Table 1

Patient demographics and baseline clinical characteristics (safety population; N=424)

Total OL population (N=424)
Female, n (%)393 (92.7)
Mean age (SD), years31.9 (9.2)
Ethnicity, n (%)
 Hispanic or Latino2 (0.5)
 Not Hispanic or Latino422 (99.5)
Mean BMI (SD), kg/m222.7 (3.8)
Mean SLE disease duration (SD), years6.0 (4.8)
BILAG organ domain involvement*, n (%)
 ≥1A or 2B137 (32.3)
 ≥1A20 (4.7)
 ≥1B292 (68.9)
 No A or B127 (30.0)
BILAG organ system involvement (A or B scores), n (%)
 General14 (3.3)
 Mucocutaneous163 (38.4)
 Neurological0 (0)
 Musculoskeletal74 (17.5)
 Cardiovascular and respiratory1 (0.2)
 Vasculitis34 (8.0)
 Renal97 (22.9)
 Haematology79 (18.6)
Mean SELENA-SLEDAI score (SD)8.0 (4.1)
SELENA-SLEDAI category
 ≤9277 (65.3)
 ≥10147 (34.7)
SLE flare index, n (%)
 ≥1 Flare63 (14.9)
 ≥1 Severe flare9 (2.1)
Mean PGA (SD)1.5 (0.5)
SDI score
 Mean (SD)0.2 (0.4)
 Median (minimum, maximum)0 (0, 3)
ANA
 Positive (Index ≥0.80), n (%)424 (100.0)
Anti-dsDNA
 Positive (≥30 IU/mL), n (%)324 (76.4)
Complement level, n (%)
 Low C3 (<90 mg/dL) and/or low C4 (<10 mg/dL)278 (65.6)
 No low C3 or C4146 (34.4)
Mean proteinuria level (SD), g/24 hours0.8 (1.2)
Proteinuria category (g/24 hours), n (%)
 ≤0.5247 (58.3)
 >0.5177 (41.7)
  >0.5 to <157 (13.4)
  1 to <271 (16.7)
  ≥249 (11.6)
Medication at baseline
 Corticosteroids, n (%)415 (97.9)
  Mean daily prednisone† dose (SD), mg/day16.1 (9.9)
 Antimalarials, n (%)328 (77.4)
 Immunosuppressants/immunomodulatory agents, n (%)270 (63.7)
 Aspirin, n (%)47 (11.1)
 NSAIDs, n (%)6 (1.4)
 Traditional Chinese medication, n (%)66 (15.6)
  • Note: Baseline was defined as the last available value prior to belimumab initiation: day 1 for patients randomised to belimumab in the double-blind period and week 52 for patients randomised to placebo in the double-blind period.

  • *Patients may have been counted in more than one category.

  • †Prednisone equivalent.

  • ANA, anti-nuclear antibodies; BILAG, British Isles Lupus Assessment Group; BMI, body mass index; C, complement; dsDNA, double stranded DNA; NSAIDs, non-steroidal anti-inflammatory drugs; OL, open-label; PGA, Physician’s Global Assessment; SD, standard deviation; SDI, Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index; SELENA-SLEDAI, Safety of Estrogens in Lupus Erythematosus National Assessment version of the SLE Disease Activity Index; SLE, systemic lupus erythematosus.