Participants who were free of new or newly enlarging T2 hyperintense lesions were assessed on Brain MRI scans.

An adverse event (AE) was any unfavorable and unintended sign (including an abnormal assessment such as an abnormal laboratory value), symptom, or disease temporally associated with the use of a medicinal (investigational) product, whether or not related to the medicinal (investigational) product. An SAE was any untoward medical occurrence that at any dose resulted in death, in the view of the Investigator, placed the participant at immediate risk of death, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, resulted in a birth defect. TEAEs were defined as AEs occurring or worsening after beginning study treatment (after the first dose).

An AE was any unfavorable and unintended sign (including an abnormal assessment such as an abnormal laboratory value), symptom, or disease temporally associated with the use of a medicinal (investigational) product, whether or not related to the medicinal (investigational) product.

An adverse event (AE) is any untoward medical occurrence in a participant or clinical investigation participant administered a pharmaceutical product and which does not necessarily have a causal relationship with this treatment.

An AE was any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of the study drug, whether or not related to the study drug. A serious adverse event (SAE) was any untoward medical occurrence that, at any dose: resulted in death; in the view of the Investigator, placed the participant at immediate risk of death (a life-threatening event); required inpatient hospitalization or prolongation of existing hospitalization; resulted in persistent or significant disability/incapacity; resulted in a congenital anomaly/birth defect; was any other medically important event that, in the opinion of the Investigator, jeopardized the participant or required intervention to prevent one of the other outcomes above. TEAE was defined as having an onset date that was on or after the start of study treatment (BG00012), or that worsened after the start of study treatment.

Percentage of participants with potentially clinically significant hematology laboratory abnormalities.

Percentage of participants with post-baseline liver enzyme values above the upper limit of normal (ULN). Liver enzymes included alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transpeptidase (GGT), and bilirubin. Elevated ALT/AST (ALT/AST ≥ 3\*ULN) concurrent with elevated total bilirubin was also evaluated.

Percentage of participants with post-baseline values for selected urinalysis parameters requiring further evaluation. For urine microscopy, results were categorized for male and female participants. For males, normal/negative was considered 0 to 3 red blood cells/high-power field (rbc/hpf), and positive was categorized in the following stages: 4 to 10, 11 to 20, 21 to 149, and ≥ 150 rbc/hpf. For females, normal/negative was considered 0 to 8 rbc/hpf, and positive was categorized in the following stages: 9 to 20, 21 to 30, 31 to 149, and ≥ 150 rbc/hpf.