Efficacy and Safety of HN2301 in Refractory Myasthenia Gravis(MG)

Inclusion Criteria * Age: 18-80 years, no gender restriction; * Confirmed diagnosis of generalized myasthenia gravis (MG) with positive AchR or MuSK antibodies, meeting at least one of the following conditions: (1) Repetitive nerve stimulation suggesting neuromuscular transmission defect; (2) Positive response to neostigmine test; (3) Clinically judged improvement of --MG symptoms after oral cholinesterase inhibitor therapy; * Clinical classification of MG according to MGFA types IIa-IVb (including IIa, IIb, IIIa, IIIb, IVa, IVb); * Baseline MG-ADL (Myasthenia Gravis Activities of Daily Living) score ≥6, with ocular-related score \<50%; * Poor response and/or lack of effective treatment under standard therapies, defined as no improvement or worsening of symptoms despite stable treatment with corticosteroids, immunosuppressants (e.g., azathioprine, mycophenolate mofetil, tacrolimus, cyclosporin A, cyclophosphamide), or rituximab; * Expected survival time greater than 12 weeks; * Adequate bone marrow, coagulation, cardiopulmonary, liver, and renal function；Bone marrow function: ANC ≥1.5×10⁹/L, ALC ≥0.8×10⁹/L, Hb ≥80g/L; transfusions or growth factors must not be used within 7 days prior to screening to meet these criteria.Coagulation function: INR or APTT ≤1.5×ULN. * Cardiac function: left ventricular ejection fraction (LVEF) ≥40% assessed by echocardiogram (ECHO). * Pulmonary function: CTCAE grade ≤1 dyspnea and room air SpO₂ ≥92% (measured by pulse oximetry). * Liver func…