Rituximab for the Treatment of New-onset AChR-Myasthenia Gravis

Myasthenia gravis (MG) is the most common acquired disorder of neuromuscular junction (NMJ), the most common antibody (in 85% MG patients) being the nicotinic acetylcholine receptor (AChR). Traditional medical treatments of new-onset MG include anticholinesterase inhibitors, immunomodulating therapies such as intravenous immunoglobulin (IVIG) and plasma exchange (PLEX) and immunosuppressive agents such as corticosteroids, azathioprine, mycophenolate mofetil, cyclosporine, methotrexate and cyclophosphamide. Since a status of complete stable remission (CSR, defined as remission of MG without pharmacological treatment≥1 year) is difficult to achieve, the international consensus guidance for management of MG proposed "minimal manifestation (MM) or better status" with no greater than mild adverse events as a practical goal of MG treatment. Given the balance between efficacy and safety, a more aggressive strategy and approach for immune therapies are critical in early stage of new-onset MG. In clinical practice, biological agent monoclonal antibody rituximab (RTX), specifically targeting B-lymphocyte differentiation membrane antigen CD20, has been increasing in recent years for some immune-mediated neurological diseases such as multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD), and gradually represented potential advantages in immunosuppressive therapy-refractory and new-onset AChR-MG. However, up to now, the individualized regimen, optimal dosage and clinical benefit of RTX monotherapy for early stage of new-onset AChR-MG still need to be elucidated. This study was performed to assess the long-term clinical efficacy and safety of individualized low-dose 100 mg RTX monotherapy approach in new-onset AChR-MG patients.

Sex

All

Minimum age

18 Years

Inclusion Criteria:

1. The patients signed the informed consent form, and the subjects were willing to complete the research protocol as planned;
2. The age is over 18 years old, and the gender is not limited (women of childbearing age have a negative pregnancy test);
3. Meet the diagnostic criteria of the Chinese Guidelines for the Diagnosis and Treatment of Myasthenia Gravis (2020 Edition);
4. The subjects of the study are all Chinese Han people;
5. Good physical condition;
6. Complete demographic and clinical data during the baseline survey and follow-up;
7. Serum AChR antibody positive;
8. New-onset AChR-MG, with symptoms no more than 12 months;
9. American Myasthenia Gravis Foundation (MGFA) clinical classification grades I to IV (grade I only indicates ocular muscle weakness, grade II mild systemic disease, grade III moderate systemic disease, grade IV severe systemic disease , Grade V requires intubation crisis);
10. The patient has never received immunosuppressive therapy or RTX therapy. If receiving cortisol hormone therapy, the oral dose should be less than 3 months, and the daily dose should not exceed 40 mg.

Exclusion Criteria:

1. Myasthenic crisis at screening (MGFA grade V);
2. Accompanied with serious physical diseases, such as severe heart failure;
3. Liver and kidney insufficiency or elevated transaminases (AST/ALT elevation exceeds 2.5 times the upper limit of normal)
4. Suffering from clinical depression symptoms and serious mental illness;
5. Combined with other neurological diseases, with a history of organic brain diseases and traumatic brain injury;
6. Use of immunosuppressive agents, including rituximab, azathioprine, mycophenolate mofetil, cyclophosphamide, mycophenolate mofetil, cyclosporine, tacrolimus or methotrexate, etc.;
7. Potential acute or chronic viral or bacterial infection, such as HIV, latent hepatitis B, tuberculosis, etc.;
8. Vaccination history within 4 weeks before enrollment;
9. During pregnancy or breastfeeding;
10. Those who cannot sign the informed consent;
11. Patients with poor compliance;
12. Any other situation in which the investigator believes that the patient should not participate in this trial.

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