Abstract
PURPOSE: There are limited data regarding the role of proactive therapeutic drug monitoring (TDM) in patients with inflammatory bowel disease (IBD) treated with adalimumab (ADM). The aim of the study was to investigate the long-term outcome of patients with IBD undergoing proactive versus reactive TDM in terms of treatment failure.
METHODS: This single-center, retrospective, cohort study included consecutive patients with IBD who received maintenance ADM therapy and underwent TDM from January 2018 to March 2023. The proactive TDM group consisted of patients who had at least one proactive TDM during the follow-up time, while the reactive TDM group consisted of patients who underwent only reactive TDM. Patients were followed from first TDM until treatment failure or the end of the follow-up period (May 2024). Treatment failure was defined as either drug discontinuation due to loss of response/serious adverse event or an IBD-related surgery.
RESULTS: The study population consisted of 277 patients with IBD (n = 206, 74% with Crohn's disease), who underwent either proactive (n = 217) or reactive (n = 60) TDM. Patients were followed for a median of 39.5 (interquartile range 25.1-55.2) months. Multiple Cox regression analysis identified proactive TDM to be associated with less treatment failure [hazard ratio (HR 0.26, 95% confidence interval (CI) 0.16 to 0.42, p < 0.001], while stricturing CD (HR 2.1, 95% CI 1.3 to 3.5, p = 0.003) and antibodies to ADM at first TDM (HR 2.5, 95% CI 1.4 to 4.4, p = 0.002) were associated with treatment failure.
CONCLUSIONS: In this large cohort study, proactive when compared to reactive TDM was associated with less treatment failure in patients with IBD receiving ADM maintenance therapy.