Safety and Efficacy of a Neonatal Fc Receptor Antagonist in Patients With Anti-NMDAR Encephalitis

This retrospective study investigates the safety and effectiveness of efgartigimod in improving clinical outcomes for patients with anti-NMDAR encephalitis in a real-world setting.

We analyzed data from 26 patients diagnosed with anti-NMDAR encephalitis at the Third Affiliated Hospital of Sun Yat-sen University between October 2022 and June 2024. The patients were divided into two groups: 13 received efgartigimod treatment, while 13 did not. Clinical outcomes were assessed using the modified Rankin Scale (mRS), the Clinical Assessment Scale in Autoimmune Encephalitis (CASE), and clinical symptoms, along with an analysis of treatment-emergent adverse events (TEAEs), cerebrospinal fluid (CSF) antibody titers, and blood serum IgG levels.

Efgartigimod treatment was associated with significant clinical improvement, as indicated by greater reductions in mRS and CASE scores at discharge and follow-up compared to the control group. At follow-up, 84.6% of patients in the efgartigimod group achieved an mRS score of ≤ 2, compared to 46.2% in the control group. Additionally, patients receiving Efgartigimod exhibited a notable reduction in CSF anti-NMDAR antibody titers and serum IgG levels. The most common TEAEs were mild to moderate infections, with no significant safety concerns identified.

In this exploratory study, efgartigimod demonstrated a favorable safety profile for patients with anti-NMDAR encephalitis and appeared to facilitate the recovery of clinical symptoms and neurological function. However, further prospective randomized studies with larger patient cohorts are necessary to confirm the safety and efficacy of efgartigimod.