This study aims to evaluate the rapid efficacy and safety of efgartigimod in Chinese myasthenia gravis (MG) population.

We enrolled Chinese MG patients aged 18 and older treated with efgartigimod, classified as MGFA I-IV, with a baseline MG-ADL score of at least 4. During the treatment, corticosteroids dosage could be adjusted as appropriate or the non-steroidal immunosuppressive therapies (NSISTs) added. Prior to each infusion, MG-ADL scores, IgG levels, and routine laboratory tests were evaluated,  and prednisone tapering and adverse events were recorded.

25 Chinese MG patients were enrolled, including 3 with ocular MG (OMG) and 22 with generalized MG (GMG). During the 8-week follow-up, overall efficacy in GMG patients was significant. Among AChR-GMG patients, 13 (68%) showed a reduction of at least 2 points in MG-ADL scores within the first week, increasing to 16 (84%) by the end of treatment, with 8 (42%) achieving minimal symptom expression (MSE). Only 1 patient experienced exacerbation. Both MuSK-MG patients showed a 9-point reduction in MG-ADL scores. Among OMG patients, 1 achieved MSE within the treatment cycle, while 2 showed minor improvements. Patients who added NSIST (primarily tacrolimus) concurrently with efgartigimod did not achieve better improvement compared to others. The average prednisone reduction was 27.4%. Only one patient experienced transient vomiting and diarrhea; no serious adverse reactions reported.

This study confirmed the short-term efficacy and safety of efgartigimod in Chinese MG patients. Careful consideration is needed regarding its application in OMG and the addition of NSISTs during the treatment. Efgartigimod could potentially serve as an alternative to long-term corticosteroids therapy.