A protocol-defined relapse was defined as new or recurrent neurologic symptoms not associated with fever or infection that lasted at least 24 hours, and were separated by at least 30 days from onset of a preceding relapse. All protocol-defined relapses were evaluated by an independent neurolgic evaluation committee. The proportion of subjects with a relapse was estimated using the Kaplan-Meier method, which was based on the time-to-first-relapse survival distribution.

The analysis was based on the ITT population, defined as all subjects who were randomized and received at least 1 dose of study medication. Among subjects who switched to an alternative therapy for multiple sclerosis, all the data before the switch were used for the analysis. In all other subjects, all relapses were included in the analysis.

The number of new or newly enlarging T2 hyperintense lesions at 2 years that developed in each subject compared to baseline assessed on brain magnetic resonance imaging (MRI) scans. The estimates of mean T2 lesion count were calculated from a negative binomial regression model adjusted for region and baselineT2 lesion volume

Of the 540 subjects included in the MRI cohort, 469 subjects (165 placebo, 152 BG00012 BID, 152 BG00012 TID) had post-baseline T2 data and were included in the analysis. Missing data before the use of alternative MS medications and visits after patients switched to alternative MS medications were imputed with the use of a constant rate assumption.

The number of Gd-enhancing lesions was assessed using brain MRI scans following administration of gadolinium, a contrast agent. The mean number of Gd-enhancing lesions at 2 years was the average of the number of lesions at 2 years in a treatment group.

Of the 540 subjects included in the MRI cohort, 469 (165 placebo,152 BG00012 BID,152 BG00012 TID) had post-baseline Gd-enhancing lesion data & were included in the analysis. Missing data before the use of alternative MS medications & visits after patients switched to alternative MS medications were imputed with the use of a constant rate assumption

Note: This outcome measure represents the categorical analysis for the previously listed secondary outcome measure "Number of Gadolinium-enhancing T1-weighted lesions"

Of the 540 subjects included in the MRI cohort, 469 (165 placebo,152 BG00012 BID,152 BG00012 TID) had post-baseline Gd-enhancing lesion data & were included in the analysis. Missing data before the use of alternative MS medications & visits after patients switched to alternative MS medications were imputed with the use of a constant rate assumption

A protocol-defined relapse was defined as new or recurrent neurologic symptoms not associated with fever or infection that lasted at least 24 hours, and were separated by at least 30 days from onset of a preceding relapse. All protocol-defined relapses were evaluated by an independent neurologic evaluation committee. The adjusted annualized relapse rate was calculated from a negative binomial regression model, adjusted for baseline EDSS (≤ 2.0 vs. >2.0), age (<40 versus ≥40 years), region, and the number of relapses in the 1 year prior to enrollment.

The ITT population was defined as all subjects who were randomized and received at least 1 dose of study medication. Among subjects who switched to an alternative therapy for multiple sclerosis, all the data before the switch were used for the analysis. In all other subjects, all relapses were included in the analysis.

The EDSS is based on a standardized neurological examination and focuses on symptoms that commonly occur in MS. EDSS scores range from 0.0 (normal) to 10.0 (death due to MS). Disability progression was defined as ≥ 1.0 point increase in subjects with a baseline EDSS of ≥1.0, or a ≥1.5 point increase in subjects with a baseline EDSS = 0, and required that the increase from baseline was confirmed ≥12 weeks later. The proportion of subjects with confirmed (12-week) disability progression was estimated using the Kaplan-Meier method, which was based on the time-to-first-progression survival distribution.

The analysis population consisted of the ITT population (all subjects who were randomized and received at least 1 dose of study medication) who had a baseline EDSS assessment. Analysis were based on all observed data. Onset of disability progression must begin before a subject switched to alternative MS medication.