Therapeutic drug monitoring of biologics in inflammatory bowel disease: An evidence-based multidisciplinary guideline

Therapeutic drug monitoring (TDM) has emerged as a valuable tool for optimizing the use of biologics in inflammatory bowel disease (IBD). However, variations in focus, methodology, and recommendations among relevant guidelines and consensuses have contributed to inconsistencies in their quality. This guideline synthesizes current evidence to standardize TDM of biologics in IBD, and improve patient outcomes. This multidisciplinary guideline was developed in collaboration with pharmacy, gastroenterology, and pharmacology associations in China. The guideline development group included 9 experts in clinical pharmacy, 4 experts in TDM, 8 gastroenterologists, and 2 methodologists. A comprehensive search was conducted across PubMed, Embase, Web of Science, the Cochrane Library databases, as well as key gastroenterology-relevant guideline websites. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach was utilized, and this guideline was registered on the Guideline International Network website. Internal and external reviews were conducted. We proposed 5 clinical questions under two overarching themes. Based on the current evidence and the clinical opinions of the core working group members, the initial recommendations were made. Following comprehensive internal and external review processes, 14 recommendations (1 strong and 13 weak) were finalized for the clinical questions. To our knowledge, this is the first evidence-based clinical practice guideline on TDM in patients with IBD developed using the GRADE approach. It addresses five key questions: whether TDM leads to better therapeutic outcomes than conventional treatment, what indicators should be monitored, when TDM should be initiated, what the therapeutic drug trough concentration thresholds are, and which TDM method (proactive or reactive) can better improve therapeutic outcomes.