Week 2 Adalimumab Levels Predict Short-term Clinical Remission in Patients With Inflammatory Bowel Disease

Area of Science:

• Gastroenterology
• Pharmacology
• Immunology

Background:

• Therapeutic drug monitoring (TDM) for anti-tumor necrosis factor (TNF) therapies, like adalimumab, in inflammatory bowel disease (IBD) lacks clear guidelines for early intervention.
• The predictive value of early serum trough levels for long-term clinical outcomes in IBD patients treated with adalimumab is not well-established.

Purpose of the Study:

• To investigate if a week 2 serum trough level of adalimumab can predict clinical outcomes in patients with IBD.
• To determine an optimal week 2 adalimumab threshold for predicting clinical remission and endoscopic healing.

Main Methods:

• Retrospective analysis of consecutive IBD patients with available week 2 serum adalimumab levels.
• Receiver operating characteristic (ROC) curve analysis to identify an optimal week 2 adalimumab threshold.
• Comparison of week 12 clinical remission (CR) and short-term endoscopic healing rates between patients above and below the identified threshold.
• Multivariate logistic regression to assess the association between week 2 adalimumab levels and CR.

Main Results:

• An optimal week 2 adalimumab threshold of 11.9 mcg/mL was identified via ROC analysis.
• Patients with week 2 adalimumab levels >11.9 mcg/mL demonstrated significantly higher odds of achieving week 12 CR (OR=3.34, P=0.04).
• While numerically higher, short-term endoscopic healing rates were not statistically significant between groups (71.4% vs. 28.5%, P=0.11).

Conclusions:

• Week 2 serum adalimumab levels appear to be a significant predictor of short-term clinical remission in IBD patients.
• Further research is warranted to evaluate the benefit of early dose optimization for patients with week 2 adalimumab levels at or below 11.9 mcg/mL.