Long-Term Adverse Events of Rituximab in Multiple Sclerosis Patients, Isfahan, Iran.

Background: This study's objective was to assess the adverse events (AEs) of rituximab (RTX) therapy in people with multiple sclerosis (pwMS).

Methods: This observational study was conducted on clinical data of pwMS who visited an MS center in Iran from January 2015 to January 2018 and underwent RTX therapy. The primary efficacy outcomes assessed were disability progression and the annual relapse rate. Initially the patients received 2 g of RTX (Zytux AryoGen Pharmed Company Iran) delivered in four 500-mg doses via an intravenous line each of which took 6 hours to avoid unwanted reactions. Afterward two 500-mg doses of RTX were administered every 6 months. we administered each dose within 4-6 hours to minimize unwanted reactions.

Results: A total of 307 RTX-treated patients were included in the study. Around 75.2% of patients were female. The mean (standard deviation (SD)) age was 37.9 (9) years, and the mean (interquartile range (IQR)) disease duration was 7 (7) years. During treatment, the Expanded Disability Status Scale (EDSS) remained unchanged for patients with shorter disease duration (<3 years), and it was significantly improved for patients with longer disease duration (>3 years, P value = 0.015). Around 39.4% of the patients had at least one side effect, most of which were minor infections of the urinary and respiratory tract, all mild in nature.

Conclusions: RTX treatment is well-tolerated and safe, with a minor risk of mild infusion reactions and minor side effects for MS patients.