Efficacy of ravulizumab in patients with generalized myasthenia gravis by time from diagnosis: A post hoc subgroup analysis of the CHAMPION MG study

Abstract Introduction/Aims The CHAMPION MG study demonstrated that ravulizumab significantly improved Myasthenia Gravis‐Activities of Daily Living (MG‐ADL) and Quantitative Myasthenia Gravis (QMG) total scores versus placebo in adults with acetylcholine receptor antibody‐positive generalized myasthenia gravis (AChR+ gMG). This post hoc analysis aimed to assess these outcomes by time from MG diagnosis. Methods Changes from baseline to week 26 in MG‐ADL and QMG total scores were analyzed by time from MG diagnosis to study entry (≤2 vs. >2 years). Within each subgroup, least‐squares (LS) mean changes for ravulizumab and placebo were compared using mixed models for repeated measures. Results In ravulizumab‐treated patients, differences in LS mean (standard error of the mean) changes from baseline to week 26 were not statistically significant in the ≤2‐years subgroup versus the >2‐years subgroup for MG‐ADL (−4.3 [0.70] vs. −2.9 [0.37]; p = .0511) or QMG (−4.3 [0.94] vs. −2.5 [0.50]; p = .0822) scores. No clear trends were observed in the placebo group. LS mean changes from baseline were significantly greater for ravulizumab versus placebo in both the ≤2 and >2 years from diagnosis subgroups for MG‐ADL and QMG scores (all p < .05). The difference in treatment effect between the ≤2‐years and >2‐years subgroups was not statistically significant. No clinically meaningful between‐subgroup differences in treatment‐emergent adverse events were observed in ravulizumab‐treated patients. Discussion Ravulizumab treatment improved clinical outcomes for patients with AChR+ gMG regardless of time from diagnosis. A numerical trend was observed favoring greater treatment effect with earlier versus later treatment after diagnosis. Further studies are required for confirmation.