Vedolizumab in inflammatory bowel disease: pharmacokinetics and the role of immunomodulator co-therapy.

Vedolizumab (VED) is a gut-selective monoclonal antibody and an effective biological agent for many patients with inflammatory bowel disease (IBD). Therapeutic drug monitoring has been used to optimise treatment with other biological agents; however, the clinical applicability of measuring vedolizumab trough concentrations is unclear. Initial registration trial data demonstrated a positive exposure-efficacy relationship of vedolizumab in IBD. However, there is conflicting data in more recent studies, with no definitive benefit of vedolizumab dose-escalation and no consistent target vedolizumab trough concentration identified. Also, unlike with anti-tumour necrosis factor agents, the clinical benefit of immunomodulator co-therapy with vedolizumab is uncertain. Although initial research suggested no clinical advantage of combining vedolizumab with an immunomodulator, more recent studies have shown potential benefit. This narrative review aims to explore current evidence on vedolizumab pharmacokinetics and whether immunomodulator co-therapy should be considered with vedolizumab.