Three separate clinical trials have discovered that ocrelizumab can significantly reduce new attacks in patients with relapsing MS, as well as slow the progression of symptoms caused by primary progressive MS.
 
In one study, patients with primary progressive MS were randomized to receive either ocrelizumab, or a placebo. The proportion of patients with 12-week confirmed disability progression was 39.3 percent with the placebo versus 32.9 percent with ocrelizumab. After 24 weeks, the proportion with confirmed disability progression was 35.7 percent with placebo versus 29.6 percent with ocrelizumab. By week 120, timed 25-foot walk worsened by 55.1 per cent for placebo versus 38.9 percent for ocrelizumab. Patients given ocrelizumab were also found to have fewer new brain lesions and less brain volume loss than those given the placebo.
 
Researchers also tested ocrelizumab in two separate studies of patients with relapsing remitting MS. In both studies, patients were randomized to receive either ocrelizumab or an already established treatment for relapsing MS: subcutaneous interferon-beta, injected three times weekly. Relapse rates in patients given ocrelizumab were 46 percent lower in one study and 47 percent lower in the other. Ocrelizumab was found to reduce the risk of disability progression after 12 weeks and 24 weeks, and reduced the number of new brain lesions.
 
The studies were published in the New England Journal of Medicine.