REAL-WORLD PATIENT-REPORTED IMPACT OF MYASTHENIA GRAVIS: INITIAL DATA FROM THE MYREALWORLD™ MG STUDY American Association of Neuromuscular & Electrodiagnostic Medicine Annual Meeting Aurora, CO, October 13–16, 2021 Berrih-Aknin S1, Claeys KG2,3, Friconneau M4, Mantegazza R5,6, Meisel A7, Murai H8, Palace J9, Saccà F10, Bagshaw E11, Larkin M11, Beauchamp J12, De Ruyck F12, Paci S12, Phillips G12 1
Sorbonne Université, Paris, France 2 University Hospitals Leuven, Leuven, Belgium 3 KU Leuven, Leuven, Belgium 4 AFM-Téléthon, Paris, France 5 Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy 6 Associazione Italiana Miastenia e Malattie Immunodegenerative, Milan, Italy 7 Charité – Universitätsmedizin Berlin, Berlin, Germany 8 International University of Health and Welfare, Narita, Japan 9 University of Oxford, Oxford, UK 10 Federico II University, Naples, Italy 11 Vitaccess Ltd, Oxford, UK 12 argenx BV, Ghent, Belgium
Background Myasthenia gravis (MG) is a chronic immunoglobulin G-mediated autoimmune disease, causing debilitating muscle weakness. As with most rare diseases, there is little patient-reported data with which to understand and address patient needs.
Objectives MyRealWorld™ MG, an ongoing two-year, international, prospective, observational study, aims to explore the real-world patient-reported impact of MG. This analysis presents first-entered data (i.e., equivalent to baseline) for key variables.
Table 1: Type of antibodies present Response
42.4% of participants had a depression score high enough to meet the threshold for diagnosis (Figure 4a), as did 52.4% for anxiety (Figure 4b)
MG-ADL (Myasthenia Gravis Activities of Daily Living)
Frequency (%)
% of those with known antibody type
N
466
Acetylcholine receptor (AChR)
383 (82.2%)
87.8%
Muscle-specific kinase (MuSK)
36 (7.7%)
8.3%
Lipoprotein-related protein 4 (LRP4)
8 (1.7%)
1.8%
Other
9 (1.9%)
2.1%
Unknown
30 (6.4%)
MG-specific survey assessing symptom severity2 On a scale 0–24, where 0 = normal and 24 = severe symptoms in all domains, mean score was 5.6; SD 4.0; N = 652
Figure 4a: HADS depression severity distribution; N = 672
Participants were most likely to have problems with double vision, breathing, and eyelid droop severity; see Figure 2 Figure 2: MG-ADL severity distribution; N = 652
MG treatments The most commonly received routine treatment in the 30 days prior to data collection was anticholinesterase medication (76.8%); N = 605; see Table 2 Table 2: Routine medications used in the past 30 days
Methods Participants used the MyRealWorld MG smartphone application to complete the following: Personal profile about demographics, MG characteristics, and previous care Monthly tracker about treatments, healthcare visits, adverse events, and productivity Monthly selection of validated patient-reported outcomes instruments about symptoms, functioning, quality of life, and impact of the COVID-19 pandemic.
Results Data were extracted on 30 April 2021 from 848 participants who met analysis criteria, of 1,431 registered. Data for key variables are presented below. Demographics Mean age of participants was 47 years; standard deviation (SD) 14.3; median 47 years; range 18–90; N = 812 Most participants were female (69.7%); N = 812
MG diagnosis and classification Mean age at diagnosis was 39 years; SD 16.7; N = 799
Response
Frequency (%)
N
605
Anticholinesterases
460 (76.8%)
Non-steroidal immunosuppressive therapies (NSIST)
285 (47.1%)
Corticosteroids
278 (46.4%)
Lifestyle modification
89 (14.9%)
Intravenous immunoglobulin (IVIG)
87 (14.5%)
Eculizumab
25 (4.2%)
EQ-5D-5L (EQ-5D 5-level version)
Rituximab
24 (4.0%)
Generic survey assessing general health and quality of life3
Plasma exchange (PLEX)
20 (3.3%)
Others
183 (30.2%)
Prefer not to answer
6 (1.0%)
Unknown
1 (0.2%)
Patient-reported outcome instruments
Figure 4b: HADS anxiety severity distribution; N = 672
On a scale <0–1, where <0 = worse than death and 1 = best possible health, mean index score was 0.8; SD 0.2; N = 617 Participants reported most problems with tiredness, pain/discomfort, and usual activities; see Figure 3
Figure 3: EQ-5D-5L severity distribution; N = 617
MG-QOL-15r (Myasthenia Gravis Quality Of Life 15-item revised scale) MG-specific survey assessing quality of life1 On a scale 0–30, where 0 = no quality-of-life impairment and 30 = severe impairment in all domains, mean score was 11.5; SD 7.2; N = 679 Participants were most likely to have problems with planning, work, and hobbies; see Figure 1
Discussion & Conclusions
Figure 1: MG-QOL-15r severity distribution; N = 679
This first formal analysis of the MyRealWorld MG study indicates that, despite current treatments, patients still experience moderate burden and impairment to their quality of life as a result of living with MG. Our results also indicate a considerable impact of psychiatric comorbidities, which warrants investigation.
Mean delay between symptom onset and diagnosis was 2 years; N = 799, and between seeking medical care and diagnosis was 1 year; N = 794 The most common Myasthenia Gravis Foundation of America (MGFA) clinical classification at diagnosis, as judged by participants if not professionally assessed, was IV (severe muscle weakness; 32.6%); N = 803, and at the time of data collection was III (moderate weakness; 38.2%); N = 804
Further scheduled analyses over the course of the study will develop a more longitudinal picture of MG burden.
HADS (Hospital Anxiety and Depression Scale) 88.4% of participants had generalized MG; N = 805 70.1% of participants who knew their antibody status were positive for MG antibodies; N = 665. The type of antibodies present for those reporting are shown in Table 1; N = 466
Generic survey assessing levels of anxiety and depression4 On a scale 0–21, where 0 = normal, ≥8 = threshold for anxiety or depression diagnosis, and 21 = severe disease, mean depression score was 6.8; SD 4.2, and mean anxiety score was 8.1; SD 4.2; N = 672
References 1
Burns TM et al. Muscle Nerve 2016;54(6):1015–22 2 Wolfe GI et al. Neurology 1999;52(7):1487–9 3 Herdman M et al. Qual Life Res 2011;20(10):1727–36 4 Zigmond AS and Snaith RP. Acta Psychiatr Scand 1983;67(6):361–70