TITRATE (inducTIon for acuTe ulceRATivE Colitis)

Previous studies performed in the AMC demonstrated that the patients with acute severe UC receiving IFX are different from patients receiving IFX while in remission.(5) The clearance of IFX is not only determined by demographic parameters (gender, body weight), blood chemistry (CRP, albumin) and anti‐drug antibodies, but also disease related variables play an important role. Among others, we have demonstrated that faecal loss of IFX in ASUC patients increases IFX clearance during the induction phase (3). Furthermore, increased expression of TNF‐α, the target of IFX, influences the clearance of IFX due to target mediated drug disposition (TMDD). Active IBD with high tissue concentrations of TNF‐α thereby acts as a sink for anti‐TNF‐α antibodies (4). The PK of IFX has been mainly characterized during maintenance therapy. Evaluation of factors that influence the clearance of IFX during induction therapy will allow further optimization an individualization of IFX therapy in ASUC patients. At present, determination of IFX concentrations in the serum with an enzyme‐linked immunosorbent assay (ELISA) is time consuming; physicians often receive the results after as many as 10‐20 days. To allow for proactive adjustments in dosing, faster laboratory results are required, preferably in a point‐of‐care setting. This test is now made available by Bühlmann Laboratories (Switzerland). The study hypothesis is that in patients with acute severe UC an intensified and personalized IFX dosing regimen using individual PK data from point of care tests as a rapid input to the dashboard system during the induction phase will lead to improved clinical outcomes when compared to standard dosing regimen.