Bowel urgency in ulcerative colitis: effect of baseline urgency and change in urgency in response to mirikizumab.

Background: Mirikizumab has demonstrated efficacy in moderately to severely active ulcerative colitis. A 1-2-point change in Urgency Numeric Rating Scale (NRS) score can be meaningful for patients. In these post-hoc analyses, we evaluated the efficacy of mirikizumab compared to placebo by baseline Urgency NRS score groups (0-3, 4-6, and 7-10) and its effect on bowel urgency severity over time.

Methodology: Urgency NRS was measured as a secondary outcome at baseline, week 12, and week 52. Bowel urgency improvement was assessed for patients who achieved and did not achieve multiple efficacy endpoints. Data were analyzed using Fisher's exact test with nonresponder imputation.

Results: At weeks 12 and 52, a significantly higher percentage of mirikizumab-treated patients achieved clinical response as well as clinical, endoscopic, and symptomatic remission compared to placebo-treated patients, regardless of baseline Urgency NRS score category (higher proportions versus placebo, delta 9%-45%). Improvement in Urgency NRS score category at weeks 12 and 52 for mirikizumab-treated patients was observed when other efficacy outcomes were achieved (13%-90%) and not achieved (12%-75%).

Conclusions: A greater proportion of mirikizumab-treated patients with ulcerative colitis achieved symptomatic, clinical, and endoscopic remission endpoints compared to placebo-treated patients, regardless of baseline bowel urgency severity. After one year, bowel urgency was improved to a greater extent with mirikizumab than with placebo, even for patients who did not achieve other clinical outcomes. Small improvements in bowel urgency are associated with significant health-related quality-of-life improvements. Monitoring shifts in urgency severity over time using the Urgency NRS can aid in understanding patients' treatment outcomes.

Trial registration: LUCENT-1 (NCT03518086) Registered 04 May 2018 https://clinicaltrials.gov/study/NCT03518086 . LUCENT-2 (NCT03524092) Registered 10 May 2018 https://clinicaltrials.gov/study/NCT03524092 .