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.