Efgartigimod for Consolidation Therapy in gMG

Inclusion criteria

• Age ≥18 years, male or female.
• Diagnosis of myasthenia gravis (MG) based on the following:

• Typical clinical features of MG.
• At least one of the following:

Seropositive for anti-AChR antibodies (confirmed by reliable assay). Abnormal neuromuscular transmission on electrophysiological testing (e.g., RNS or SFEMG).

Positive neostigmine test or documented response to cholinesterase inhibitors.

• MGFA classification II-IV at consolidation baseline.
• Seropositive for anti-AChR antibodies (required for enrollment).
• Hospitalized for myasthenic crisis (MC) in the acute exacerbation and completed one treatment cycle of efgartigimod: acute exacerbation definition: Presence of MC warning signs (new or worsening within 2 weeks): Bulbar symptoms: Dysphagia, choking, weak cough, dysarthria. Respiratory symptoms: Dyspnea, respiratory muscle weakness. Generalized weakness: Head drop, jaw weakness, facial weakness. One treatment cycle of efgartigimod: 10 mg/kg IV, once weekly for 4 doses.
• ≥2-point improvement in MG-ADL score from acute exacerbation baseline by Day 4 of efgartigimod treatment.
• Willing and able to provide written informed consent before study participation.

Exclusion criteria

• Treatment with IVIg, plasma exchange (PE), IV methylprednisolone (IVMP), or immunoadsorption (IA) within 1 month before consolidation baseline.
• Thymectomy within 6 months before exacerbation baseline.
• Use of immunomodulatory monoclonal antibodies or investigational drugs (not listed above) within 3 months before baseline or 5 half-lives (whichever is longer).
• Pregnancy or lactation (women of childbearing potential must have negative pregnancy test and use contraception).
• Known hypersensitivity to efgartigimod or any FcRn-targeting therapy.
• Clinically significant comorbidities, including severe cardiovascular, hepatic, renal, pulmonary, or hematologic disorders, active malignancy and uncontrolled systemic infections.
• Other autoimmune diseases that may interfere with efficacy assessment (e.g., uncontrolled thyroid disease, severe rheumatoid arthritis).
• Any other condition deemed unsuitable by the investigator.