Therapeutic Drug Monitoring in Inflammatory Bowel Disease

Decades of cutting edge innovation in Inflammatory bowel disease (IBD) has yielded a diverse therapeutic armamentarium and warranted a shift in desired clinical endpoint (CE) from symptomatic management towards mucosal healing, histologic outcomes, serial biomarker trends and endoscopic remission. Despite these advancements, disease remission and therapeutic response rates remain suboptimal. This is due to failure to respond to therapy during the induction period (primary non-responder) or a subsequent loss of response (secondary non-responder). To address this area of unmet need, therapeutic drug monitoring (TDM) provides an opportunity to optimize dosing and therapeutic drug concentrations as per desired end clinical targets to improve response rates and offset aggressive disease complications. This further provides a platform for IBD therapeutic stratification based on patient, non-patient related factors and desired CE. In this chapter we aim to discuss a background regarding current TDM applications for various Food and Drug Administration (FDA)-approved IBD therapies and pinpoint deficiencies to enhance its smooth clinical implementation with a view to elucidating precision medicine as a novel therapeutic avenue in IBD.