Eculizumab is effective in improving functional ability and muscle strength in patients with gMG, a rare autoimmune disease characterized by fatigable muscle weakness. To optimize treatment outcomes, it is important to understand the differences in characteristics between responders and non-responders.

Patients were enrolled in a gMG registry that collects clinical practice data on the effectiveness of eculizumab in patients with gMG in the USA. The analysis population included patients with MG-ADL total scores both prior to eculizumab initiation, and at or after enrollment in the registry. Response to eculizumab was defined as an improvement of ≥ 3 points in MG-ADL total score; non-response was an improvement of < 3 points, no change or worsening in score. Predictors of response analyzed included patient demographics, disease characteristics and treatment duration. Analysis data cut-off was July 5, 2022.

In the analysis population (n = 80), 87.5% of patients were White, 58.8% were male and mean (standard deviation; SD) age at diagnosis was 54.7 (19.9) years. At the time of analysis, 65% of patients met the definition of response to eculizumab treatment. There were no statistically significant differences in demographics between responders and non-responders. Responders had a significantly higher MG-ADL total score before treatment compared with non-responders (mean [SD] 9.1 [3.4] vs 6.4 [3.4]; p < 0.05). Duration of eculizumab treatment was similar between responders and non-responders (mean [SD] 1.8 [1.2] years vs 1.7 [0.9] years, respectively).