P484 Do vedolizumab trough levels predict response to consecutive therapy in Inflammatory Bowel Disease?

Levartovsky, A.(1);Cohen, I.(1);Abitbol, C.M.(1);Yavzori, M.(1);Fudim, E.(1);Picard, O.(1);Kopylov, U.(1);Ben-Horin, S.(1);Ungar, B.(1);

(1)Sheba Medical center, Department of Gastroenterology, Tel Hashomer, Israel;

Background

Vedolizumab trough serum levels have been associated with clinical and endoscopic response in patients with inflammatory bowel disease (IBD), albeit findings have not been conclusive. A recent study demonstrated that higher trough vedolizumab levels before therapy escalation predict optimal outcome. Our aim was to identify whether vedolizumab trough levels predict outcome of consecutive biologic or immunomodulatory therapy.

Methods

This retrospective study included IBD patients consecutively receiving vedolizumab therapy between November 2014 and June 2021 at Sheba Medical Center. Only patients who lost response to vedolizumab therapy, and had available trough levels prior to therapy cessation were included. Clinical and endoscopic scores, as well as drug retention, were recorded at 6 and 12 months post switching therapy.

Results

Overall, 66 IBD patients (36 CD, 30 UC) who lost response to vedolizumab therapy were included. They were treated with vedolizumab for a median of 47 weeks (IQR 31-85). Seventy-two percent of patients (48/66) were priorly treated with anti-TNF therapy (infliximab or adalimumab). After vedolizumab cessation, 66.7% of patients were switched to biologic therapy. These included 25.8% (17/66) to ustekinumab, 22.7% (15/66) to infliximab, 7.6% (5/66) to adalimumab, 6.1% (4/66) to certolizumab and 4.5% (3/66) to golimumab. The remaining 33.3% of patients switched to tofacitinib (10.6%), 5-ASA derivates or immunomodulator monotherapy (12.1%) or to a study therapy protocol (10.6%).
Median vedolizumab trough levels at therapy cessation were 32.25 μg/ml (IQR 12.8-61.4). Trough drug levels at therapy cessation were not associated with retention of biological or immunomodulatory therapy at 6 months [median 29.1 μg/ml (IQR 12.4–57.6) vs 33.8 μg/ml (IQR 27.9–58), p = 0.43] and at 12 months [median, 38.2 μg/ml (IQR 14.5–76.3) vs 30.1 μg/ml (IQR 11.5–45), p = 0.57] for patients who retained consecutive therapy versus those who did not.

Conclusion

Vedolizumab trough serum levels before therapy cessation due to loss of response do not predict retention of consecutive therapy.