Key Inclusion Criteria Core Phase:
diagnosis of multiple sclerosis
at least one MS relapse during the previous year or two MS relapses in the previous 2 years or evidence of Gd enhancing lesions on MRI within 6 months EDSS score of 0 to 5.5, inclusive
Key Exclusion Criteria Core Phase:
patients with progressive MS
patients with an active, chronic disease of the immune system other than MS
patients meeting the definition of ADEM
patients with severe cardiac disease or significant findings on the screening ECG.
patients with severe renal insufficiency
Key Inclusion Criteria Extension Phase:
Applies to all patients participating in the Core Phase and then entering the Extension Phase. 1. Patients that originally met Core Phase Inclusion criteria and completed the Core phase on or off of study drug.
Applies to patients newly recruited to participate in the Extension Phase.
All newly recruited patients' that enroll directly into the Extension Phase must fulfill the local country health authority product label approved for pediatric age group for inclusion criteria.
Central review (including initial MRI report) of the diagnosis of pediatric MS will be required for all newly recruited patients.
Key Exclusion Criteria Extension Phase:
Applies to patients who completed the Core Phase, but prematurely discontinued study drug.
Premature discontinuation of the study drug during the Core Phase due to:
an adverse event,
serious adverse event,
other conditions leading to permanent study drug discontinuation due to safety reasons
Patients with known new events or concomitant medications (washout periods required prior to Visit 15) that would exclude them from the Core Phase exclusion criteria. Serological or other additional tests will not be required.
Applies to patients newly recruited in the younger cohort to participate in the Extension Phase.
1. All newly recruited patients in the younger cohort that enroll directly into the Extension Phase must fulfill the exclusion criteria for the core phase.