OBJECTIVES: In the absence of head-to-head trials, a matching-adjusted indirect comparison (MAIC) was conducted to compare the efficacy of efgartigimod vs ravulizumab in adult patients with generalized, acetylcholine receptor autoantibody positive (AChR+) myasthenia gravis (gMG).

METHODS: The MAIC was based on the published aggregate data for ravulizumab from CHAMPION and the individual patient data (IPD) from ADAPT for efgartigimod. The ADAPT population was restricted to align with the inclusion criteria of CHAMPION (n=110 and n=175, respectively). ADAPT IPD were then weighted to match the baseline characteristics of the population in CHAMPION for treatment effect modifiers, including baseline MG-ADL score, time from diagnosis, use of glucocorticoids and of non-steroidal immunosuppressive drugs. The endpoint of interest was the difference in least square (LS) mean change from baseline in MG-ADL vs placebo, estimated using a mixed model for repeated measures. The efficacy of efgartigimod vs ravulizumab was compared at time of best-response (week 4 for efgartigimod and week 26 for ravulizumab). The number needed to treat (NNT) to have one more patient with minimum two points improvement in MG-ADL (minimum clinically meaningful significant improvement) compared with placebo was estimated for efgartigimod and ravulizumab at time of best response.

RESULTS: The effective sample size of the reweighted ADAPT population was 102.4, indicating good study feasibility. After adjustment, efgartigimod was associated with significantly greater improvement in MG-ADL compared with ravulizumab at time of best-response (-1.4; 95%CI=[-2.8,0.0], p<0.05). The NNT to have one more patient with minimum two points improvement in MG-ADL was 3.2 for efgartigimod and 9.2 for ravulizumab.

CONCLUSIONS: The MAIC suggested an improved efficacy with efgartigimod compared with ravulizumab in adult patients with gMG and AChR+.