Effectiveness and safety of efgartigimod in myasthenia gravis: A meta-analysis of different antibody subtypes

Objective: To assess the effectiveness and safety of intravenous efgartigimod in patients with myasthenia gravis (MG) and to compare treatment responses between anti-acetylcholine receptor antibody (AChR-Ab)-positive and -negative subtypes. Methods: A comprehensive search was conducted in the PubMed, Scopus, Web of Science, and Cochrane CENTRAL databases up to 15 October 2025. Clinical trials and cohort studies evaluating the effectiveness and safety of efgartigimod in patients with MG were included. A random-effects model was used to pool mean differences (MDs) for continuous outcomes and proportions for categorical outcomes, with corresponding 95% confidence intervals (CIs). Subgroup analyses were performed based on study design and MG subtype. Results: Twenty-nine studies (1594 patients) were included. Overall, 83% of patients achieved clinically meaningful improvement (CMI; ≥ 2-point reduction in MG Activities of Daily Living [MG-ADL] score), and 36% achieved minimal symptom expression (MSE; MG-ADL score of 0 or 1) with no significant difference between AChR-Ab-positive and AChR-Ab-negative subtypes. MG-ADL score significantly decreased from baseline (MD: -4.3 points, 95% CI: -4.99 to -3.61), with no difference between the MG subtypes. Quantitative MG score (QMG; MD: -3.6 points, 95% CI: -4.28 to -2.91), MG Quality of Life 15-item revised scale (MG-QoL15r), IgG levels, and corticosteroid use showed significant reductions in the AChR-Ab-positive subtype; however, these outcomes were not reported in the AChR-Ab-negative subtype. Serious adverse events were reported in 4.42% of patients. Conclusion: Efgartigimod significantly improved clinical symptoms and quality of life in patients with MG and may offer a steroid-sparing effect, with no significant differences observed between subtypes.