In adults aged 55 and older with multiple sclerosis (MS), treatment with ocrelizumab is associated with higher rates of infection-related hospitalizations and infections, according to a study. This was reported by a research team led by Seungwon Lee and Farrah J. Mateen in "The Lancet Regional Health. Americas" (DOI: 10.1016/j.lana.2026.101640). Registration trials for ocrelizumab excluded adults over 55 years of age.
This retrospective cohort study analyzed electronic patient records from Massachusetts General Hospital from June 2017 to January 2026. It compared 800 elderly MS patients who received at least 600 milligrams of ocrelizumab intravenously with 800 elderly patients who had never received B-cell-depleting therapy. The median follow-up time was 3,5 and 8,2 years, respectively.
A total of 429 infection-related hospitalizations occurred (164 in the ocrelizumab group, 265 in the control group), along with 10 infection-related deaths (2 vs. 8) and 4538 infections (1597 vs. 2941). After adjustment, ocrelizumab was associated with a higher rate of infection-related hospitalizations (IRR 1,67; 95% confidence interval 1,15–2,43; p = 0,008) and infections (IRR 1,42; 95% confidence interval 1,20–1,68; p < 0,001). Higher disability and comorbidity independently increased the risk for both endpoints. Female sex was associated with a higher risk of infection (IRR 1,36; 1,12–1,64; p = 0,002), mainly through urinary tract infections, which accounted for 91,46 percent of the observed sex difference.
The authors view the results as supporting an individual benefit-risk assessment, particularly with regard to urinary tract infections in older patients. They advocate for specific monitoring and prevention protocols for urinary tract infections in older patients treated with ocrelizumab, as well as the inclusion of this age group in future clinical trials. This work was funded by an Investigator-Initiated Grant from Genentech.
