Therapeutic Drug Monitoring of TNF Antagonists in Inflammatory Bowel Disease.

Although tumor necrosis factor (TNF)-α antagonists play a critical role in the treatment of moderate-to-severe inflammatory bowel disease (IBD), several factors can impact treatment response. The degree of systemic inflammation, serum albumin concentration, disease type, body mass index, gender, concomitant therapy with immunosuppressive agents, and especially development of antidrug antibodies (ADAs) are key determinants of TNF antagonist pharmacokinetics and clinical outcomes. Therefore, measurement of serum drug and antibody concentrations in patients with IBD who are on TNF antagonists has the potential to guide clinical decision-making, optimize treatment, improve outcomes, and reduce healthcare costs. Multiple strategies to prevent ADA formation exist, including multiple clinical algorithms that employ therapeutic drug monitoring to optimize treatment following a secondary loss of therapeutic response. An individualized approach is needed, however, to identify early predictors of ADA development and other confounders of TNF antagonist therapy.