Tocilizumab, a humanized IL-6R
monoclonal antibody, has been used in
autoimmune diseases closely related to humoral immunity. This report aims to evaluate the efficacy and safety in patients with anti-
acetylcholine receptor-positive (AChR+)
generalized myasthenia gravis (
gMG). We performed a prospective, open-label, single-arm study in patients with
gMG in a 48-week follow-up. All patients were AChR+ and were given
tocilizumab by
intravenous infusion at a dose of 8 mg/kg at intervals of 4 weeks. The primary endpoint was mean change from baseline in quantitative MG (QMG) score at week 12. The secondary endpoints were mean changes from baseline in MG
activities of daily living (MG-
ADL) score, AChR-ab titers, and the dosage of oral
prednisone at week 12. At week 48, QMG, MG-
ADL, and the use of
prednisone were also evaluated. Fourteen
gMG patients were enrolled and all of them completed the study.
Tocilizumab treatment started 8 (4-192) months after the onset of
gMG. During
tocilizumab treatment, the QMG score was significantly decreased from 15.5 (interqualile range, 9-26) at baseline to 4 (0-9) at week 12 (p < 0.001). The change of
ADL was decreased from 14.5(11-19) at baseline to 4 (0-19) at week 12 (p < 0.001) and the change of AChR-ab titers from 15 (7.5-19) at baseline to 6.8 (11.6-4.3) at week 12 (p < 0.001). The dosage of
prednisone decreased from baseline 60 (20-65) mg/d to 30 (30-50) mg/
d at week 12 (p < 0.001). By the end of the study, the QMG score was 2 (0-7) and MG-
ADL score was 1.5 (0-6). 12 (85.7%) patients achieved minimal manifestations. 4 (28.6%) patients were able to discontinue
prednisone. No patients experienced exacerbation at the end of the study. No serious adverse events were observed during follow-up.
Tocilizumab treatment was associated with a good clinical response and safety over a 48-week observation period, as evidenced by significant improvements in QMG and MG-
ADL.