Therapeutic drug monitoring of ustekinumab in Crohn’s disease patients: a real-world study

Crohn’s disease (CD) is a chronic inflammatory disorder. Ustekinumab (UST) is an effective treatment for CD. Therapeutic drug monitoring (TDM) enhances clinical efficacy while minimizing side effects. This study aimed to evaluate the UST trough level (TL) and anti-drug antibodies (ADAs) and to assess the response of patients with CD to optimize UST treatment. This single-center, cross-sectional study included 76 adult patients with CD receiving maintenance UST for at least 24 weeks. The serum TL of UST and clinical remission were assessed at the same visit, immediately before the next dose. Patients were categorized into two groups: Group A, patients reaching the UST target TL (≥1 µg/mL), and Group B, patients failing to reach it. The association between UST exposure and remission was assessed by binary logistic regression. The remission rate was significantly higher in Group A (78.2%) than in Group B (28.6%) ( p < 0.001). Based on the TL of UST, ADA positivity, and disease activity, recommendations were made to continue treatment in 43 patients, escalate therapy or shorten the dosing interval in 20 patients, and switch to another biologic agent in 13 patients. Accordingly, TDM of UST could serve as a valuable approach for optimizing CD therapy.