The efficacy and safety of efgartigimod for refractory myasthenia gravis: a systematic review and meta-analysis

Myasthenia gravis (MG) is a chronic autoimmune disorder affecting the neuromuscular junction, where autoreactive immunoglobulin G (IgG) plays a key role in disease pathogenesis. The novel biologic Efgartigimod is a neonatal Fc receptor (FcRn) antagonist, promotes the lysosomal degradation of IgG, and may offer a targeted approach for managing MG. Despite the growing interest in efgartigimod, there remains a lack of comprehensive evaluation of its efficacy and safety in different MG subtypes.

Comprehensive retrieval and screening were conducted on Pubmed, Embase, Web of Science, and Cochrane library to search studies on efgartigimod treatment. The data on response rates and adverse events were extracted, and the pooled effect size (ES) with the 95% confidence interval (CI) was calculated by fixed or random effect models. Sensitivity analysis and subgroup analysis were employed to test the heterogeneity. Funnel plots and trim-and-fill methods were used to test for publication bias.

Data from 10 studies involving 305 patients were analyzed. The overall treatment response rate was 78% (95% CI: 67%-87%, I² = 73.4%). Subgroup analysis revealed pooled response rates of 79.2% (95% CI: 68.5%-88.4%, I² = 25.08%) in acetylcholine receptor antibody-positive MG (AChR+MG) patients and 76.2% (95% CI: 56.8%-91.5%, I² = 85.95%) in group that did not differentiate auto-antibody types. The pooled incidence of adverse events was 38% (95% CI: 17%-51%, I² = 92.59%), with infections (7%, 95% CI: 2%-14%, I² = 62.5%), headache (7%, 95% CI: 1%-18%, I² = 82.69%) and other (16%, 95% CI: 7%-28%, I² = 71.81%). Among them, grade 3-4 adverse events are 1% (95% CI: 0%-2%, I² = 0%).

Our study demonstrates that efgartigimod is highly effective and well-tolerated in patients with refractory MG. These findings suggest that efgartigimod is a promising drug for the treatment of MG.