Switching biologics used in inflammatory bowel diseases: how to deal with in practice?

Inflammatory bowel disease patients do not all respond to biological treatment since several patients will initially respond but will lose response or develop side effects over time. In such cases, a switch from one biologic to another offers a valuable clinical solution. This requires to evaluate both patient and drug profiles in combination with the reason(s) for switching in order to adequately select the second-line biologic. Therapeutic drug monitoring is obviously a useful tool but is currently limited to the use of anti-TNFα. In this review paper, we provide overview and guidance on switching biologics in clinical practice, with the emphasis on the motivations for switching, the selection of the second-line biologic, as well as explanations on how and when to switch.