Potentially clinically significant abnormalities (PCSAs) determined by laboratory tests, electrocardiogram (ECG), or vital signs and safety findings on MRI during the study period.

Multiple sclerosis (MS) relapse was defined as a monophasic, acute or subacute onset of new neurological symptoms or worsening of previous neurological symptoms with an objective change on neurological examination. Symptoms were attributable to MS, lasted for \>=24 hours with or without recovery, present at normal body temperature, and preceded by \>=30 days of clinical stability.

An AE was any untoward medical occurrence in a participant or clinical study participant, temporally associated with the use of study drug, whether or not considered related to the study drug. An SAE was any untoward medical occurrence that at any dose: resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent disability/incapacity, was a congenital anomaly/birth defect or was an important medical event. TEAEs were defined as AEs that developed, worsened or became serious during the respective on-treatment periods.