A Study of Dimethyl Fumarate (DMF) in Relapsing Forms of Multiple Sclerosis (RMS) Participants in China

• Dimethyl fumarate (Drug), also known as Tecfidera, DMF, BG00012: Administered as specified in the treatment arm.

Primary outcomes

• Annualized Relapse Rate (ARR) [Week 48]: ARR is defined as the number of confirmed MS relapses in a year. MS relapse is defined as new or recurrent neurologic symptoms, not associated with fever or infection, lasting for at least 24 hours, accompanied by one or more of the following: New objective neurological findings upon examination by the treating neurologist that are functionally consistent with findings on the Expanded Disability Status Scale (EDSS) (performed within 5 days of onset of symptoms) with an increase over the prior visit of ≥0.5 for the total score, an increase of ≥2 in 1 functional system (FS), except bladder/cognitive changes, and/or an increase of ≥1 in 2 FS, except bladder/cognitive changes

Secondary outcomes

• Change From Baseline in Number of Gadolinium-Enhancing (GdE) Lesions [Week 24]
• Number of GdE Lesions [Week 24 and 48]
• Percentage of Participants GdE-Lesion Free [Week 24 and 48]
• Percentage of Participants Relapsed [Week 48]
• Number of New T1 Hypo-Intense Lesions [Baseline, Week 24 and 48]
• Number of New/Newly Enlarging T2 Hyperintense Lesions [Baseline, Week 24 and 48]
• Total T2 Lesion Volume [Week 24 and 48]
• Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs) [Up to Week 50]: An AE is any untoward medical occurrence in a participant or clinical investigation participant administered a pharmaceutical product and that does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal assessment such as an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal (investigational) product, whether or not related to the medicinal (investigational) product. An SAE is any untoward medical occurrence that at any dose results in death, in the view of the Investigator, places the participant at immediate risk of death, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, results in a congenital anomaly/birth defect and is a medically important event.
• Number of Participants With Change from Baseline in Clinical Laboratory Parameters, Electrocardiogram (ECG), and Vital Signs [Baseline to Week 48]
• Number of Participants With Columbia-Suicide Severity Rating Scale (C-SSRS) Events [Baseline to Week 48]: The C-SSRS is a clinician-administered instrument that systematically assess suicidal ideation and behavior rating scale. It rates an individual's degree of suicidal ideation (SI) on a scale, ranging from "wish to be dead" to "active suicidal ideation with specific plan and intent." The scale identifies SI severity and intensity, which may be indicative of an individual's intent to commit suicide. C-SSRS SI severity subscale ranges from 0 (no SI) to 5 (active SI with plan and intent). The scale identifies specific behaviors ranging from "preparatory acts or behavior" to "suicide" which may be indicative of an individual's intent to complete suicide.

Sex: All, ages: 18 Years to 65 Years

Key Inclusion Criteria:

* Must have a baseline (pre-dose on Day 1) Expanded Disability Status Scale (EDSS) between 0.0 and 5.0, inclusive.
* Must have experienced at least 1 documented relapse within the 12 months before screening, with a prior brain magnetic resonance imaging (MRI) demonstrating lesion(s) consistent with MS or have showed evidence of GdE lesion(s) of the brain on an MRI performed within the 6 weeks prior to screening.

Key Exclusion Criteria:

* An MS relapse that occurred within the 30 days prior to screening and/or the participant has not stabilized from a previous relapse prior to screening.
* Current hepatitis C infection and current hepatitis B infection. Participants with immunity to hepatitis B from previous natural infection or vaccination are eligible to participate in the study.
* History of severe allergic or anaphylactic reactions or of any allergic reactions that, in the opinion of the Investigator, are likely to be exacerbated by any component of the study treatment.
* History or positive test result at screening for human immunodeficiency virus (HIV).
* Use at the time of enrollment and/or anticipated ongoing use of any traditional and/or unlicensed medicines and/or traditional therapies and/or herbal preparations, which are known or considered by the Investigator to affect MS and endpoints that are being considered in the study, including safety and efficacy.
* Current enrollment in any other investigational drug study or participation in any other investigational study within 6 months prior to screening.

NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.

• Medical Director, Study director, Biogen