Participants with relapsing-remitting MS who are newly prescribed and will start treatment with Tecfidera in a real-world clinical practice setting will be observed prospectively for up to 24 months.

This is a non-interventional study.

An AE is defined as any untoward medical occurrence in a participant administered a pharmaceutical product that does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a study drug, whether or not related to the study drug.

An ADR is defined as all the adverse and unintended responses which are generated from the normal administration/use of study drugs which are cases of not excluding the casual relationship with the study drug, and which shall be regarded as ADRs in the case the relationship with study drug is not known among AEs reported voluntarily.

A SAE is defined as any untoward medical occurrence at any dose that meets any of the following criteria: is fatal or life-threatening; requires inpatient hospitalization or prolongation of existing hospitalization; results in persistent or significant disability/incapacity; constitutes a congenital anomaly/birth defect; or includes other important medical events.

SADRs are defined as SAEs considered related to Tecfidera by the treating physician.

An AE is defined as any untoward medical occurrence in a participant administered a pharmaceutical product that does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a study drug, whether or not related to the study drug. Expectedness of events are determined according to the approved local label. Unexpected AE is except for any expectedness of events. An unexpected AE is defined as an AE with a difference in nature, severity, specificity, or outcome, compared to the product licensure/safety notification of the drug.

Annualized relapse rate will be calculated as the total number of relapses experienced divided by the total number of participant-years on study treatment. A relapse is defined as the appearance of a new neurological abnormality, or worsening of previously stable, or improving pre-existing neurological abnormality, separated by at least 30 days from the onset of a preceding clinical demyelinating event.