Personalized Ofatumumab therapy for autoimmune encephalitis: A case series of four patients

Autoimmune encephalitis (AE), a prevalent neuroimmunological disorder, is primarily managed with immunotherapy. However, a subset of patients exhibits suboptimal responses to first-line treatments, and second-line options remain limited. This study investigates the efficacy and safety of a personalized ofatumumab (OFA) regimen guided by monitoring CD27 + CD19+ memory B cells in refractory AE.

We report three cases of anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis and one case of antibody-negative AE (NA-AE) refractory to corticosteroids and intravenous immunoglobulin (IVIG). OFA was initiated at 20 mg subcutaneously on days 0 and 7, with subsequent doses administered when peripheral blood CD27 + CD19+ memory B cells exceeded 0.05 % of peripheral blood mononuclear cells (PBMCs).

After a median follow-up of 10 months (range: 6-12 months), all patients demonstrated clinical improvement, with significant reductions in modified Rankin Scale (mRS) and Clinical Assessment Scale in Autoimmune Encephalitis (CASE) scores. One patient experienced relapse post-SARS-CoV-2 infection, while the remainder remained recurrence-free without drug-related adverse events.

CD27 + CD19+ memory B cell-guided OFA therapy may offer a novel strategy for refractory AE.