- He/she must have been on therapy for at least 6 months (unless experiencing highly active disease), have at least 9 T2-hyperintense lesions on a brain MRI scan, and have experienced ≥1 relapse within the last 6 months prior to study screening with ≥1 new T1-Gd+ lesion on a brain MRI scan performed ≤6 months prior to study screening or ≥2 new T2 lesions on a brain MRI scan performed ≤6 months prior to study screening, with comparison made to a T2 MRI scan performed up to 18 months before study screening