Efficacy and Safety of Efgartigimod in the Treatment of Guillain-Barré Syndrome(GREAT)

The goal of this clinical trial is to evaluate the safety and effectiveness of Efgartigimod in patients with Guillain-Barre syndrome (GBS). The main questions it aims to answer are: Is Efgartigimod a safe treatment option for GBS patients? Does treatment with Efgartigimod improve patient outcomes? Participants will: Take drug Efgartigimod or Intravenous Immunoglobulin during hospitalization Undergo six blood draws in six follow-up study visits to evaluate the concentration of IgG Keep a diary of their symptoms and drugs using at the same time

Inclusion Criteria: 1. Aged 18-70 years 2. Diagnosis of sensorimotor or pure motor Guillain-Barré syndrome (GBS) based on the 2023 EAN/PNS guidelines (corresponding to classical GBS in the Chinese Guidelines for the Diagnosis and Treatment of Guillain-Barré Syndrome 2024). 3. Onset of GBS within 14 days 4. GBS Disability Scale (GBS-DS) score of 3 to 5 Exclusion Criteria: 1. Patients with other diagnoses cannot be excluded 2. Patients with recurrent GBS 3. Patients with more than 14 days after onset of symptoms 4. GBS DS of 2 or less 5. Patients unable to cooperate with scale assessments due to psychiatric disorders or impaired consciousness 6. Positive serum test at screening for an active viral infection with any of the following conditions: Hepatitis B virus (HBV) that is indicative of an acute or chronic infection; Hepatitis C virus (HCV) based on HCV antibody assay; Positive HIV serology at screening 7. Patients with any known severe bacterial, viral or fungal infection or any major episode of infection that required hospitalization or injectable antimicrobial therapy in the last 8 weeks prior to Screening 8. Total IgG level ≤ 6 g/L at screening 9. Concomitant diseases that can cause peripheral neuropathy, such as metabolic neuropathies (e.g., diabetes, alcoholism), connective tissue disease-associated neuropathies (e.g., rheumatoid arthritis, Sjögren's syndrome, systemic lupus erythematosus), or trauma, which may confound the trial results 10. Subjects with serious underlying diseases, such as cardiac dysfunction, coagulopathy dysfunction 11. Pregnant and lactating women, and those intending to become pregnant during the trial or within 90 days after the last dosing 12. Patients who have a history of malignancy, including malignant thymoma, or myeloproliferative or lymphoproliferative disorders, unless deemed cured by adequate treatment with no evidence of recurrence for ≥ 3 years before Screening. Patients with completely excised non-melanoma skin cancer (such as basal cell carcinoma or squamous cell carcinoma) or cervical carcinoma in situ would be permitted at any time 13. Use of investigational drug within 3 months or 5 half-lives of the drug (whichever is longer) prior to Screening 14. Use of immunosuppressants, monoclonal antibodies, or other immunomodulatory drugs within 6 months prior to enrollment; use of corticosteroids at a dose exceeding 20 mg within 3 months prior to enrollment; or use of IVIG or plasma exchange (PE) within 1 month prior to enrollmen