Study to Assess Safety, Efficacy, and Cellular Kinetics of YTB323 in Generalized Myasthenia Gravis

Inclusion Criteria

• •1. Confirmed gMG diagnosis supported by the following:
• •* Documented report of positive serology testing for either AChR antibodies or MuSK antibodies at screening AND at least one of the following:
• •* History of abnormal neuromuscular transmission test demonstrated by repetitive nerve stimulation or single-fiber electromyography
• •* History of positive acetylcholinesterase inhibitor test
• •* Improvement in MG signs on an oral acetylcholinesterase inhibitor as assessed by the treating physician
• •2. MGFA Class III-IVa (gMG) at screening
• •3. Treatment-resistant gMG as defined by: MG-ADL score ≥ 6 (≥50% non-ocular) at screening despite adequate treatment trials with at least two different non-steroidal immunosuppressive drugs given at adequate doses and duration of therapy.
• •4. If on chronic corticosteroids, must be on a stable dose of corticosteroids for ≥1 month prior to screening and have the ability and willingness to taper to a maximum dose of 10 mg prednisolone daily or equivalent at least one week before leukapheresis
• •5. If treated with cholinesterase inhibitors, patients must be on a stable dose for at least two weeks prior to screening