Abstract
BACKGROUND: Guillain-Barré syndrome (GBS) is an acute autoimmune neuropathy with limited effective treatments. Efgartigimod, a neonatal Fc receptor (FcRn) antagonist, may offer a novel treatment by reducing pathogenic immunoglobulin G. OBJECTIVES: To evaluate the efficacy, safety, and immunological effects of efgartigimod in patients with GBS. DESIGN: A retrospective, observational, monocentric study. METHODS: The study included 36 patients with GBS who received efgartigimod treatment. Efficacy was evaluated using the GBS-Disability Scale (GBS-DS) and Medical Research Council (MRC) scores over 8 weeks. Additionally, exploratory lymphocyte subset analysis was conducted on 13 patients before and after treatment. RESULTS: Patients were stratified into those receiving efgartigimod as first-line therapy (n = 17) and as escalation therapy after intravenous immunoglobulin or plasma exchange (n = 19). Both cohorts showed significant and sustained clinical improvement over 8 weeks (p < 0.05). More importantly, the first-line cohort demonstrated a more rapid initial response, with a significantly greater reduction in GBS-DS score (ΔGBS-DS: 2.0 vs 0.0 at week 1, p = 0.003) and increase in MRC score (ΔMRC: 9.0 vs 6.0, p = 0.016) compared to the escalation cohort. This led to a higher percentage of achieving a favorable outcome (GBS-DS ⩽2) and a shorter median time to this outcome (6 vs 25 days, p < 0.001) in the first-line cohort. Regression analysis within the entire cohort confirmed that greater baseline severity and need for mechanical ventilation were associated with a longer time to favorable outcome. Exploratory analysis suggested a decrease in the proportions of CD3+CD4+ and CD4+HLA-DR+ T cells following efgartigimod treatment. Only two mild adverse events were reported. CONCLUSION: Efgartigimod shows efficacy as both a rapid-onset first-line therapy and a rescue option for refractory GBS, with a favorable safety profile and potential immunomodulatory effects, supporting further prospective evaluation.