P506 Increased risk of anti-drug antibodies to a second anti-TNF in patients who developed antibodies to the first anti-TNF
H. Yanai1,2, S. Amir2, I. Avni Biron1,2, T. Tsadok Perets1,2, R. Shamir2,3, I. Dotan1,2, A. Assa2,3
1Rabin Medical Center, IBD Center- Division of Gastroenterology, Petah-Tikva, Israel, 2Tel Aviv University, Sackler Faculty of Medicine-, Tel Aviv, Israel, 3Schneider Children’s Medical Center, The Institute of Gastroenterology- Nutrition and Liver diseases, Petah Tikva, Israel
Background
Evidence regarding predisposition to develop anti-drug antibodies to a second anti-TNF in patients with inflammatory bowel diseases (IBD) who previously developed antibodies to a first anti-TNF (either infliximab or adalimumab) is conflicting. We aimed to assess the rates of such consecutive immunogenicity.
Methods
The medical records of all patients with IBD followed at the Rabin and Schneider Medical Centers (all ages) from 2014 to 2019, who were treated with an anti-TNF agent were reviewed. Clinical data including age at diagnosis, gender, disease type, concomitant use of immunomodulators, as well as drug trough levels (TLs) and anti-drug antibodies (ADAs) for both agents were registered. Patients who switched from one anti-TNF to another and had comprehensive clinical and pharmacokinetic data were assessed for consecutive immunogenicity.
Results
Overall, 1570 patients were tested for TLs and ADAs (infliximab,
Conclusion
The rate of consecutive immunogenicity in anti-TNF treated patients is significantly higher than the overall immunogenicity against the first anti-TNF. This higher rate of consecutive immunogenicity may be associated with a predisposition to developing anti-drug antibodies to anti-TNF agents. It may also be a consequence of the relatively low rates of combination therapy following an immunogenic failure.