Table 1.
Baseline demographics and disease characteristics
| Characteristic, mean (SD) | Total efficacy population (N = 185) | MRI/CRP-positive subpopulation (n = 142) | MRI- and CRP-negative subpopulation (n = 43)a |
|---|---|---|---|
| Female, n (%) | 101 (54.6) | 77 (54.2) | 24 (55.8) |
| Age, years | 38.0 (10.8) | 38.3 (11.1) | 37.2 (10.1) |
| Symptom duration, years | 10.0 (8.9)b | 10.5 (9.4)c | 8.3 (6.6)d |
| HLA-B27 positive, n (%) | 145 (78.4) | 114 (80.3) | 31 (72.1) |
| BASDAI (0–10) | 6.5 (1.5) | 6.4 (1.5) | 6.7 (1.5) |
| ASDAS (0–10) | 3.3 (0.8)e | 3.4 (0.8)f | 2.9 (0.6)d |
| Patient Global Assessment of Disease Activity (0–10 cm VAS) | 6.8 (1.8) | 6.8 (1.9) | 6.8 (1.8) |
| Physician Global Assessment of Disease Activity (0–10 cm VAS) | 5.7 (1.6)g | 5.6 (1.6) | 6.1 (1.7)h |
| Total back pain (0–10 cm VAS) | 6.9 (1.8) | 6.8 (1.8) | 7.3 (1.5) |
| BASFI (0–10) | 4.7 (2.1)g | 4.7 (2.2)i | 4.8 (2.0) |
| Inflammation/morning stiffnessj (0–10 cm VAS) | 6.6 (2.0) | 6.6 (2.1) | 6.7 (1.7) |
| Elevated baseline CRP,k n (%) | 48 (33.6)l | 48 (46.2)m | 0 |
| CRP, k mg/L | 7.2 (11.0) | 9.0 (12.0) | 1.4 (1.1) |
| SPARCC MRI score, SIJ | 4.9 (9.7)n | 6.3 (10.7)c | 0.4 (0.5)h |
| SPARCC MRI score, spine | 4.3 (5.8)o | 5.5 (6.1)p | 0.5 (0.6)h |
| HAQ-S (0–3) | 1.0 (0.6) | 1.0 (0.5) | 1.1 (0.6) |
| BASMI linear (0–10) | 2.7 (1.2)g | 2.7 (1.3)i | 2.7 (1.1) |
Abbreviations: ASDAS Ankylosing Spondylitis Disease Activity Score, BASDAI Bath Ankylosing Spondylitis Disease Activity Index, BASFI Bath Ankylosing Spondylitis Functional Index, BASMI Bath Ankylosing Spondylitis Metrology Index, CRP C-reactive protein, HAQ-S Health Assessment Questionnaire for the Spondyloarthropathies, HLA-B27 human leukocyte antigen B27, MRI Magnetic resonance imaging, SPARCC Spondyloarthritis Research Consortium of Canada, VAS Visual analogue scale
aThe baseline data for the MRI- and CRP-negative subpopulation includes 42 patients with confirmed absence of MRI inflammation and normal CRP at baseline and 1 patient with normal CRP but missing baseline MRI,bn = 180,cn = 140,dn = 40,en = 178,fn = 138,gn = 184,hn = 42,in = 141,jMean of BASDAI questions 5 and 6,kBased on either standard or high-sensitivity CRP values,ln = 143,mn = 104,nn = 182,on = 181,pn = 139