Efficacy and safety of Rituximab in myasthenia gravis: A French multicentre real-life study.

INTRODUCTION 15% of myasthenia gravis (MG) patients are refractory to conventional treatment. Case reports and a few studies show likely benefit of rituximab in these cases. Our objective was to assess the efficacy and the safety of rituximab in MG patients, in a multicentric real-life study. METHOD Inclusion criteria were age > 18 years old, MG with anti-Acetylcholine receptor (ACh-R) antibodies, anti-Musk antibodies or significant decrement after repetitive nerve stimulation, MG Foundation America (MGFA) score > II, refractory or steroid-dependent MG, treatment with rituximab. Efficacy was assessed at 6 months with the MGFA Post interventional score (MGFA-PIS), the Myasthenic Muscle score (MMS) and the number of patients with steroids under 10 mg/d. Adverse events were collected. RESULTS 29 patients were included: 20 anti-ACh-R MG, 5 anti-Musk MG and 4 seronegative MG. MGFA PIS was improved or better (Improved, Minimal Manifestations or Remission) in 86.2% of patients after 6 months of treatment (p<0.0001). The mean MMS increased from 68.8 to 83.1 (p<0.0001). Decrease of steroid dosage (<10 mg/d) was effective in 57.9% of treated patients. 42.8% of patients presented adverse events: infections (21.4% of the patients), infusion reaction (7%), bradycardia (3.7%) or cytopenia (7%). CONCLUSION Our study demonstrates the efficacy and safety of rituximab in MG patients. Additional studies are still necessary to set the actual place of rituximab in pharmacopeia of MG treatment and to establish precise recommendations for infusion protocol.