Ustekinumab Trough Concentrations Are Associated with Biochemical Outcomes in Patients with Crohn's Disease.

OBJECTIVE: It is unknown whether ustekinumab (UST) levels can predict clinical outcomes in Crohn's disease (CD) patients. We assessed the exposure-response relationship of UST trough concentrations with biochemical outcomes at week 24 in a prospective, real-world setting. METHODS: We performed a prospective study in patients with CD starting UST in four academic centres in the Netherlands. All patients received a weight-adjusted intravenous (IV) UST induction dose, followed by one subcutaneous (SC) dose of 90 mg UST at 8 weeks. Maintenance therapy consisted of 90 mg subcutaneous UST every 8 or 12 weeks. Individual UST concentration time course during treatment were estimated using a population pharmacokinetic (PK) model. Quartile analysis and logistic regression were performed to analyse if UST concentrations at week 8 were associated with biochemical remission rates at week 24 (C-reactive protein (CRP) ≤ 5 mg/L and / or faecal calprotectin (FC) ≤ 250 mg/kg). RESULTS: In total, 124 patients with CD were included. Patients achieving biochemical remission at week 12 and 24 had significantly higher UST levels at week 8 compared to patients without biochemical remission (6.6 µg/mL versus 3.9 µg/mL, P < 0.01 and 6.3 µg/mL versus 3.9 µg/mL, P < 0.01, respectively). In quartile analysis, patients with UST levels in the highest quartile (≥ 6.3 µg/mL at week 8) had higher biochemical remission rates at week 12 and week 24. There was no association between UST levels at and corticosteroid-free clinical remission rates. CONCLUSION: In this real-world cohort of patients with CD, UST levels in the highest quartile (≥ 6.3 µg/mL) at week 8 were associated with higher biochemical remission rates at week 24.

Ustekinumab for Crohn's Disease: Results of the ICC Registry, a Nationwide Prospective Observational Cohort Study.

BACKGROUND AND AIMS: Ustekinumab is approved for the treatment of Crohn's disease [CD]. Systematically registered prospective real-world data are scarce. We therefore aimed to study the effectiveness, safety and usage of ustekinumab for CD in everyday practice. METHODS: We prospectively enrolled CD patients initiating ustekinumab in regular care between December 2016 and January 2019. Clinical (Harvey Bradshaw Index [HBI]), biochemical (C-reactive protein [CRP] and faecal calprotectin [FCP]), extra-intestinal manifestations and, peri-anal fistula activity, ustekinumab dosage, concomitant medication use, and adverse events were documented at weeks 0, 12, 24, and 52. The primary outcome was corticosteroid-free clinical remission. RESULTS: In total, 221 CD patients were included (98.6% anti-tumour necrosis factor [TNF] and 46.6% vedolizumab exposed) with a median follow-up of 52.0 weeks [interquartile range 49.3-58.4]. Corticosteroid-free clinical remission rates at weeks 24 and 52 were 38.2% and 37.1%, respectively. An initial dosing schedule of 8 weeks, compared to 12 weeks, correlated with a lower discontinuation rate [20.0% vs 42.6%, p = 0.01], but comparable corticosteroid-free clinical remission at week 52 (46.3% [q8w] vs 34.6% [q12w], p = 0.20). There was no clinical benefit of combination therapy after 52 weeks when compared to ustekinumab monotherapy [combi 40.6% vs mono 36.0%, p = 0.64]. At baseline, 28 patients had active peri-anal fistula, of whom 35.7% showed complete clinical resolution after 24 weeks. During follow-up we encountered six severe infections [3.5 per 100 patient-years], with all patients being on concomitant immunosuppressant therapies. Ustekinumab treatment discontinuation was observed in 75 [33.9%] patients mainly due to lack of response. CONCLUSION: Ustekinumab is a relatively safe and effective treatment option for CD patients with prior failure of anti-TNF and anti-integrin therapies.