Observation of the efficacy of ofatumumab in the treatment of neuromyelitis optica spectrum disorders

Abstract

Objective To investigate the efficacy and safety of ofatumumab in the treatment of neuromyelitis optica spectrum disorders (NMOSDs). Methods The clinical data of 25 patients with NMOSDs hospitalized in The First Affiliated Hospital of Zhengzhou University from April 2022 to March 2023 and treated with ofatumumab were retrospectively analyzed. They were divided into 2 groups, Group A with 12 cases receiving regular medication, and Group B with 13 cases receiving medication based on the percentage of CD19+B lymphocytes. Annual relapse rate (ARR), the number of relapses, the frequency and time of relapses, and the symptoms of relapses were calculated before and at one year of medication. The neurological function was assessed by Expanded Disability Status Scale (EDSS) before and at one year of medication. The adverse drug reactions were recorded during medication. Results After one year treatment with ofatumumab, 3 patients (12%) experienced recurrence. One patient in Group A experienced recurrence twice, one month and 5 months after treatment, respectively. At the second recurrence, the percentage of CD19+B lymphocytes was 2.80%. Two patients in Group B experienced recurrence, one patient relapsed twice at 2 and 6 months after medication. The percentage of CD19+B lymphocytes was 0.80% and 0.21%, respectively; another patient relapsed once at 2 months after medication. At the time of recurrence, the percentage of CD19+B lymphocytes was 0.70%. There was a statistically significant difference in ARR before and after one year treatment (F = 29.061, P = 0.000). After one year's treatment, the ARR of Group A (t = 13.215, P = 0.001) and Group B (t = 19.259, P = 0.000) was decreased than before. There were 8 cases of the injection site pain, 3 cases of fever after injection, and one case of headache after injection. There were no serious adverse reactions such as disability and death, and EDSS scores were not increased. Conclusions Continuous administration of ofatumumab every 3 months or based on the percentage of CD19+B lymphocyte can reduce recurrence. Combination with corticosteroids should be alert to the risk of infection.

Keywords

• neuromyelitis optica
• ofatumumab (not in mesh)
• recurrence
• drug-related side effects and adverse reaction