Table II.
GEMINI 1 and GEMINI 2 Patient Vedolizumab ADA Status Using the ECL Assay.
| Maintenance study ITT2a | Non-ITT | Combined | ||||
|---|---|---|---|---|---|---|
| Placebob (from week 6) | Vedolizumab Q8W | Vedolizumab Q4W | Placeboc (from week 0) | Vedolizumab Q4W (week 6 nonresponders) | Continuous vedolizumabd | |
| ADA status up to week 52, n (%) | N = 278 | N = 276 | N = 279 | N = 295 | N = 872 | N = 1427 |
| ADA negative | 218 (78) | 259 (94) | 269 (96) | 287 (97) | 813 (92) | 1341 (94) |
| ADA positive | 60 (22) | 17 (6) | 10 (4) | 8 (3) | 59 (7) | 86 (6) |
| Transiently positive | 12 | 12 | 8 | 1 | 46 | 66 |
| Persistently positive | 48 | 5 | 2 | 7 | 13 | 20 |
| Any neutralizing ADA positivee | 46 | 10 | 4 | 3 | 42 | 56 |
| ADA status at week 66,f n (%) | N = 24 | N = 26 | N = 35 | N = 44 | N = 249 | N = 310 |
| ADA positive | 3 (13) | 5 (19) | 3 (9) | 0 | 37 (15) | 45 (15) |
Not all patients had evaluable samples. N = total number of patients with samples tested in each treatment group. Proportions are based on nonmissing values
ADA vedolizumab anti-drug antibody, ECL electrochemiluminescence, ITT intent to treat, Q4W every 4 weeks, Q8W every 8 weeks
aPatients who were responders to vedolizumab induction at week 6 and were randomized into the maintenance-phase ITT population
bPatients who received vedolizumab during induction and were randomized to placebo at the maintenance phase
cPatients who were randomized to placebo at both the induction and maintenance phases
dAll patients who received induction and maintenance vedolizumab, including week 6 responders who were randomized to vedolizumab in the maintenance phase plus patients who did not respond at week 6 and received maintenance vedolizumab Q4W
eNeutralizing ADA with no reportable titer was considered missing (i.e., no detectable positive neutralizing ADA was present in the sample)
fWeek 66 was the final safety visit and approximately 4.5 to 5 half-lives after the last dose of vedolizumab; 310 samples were available for this analysis