Clinical outcomes and safety of efgartigimod in Guillain-Barré syndrome: a retrospective observation study.

Background: Guillain-Barré syndrome (GBS) is a severe acute autoimmune neuropathy with limited established therapeutic options. Efgartigimod, a human IgG antibody Fc fragment, can increase IgG degradation, which thus may be a promising therapeutic medicine for GBS. The aims of this study were to evaluate the clinical effectiveness and safety of efgartigimod in GBS patients. Methods: A retrospective study was conducted on GBS patients at the first affiliated hospital of Zhengzhou university and Nanyang central hospital from February 2024 to June 2025. The medical records of patients received IVIg, efgartigimod, or IVIg sequential efgartigimod (ISE) were reviewed. Disease severity was evaluated using GBS disability score (GBS-DS) and Inflammatory Neuropathy Cause and Treatment (INCAT) disability score at baseline, week1, week2, week3, week4, and the final follow-up. The primary outcome was the proportion of good improvement, defined as a reduction of at least 2 points in the GBS-DS score compared to the baseline. All adverse events occurred during the treatment period were documented. Results: 52 patients were enrolled and received IVIg (n=20), efgartigimod (n=16), or ISE (n=16). Good improvement was higher in the efgartigimod group than IVIg group both at week 2 (37.5% vs. 0%, p<0.01) and the final visit (81.3% vs. 40.0%, p=0.02). Throughout follow-up, the proportion with GBS-DS ≤1 in the efgartigimod group was consistently higher compared to the other two groups. Although not statistically significant, the mean time to reach GBS-DS ≤1 was shorter in the efgartigimod group (2.6± 1.2 weeks) compared to the IVIg (3.1 ± 1.1 weeks), In the ISE group, the average time to achieve GBS-DS ≤ 1 was 2.8 ± 1.2 weeks. Regarding safety, the incidence of treatment-related adverse events (TEAEs) was lower in the efgartigimod group18.8% (3/16) than in the IVIg50.0% (10/20) and ISE 43.8% (7/16) groups. Conclusions: Based on the preliminary finding, the retrospective real-world data suggesting a potential signal of benefit for efgartigimod in GBS, with no new safety concerns identified. However, this study cannot establish comparative efficacy given the methodological limitations, and large-scale well-controlled head-to-head trials remain imperative.