Efficacy of ofatumumab combined with corticosteroids in the treatment of autoimmune encephalitis: a 6-month cohort study

This study investigated the efficacy of ofatumumab (OFA) combined with corticosteroids in autoimmune encephalitis (AE) patients refractory to conventional treatment.

Eighteen AE patients admitted to Ruijin Hospital between June 2022 and September 2023 received four subcutaneous 20-mg OFA injections at 0, 1, 6, and 12 weeks combined with standard corticosteroid therapy.

Clinical symptoms, modified Rankin scale (mRS) scores, Clinical Assessment Scale for Autoimmune Encephalitis (CASE) scores, serum immunoglobulin (Ig) levels (IgG and IgM), and peripheral blood CD20 + B cell levels were documented before OFA administration and at 1, 2, 6, 12, and 24 weeks post-treatment. OFA treatment significantly improved psychiatric symptoms (P = 0.025), cognitive dysfunction (P = 0.008), and seizure frequency (P = 0.014). The mRS and CASE scores improved after two injections in patients with anti-NMDAR encephalitis (P = 0.041), but not in patients with anti-LGI1 encephalitis (P > 0.05). The mRS scores significantly improved at 12 weeks post-treatment in antibody-negative encephalitis. Blood CD20 + B cell levels dropped to zero after an average of 2.5 injections. No significant changes could be observed in serum IgG and IgM levels (P > 0.05). Seven patients had mild fever or pulmonary infections post-treatment.

This study suggests that OFA is a safe and effective treatment for a subset of AE patients, particularly in cases of anti-NMDAR encephalitis, though further research is needed on long-term outcomes and recurrence.