The primary objective of the study is to evaluate the real-world clinical effectiveness, as measured by the proportion of participants relapsed at 12 months, in participants treated with dimethyl fumarate (DMF).

Secondary objectives of the study are: To evaluate the real-world clinical effectiveness, as measured by the proportion of participants relapsed at 12 months, in participants treated with DMF, glatiramer acetate (GA), teriflunomide, or fingolimod both in the overall participant cohort and in a subset of participants who were naïve to disease-modifying therapy (DMT) and were diagnosed with multiple sclerosis (MS) within 3 years of starting the index therapy; To compare relapse activity, defined as annualized relapse rate (ARR), among participants treated with DMF, GA, teriflunomide, or fingolimod; To compare MS-related hospitalizations among participants treated with DMF, GA, teriflunomide, or fingolimod; To compare intravenous corticosteroid use among participants treated with DMF, GA, teriflunomide, or fingolimod.

Key Inclusion Criteria:

• Diagnosis of RRMS per McDonald criteria
• Initiated treatment with DMF, GA, teriflunomide, or fingolimod (defined as index therapy) no earlier than January 2011 and no later than 12 months prior to the date of medical record abstraction (i.e., patient has at least 12 months of data available in the medical record following initiation of index treatment). Note: Patients who have initiated the index therapy but subsequently discontinued or switched to other therapies are allowed in this study as long as there is at least 12 months of follow-up following the initiation of the index therapy.
• Have sufficient available medical records for data abstraction to meet the objectives of the study, i.e., the patient was either under the medical care of the investigating site during the entire period of the index treatment or the patient's complete MS disease and treatment history is otherwise available at the investigating site

Key Exclusion Criteria:

• Diagnosis of a progressive form of MS (progressive relapsing, primary progressive, secondary progressive) at any time before or during the period for which data will be collected
• Have received disease-modifying therapies other than one platform therapy (IFN or GA) prior to initiation of index therapy. In patients for whom GA is index therapy, only one prior IFN therapy is allowed.
• Have received any formulations of DMF, Fumaderm®, or compounded fumarates (e.g., Psorinovo) at any time prior to initiation of treatment with Tecfidera®
• Concurrent enrollment in any interventional clinical trial of an investigational product during time evaluated for medical record abstraction

NOTE: Other protocol defined Inclusion/Exclusion criteria may apply

Participants with a diagnosis of RRMS treated with dimethyl fumarate, fingolimod, teriflunomide, or glatiramer acetate in routine clinical practice.