Baseline characteristics
| Parameter | Canakinumab | Placebo | |
| n=18 | n=17 | ||
| Female | n (%) | 10 (55.6) | 13 (76.5) |
| Age | Mean (SD) | 41.06 (13.2) | 40.53 (13.2) |
| Time since diagnosis (years) | Median (IQR) | 2.6 (0.3–4.7) | 1.6 (0.3–3.8) |
| Diagnosis since <1 year | n (%) | 6 (33.3) | 8 (47.1) |
| Diagnosis since ≥5 years | n (%) | 4 (22.2) | 4 (23.5) |
| Previous bDMARDs | n (%) | 13 (72.2) | 13 (76.5) |
| Previous anakinra | n (%) | 12 (66.7) | 13 (76.5) |
| Previous TNF inhibitors | n (%) | 6 (33.3) | 6 (35.3) |
| Previous tocilizumab | n (%) | 4 (22.2) | 2 (11.8) |
| 28-tender joint count | Mean (SD) | 6.94 (4.4) | 7.29 (5.2) |
| 28-swollen joint count | Mean (SD) | 5.22 (1.5) | 6.65 (4.7) |
| DAS28(ESR) | Mean (SD) | 5.4 (0.8) | 5.3 (1.2) |
| ESR (mm/hour) | Median (IQR) | 44 (28–70) | 50 (17.5–63) |
| CRP (mg/L) | Median (IQR) | 40.4 (20.5–85.8) | 38 (9.4–101.2) |
| Ferritin (ng/mL) | Median (IQR) | 448 (220–772) | 173.4 (60–664) |
| Fever | n (%) | 9 (50) | 8 (47.1) |
| Lymphadenopathy | n (%) | 2 (11.1) | 0 |
| Serositis | n (%) | 0 | 0 |
| Skin manifestation (rash) | n (%) | 4 (22.2) | 6 (35.3) |
| Sore throat | n (%) | 1 (5.6) | 0 |
| Myalgia | n (%) | 1 (5.6) | 0 |
bDMARD, biological disease-modifying antirheumatic drug; CRP, C-reactive protein; DAS28 (CRP), disease activity score 28 (using C-reactive protein value); DAS28 (ESR), disease activity score 28 (using erythrocyte sedimentation rate value) ; ESR, erythrocyte sedimentation rate; TNF, tumour necrosis factor.