This study aims to evaluate the efficacy and safety of inebilizumab in Chinese patients with AQP4 antibody-positive neuromyelitis optica spectrum disorder (NMOSD) through multicenter and large-sample data.

Inebilizumab is a humanized anti-CD19+ B-cell-depleting agent for the treatment of adult NMOSD patients with AQP4-IgG positivity. It has been marketed in China for about 3 years. However, there is still a lack of multicenter and large-sample data to validate its efficacy and safety in the real-world setting of China.

We conducted a real-world study in five centers in the central and western regions of China, and prospectively collected all patients who received inebilizumab treatment from March 2023 to June 2025. We analyzed the disease relapse status of patients, as well as the dynamic changes in the Expanded Disability Status Scale (EDSS) scores and CD19+ B lymphocyte counts. Adverse events were recorded too.

The study included 138 AQP4-IgG-positive NMOSD patients (86.2% female, mean age 44.8±13.9 years) with a median follow-up of 12.5 months (range 0.4–25.4 months). Only 5 patients relapsed during follow-up. Annualized relapse rate(ARR) decreased from 1.10 before treatment to 0.04. Three patients were lost to follow-up due to relapse and medication change. EDSS mean scores significantly decreased from a baseline of 3.25 to 2.53 at six month and 2.0 at 12 months (p < 0.001). CD19+ B lymphocyte counts also dropped from 268.01/μl to 4.59/μl at six months and 16.69/μl at 12 months (p < 0.001). Serum immunoglobulin levels decreased, but most patients maintained IgG levels above 5g/L. 

The large-sample real-world data from China show that inebilizumab significantly reduces the relapse rate and EDSS scores in AQP4-IgG-positive NMOSD patients with no serious adverse reactions reported. This indicates inebilizumab is an effective and safe treatment option for NMOSD patients in real-world setting. Longer follow-up data to be gathered.