Mirikizumab four-year sustained and durable efficacy and safety in ulcerative colitis: Final findings from the LUCENT-3 open-label extension study

BACKGROUND: Mirikizumab, an anti-interleukin-23 monoclonal antibody targeting the p19 subunit, has shown efficacy in inducing and maintaining clinical remission in patients with moderately-to-severely active ulcerative colitis (UC). This report summarizes the final long-term outcomes from the LUCENT-3 open-label extension (OLE) through week (W)212 of continuous treatment. METHODS: Among 868 participants who received mirikizumab induction therapy in the LUCENT clinical trial program, 544 achieved clinical response. Of these, 365 were rerandomized to mirikizumab maintenance, with 324 completing W52, 316 entering the OLE, and 182 completing the OLE (4 years of continuous treatment), resulting in 835.3 total patient years of exposure. These analyses include efficacy and safety data from the LUCENT-3 cohort, stratified by LUCENT-1 baseline biologic experience, W52 remitter, and W52 responder status on entering the OLE study. Outcomes were analyzed using modified nonresponder imputation, traditional nonresponder imputation, and observed cases (OC) to handle missing data. RESULTS: At W212, W52 Maintenance Remitters showed 77.7% clinical, 77.7% corticosteroid-free (CSF), 81.3% endoscopic, 66.0% histologic-endoscopic mucosal (HEMR), 94.3% symptomatic, and 73.6% bowel urgency (BU) remission rates (OC); 67.9% achieved histologic-endoscopic mucosal improvement (HEMI), 97.1% sustained clinical response, and 92.9% achieved BU clinically meaningful improvement (CMI). At W212, W52 Maintenance Responders showed 68.7% clinical, 68.7% CSF, 70.2% endoscopic, 55.1% HEMR, 92.7% symptomatic, and 74.8% BU remission rates (OC). For W52 Maintenance Completers, reductions in stool frequency, rectal bleeding, bowel urgency, and abdominal pain from baseline were sustained to W212. W52 Maintenance Remitters and Responders achieved Inflammatory Bowel Disease Questionnaire (IBDQ; quality of life measure) response (70%) and remission (>66%) at W212. Across biologic failed and bionaive subgroups, efficacy results were generally similar. For over 160 weeks of OLE treatment in the safety population, no new safety signals emerged from long-term exposure compared with induction and maintenance treatment. CONCLUSIONS: Mirikizumab provided sustained symptomatic, clinical, endoscopic, and histologic benefits over 4 years in responding patients with moderately-to-severely active UC, including those with prior biologic failure. These treatment goals, which are integral to comprehensive disease management, support the long-term use of mirikizumab.