Value of Pharmacokinetic Assays in the Prediction of Therapeutic Response in Ulcerative Colitis

Vedolizumab (VDZ) is a monoclonal antibody that binds to the heterodimer α4β7 integrin and which has shown its efficacy in Ulcerative Colitis (UC) by inducing and maintaining clinical response/remission. The French marketing authorization was obtained for Ulcerative Colitis in patients in failure with anti-Tumor Necrosis Factor (anti-TNF) agents. In the pivotal study, correlation between drug levels and clinical response during induction and maintenance therapy were reported. Moreover, in 3.7% of cases, anti-vedolizumab antibodies were reported during the time-course and 1% had samples that were persistently positive. Up to now, data on the pharmacologic VDZ parameters are scarce and the relationships as well as the predictive value of the measurement of VDZ concentrations and VDZ monoclonal antibodies (mAbs) during the induction and maintenance phases remains unknown. It could be of paramount interest to early identify UC patients under VDZ who will be responders to VDZ induction and to identify those who will achieve clinical remission under maintenance therapy with VDZ.