Primary, key secondary, and subgroup efficacy analyses (mITT population)
| Belimumab (n=299)a | Placebo (n=149) | |
|---|---|---|
| SRI-S2K responseb at Week 52, n (%) | 145 (48.7) | 62 (41.6) |
| Odds ratio (95% CI) vs placebo | 1.40 (0.93–2.11) | |
| P-value | p=0.1068 | |
| SRI responsec at Week 52, n (%) | 146 (49.0) | 62 (41.6) |
| Odds ratio (95% CI) vs placebo | 1.42 (0.94–2.15) | |
| Number of patients with severe SFI flare over 52 weeks, n/n (%) | 58 (19.4) | 37 (24.8) |
| Hazard ratio (95% CI) vs placebo | 0.77 (0.51–1.17) | |
| Patients who experienced a reduction in prednisone dosed, n/n (%) | 27/184 (14.7) | 12/95 (12.6) |
| Adjusted odds ratio (95% CI) | 1.30 (0.61–2.80) | |
| SRI-S2Ka response at Week 52 in subgroups | ||
| Patients with baseline SS-S2K score≤9, n/n (%) | 62/140 (44.3) | 24/56 (42.9) |
| Odds ratio (95% CI) vs placebo | 0.97 (0.51–1.85) | |
| P-value | p=0.9198 | |
| Patients with baseline SS-S2K score≥10, n/n (%) | 83/158 (52.5) | 38/93 (40.9) |
| Odds ratio (95% CI) vs placebo P-value | 1.76 (1.03–3.00) p=0.0384 | |
| Patients with low baseline C3 and/or C4 levels, n/n (%) | 51/108 (47.2) | 14/57 (24.6) |
| Odds ratio (95% CI) vs placebo | 3.00 (1.45–6.23) | |
| P-value | p=0.0031 | |
| Patients without low baseline C3 or C4 levels, n/n (%) | 94/190 (49.5) | 48/92 (52.2) |
| Odds ratio (95% CI) vs placebo | 0.92 (0.55–1.54) | |
| P-value | p=0.7554 | |
| Patients with low C3 and/or C4 and anti-dsDNA≥30 IU/mL, n/n (%) | 41/91 (45.1) | 12/50 (24.0) |
| Odds ratio (95% CI) vs placebo | 3.00 (1.35–6.68) | |
| p-value | p=0.0072 | |
| Patients without low C3, C4 or anti-dsDNA≥30 IU/mL, n/n (%) | 104/207 (50.2) | 50/99 (50.5) |
| Odds ratio (95% CI) vs placebo | 1.01 (0.62–1.66) | |
| P-value | p=0.9556 | |
| Patients from US/Canada, n/n (%) | 49/131 (37.4) | 25/65 (38.5) |
| Odds ratio (95% CI) vs placebo | 0.97 (0.52–1.81) | |
| P-value | p=0.9334 | |
| Patients from the rest of the world, n/n (%) | 96/167 (57.5) | 37/84 (44.0) |
| Odds ratio (95% CI) vs placebo | 1.81 (1.05–3.13) | |
| P-value | p=0.0324 | |
aOne patient in the belimumab group was excluded from the analyses as they did not have a baseline or screening PGA score; bmodified S2K scoring for proteinuria; cwith SELENA-SLEDAI scoring of proteinuria; dreduction in prednisone dose, in patients initially treated with >7.5 mg/day, by ≥25% to≤7.5 mg/day during Weeks 40–52.Anti-dsDNA, anti-double-stranded deoxyribonucleic acid; C, complement; CI, confidence interval; mITT, modified intent-to-treat; SELENA-SLEDAI, Safety of Estrogens in Lupus Erythematosus-SLE Disease Activity Index; SFI, SLE flare index; SRI-S2K, SLE Responder Index-SLEDAI-2000; SS, SELENA-SLEDAI.