Fewer Serious Infections Found in MS Patients Treated with Natalizumab Vs Ocrelizumab

A study based on a large insurance claims database found that individuals diagnosed with multiple sclerosis (MS) treated with natalizumab (Tysabri; Biogen, Cambridge, MA) experienced lower rates of infection-related hospitalizations than those treated with ocrelizumab (Ocrevus; Genentech, South San Francisco, CA). The differences in hospitalizations between the two groups were significant, with 3.2% of those treated with natalizumab experiencing ≥1 inpatient infection-related encounter (hospitalization) compared with 7.8% in those taking ocrelizumab (OR: 0.39 [95% CI, 0.24-0.64], P=.0002). The mean annualized rate of infection-related hospitalization was significantly lower for natalizumab-treated than ocrelizumab-treated patients (0.07 vs 0.17 encounters per year; mean difference, –0.01 [95% CI, –0.15, –0.06], P<.0001).

Researchers evaluated retrospective Optum claims data from 2017 to 2021 for individuals diagnosed with MS and treated with either of the two disease-modifying therapies. Outcomes included the proportion of patients experiencing ≥1 inpatient infection encounter and the annualized rate of infection-related hospitalizations.

Data were available for 909 natalizumab-treated patients and 4,174 ocrelizumab-treated patients. After inverse probability weighting, natalizumab and ocrelizumab cohorts were well-balanced, with all standardized mean differences ≤0.1. Mean (SD) follow-up times were 374 days (354 days) and 414 days (335 days) for natalizumab- and ocrelizumab-treated patients, respectively. Data from this real-world head-to-head study were presented at the eighth annual Americas Committee for Treatment and Research in Multiple Sclerosis (ACTRIMS) Forum 2023.