Talquetamab in Patients With Refractory Generalized Myasthenia Gravis

Prior treatment

• Patients who have had their glucocorticoid dose adjusted, or who have received immunoglobulins, plasma exchange, neonatal Fc receptor inhibitors, or complement inhibitors within ≤4 weeks.
• Patients who have undergone thymectomy, received B-cell depletion therapy, or had their dose of non-steroidal immunosuppressants (such as azathioprine, tacrolimus, mycophenolate mofetil, cyclophosphamide, etc.) adjusted within ≤3 months.
• Patients who have participated in any interventional clinical trial or received investigational treatment within ≤3 months, or within 5 half-lives of the received investigational drug (whichever is longer).
• Patients with concurrent severe liver, kidney, cardiac, pulmonary, or coagulation dysfunction.
• Patients with concurrent chronic infections such as Human Immunodeficiency Virus, Hepatitis B Virus, Hepatitis C Virus, or Mycobacterium tuberculosis.

• The patient must sign the informed consent form for participation in the study and agree to comply with the study procedures.
• Age 18-70 years.
• Must meet the clinical diagnostic criteria for MG, defined as presenting with a typical pattern of weakness (predominantly affecting proximal muscles, fatiguability, fluctuating severity, worse with prolonged effort and better after rest) and meeting any one of the following three conditions: documented history of abnormal neuromuscular transmission confirmed by single-fiber electromyography or repetitive nerve stimulation; documented history of a positive neostigmine test; or improvement in MG signs following oral administration of an acetylcholinesterase inhibitor. Additionally, the Myasthenia Gravis Foundation of America (MGFA) clinical classification must be II-IV, and the patient must be positive for anti-AChR antibodies.
• Must meet the definition of "refractory myasthenia gravis" according to the Chinese Guidelines for the Diagnosis and Treatment of Myasthenia Gravis (2025 Edition): defined as having a suboptimal response to conventional immunotherapeutic drugs, intolerance to or having contraindications for adverse drug reactions, or experiencing frequent disease relapses requiring regular rescue therapy, making it difficult to achieve treatment goals.
• Myasthenia Gravis Activities of Daily Living (MG-ADL, Appendix 1) score ≥6, with \>50% of the score derived from non-ocular items.
• Quantitative Myasthenia Gravis (QMG) score (Appendix 2) ≥8, with \>50% of the score derived from non-ocular items.
• The dosage of pyridostigmine bromide must be stable for at least 1 week prior to the treatment period.