P574 Clinical outcomes in extending of injection period of ustekinumab from every 8 to 12 weeks in patients with Crohn’s disease (CD-EXTEND Study)

Abstract

Abstract Background De-escalation was a useful strategy for improving patient’s QOL and reduction of medical expenses. However, de-escalation of ustekinumab (UST) for the patients with Crohn’s disease (CD) has not been reported. The aim of this study was to elucidate clinical outcomes of de-escalation of UST. Methods This was a single-centre prospective observational study approved by the institutional review board of our hospital. CD patients who selected de-escalate UST treatment after administration of intravenous UST 6 mg/kg and subcutaneous UST 90mg every 8 weeks until 54 weeks were enrolled in this cohort. Primary endpoint was clinical remission rate at one year, including patients treated with re-escalation. Secondary endpoints were persistency of de-escalation of every 12 weeks and re-escalation effects of every 8 weeks. We also compared backgrounds and biomarkers including CRP, fecal calprotectin (FC) for persistent and non-persistent groups. Cut-off values of prediction for non-persistent was calculated by receiver operating characteristic (ROC) curve. Definition of clinical remission was CDAI<150 for CD. Results In total, 30 participants were included in the final analysis. Clinical remission rate at one year was 96.7% (29/30). Persistency of de-escalation at one year was 76.7% (23/30). Persistency after re-escalation was 85.7% (6/7). There was no difference between the backgrounds of persistent (n=23) and non-persistent groups (n=7). CRP titer at week 12 was significantly higher in non-persistent group than persistent group (Median 0.59 vs 0.17 mg/dL, p=0.021). FC titer at week 0, 12 and amount of change at week 24 was significantly higher in non-persistent group than persistent group (Median 660 vs 120 μg/g, p=0.021;1341 vs 61 μg/g, p=0.001; 528 vs 4 μg/g, p=0.04). Cut-off values of prediction for non-persistent from CRP at week 12, FC at week 0, 12 were 0.33 mg/dL, 314 μg/g, 581.5 μg/g, respectively. Conclusion De-escalation was feasible strategy for CD patients treated with UST. CRP and FC were good prediction biomarker for non-persistence