Ofatumumab treatment for severe refractory anti-NMDAR encephalitis: A case series.

Rituximab is recommended as the preferred second-line immunotherapy for autoimmune encephalitis (AE). However, Ofatumumab (OFA), a novel fully human anti-CD20 antibody, has been reported infrequently in patients with AE. Among the various forms of AE, anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis is the most common and severe. This study presents three cases of severe anti-NMDAR encephalitis treated with OFA following the failure of first-line immunotherapy. The results indicated that the patients experienced no significant adverse reactions after receiving OFA, and their clinical symptoms improved markedly within one week of treatment. One month post-treatment with OFA, scores on the Glasgow Coma Scale (GCS) and the Barthel Index of Activities of Daily Living (Barthel-ADL) increased, while scores on the modified Rankin Scale (mRS), Clinical Assessment Scale in Autoimmune Encephalitis (CASE), and Paroxysmal Sympathetic Hyperactivity Assessment Measure (PSH-AM) decreased. During the three-month and six-month follow-up periods, patients exhibited further symptomatic improvement, suggesting that OFA is a safe and effective treatment option for anti-NMDAR encephalitis. These findings propose a novel therapeutic strategy for severe refractory anti-NMDAR encephalitis.