Predictive models assessing the response to ustekinumab highlight the value of therapeutic drug monitoring in Crohn's disease.

BACKGROUND: Despite the therapeutic efficacy of Ustekinumab (UST) in Crohn's disease (CD), loss of response (LOR) is observed over time. This study aims to evaluate the impact of the UST pharmacokinetics (PK) at induction on clinical and endoscopic outcomes, as well as to find predictive markers of UST response. METHODS: This retrospective study included 80 CD patients. Pharmacokinetics data (trough levels (TLs)) combined with clinical and biological parameters were fed into tailored logistic regression and tree-based ensemble techniques to predict clinical and endoscopic outcomes at one year of follow-up. RESULTS: TLs at week 16 were significantly lower among patients with moderate to severe endoscopic activity during the follow-up (p = 0.04). The best model to predict endoscopic outcome was obtained at week 16 by Random Forest with an area under the receiver operating characteristic curve of 0.92 ± 0.08, sensitivity 91% and specificity 75%, with key inputs such as lymphocyte and monocyte counts at week 8, and UST TLs and CRP at week 16. CONCLUSIONS: This real-world study confirms the relationship between early UST TLs and both clinical and endoscopic outcomes. Models were developed for the task of predicting clinical and endoscopic remission in CD patients treated with UST, highlighting the clinical relevance of UST TLs at week 16.

Collecting New Peak and Intermediate Infliximab Levels to Predict Remission in Inflammatory Bowel Diseases.

BACKGROUND: The loss of response to infliximab is a challenge for clinicians in the management of inflammatory bowel disease (IBD). Mounting evidence suggests that therapeutic drug monitoring at induction may predict remission during maintenance. The aim of the study was to improve predictive models of remission by exploring new peak and intermediate infliximab measurements during induction. METHODS: This was a prospective multicenter study evaluating the pharmacokinetics of infliximab during induction in a pioneer cohort of 63 patients with IBD. Pharmacokinetics data including peak, intermediate, and trough levels were combined with clinical and biological parameters and were subsequently fed into tailored logistic regression and tree-based techniques to predict remission at week 30. RESULTS: Infliximab peak levels at week 2, intermediate levels at week 3, and trough levels at week 6 were correlated with remission at week 30. Predictive models exhibited an increased accuracy over the successive timepoints of the induction with key inputs such as albumin, C-reactive protein, eosinophils, neutrophils, lymphocytes, intermediate level at week 3, trough level at week 6, and age at diagnosis. Our predictive model of remission at week 30 was obtained with an area under the receiver operating characteristic curve of 0.9 ±â€…0.12, a sensitivity of 89%, and a specificity of 75%. CONCLUSIONS: This study showed the clinical relevance of measuring new infliximab levels to predict remission in patients with IBD. These findings lay the foundation for a personalized medicine in which biotherapies could be monitored at an early stage, thereby improving patients' clinical management.