Efgartigimod as adjunctive therapy in refractory autoimmune glial fibrillary acidic protein astrocytopathy: a case series

Autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy is a recently identified inflammatory disorder of the central nervous system for which a subset of patients responds poorly to conventional immunotherapy. This study evaluated the efficacy and safety of adding efgartigimod to corticosteroids in refractory cases.

We retrospectively analyzed five patients with autoimmune GFAP astrocytopathy treated with intravenous methylprednisolone and efgartigimod between March and October 2025 at three tertiary centers in China. All patients had insufficient response to initial immunotherapy. Demographics, clinical features, laboratory findings, treatment, and outcomes were assessed.

Median age was 44 years (range 38–54); four patients (80%) were male. Clinical phenotypes included meningoencephalomyelitis (60%) or meningoencephalitis (40%). Despite initial intravenous methylprednisolone with or without plasma exchange, one relapsed, one had no meaningful clinical improvement, and three progressed. After efgartigimod initiation, four patients (80%) achieved complete neurological recovery (modified Rankin Scale (mRS) 0) in a median of 12.5 days (range 1–26 days); one patient improved from mRS 5 to 4. No relapses occurred during a median follow-up of 8 months (range 6–9 months). Serum and CSF total IgG levels decreased significantly after treatment (p = 0.004 and p = 0.015, respectively), with a consistent but non-significant decline in CSF GFAP-IgG titers (p = 0.063).

In this case series, adding efgartigimod to corticosteroids was associated with rapid clinical improvement and sustained remission in refractory autoimmune GFAP astrocytopathy. These findings support further evaluation of FcRn blockade as a potential adjunctive therapy.