P377 Serum adalimumab trough levels required for mucosal healing during maintenance therapy in patients with Crohn’s disease
H. Imaeda*, Y. Morita, T. Fujimoto, K. Takahashi, M. Shioya, A. Nishida, O. Inatomi, S. Bamba, M. Sasaki, T. Tsujikawa, M. Sugimoto, A. Andoh
Shiga University of Medical Science, Department of Medicine, Otsu, Japan
Few data are available to support the clinical relevance of adalimumab (ADA) trough levels for prediction of endoscopic disease activity in Crohn’s disease (CD).1 This study evaluated the endoscopic disease activities in relation to clinical outcome using several laboratory markers including serum ADA trough levels in patients with CD undergoing scheduled ADA maintenance therapy.
In total, 40 patients with CD during ADA maintenance therapy were enrolled. Serum ADA trough levels were measured by an enzyme-linked immunosorbent assay using avidin-coated blocking-less type plate.2 Endoscopic disease activity assessed using modified Rutgeerts endoscopic scoring system.1
Endoscopic mucosal healing (MH) significantly correlated with serum adalimumab trough levels, and they were required above 7.90 μg/mL (area under the curve [AUC], 0.786; 95% CI, 0.657–0.925; p < 0.001). Eleven patients (78.6%) of MH group got ADA trough levels above 7.90 μg/mL, in contrast 8 patients (30.8%) of non-MH group had below 7.90 µg/mL. In this study, the significant difference of laboratory markers between MH and non-MH group was found in CRP (p < 0.05). The cut-off values of CRP for MH was below 0.09 mg/dL (area under the curve [AUC], 0.709; odds ratio, 5.87; 95% CI, 0.542–0.876; p < 0.05). Previous anti-TNF drugs use is one of predictable markers to prevent from achieving endoscopic MH.
Serum adalimumab trough levels above 7.90 μg/mL were required for endoscopic mucosal healing. This is 1.42 times higher than the concentration required to achieve normalisation of laboratory markers. Monitoring serum adalimumab trough levels is useful for achieving endoscopic mucosal healing in patients with CD.
 Imaeda H, Bamba S, Takahashi K, et al. Relationship between serum infliximab trough levels and endoscopic activities in patients with Crohn’s disease under scheduled maintenance treatment. J Gastroenterol 2014;49(4):6748–42.
 Imaeda H, Takahashi K, Fujimoto T, et al. Clinical utility of newly developed immunoassays for serum concentrations of adalimumab and anti-adalimumab antibodies in patients with Crohn’s disease. J Gastroenterol 2014;49(1):1009–.