Additional Relevant Details The first prospectively defined secondary efficacy endpoint of change from baseline in Quantitative Myasthenia Gravis (QMG) total score, a physician-administered assessment of MG clinical severity, with eculizumab treatment compared to placebo at week 26, achieved a p-value of 0.0129 as measured by a worst-rank analysis. In addition, the second and third prospectively defined secondary efficacy endpoints of responder status in MG-ADL and QMG achieved p-values <0.05: the proportion of patients with at least a 3-point reduction in MG-ADL total score and no rescue therapy from baseline to week 26 with eculizumab treatment compared to placebo achieved a p-value of 0.0229, and the proportion of patients with at least a 5-point reduction in QMG total score and no rescue therapy from baseline to week 26 with eculizumab treatment compared to placebo achieved a p-value of 0.0018.


Pre-specified sensitivity analyses were prospectively defined to validate results for the primary and first secondary endpoints. Three of the four prospectively defined sensitivity analyses around the primary endpoint of MG-ADL achieved p-values <0.05, including the sensitivity analysis for change from baseline in MG-ADL using repeated measures, which showed a mean change with eculizumab treatment at week 26 of -4.2 versus a mean change with placebo at week 26 of -2.3 and achieved a p-value of 0.0058. Additionally, all four prospectively defined sensitivity analyses around the first secondary endpoint of QMG achieved p-values <0.05, including the sensitivity analysis for change from baseline in QMG using repeated measures, which showed a mean change with eculizumab treatment at week 26 of -4.6 versus a mean change with placebo at week 26 of -1.6 and achieved a p-value of 0.0006.