In patients with relapsing remitting MS, Extavia was more effective than placebo in reducing the number of annual relapses: patients receiving the medicine had on average 0.84 relapses a year, when patients on placebo had 1.27 relapses.
One of the two studies in patients with secondary progressive MS showed a significant delay in the time to disability progression (31% risk reduction due to Extavia) and in the time to becoming wheelchair bound (39%). In the second trial, no delay in the time to disability progression was seen. In both trials, Extavia showed a reduction in the number (30%) of clinical relapses.
In the study of patients with a single demyelinating event, Extavia was shown to reduce the risk of developing clinically defined MS: 28% of the patients who received Extavia developed MS, against 45% of those who received placebo.