Blinatumomab for Treatment of Refractory Myasthenia Gravis

Inclusion Criteria:

• Age at onset > 18 years old

• The diagnosis of MG was based on the presence of typical myasthenic symptoms andsupported by positive autoantibodies, electrophysiological studies, and/or theneostigmine test.

• Positive or negative for anti-AChR, and/or anti-MuSK, and/or anti-LRP4 antibodies.

• Refractory myasthenia gravis (MG) patients are defined as those who meet any of thefollowing criteria: For patients with ocular MG, the condition is defined as havingno significant improvement in disease symptoms (QMG score improvement <25%) afteradequate dosing and duration of existing immunosuppressive drugs and targetedbiologics, with no change or worsening in the post-intervention status (PIS), or ifthe PIS improves but disease symptoms worsen or relapse during the regular taperingof immunosuppressive treatment, severely affecting daily quality of life. Forgeneralized MG, the patient must meet the following conditions: no improvement orworsening in PIS after adequate dosing and duration of existing immunosuppressivedrugs and targeted biologics; improvement in PIS, but with an MG-ADL score ≥6persisting for at least six months; remission or improvement in PIS, but with ≥2episodes of disease exacerbation (MG-ADL ≥6) per year during tapering ofimmunotherapy medications; patients who, after experiencing a myasthenic crisis,undergo multiple immunotherapies including intravenous efgartigimod, eculizumab,immunoglobulin, plasma exchange, and high-dose intravenous methylprednisolone, andactive infection control, but still cannot be weaned off the ventilator due torespiratory muscle weakness from MG for more than 14 days. (Note: This includespatients who cannot tolerate existing treatment drugs due to contraindications,comorbidities, or adverse drug reactions.)

• Receiving stable doses of medication prior to enrollment

• Written informed consent

Exclusion Criteria:

• Patients who have thymoma or have undergone thymectomy within six months

• Patients who have used other biologics prior to enrollment that may affect theefficacy assessment of blinatumomab.

• Severe cardiovascular, hepatic, renal, respiratory, or endocrine diseases,malignancies, or uncontrolled acute or chronic infections

• Pregnancy or lactation, unwillingness to avoid pregnancy

• Patients with other diseases that may affect the assessment of muscle strength

• Other conditions that would preclude participation