DOP33 Long-term clinical efficacy of ustekinumab in refractory Crohn’s disease : a multi-centre Belgian cohort study

Ustekinumab (UST) was recently approved in Belgium for moderate to severe Crohn’s disease (CD). Long-term real-life data are currently scarce, especially in refractory populations. We collected data in patients initiating UST therapy between September 2016 and September 2017. Patients received intravenous (IV) UST 6 mg/kg at baseline, with 90 mg subcutaneously thereafter every 8 weeks. The primary endpoints, clinical response and remission at 1 year, were defined as a reduction in Harvey Bradshaw Index (HBI) of ≥3 and an HBI ≤4, respectively. Biological response was defined as 50% drop in C-reactive protein (CRP) and/or CRP <5 mg/l and biological remission as CRP < 5 mg/l, if CRP >5 mg/l at baseline. Primary nonresponse was defined as drug stop due to the absence of clinical improvement before Week 8 while loss of response as drug stop due to secondary loss of response after initial response to the drug. Data were analysed in an intention-to-treat manner. Demographic and baseline data of the study population of 163 patients are presented in Table 1. Importantly all patients were refractory to at least one anti-TNF and >70% of patients to anti-TNF and vedolizumab. Data at 1 year were available for all but 8 patients due to loss of follow-up. Eleven patients with HBI ≤ 4 at baseline were excluded. By 1 year of follow-up, 42.1% experienced a clinical response including 35.7% of patients with clinical remission. 38.8% and 24.3% of the population obtained a steroid-free clinical response and remission, respectively. Treatment intensification (new IV infusion and/or q4w) was reported in 6.6% of patients. UST was discontinued in 35.5% of patients after 1 year. Reasons for UST withdrawal were primary nonresponse (n = 3), intense arthralgia (n = 1), loss of response (n = 47), and patient decision (n = 4). CRP significantly decreased from baseline (16.1 mg/l, IQR [10.6–28.8]) to 6.6 mg/l at 1 year (IQR [6.6–15.1], p < 0.0001). At Week 52, a 50% drop in CRP was observed in 33.6% and 25.4% achieved a biological remission. Eleven patients (6.7%) of patients experienced side effects, including one patient who discontinued therapy due to intense arthralgia. This real-life cohort study confirms the clinical efficacy of ustekinumab at 1 year even in a population of highly refractory CD patients.