Real-world experience of ocrelizumab in patients with multiple sclerosis: A single-center study

Objective: We aimed in this study to obtain real-world data in MS patients treated with ocrelizumab at our center and examine the drug's efficacy, safety, and side effects. Methods: We conducted a retrospective study and included MS patients receiving at least one infusion therapy of ocrelizumab at our center. Demographic information, clinical and radiological course of the patients, whether they were infected with the COVID-19 virus, vaccination status, and drug-related safety data were collected and analyzed. Results: Two hundred and forty patients meeting the inclusion criteria were included. Before ocrelizumab treatment, the mean annualized relapse rate (ARR) was 0.816 (CI:0.66-0.99) in the RRMS group fell to 0.10 (CI: 0.06- 0.16) after the ocrelizumab initiation(p<0.001). Similarly, ARR fell from 0.44 (CI:0.28-0.67) to 0.04 (CI:0.001-0.13) in the SPMS group after treatment initiation (p<0.001). The most common reason for the treatment change with ocrelizumab was increased disease activity (n:101, measured either clinically, radiological, or both ), disease progression (n:60), or the adverse effects (n: 23 ) of previous DMT. Infection was seen in 80 of 240 patients. The most frequent condition was COVID-19 infection (n=45) related to a pandemic, followed by urinary tract infection (n=18) and upper respiratory tract infection (n=14). While the cancer screening results of 1 patient were within normal limits at the beginning, breast cancer was detected six months after starting ocrelizumab. Conclusions: Our real-world data with ocrelizumab have shown that it is an effective and well-tolerated disease-modifying therapy supporting the results of pivotal studies.