Epidemiological Study of Treatment Approaches in AChR-Antibody Positive Generalized Myasthenia Gravis in Russia

This is a multicenter, non-interventional, retrospective-prospective, single-arm observational study designed to describe real-world treatment approaches and clinical outcomes among adults with acetylcholine receptor (AChR) antibody-positive generalized myasthenia gravis (gMG) in routine clinical practice in Russia.

The primary objective is to characterize the demographic and clinical profile of adult AChR-Ab-positive gMG patients. Key secondary objectives include assessing disease severity over time (MG-ADL, QMG, MGFA class), evaluating rates, duration, and reasons for all-cause and gMG-related hospitalizations, describing diagnostic pathways and treatment strategies (including first-line regimens and use of therapies such as anticholinesterase agents, corticosteroids, immunosuppressants, IVIG, plasmapheresis/plasma filtration, thymectomy, rituximab, and complement C5 inhibitors), exploring patterns and outcomes of myasthenic crises, and documenting meningococcal vaccination and any prophylactic antibiotic use prior to initiation of C5 inhibitor therapy.

Approximately 100 adults will be enrolled consecutively across about 10 specialized sites. The study will sequentially include only those patients who have signed the informed consent form (ICF). Eligible patients will be enrolled consecutively at each site to minimize selection bias. Data are collected from existing paper/electronic medical records (secondary data collection) and recorded into an eCRF at seven timepoints: baseline (with retrospective abstraction, including medical history from diagnosis) and prospective follow-up every 6 months up to Month 36 (±1 month windows). No study-mandated interventions, tests, or visit schedules are imposed; all care follows routine practice.

• MG-ADL total score and change from baseline [Time frame: Baseline (Month 0) and Months 6, 12, 18, 24, 30, 36 (±1 month)]
• QMG total score and change from baseline [Time frame: Baseline (Month 0) and Months 6, 12, 18, 24, 30, 36 (±1 month)]
• Distribution of MGFA clinical classification over time [Time frame: Baseline (Month 0) and Months 6, 12, 18, 24, 30, 36 (±1 month)]
• Number and proportion of patients with all-cause hospitalization [Time frame: From Baseline through Months 6, 12, 18, 24, 30, 36 (±1 month)]
• Duration of all-cause hospitalizations (days per participant) [Time frame: From Baseline through Months 6, 12, 18, 24, 30, 36 (±1 month)]
• Number and proportion of patients with gMG-related hospitalization [Time frame: From Baseline through Months 6, 12, 18, 24, 30, 36 (±1 month)]
• Duration of gMG-related hospitalizations (days per participant) [Time frame: From Baseline through Months 6, 12, 18, 24, 30, 36 (±1 month)]
• Time from MG symptom onset to gMG diagnosis (months) [Time frame: Retrospective period prior to Baseline]
• Prior misdiagnoses before gMG diagnosis (number and proportion by category) [Time frame: Retrospective period prior to Baseline]
• Diagnostic examinations for gMG confirmation and available results [Time frame: Retrospective period prior to Baseline]
• Diagnostic test usage and results [Time frame: Retrospective period prior to Baseline]
• Drug therapies received (proportion by class) [Time frame: 12 months pre-Baseline and Baseline to Month 36 (±1 month)]