Efficacy and safety of ocrelizumab in pediatric multiple sclerosis.

INTRODUCTION: Ocrelizumab, a highly effective anti-CD20 monoclonal antibody, is approved for adult use, but pediatric data remain limited. This retrospective cohort study evaluates its safety and efficacy in pediatric-onset multiple sclerosis (POMS) patients at two tertiary hospitals in the UAE-Cleveland Clinic Abu Dhabi (CCAD) and Sheikh Shakhbout Medical City (SSMC). METHODS: Electronic medical records of patients treated with ocrelizumab before age 18 were reviewed. Data collected included demographics, disease characteristics, use of prior disease-modifying therapies, relapse rates, MRI findings, immunoglobulin G (IgG) levels, and Expanded Disability Status Scale (EDSS) scores. RESULTS: Twenty-nine POMS patients (19 CCAD, 10 SSMC) received ocrelizumab before age 18. The cohort was predominantly female (6.25:1 ratio) and UAE nationals (83%). Most had relapsing-remitting MS (97%), with a mean onset age of 14.6 years and a mean treatment initiation age of 15.6 years. Median time from ocrelizumab initiation to last follow-up was 15 months. The annualized relapse rate (ARR) in the RRMS group decreased by 97% post-treatment. EDSS scores remained stable. Two patients experienced mild infusion reactions. Nine (31%) had infections post-treatment, including four COVID-19 cases. One relapse occurred while off treatment; two patients had new MRI lesions. IgG levels remained stable. CONCLUSION: In this cohort, ocrelizumab was well-tolerated with reduced relapse rates and stable disability scores over the short-term follow-up. Larger, prospective studies with longer-term data are needed to confirm safety and efficacy.