A systematic review of efgartigimod as an effective treatment for myasthenic crisis

Efgartigimod is a neonatal Fc receptor (FcRn) inhibitor that primarily diminishes antibody levels by inhibiting antibody (IgG) reabsorption and is noted for its rapid onset of action and low immunogenicity. Currently, efgartigimod is approved for the treatment of anti-acetylcholine receptor (AChR) antibody-positive generalized myasthenia gravis (gMG), yet there are no relevant clinical trials for myasthenic crisis (MC). Consequently, we performed a systematic review of the available literature to evaluate the clinical efficacy of efgartigimod for the treatment of MC. We conducted a search of the PubMed, Web of science, Embase, and Scopus databases for all observational studies published until September 30, 2024. Risk of bias was assessed using the Joanna Briggs Institute (JBI) Case Report and Series Critical Assessment Checklist for quality assessment of included studies. A total of nine case reports/series, all observational studies, were included. Twenty MC patients were included, all of whom exhibited clinically significant improvement after treatment with Efgartigimod, with a sustained decrease in AChR antibody serum titers and a significant decrease in IgG levels throughout the treatment cycle. Efgartigimod demonstrates favorable clinical efficacy. Efgartigimod may serve as an effective treatment for patients with MC. However, further studies are required to clarify the efficacy of Efgartigimod alone. PROSPERO registration number: CRD42023430032.