Real-world observational study of ocrelizumab and ofatumumab in patients with multiple sclerosis in Brazil

Abstract

Background: Anti-CD20 therapies are widely used in multiple sclerosis (MS), and real-world data may complement findings from clinical trials. Objective: The objective is to evaluate the effectiveness and safety of ofatumumab and ocrelizumab in patients with MS in a real-world setting. Methods: This was a single-center, retrospective, longitudinal observational study based on medical record review from January 2021 to October 2025 at a tertiary neurological referral center. Patients aged 18 to 65 years with an MS diagnosis according to the 2010/2017 McDonald criteria, receiving continuous treatment with either ofatumumab or ocrelizumab for at least 6 months, under regular neurological follow-up, and with complete data available were included. Results: The final sample comprised 166 patients: 62 receiving ofatumumab and 104 receiving ocrelizumab. Female patients predominated in both groups (74.2% in the ofatumumab group and 71.2% in the ocrelizumab group). Mean age was 38.7±9.76 and 41.8±11.51 years, respectively. Ofatumumab was used predominantly in relapsing-remitting MS (91.9%), whereas ocrelizumab was more frequently prescribed for progressive phenotypes (PPMS 15.4%; SPMS 17.3%). Previous exposure to another disease-modifying therapy was observed in 58.1% and 84.6% of patients, respectively. Among treatment-naive patients, the main indication for anti-CD20 initiation was high inflammatory and/or radiological activity. On MRI follow-up, no new FLAIR or gadolinium-enhancing lesions were observed in the ofatumumab group, compared with 2.9% and 1.0%, respectively, in the ocrelizumab group. Infusion-related reactions within 48 hours were more frequent with ofatumumab (37.1% vs 16.3%). Treatment-related infections occurred in 3.2% and 10.6%, while malignancies were reported in 1.6% and 1.0%, respectively. Conclusion: In this real-world cohort, both therapies showed an overall acceptable safety profile. Ofatumumab demonstrated better radiological control in the evaluated sample, whereas ocrelizumab was more frequently used in patients with progressive disease and greater prior DMT exposure. Further comparative studies are warranted.