The long game in ulcerative colitis: mirikizumab’s four-year outcomes

Mirikizumab is a targeted, humanized IgG4 monoclonal antibody with specific inhibition for the p19 subunit of interleukin-23. It is now established as a key addition to the growing list of licensed medical therapies for ulcerative colitis, and pivotal clinical trials have provided robust short-term data regarding its efficacy and safety.1 Long-term extension (LTE) studies serve as the crucible where the initial promise of advanced therapies is tested against the chronicity of moderately to severely active ulcerative colitis (UC). While pivotal trials establish short-term efficacy, it is the LTE that sheds light on the true trajectory of drug durability and safety exposing potential challenges of secondary loss of response and safety upon prolonged drug exposure. In the current issue of Inflammatory Bowel Diseases, Sands et al. present the final four-year findings from the LUCENT-3 open-label extension, providing outcomes through Week 212 of continuous treatment.2 Patients who had completed the 52-week maintenance therapy in the LUCENT-2 phase were eligible to enter the long-term extension; therefore, efficacy and safety data are reported in patients with 4 years of continuous treatment with mirikizumab. In the analysis presented, the cohort was stratified by their status at entry—specifically distinguishing ­between Week 52 remitters (the “best-case” cohort) and Week 52 responders—allowing for a granular assessment of durability in different responder profiles.