Efficacy outcomes at the end of the maintenance period (Week 96) of C-OPTIMISE (n=313)
| Imputation | CZP 200 mg Q2W (n=104) | P vs placebo | CZP 200 mg Q4W (n=105) | P vs placebo | Placebo (n=104) | |
| ASDAS disease activity state, n (%) | ||||||
| ID (<1.3) | OC | 75/87 (86.2) | – | 58/83 (69.9) | – | 14/24 (58.3) |
| LD (≥1.3 and <2.1) | OC | 12/87 (13.8) | – | 19/83 (22.9) | – | 6/24 (25.0) |
| HD (≥2.1 and ≤3.5) | OC | 0/87 (0) | – | 6/83 (7.2) | – | 4/24 (16.7) |
| vHD (>3.5) | OC | 0/87 (0) | – | 0/83 (0) | – | 0/24 (0) |
| Disease activity responses from Week 0, n (%) | ||||||
| ASDAS clinical improvement* | ||||||
| CII | NRI | 86 (82.7) | <0.001 | 79 (75.2) | <0.001 | 22 (21.2) |
| MI | NRI | 70 (67.3) | <0.001 | 61 (58.1) | <0.001 | 11 (10.6) |
| ASAS responder rates* | ||||||
| 20 | NRI | 89 (85.6) | <0.001 | 82 (78.1) | <0.001 | 24 (23.1) |
| 40 | NRI | 88 (84.6) | <0.001 | 77 (73.3) | <0.001 | 22 (21.2) |
| 5/6 | NRI | 73 (70.2) | <0.001 | 66 (62.9) | <0.001 | 13 (12.5) |
| Partial remission | NRI | 81 (77.9) | <0.001 | 74 (70.5) | <0.001 | 18 (17.3) |
| BASDAI50a | NRI | 87 (83.7) | <0.001 | 81 (77.1) | <0.001 | 23 (22.1) |
| Change from Week 48 | ||||||
| Efficacy outcomes, LS mean±SE | ||||||
| ASDAS | MMRM | 0.2±0.1 | <0.001 | 0.5±0.1 | <0.001 | 1.7±0.1 |
| BASDAI | MMRM | 0.6±0.2 | <0.001 | 0.8±0.2 | <0.001 | 3.0±0.2 |
| BASFI | MMRM | 0.3±0.2 | <0.001 | 0.5±0.2 | <0.001 | 1.9±0.2 |
| BASMI | MMRM | 0.0±0.1 | 0.074 | −0.0±0.1 | 0.036 | 0.2±0.1 |
| MRI outcomes, mean (SD; n) | ||||||
| SIJ SPARCC score | OC | 0.2 (2.4; 79) | 0.195 | 0.6 (3.8; 77) | 0.432 | 1.1 (3.6; 24) |
| ASspiMRI-a | OC | 0.0 (0.8; 79) | 0.040 | 0.0 (0.8; 78) | 0.074 | 0.4 (0.9; 24) |
| Additional outcomes, mean (SD; n) | ||||||
| MASES | OC | 0.1 (0.6; 90) | – | 0.1 (0.6; 84) | – | −0.1 (0.9; 24) |
| Tender joint count | OC | −0.1 (0.6; 90) | – | 0.1 (0.9; 84) | – | 0.0 (1.0; 24) |
| Swollen joint count | OC | 0.0 (0.2; 90) | – | 0.0 (0.2; 84) | – | 0.0 (0.0; 24) |
P values were obtained using a logistic regression model or, for MRI outcomes, an ANCOVA model, with factors for treatment group, geographical region and mNY classification (Week 48 baseline was included as a covariate in the ANCOVA model).
*Calculated from Week 0 baseline.
ANCOVA, analysis of covariance; ASAS, Assessment of Spondyloarthritis international Society; ASDAS, Ankylosing Spondylitis Disease Activity Score; ASDAS-ID/LD/HD/vHD, ASDAS-inactive disease/low disease/high disease/very high disease; ASspiMRI-a, Ankylosing Spondylitis spine MRI score for activity; BASDAI50, Bath Ankylosing Spondylitis Disease Activity Index 50% improvement; BASFI, Bath Ankylosing Spondylitis Functional Index; BASMI, Bath Ankylosing Spondylitis Metrology Index; CII, clinically important improvement; CZP, certolizumab pegol; LS, least squares; MASES, Maastricht Ankylosing Spondylitis Enthesitis Score; MI, major improvement; MMRM, mixed effect model for repeated measures; mNY, modified New York; NRI, non-responder imputation; OC, observed case; Q2W, every 2 weeks; Q4W, every 4 weeks; SIJ SPARCC, sacroiliac joint Spondyloarthritis Research Consortium of Canada.