P391 Relative association of bowel urgency clinically meaningful improvement or bowel urgency remission versus stool frequency remission and rectal bleeding remission with improvement in Inflammatory Bowel Disease Questionnaire scores in patients with moderately-to-severely active Ulcerative Colitis: An analysis from LUCENT-1 and LUCENT-2 phase 3 clinical trials

Abstract Background Bowel urgency is increasingly being recognized as an impactful symptom in patients with ulcerative colitis (UC)1. However, limited information is available regarding its potential association with other patient reported outcomes. We assessed the association of bowel urgency clinically meaningful improvement (CMI) or bowel urgency remission with Inflammatory Bowel Disease Questionnaire (IBDQ) scores whilst adjusting for the potential confounding effects of stool frequency (SF) and rectal bleeding (RB) remission using data from LUCENT-1 (NCT03518086) and LUCENT-2 (NCT03524092) phase 3 trials. Methods Bowel urgency severity was assessed by the Urgency Numeric Rating Scale (UNRS) (0=no urgency to 10=worst possible urgency). Bowel urgency CMI was defined as ≥3-point decrease in UNRS compared to baseline and bowel urgency remission was defined as UNRS of 0 or 1.2 IBDQ scores (range: 32–224) were calculated; higher scores indicate better quality of life. Mediation analyses were performed to examine the relative association between direct effects of bowel urgency CMI and bowel urgency remission (separate predictors) and IBDQ scores while adjusting for the potential confounding effects of SF remission and RB remission (mediators). Analyses were treatment agnostic and combined patients from mirikizumab and placebo groups from LUCENT-1 (N=1162) and LUCENT-2 (N=544) trials at Week (W) 12 and 40 (W52 of continuous treatment). Results At W12 and W52, bowel urgency remission directly accounted for 44.8% and 32.5% improvement in IBDQ total score, respectively; 22.7% and 39.1% of improvement was mediated by RB remission and 32.5% and 28.4% by SF remission, respectively. At W12, bowel urgency remission resulted in the largest proportion of improvement in each of the IBDQ domain subscores, whereas at W52, RB remission had a greater confounding effect (Fig. 1A). At W12 and W52, bowel urgency CMI accounted for 70% and 57.3% improvement in IBDQ total score, respectively; 12.8% and 25.6% of effects were mediated by RB remission and 17.2% and 17.1% by SF remission, respectively (Fig. 1B). Bowel urgency CMI accounted for the largest proportion of association with improvement in each of the IBDQ domain subscores at both W12 and W52. Conclusion Improvements in IBDQ scores were primarily ascribed to bowel urgency remission and bowel urgency CMI relative to RB remission and SF remission, particularly at W12, in patients with moderately-to-severely active UC. These findings suggest that bowel urgency is a critical and independent symptom that considerably impacts patients’ quality of life. References: