Lesions were measured using Gd-enhancing T1-weighted MRI scans. The number of T1-weighted lesions per scan was obtained from the number of T1-weighted lesions observed during a specified week divided by the number of scans performed that same week. To obtain the number of T1-weighted lesions per scan averaged during Weeks 12, 16, 20, and 24, the number of lesions per scan at each week was summed and then divided by the number of visits with non-missing lesion counts.

Randomized participants who had a Gd-enhancing T1-weighted MRI lesion for at least 1 time point among Weeks 12, 16, 20, or 24.

Lesions were measured using Gd-enhancing T1-weighted MRI scans. The number of T1-weighted lesions per scan was obtained from the number of T1-weighted lesions observed during a specified week divided by the number of scans performed that same week. Least squares (LS) mean was calculated using an analysis of variance (ANOVA).

Randomized participants who had a Gd-enhancing T1-weighted MRI assessment at the specified time points.

Lesions were measured using Gd-enhancing T1-weighted MRI scans. The number of new T1-weighted lesions per scan was obtained from the number new T1-weighted lesions observed during a specified week divided by the number of scans performed that same week.

Randomized participants who had a Gd-enhancing T1-weighted MRI assessment at the specified time points.

Lesions were measured using T2-weighted proton density MRI scans.

Randomized participants who had a T2-weighted MRI assessment at the specified time points.

The total volume of T2-weighted lesions was measured using T2-weighted proton density MRI scans. LS mean was calculated using an ANOVA model.

Randomized participants who had a T2-weighted MRI assessment at the specified time points.

The EDSS is a rating scale for quantifying disability in multiple sclerosis (MS) participants. The EDSS has 8 functional systems (pyramidal, cerebellar, brain stem, sensory, bowel and bladder, visual, cerebral, and other) each rated on a scale from 0 (normal) to 5 (severe disability) or 0 (normal) to 6 (severe disability). The EDSS score was computed based on an algorithm of these components, and scores ranged from 0.0 (normal neurological exam) to 10.0 (death due to MS) in increments of 0.5.

Randomized participants who had EDSS scores at the specified time points.

A confirmed relapse was defined as the appearance of 1 or more new neurological symptom(s) attributable to MS or the worsening of 1 or more previously observed symptoms. This change in clinical state was to last at least 48 hours and be immediately preceded by an improving neurological state of at least 30 days from onset of previous relapse. New or worsening neurological symptoms were accompanied by objective EDSS changes on examination (an increase from baseline of at least 1 point on the EDSS, at least 1 point on 2 EDSS functional systems, or at least 2 points on 1 EDSS functional system). A relapse may or may not have required systemic corticosteroid treatment. If a relapse did not occur during the specified time frame, the time to the first confirmed relapse was censored to the date of the participant's last available visit at or prior to Week 24, Week 48, and Week 48 for the respective time frames.

Randomized participants who had a relapse assessment for the specified time periods. Twenty-one (21), 24, 24, 28, 23, 26, and 26 participants were censored in the following arms respectively: 4 mg, 12 mg, 40 mg, and 120 mg LY2127399 Q4W, 4 mg and 120 mg LY2127399 Q12W, and placebo.

A confirmed relapse was defined as the appearance of 1 or more new neurological symptom(s) attributable to MS or the worsening of 1 or more previously observed symptoms. This change in clinical state was to last at least 48 hours and be immediately preceded by an improving neurological state of at least 30 days from onset of previous relapse. New or worsening neurological symptoms were accompanied by objective EDSS changes on examination (an increase from baseline of at least 1 point on the EDSS, at least 1 point on 2 EDSS functional systems, or at least 2 points on 1 EDSS functional system). A relapse may or may not have required systemic corticosteroid treatment. Percentage of relapse-free participants=[(number of participants who did not relapse)/(number of pts assessed)]*100.

Randomized participants who had a relapse assessment at the specified time points.

The number of confirmed relapses per year, ARR=[(number of relapses from baseline through Week 24 or baseline through Week 48)/(the time in days between the same interval)]*365.25. A confirmed relapse was defined as the appearance of 1 or more new neurological symptom(s) attributable to MS or the worsening of 1 or more previously observed symptoms. This change in clinical state was to last at least 48 hours and be immediately preceded by an improving neurological state of at least 30 days from onset of previous relapse. New or worsening neurological symptoms were accompanied by objective EDSS changes on examination (an increase from baseline of at least 1 point on the EDSS, at least 1 point on 2 EDSS functional systems, or at least 2 points on 1 EDSS functional system). A relapse may or may have not required systemic corticosteroid treatment.

Randomized participants who had a relapse assessment for the specified time periods.

The MSFC is a composite scale consisting of 3 components [Timed 25-Foot Walk, 9-Hole Peg Test (9-HPT), and 3-Second Paced Auditory Serial Addition Test (PASAT-3)]. The Timed 25-Foot Walk was a quantitative measure of lower extremity function. The 9-HPT was a quantitative measure of upper extremity (arm and hand) function. The PASAT-3 was a measure of cognitive function that specifically assessed auditory information processing speed and flexibility, as well as calculation ability. Component scores ranged from 0 to 60 and were converted to standard scores (z-scores). The MSFC score was calculated as the average of the 3 standardized component scores. Higher MSFC scores reflected better neurological function.

Randomized participants who had MSFC scores at the specified time points.

The VAS is a 100-millimeter (mm) horizontal line marked with 0 mm = "poor" and 100 mm = "excellent." Participants were asked to assess their wellbeing by making a vertical mark on the scale. The score was computed as the distance from 0 mm to the vertical mark.

Randomized participants who had VAS of Wellbeing scores at the specified time points.

The QIDS-SR16 is a 16-item participant-rated measure of depressive symptomatology. Each item corresponds to 1 of 9 criterion domains for depression: change in sleep disturbance [question (Q) 1 through Q4], sad mood (Q5), decrease or increase in appetite and weight (Q6 through Q9), concentration (Q10), self-criticism (Q11), suicidal ideation (Q12), interest (Q13), energy/fatigue (Q14), and psychomotor agitation and retardation (Q15 and Q16). Each question was scored 0 (no problems) to 3 (increased symptoms). The total score=(the highest score from Q1 through Q4)+(Q5 score)+(the highest score from Q6 through Q9)+(the total score for each Q10 through Q14)+(the highest score from Q15 and Q16). A total score of 0 through 5 was considered no depression likely, 6 through 10 was mild depression, 11 through 15 was moderate depression, 16 through 20 was severe depression, and 21 or over was very severe depression.

Randomized participants who had QIDS-SR16 scores at the specified time points.

The SF-36 was a 36-item, health-related survey that assessed participant's quality of life on 8 domains: physical functioning, bodily pain, role limitations due to physical problems, role limitations due to emotional problems, general health, mental health, social functioning, vitality and 2 component scores (mental and physical health). Domain scores were calculated by summing individual items for each domain and transforming scores into 0 to 100 scale; higher scores indicated better health status or function. The mental component summary (MCS) score, based on SF-36 domains, consisted of social functioning, vitality, mental health, and role-emotional scales (range: 0 to 100). The physical component summary (PCS) score, based on SF-36 domains, consisted of physical functioning, bodily pain, role-physical, and general health scales (range: 0 to 100).

Randomized participants who had SF-36 component scores at the specified time points.

AUCtau,ss was obtained by conducting a simulation consisting of 1000 participants, which were then used to determine the noncompartmental PK parameters for each regimen.

Randomized participants who had evaluable PK data.

The percentage of participants with ADA=[(number of participants who had ADA)/(number of participants assessed)]*100.

Randomized participants who had an ADA assessment at the specified time periods.

Cell surface marker cluster designation (CD)19, CD27, and immunoglobulin D (IgD) expression levels were used to define the various B cell subsets. Cell surface markers were defined as being either present (+) or absent (-). Peripheral blood B cell subsets included: mature naive B cells (CD19+IgD+CD27-); immature/transitional (immature/tran) B cells (CD19+IgD-CD27-); switched memory B cells (CD19+IgD-CD27+); and non-switched memory B cells (CD19+IgD+CD27+). A positive or negative change indicated an increase or decrease, respectively in B cell count.

Randomized participants who had peripheral blood B cell subset cell counts at the specified time points.