Study to Evaluate the Efficacy and Safety of Dimethyl Fumarate (Tecfidera) and Peginterferon Beta-1a (Plegridy) for the Treatment of Relapsing-Remitting Multiple Sclerosis in Pediatric Participants

Participants will be randomized in a 1:2:2 ratio to receive the double-blind study treatment (Dimethyl Fumarate, Peginterferon Beta-1a, and placebo). Participants experiencing a confirmed relapse or disability progression or high lesion burden on MRI will have the option to discontinue the blinded study treatment and switch to an alternative therapy or open-label BG00012.