A Study of Belimumab Administered Subcutaneously in Subjects With Systemic Lupus Erythematosus (SLE)

Time to First Severe Flare (as Measured by the Modified SLE Flare Index)

Time to first severe SLE flare is defined as the number of days from treatment start date until the participant met an event (event date - treatment start date +1). Analyses of severe SLE flare was performed on modified SELENA SLEDAI SLE flare index that excludes severe flares that were triggered only by an increase in SELENA SLEDAI score to \>12 (since this may only represent a modest increase in disease activity). Only post-baseline severe flares were considered.

Time frame: Baseline (Day 0, prior to dosing) to Week 52

Percentage of Par. Whose Average Prednisone Dose Had Been Reduced by >=25% From Baseline to <=7.5 mg/Day During Weeks 40 Through 52 in Par. Receiving Greater Than 7.5 mg/Day at Baseline

For the analysis of steroid use, all steroid dosages were converted to a prednisone equivalent in mg. The average daily prednisone dose was calculated taking into account all steroids taken intravenously, intramuscularly, SC, intradermally and orally for both SLE and non-SLE reasons. A responder was defined as having a prednisone reduction by \>=25% from Baseline to \<=7.5 mg/day during Weeks 40 through 52. At Baseline, the average daily prednisone dose was the sum of all prednisone doses over 7 consecutive days up to, but not including Day 0, divided by 7. For this analysis, the average prednisone dose was the total prednisone dose during weeks 40 through 52 divided by the number of days during Weeks 40 through 52. Analysis was performed using a logistic regression model with covariates treatment group, Baseline prednisone dose, Baseline SELENA SLEDAI score, (\<=9 vs \>=10), Baseline complement levels (low C3 and/or C4 vs. no low C3 or C4) and race (black vs. other).