Long-Term Clinical and Psychological Efficacy and Safety of Ocrelizumab in People With Multiple Sclerosis: A Real-World Longitudinal Study

Abstract

Background: Multiple sclerosis (MS) is the most prevalent immune-mediated neurodegenerative disease affecting the central nervous system. Ocrelizumab, a humanized anti-CD20 monoclonal antibody, has demonstrated significant efficacy in reducing disease activity and improving clinical outcomes of people with MS (PwMS) in clinical trials. However, real-world data are crucial for assessing the efficacy and safety of ocrelizumab. Thus, the current study aimed to evaluate the long-term clinical and psychological efficacy and safety profile of ocrelizumab in PwMS compared with other disease-modifying therapies (DMTs). Methods: This longitudinal study was carried out between January 2022 and February 2024 in Isfahan, Iran. 51 PwMS were included, of whom 21 patients were DMT-na & iuml;ve, while 30 patients were on other DMTs, including interferon-beta, fingolimod, dimethyl fumarate, natalizumab, or teriflunomide. Demographic characteristics, clinical outcomes, including Expanded Disability Status Scale (EDSS), annualized relapse rate (ARR), timed 25-foot walk (T25FW) test, and nine-hole peg test (9-HPT), as well as psychological measures including anxiety, depression, and fatigue, were evaluated at baseline (T0), and 12 months (T1) and 24 months (T2) of follow-up. Adverse events (AEs) were obtained using chart review and patient self-reports in clinical visits. Results: ARR was significantly decreased at T1 (Z = -5.4, p < 0.001) and T2 (Z = -4.03, p < 0.001) in PwMS who received ocrelizumab. Similarly, a significant decrease was found in 9-HPT (Z = -5.16, p < 0.001) and T25FW (Cohen's d = -0.72, p < 0.001) at T1. Depression and fatigue significantly improved at T1 (Z = -3.89, p < 0.001, Cohen's d = -1.16, p < 0.001, respectively) and further at T2 (Z = -2.18, p = 0.029, Cohen's d = -1.59, p < 0.001, respectively), and anxiety at T1 (Z = -3, p = 0.003). PwMS who initiated ocrelizumab as a first-line therapy showed a significantly greater reduction in ARR, 9-HPT, and T25FW than those previously treated with other DMTs (all p < 0.05), while no significant differences were observed in terms of changing EDSS, anxiety, depression, or fatigue levels. Respiratory infections (13.7), infusion-related reactions (5.9), and headache (5.9) were the most frequent AEs, and no serious infection was observed. Conclusion: Ocrelizumab may reduce disease activity and improve functional and psychological outcomes in PwMS, while maintaining a favorable safety profile. Moreover, relapse rates and functional impairment were improved more in groups that initiated ocrelizumab as a first-line therapy than in other disease-modifying therapies. These findings suggest that ocrelizumab is a promising first-line treatment in MS. However, further studies are needed to confirm these preliminary results.