Proportion of patients with ankylosing spondylitis (AS) who were positive for antidrug antibodies (ADAs) and neutralising antibodies (NAbs) in PLANETAS: the main 54-week parallel-group study and the extension study (safety population)
| Time point | Patients positive for ADAs and NAbs, n (%) | p Value | |
|---|---|---|---|
| Maintenance group* (n=90) | Switch group† (n=84) | ||
| Main study period | |||
| Week 14 ADAs | 7 (7.8) | 8 (9.5) | 0.79 |
| NAbs | 6 (85.7) | 8 (100.0) | |
| Week 30 ADAs | 18 (20.0) | 17 (20.2) | 1.00 |
| NAbs | 17 (94.4) | 16 (94.1) | |
| Week 54 ADAs | 20 (22.2) | 22 (26.2) | 0.60 |
| NAbs | 20 (100.0) | 22 (100.0) | |
| Extension study period | |||
| Week 78 ADAs | 21 (23.3) | 25 (29.8) | 0.39 |
| NAbs | 21 (100.0) | 25 (100.0) | |
| Week 102 ADAs | 21 (23.3) | 23 (27.4) | 0.60 |
| NAbs | 21 (100.0) | 23 (100.0) | |
| ADA persistency (n/N#, %) | |||
| Sustained ADAs | 24/28 (85.7) | 24/27 (88.9) | 1.00 |
| Transient ADAs | 4/28 (14.3) | 3/27 (11.1) | 1.00 |
Percentage NAb results are based on the number of positive ADA results at that visit.
ADA persistency was defined as transient when a patient tested positive for ADAs at one or more time point but negative at the last available time point. The remaining patients with positive ADA results were considered to have shown a sustained ADA response.
N#, total number of patients with at least one positive ADA result.
*Patients treated with CT-P13 during the 54 weeks of the main study and the 48-week extension study.
†Patients treated with RP during the 54 weeks of the main study and then switched to CT-P13 during the 48-week extension study.
RP, reference product.