Ocrelizumab (OCR) is a humanized monoclonal antibody directed against CD-20 positive lymphocytes, mainly B-lymphocytes. OCR is approved for treatment of primary progressive (PPMS) and relapsing multiple sclerosis (RMS). This study aims to provide real-world safety and efficacy data of people with RMS treated with OCR in two Swiss Multiple Sclerosis (MS) centers.

We have conducted a retrospective data analysis using the patient cohorts from the Cantonal Hospital Aarau and Bern University Hospital (RMS: n = 235). Statistical analyses were performed with Mann–Whitney U-Test, Chi-squared test and Spearman-Rho-Correlation. Adjustment for multiple testing was performed by Bonferroni procedure.

After initiation of OCR, there was a decrease in disease activity in RMS patients. In our study, 152/190 (80.0 %) RMS patients fulfilled the criteria for NEDA-3 12 months and 88/104 (84.6 %) showed NEDA-3 24 months after OCR initiation. The most frequent adverse events (AEs) in our study were infections, taking place in 78/235 (33.2 %) RMS patients. COVID-19 was the most common infection, followed by urinary infections and other respiratory infections and infectious adverse events occurred significantly more frequent in patients with reduced IgG serum concentration.

Our real-world study showed OCR being associated with low rates of any type of MS disease activity as indicated by NEDA-3. The adverse event profile is comparable to the known events especially infections and an association between infections and reduced IgG serum concentration was found.