The article describes the use of efgartigimod in a disorder related to fetal antibodies against acetylcholine receptors. Efgartigimod is a neonatal Fc receptor (FcRn) blocker that selectively reduces circulating pathogenic IgG antibodies. The study focuses on treatment in the context of generalized myasthenia gravis (MG), including acute exacerbations and crises. In 12 patients with a mean age of 82.9 ± 2.5 years, there was a significant decrease in the MG-ADL score by 52.2% ± 30.8% (from 10.9 ± 2.7 to 3.6 ± 2.1) after one treatment cycle. Clinically meaningful improvement was achieved by 91.7% of patients (11/12) after an average of 1.3 ± 0.5 weeks. The greatest effect was in the MG acute exacerbation (MGAE) subgroup, where MG-ADL decreased by 69.8% ± 16.9%. Side effects were mild: transient headaches in two patients and mild upper respiratory tract infection in one. The treatment was effective and safe especially in elderly patients over 80 years of age with MGAE.[1]