This real-life study aims to describe IgG levels after switching from ocrelizumab 600 mg IV every 6 to 8 months in Patients with Multiple Sclerosis (PwMS) to ofatumumab 20 mg SC every month and showing a decreasing level of IgG during treatment by ocrelizumab in real life practice in France over 24 months of follow-up.
The primary objective is therefore to determine if the downward trend of IgG observed during ocrelizumab treatment is modified after a switch to ofatumumab, in PwMS treated during at least 18 months of ocrelizumab in real life practice, over 24 months of follow-up.