Tissue Exposure does not Explain Non-Response in Ulcerative Colitis Patients with Adequate Serum Vedolizumab Concentrations.

Vedolizumab concentrations in colonic mucosal tissue of UC patients reflect the concentration in serum regardless of the macroscopic inflammatory state of the tissue. Our data show that insufficient tissue exposure does not explain non-response in UC patients with adequate serum vedolizumab concentrations.