# The role of proactive therapeutic drug monitoring in guiding infliximab therapeutic optimization in pediatric patients with Crohn's disease: A retrospective study

## TL;DR

This study shows that adjusting infliximab treatment intervals based on drug monitoring can improve outcomes in children with Crohn's disease.

## Contribution

The study demonstrates that proactive therapeutic drug monitoring can guide treatment optimization in pediatric Crohn's disease patients.

## Key findings

- Shortening treatment intervals increased infliximab trough concentration and improved clinical outcomes.
- Factors like hormone exposure and TP levels correlated with infliximab trough concentration.
- Endoscopic and clinical remission rates improved after treatment adjustments.

## Abstract

Therapeutic drug monitoring (TDM) plays an important role in guiding treatment plan adjustments and clinical outcomes in Crohn's disease. To evaluate the role of TDM‐guided optimization of infliximab dosage in patients with pediatric Crohn's disease. Medical records of patients with pediatric Crohn's disease who were treated with infliximab and had proactive TDM from June 2020 to June 2022 at the Children's Hospital of Chongqing Medical University were included. Baseline influencing factors for infliximab trough concentration (TC) and clinical outcomes before and after the treatment change were analyzed to assess the value of adjusting treatment in the patients. Forty‐six patients (male‐to‐female ratio = 1.55:1, age <18 years) were included. Univariate and multivariate analyses showed that hormone exposure (odds ratio: 0.042, 95% confidence interval: 0.002–0.924, p = 0.044), perianal lesions (5.813, 0.984–34.349, p = 0.052), simplified endoscopic score for Crohn's disease (1.656, 1.065–2.577, p = 0.025), and total protein (TP) (0.851, 0.749–0.967, p = 0.014) were correlated with infliximab TC. Shortening the treatment interval increased the infliximab TC (pre vs. post = 1.69 ± 0.8 vs. 12.03 ± 6.64, p = 0.001, n = 12) after 93.9 ± 37.47 days, decreased the pediatric Crohn's disease activity index and simplified endoscopic score for Crohn's disease, and increased the biochemical remission, clinical remission, endoscopic remission, and endoscopic response rates; however, there was no statistical significance. Hormone exposure, perianal lesions, simplified endoscopic score for Crohn's disease, and TP levels before the first infliximab use affected the infliximab TC. Shortening the treatment interval can improve infliximab TC levels and clinical outcomes.

To understand the clinical guiding value of treatment optimization based on therapeutic drug monitoring (TDM) in pediatric Crohn's disease patients treated with infliximab. Our research finds shortening the treatment interval under the guiding of TDM can improve the infliximab trough concentration level and clinical outcomes.