Therapeutic drug monitoring of anti-tumor necrosis factor agents: lessons learned and remaining issues

Therapeutic drug monitoring (TDM) of anti-tumor necrosis factor agents (anti-TNFs) has received extensive attention due to its potential for improving treatment outcomes in patients with inflammatory bowel diseases. However, the benefits of applying TDM in clinical practice remain largely unclear due to a lack of evidence from the available prospective randomized controlled studies. The questionable evidence for TDM obtained in these studies can be caused by several design suboptimalities, including long turnaround times of sample analysis, use of inappropriate exposure targets, insufficiently precise algorithms for dose optimization, and inapt trial designs. In future studies, model-informed precision dosing in combination with rapid testing methods is recommended to maximize the potential of TDM of anti-TNFs.