This phase 3b randomized trial involved 1,013 patients with primary progressive multiple sclerosis aged 18 to 65 years. Participants were treated at 138 sites across 22 countries. They received either intravenous ocrelizumab 600 mg every six months or a placebo for 144 weeks. The main goal was to see how long it took for disability to worsen, measured by specific tests like the 9-Hole Peg Test or the Expanded Disability Status Scale.
The results showed that ocrelizumab reduced the risk of disability progression by 30% compared to placebo. Among patients with MRI activity at the start of the study, the risk reduction was even higher at 55%. The difference in disability progression was clear and statistically significant.
Regarding safety, more infections occurred in the ocrelizumab group than the placebo group. However, rates of serious adverse events were similar between the two groups. The study authors noted a manageable safety profile. Readers should understand that while the drug helps delay disability, it does not cure the disease, and infection risks remain a consideration for patients and doctors.