7-8 with an estimated cost of MG from 8074.19 € per patient/year to 1679.46 €, respectively.

CONCLUSIONS

There is a group of MG patients that suffers from persistent symptoms and exacerbations (11%-20%) or MG crises, and drug AEs, which may increase disease burden and impact on the healthcare system.

Tracking myasthenia gravis severity over time: Insights from the French health insurance claims database

BACKGROUND AND PURPOSE

Few data are available on the course of myasthenia gravis (MG) regarding disease severity and stability over time in real-world settings. This study used the French National Health Insurance Database (SNDS) to assess markers of disease severity in patients with MG longitudinally.

METHODS

All patients with MG-related claims in the SNDS between 2013 and 2020 were identified. Patients were followed for up to 8 years after the first claim. Intensive care unit (ICU) stays, treatment with intravenous immunoglobulin (IVIg) or plasma exchange (PE), and death were documented throughout the follow-up period. Standardized mortality rates were estimated, and mortality-related variables were identified using a Cox model.

RESULTS

In all, 14,459 individuals constituted the full study population, including 6354 incident patients. In the incident population, 2199 (34.6%) were admitted to ICUs at least once, principally during the first year after the index date (N = 1477; 23.3%). This proportion decreased progressively to reach 3.0% in the seventh year. A total of 2817 patients received IVIg and 432 PE, again principally in the first year. In the full study population, the standardized mortality rate was 1.08 (95% confidence interval [CI] 1.03-1.13), being lower in men (0.95, 95% CI 0.89-1.02) than in women (1.15, 95% CI 1.07-1.23) and in patients aged >65 years (1.06, 95% CI 1.01-1.11) than in younger patients (1.50, 95% CI 1.24-1.76). Male gender, older age and higher comorbidity were independently associated with mortality.

CONCLUSIONS

A subgroup of patients with MG require ICU admission and rescue therapy with IVIg or PE, indicative of poor disease control. New therapies are needed to improve disease control and reduce disease burden.

Myasthenia gravis: understanding treatment patterns and direct medical costs in the Czech Republic

BACKGROUND

Myasthenia gravis (MG) is a rare autoimmune disorder with significant clinical implications, including life-threatening myasthenic crises and exacerbations. Understanding real-world treatment patterns, especially associated direct medical costs, is essential for the effective management of healthcare delivery.

METHODS

We conducted a descriptive cohort study using health administrative claims data from the Czech Republic covering more than 1,500 prevalent MG patients. Data were analysed for healthcare resource utilization, medication costs, and hospitalization rates related to MG and its complications.

RESULTS

Acetylcholine inhibitors and corticosteroids were widely prescribed, with 91.1% and 75.2% of patients receiving them at least once, respectively. Immunosuppressive therapy was given to 45.2% of patients. Myasthenic crises occurred in 2% of patients, with a mean hospitalization cost of 21,020 EUR, while exacerbations occurred in 9.2% of patients, with lower costs (5,951 EUR per hospitalization). Outpatient intravenous immunoglobulin and plasma exchange therapies incurred additional costs of 20,700 EUR and 18,206 EUR per person-year, respectively. The mean total cost per patient-year was 1,271 EUR, with significant cost differences among patients with different treatment patterns.

CONCLUSION

This study offers real-world insights into the treatment patterns and associated direct medical costs of MG in the Czech Republic. Myasthenic crises and exacerbations pose considerable cost burdens, while outpatient therapies and common pharmacotherapies are less costly. These findings are vital for healthcare planning, economic evaluation, and resource allocation, potentially leading to enhanced patient care and outcomes.

Economic and societal burden of myasthenia gravis in Denmark, Finland, and Sweden: A population-based registry study

BACKGROUND AND PURPOSE

Health care resource utilization (HCRU) and the economic burden of myasthenia gravis (MG) are significant, but existing studies rarely include comprehensive nationwide data. We examined HCRU and direct and indirect costs associated with MG overall and by disease severity in Denmark, Finland, and Sweden.

METHODS

Data were collected retrospectively from nationwide health and social care registries. All individuals ≥18 years of age with ≥2 International Classification of Diseases diagnoses of MG between 2000 and 2020 were included. HCRU, direct (inpatient and outpatient contacts, medication) and indirect costs (early retirement, sick leave, death), and associated factors were calculated.

RESULTS

The full study cohort comprised 8622 people with MG (pwMG). Mean annual numbers of all-cause secondary health care contacts for pwMG were 3.4 (SD = 8.3), 7.0 (SD = 12.3), and 2.9 (SD = 3.9), with mean annual total costs of €12,185, €9036, and €5997 per person in Denmark, Finland, and Sweden, respectively. Inpatient periods, involving 77%-89% of study participants in the three countries, contributed most to direct costs, whereas the majority of indirect costs resulted from early retirement in Denmark and Finland, and sick leave periods in Sweden. Mean annual total costs were highest with very severe MG (€19,570-€33,495 per person across the three countries). Female sex and comorbidities, such as mental and behavioral disorders and severe infections, were also associated with higher total costs.

CONCLUSIONS

This population-based study shows a high level of HCRU and a significant direct and indirect economic burden of MG across three Nordic countries, especially for severe forms of MG.

Prevalence, Incidence, and Mortality of Myasthenia Gravis and Myasthenic Syndromes: A Systematic Review

INTRODUCTION

No systematic reviews were published in the last years investigating epidemiological data, involving myasthenia gravis (MG) and related myasthenic syndromes. This systematic review aimed to estimate the prevalence, incidence, and mortality of all MG types and myasthenic syndromes worldwide.

METHODS

All literature published up to February 2024 was retrieved by searching the databases "Medline," "Embase," "ISI Web of Science" and "CINAHL" using the following search terms: (epidemiolog* OR frequency OR prevalence OR incidence OR mortality) AND (myasth* OR "anti-acetylcholine receptor antibody" OR "AChR" OR "MuSK" OR "anti-muscle specific kinase antibody" OR "LRP4" OR "seronegative MG").

RESULTS

A total of 94 studies, performed between 1952 and 2022, were included. Prevalence of MG ranged from 20 to 475 cases per million, with a mean prevalence of 173.3 (95% confidence interval [CI]: 129.7-215.5) cases per million and a median prevalence of 129.6 cases per million. Incidence rates ranged from 2.3 to 61.3 cases per million person-years, with a mean incidence of 15.7 (95% CI: 11.5-19.9) and a median of 13.3 cases. Mortality rates showed a mean of 1.4 (95% CI: 0.8-2.1) cases per million person-years. Acetylcholine receptor (AChR)-MG was the clinical subtype more frequent in terms of prevalence and incidence.

DISCUSSION

The prevalence and incidence of MG have significantly increased over the last years worldwide, probably due to the improvement of epidemiological methodologies and current advances in diagnosis. However, we observed a significant variation in frequencies of MG between and within countries because of methodological biases and complex heterogeneity of the disease characterized by several phenotypes and different clinical responses.

The impact of diagnosis delay on European patients with generalised myasthenia gravis

OBJECTIVE

The objective was to determine the mean duration of diagnosis delay for patients with myasthenia gravis from five European countries and explore the impact of >1 year diagnosis delay.

METHODS

Patients with myasthenia gravis (N = 387) from Europe (France/Germany/Italy/Spain/United Kingdom) and their physicians participated in the Adelphi Real World Myasthenia Gravis Disease Specific Programme™. Diagnosis delay (time from symptom onset to diagnosis) was calculated and characteristics described for patients experiencing >1 year and ≤1 year diagnosis delay. Denominators varied according to outcome as missing data were not imputed.

RESULTS

Mean (standard deviation) diagnosis delay was 363.1 (520.9) days, and 27.1% (105 out of 387) of patients experienced diagnosis delay >1 year. Among patients with >1 year and ≤1 year diagnosis delay, respectively, 69.2% (72 out of 104) and 17.4% [45 out of 259] had initially received a different diagnosis (physician-reported); 40.0% (42 out of 105) and 24.1% (68 out of 282) were Myasthenia Gravis Foundation of America class III at the time of the survey (physician-reported); 72.4% (76 out of 105) and 61.3% (173 out of 282) had fatigue (subjective physician reporting from a pre-selected list of symptoms); 30.5% (32 out of 105) and 17.4% (49 out of 282) had anxiety and 21.9% (23 out of 105) and 13.1% (37 out of 282) had depression (both subjective physician reporting from a pre-selected list, Likert-style); and mean (standard deviation) MG-QoL-15r score was 14.4 (5.50) and 12.6 (7.84) (self-reported by N = 43 and N = 74 patients, respectively).

INTERPRETATION

More than a quarter of patients with myasthenia gravis experienced diagnosis delay of >1 year. These patients had a different clinical profile with regards to severity, symptoms, comorbidities and MG-QoL-15r score, compared with patients experiencing ≤1 year diagnosis delay.

Myasthenia gravis: the future is here

Myasthenia gravis (MG) stands as a prototypical antibody-mediated autoimmune disease: it is dependent on T cells and characterized by the presence of autoantibodies targeting proteins located on the postsynaptic surface of skeletal muscle, known as the neuromuscular junction. Patients with MG exhibit a spectrum of weakness, ranging from limited ocular muscle involvement to life-threatening respiratory failure. Recent decades have witnessed substantial progress in understanding the underlying pathophysiology, leading to the delineation of distinct subcategories within MG, including MG linked to AChR or MuSK antibodies as well as age-based distinction, thymoma-associated, and immune checkpoint inhibitor-induced MG. This heightened understanding has paved the way for the development of more precise and targeted therapeutic interventions. Notably, the FDA has recently approved therapeutic inhibitors of complement and the IgG receptor FcRn, a testament to our improved comprehension of autoantibody effector mechanisms in MG. In this Review, we delve into the various subgroups of MG, stratified by age, autoantibody type, and histology of the thymus with neoplasms. Furthermore, we explore both current and potential emerging therapeutic strategies, shedding light on the evolving landscape of MG treatment.

Epidemiology of seropositive myasthenia gravis in Sardinia: A population-based study in the district of Sassari

INTRODUCTION/AIMS

The global incidence and prevalence of myasthenia gravis (MG) range between 6-31/million and 10-37/100,000, respectively. Sardinia is a high-risk region for different immune-mediated disorders, but the epidemiology of MG remains unclear. We determined the epidemiology of MG with acetylcholine receptor (AChR)-immunoglobulin G (IgG) and muscle-specific tyrosine kinase (MuSK)-IgG in the district of Sassari (North-Western Sardinia; population, 325,288).

METHODS

From the laboratory of the University Hospital of Sassari (reference for AChR/MuSK-IgG testing in Sardinia since 1998) and the main neurology units in Sardinia, we retrospectively identified MG patients with (1) AChR-IgG and/or MuSK-IgG positivity by radioimmunoprecipitation assay; and (2) residency in the district of Sassari. Incidence (January 2010-December 2019) and prevalence (December 31, 2019) were calculated.

RESULTS

A total of 202 patients were included (incident, 107; prevalent, 180). Antibody specificities were AChR (n = 187 [93%]) and MuSK (n = 15 [7%]). The crude MG incidence (95% confidence interval) was 32.6 (26.8-39.2)/million, while prevalence was 55.3 (47.7-63.9)/100,000. After age-standardization to the world population, incidence decreased to 18.4 (14.3-22.5)/million, while prevalence decreased to 31.6 (26.1-37.0)/100,000. Among incident cases, age strata (years) at MG onset were: <18 (2%), 18-49 (14%), 50-64 (21%), and ≥65 (63%).

DISCUSSION

Sardinia is a high-risk region for MG, with a prevalence that exceeds the European threshold for rare disease. Identification of the environmental and genetic determinants of this risk may improve our understanding of disease pathophysiology.

The Incidence of Myasthenia Gravis in the Province of Ferrara, Italy, in the Period of 2008-2022: An Update on a 40-Year Observation and the Influence of the COVID-19 Pandemic

Myasthenia gravis (MG) is the most common neuromuscular junction disorder. We evaluated the MG incidence rate in the province of Ferrara, Northern Italy, over two time frames (2008-2018 and 2019-2022, i.e., the COVID-19 pandemic) and considered early-onset (EOMG), late-onset (LOMG), and thymoma- and non-thymoma-associated MG. Moreover, in the second period, we assessed its possible relationship with SARS-CoV-2 infection or COVID-19 vaccination. We used a complete enumeration approach to estimate the MG incidence and its temporal trend. For the period of 2008-18, 106 new cases were identified (mean incidence rate 2.7/100,000 people). The highest rates were observed for the over-70 age group and in rural areas, with 17% of thymoma-associated MG. During the COVID-19 period, 29 new cases were identified (average incidence rate 2.1/100,000 people), showing a marked (though not statistically significant) decrease in the mean annual incidence compared to the previous period. Again, the highest rate was observed for the over-70 age group. The first period was in line with our previous observations for the period between 1985 and 2007, highlighting a rising incidence of LOMG and a marked decrease in EOMG. During the COVID-19 period, incidence rates were lower in the first years whereas, when the pandemic ended, the previous trend was confirmed.

The economic burden of individuals living with generalized myasthenia gravis and facing social determinants of health challenges

Objective

Better understanding the impact of social determinants of health (SDOH) barriers from the patient perspective is crucial to improve holistic patient support in generalized myasthenia gravis (gMG), a rare autoimmune disorder with high disease and treatment burden. The objective of this study was to identify economic challenges experienced by individuals living with gMG and SDOH barriers to better address current unmet needs.

Methods

Adults (18-75 years) living with gMG and experiencing SDOH barriers in the United States were recruited to a mixed-methods study including qualitative interviews and a web-based quantitative survey. Quotas were implemented to include a balanced spread of baseline demographic categories including insurance type, living environment, and employment status among the study sample. Direct and indirect economic challenges were identified by degree of concern.

Results

The survey was completed by 38 individuals living with gMG, the majority of whom were enrolled in public insurance and not employed. The most commonly reported major economic concerns were managing funds for emergency care (66%), loss of income (61%), and non-medical expenses (58%), highlighting the diversity of economic challenges. Individuals who were using public insurance plans, living in non-urban environments, and unemployed experienced pronounced challenges around managing non-medical costs and accessing government assistance.

Conclusion

Both direct and indirect costs were emphasized as major concerns among individuals living with gMG and SDOH barriers. Increasing access to relevant, personalized, and holistic resources, including care management, should be prioritized to improve disease management and outcomes for individuals living with gMG.