Objective: To evaluate the effectiveness and safety of Ocrelizumab treatment for Pediatric-onset multiple sclerosis (POMS)

Background: POMS patients tend to have a higher rate of relapses and progression to secondary progressive course at earlier age compared to adult-onset MS. Although Ocrelizumab, a recombinant humanized anti-CD20 monoclonal IgG1, approved by FDA and EMA for adult patients with multiple sclerosis (AOMS), limited data in the literature is found in regards to its efficacy and safety in POMS subsets.

Methods: A retrospective study was conducted on POMS patients who had Ocrelizumab treatment initiated at an age younger than 18 years old with at least one year of follow-up were included. The primary end-point was the proportion of relapse-free patients at the end of observational period. The secondary end-points were the change of annualized relapse rate (ARR), Expanded Disability Status Scale (EDSS) score, and proportion of patients with no MRI activity (new/enlarging T2 lesions and gadolinium (Gd) enhancing lesions).

Results: Of the 24 POMS patients enrolled in the study, 58.3 % were females with a mean age of 16.33 years. Prior to the administration of Ocrelizumab, all patients had clinical and radiological activities, of whom 23 were naïve and one had prior therapy. The median duration of follow-up under Ocrelizumab was 15 months. At the end of follow-up visits, 91.7 % of patients were relapse-free, with a decrease in the mean ARR from 1.08 to 0.08; p < 0.001. Nonetheless, only one patient (4.2 %) had MRI activity during the treatment course. Mean EDSS was stabilized in 75 % of patient and improved in 16.7 % patients. None of the patients had serious side effects

Conclusion: Ocrelizumab can be considered a safe and effective treatment for POMS with RRMS.