Retrospective Assessment of an Adalimumab Model–Informed Precision Dosing Support Tool for Use in Pediatric Inflammatory Bowel Disease

Abstract

OBJECTIVES Therapeutic drug monitoring in pediatric inflammatory bowel disease (IBD) has been used to achieve and maintain remission. Few guidelines exist to aid clinicians in the adjustment of anti–tumor necrosis factor therapies. The objective was to assess the agreement between real-world postinduction and posteriori analysis of retrospective data, using 2 novel pharmacokinetic (PK) models for adalimumab. METHODS A retrospective chart review was conducted in pediatric IBD patients treated with adalimumab. A Bayesian clinical decision support tool (InsightRX) was used. Postinduction serum concentration measurements of adalimumab were performed by drug-tolerant, homogenous shift mobility assay. Predicted serum adalimumab concentrations from both models were compared to the actual serum concentrations through a Bland-Altman analysis. Paired sample t test was used for equivalence. RESULTS A total of 47 patients were included. Forty-one patients (87%) had Crohn disease, and 30 (64%) were male. Most were induced with 160 mg of adalimumab and maintained on 40 mg biweekly. No significant difference resulted between the de Klaver average prediction and mean population concentration (p = 0.294). Significant difference was observed between Ternant and mean population serum adalimumab concentration (p < 0.001). The Bland-Altman plot for the de Klaver method showed no proportional bias. Additionally, 49% of patients required a dose adjustment during maintenance therapy. CONCLUSIONS The de Klaver model was able to provide less bias than the Ternant model and may aid in predicting serum adalimumab concentrations. Approximately half of the patients required dose adjustment during maintenance therapy to obtain a therapeutic drug concentration or achieve clinical remission.