Secondary efficacy endpoint results (HDA1 and HDA2 subcutaneous subgroups)
| HDA1 subcutaneous | HDA2 subcutaneous | |||
| Placebo (n=78) | Belimumab 200 mg (n=186) | Placebo (n=141) | Belimumab 200 mg (n=296) | |
| Prednisone reduction by ≥25% from baseline to ≤7.5 mg/day during weeks 40–52 (n)* | 50 | 124 | 90 | 188 |
| Responders, n (%) | 5 (10.0) | 24 (19.4) | 10 (11.1) | 30 (16.0) |
| Observed difference vs placebo | – | 9.35 | – | 4.85 |
| OR (95% CI)† vs placebo | – | 2.10 (0.74 to 5.98) | – | 1.54 (0.71 to 3.32) |
| P value† | – | 0.1642 | – | 0.2746 |
| Risk of any flare, number of patients with flare (%) | 57 (73.1) | 123 (66.1) | 99 (70.2) | 184 (62.2) |
| HR (95% CI) vs placebo‡ | – | 0.93 (0.68 to 1.29) | – | 0.83 (0.65 to 1.06) |
| P value‡ | – | 0.6797 | – | 0.1365 |
| Risk of severe flare, number of patients with severe flare (%) | 22 (28.2) | 30 (16.1) | 32 (22.7) | 42 (14.2) |
| HR (95% CI) vs placebo‡ | – | 0.52 (0.30 to 0.92) | – | 0.59 (0.37 to 0.94) |
| P value‡ | – | 0.0254 | – | 0.0253 |
HDA1: SELENA-SLEDAI score ≥10 at baseline with low complement and positive anti-dsDNA; HDA2: SELENA-SLEDAI score ≥10 at baseline with low complement and/or positive anti-dsDNA.
*Includes only subjects with baseline prednisone >7.5 mg/day.
†OR (95% CI) and p values were from logistic regression for the comparison between belimumab and placebo with covariates of baseline prednisone dose, baseline SELENA-SLEDAI score and race (black African ancestry vs other).
‡From Cox proportional hazard model for the comparison between belimumab and placebo, adjusting for SELENA-SLEDAI score, race (black African ancestry vs other) and baseline proteinuria level (<2 vs ≥2 g/24-hour equivalent).
dsDNA, double-stranded DNA; HDA, high disease activity; SELENA-SLEDAI, Safety of Estrogens in Lupus Erythematosus National Assessment-SLE Disease Activity Index.