Efficacy and Safety of Telitacicept and Mycophenolate Mofetil in the Treatment of Neuromyelitis Optica Spectrum Disorders.

BACKGROUND AND OBJECTIVES: To compare the efficacy and safety of telitacicept versus mycophenolate mofetil (MMF) in reducing relapses and disability in adults with neuromyelitis optica spectrum disorder (NMOSD). METHODS: In this retrospective cohort study, we analyzed 41 adults with NMOSD (2015 diagnostic criteria). Patients received ≥6 months of telitacicept or MMF treatment. Primary outcomes were annualized relapse rate (ARR) and relapse-free survival; secondary outcomes included Expanded Disability Status Scale (EDSS) score, CD19 + B-cell count, and safety. RESULTS: Over a median follow-up of 8 months for telitacicept (n = 15) and 9 months for MMF (n = 26), patients receiving telitacicept exhibited an 86.7% relapse-free rate (13/15) versus 57.6% (15/26) with MMF, with a significantly prolonged time to first relapse (hazard ratio 0.22, 95% confidence interval: 0.05-0.91; P = 0.04). The magnitude of ARR reduction was significantly greater with telitacicept (median ΔARR 2.0 [interquartile range (IQR) 2.0-4.0]) than with MMF (2.0 [1.0-2.0]; P = 0.007). Neurological function improved markedly, evidenced by a 2.5-point reduction (IQR: 2.0-3.0) in EDSS scores with telitacicept versus 0.5 points (IQR: 0.5-1.0) for MMF ( P < 0.001). Mechanistically, telitacicept induced deeper CD19 + B-cell suppression (Δ51.0 cells/μL [42.0-70.0]) than MMF (Δ28.5 cells/μL [8.0-40.2]; P = 0.002). Safety profiles favored telitacicept, with adverse events occurring in 20.0% (3/15) versus 42.3% (11/26) in the MMF group, though no severe events were observed in either cohort. CONCLUSION: Both telitacicept and MMF demonstrated favorable clinical efficacy and safety in NMOSD treatment. Compared with MMF, telitacicept exhibits potential advantages and holds promising prospects for clinical application.