P598. Adalimumab trough levels in a prospective cohort of Crohn's disease patients
C.J. van der Woude1, E. Bultman1, J. Deuring1, R. West2, Z. Zelinkova1, M. Peppelenbosch1, 1Erasmus MC, Gastroenterology and Hepatology, Rotterdam, Netherlands, 2St Franciscus hospital, Gastroenterology and Hepatology, Rotterdam, Netherlands
Adalimumab (ADA) is effective for induction and maintenance of remission in Crohn's disease (CD) patients. Controversy exists as to the importance of ADA trough levels for its clinical efficacy and whether monitoring ADA levels is necessary during therapy. Hence we decided to investigate the relationship between dosing regimen of ADA and clinical response to the medication with ADA trough levels in a cohort of anti-TNF naïve patients.
231 CD patients in a single tertiary center that started ADA treatment (160/80/40EOW) between July 2007 and September 2010 were followed prospectively for study at week 0, 4, 12, 20, 28, and 52. Disease activity was scored by determining CDAI. ADA trough levels were measured at week 0, 12, 28 and 52.
Of 231 CD patients treated with ADA and followed prospectively, 72 patients were naive for anti-TNF medication and fulfilled the inclusion criteria. Trough levels, although divergent between patients, are stable between week 12 and week 52 and are independent from medication and most life-style factors, although a weak negative relationship with BMI exists. Clinical response to ADA is not related to ADA trough levels.
No ADA cut-off trough level could be determined and there is no place for ADA level determinations in clinical practice.