P470 Ustekinumab Trough Levels are not Associated with Clinical Response in Inflammatory Bowel Disease Patients
Zelinkova, Z.(1);Lipovska, A.(2);Otottova, K.(2);Lucenicova, J.(3);Kadleckova, B.(2);
(1)St. Michael`s Hospital, Gastroenterology&Digestive Endoscopy, Bratislava, Slovakia;(2)St. Michael`s Hospital, Department of Gastroenterology&Digestive Endoscopy, Bratislava, Slovakia;(3)St. Michael`s Hospital, Department Clinical Biochemistry&Hematology, Bratislava, Slovakia
In total, 61 IBD patients were included (mean age 38 years, range 22-70; 38 women; 54 CD/6 UC/1 IBD-U). All patients were antiTNF experienced, minority (11; 18%) had also been treated with vedolizumab prior UST. Thirty-nine pts (64%) were responders, out of these 15 pts (38%) required dose escalation at some point of the treatment due to secondary loss of response.
UST through levels at week 8 were significantly higher than the maintenance levels (mean 5.6±SEM 0.7µg/mL vs. 2.2±0.3µg/mL; p<0.001). There were no significant differences between responders and non-responders neither in trough levels after induction (5±0.8µg/mL vs. 6.4±1.1µg/mL, p=n.s.), nor in trough levels during maintenance therapy (2.3± 0.4µg/mL vs. 1.9 ±0.4µg/mL, p=n.s.). Patients requiring dose escalation did not differ from stable responders in maintenance trough levels (2.4±0,6 µg/mL vs. 2,3 ±0,4 µg/mL).
In this limited size real-world cohort of IBD patients, we found no difference in pharmacokinetics between reponders and non-reponders to ustekinumab.