Doggrell Sheila A
School of Pharmacy and Medical Sciences, Gold Coast Campus, Griffith University, Gold Coast, Queensland, Australia.
Expert Opin Biol Ther. 2025 Jun;25(6):593-598. doi: 10.1080/14712598.2025.2508836. Epub 2025 May 21.
Ulcerative colitis (UC) includes a dysregulated immune response. The conventional therapy includes immunosuppressants, and biologics targeting inflammatory mediators, but these are often inadequate, or subjects become unable to tolerate them.
QUASAR: the induction and maintenance components of the phase 3 trial of guselkumab, which inhibits IL-23 by dual mechanisms, in subjects with moderate-to-severe UC. QUASAR enrolled those that had an inadequate response and/or intolerance to corticosteroids, immunosuppressants, biologics, or Janus kinase (JAK) inhibitors. In both parts of the trial, guselkumab improved clinical remission with no excess of adverse events.
For those enrolled throughout, after the maintenance part, the benefit with guselkumab on clinical remission was 24% percentage points (45 vs 21%), which is relatively small. There is no direct comparison of guselkumab with other IL-23 inhibitors in UC. Indirectly comparing trials suggests the clinical remission rates at the end of the trials was higher with guselkumab than with the other approved IL-23, inhibitors, mirikizumab or risankizumab (17 or 15% points, respectively). Thus, guselkumab may be more efficacious than the other 1 L-23 antagonists, possibly due to its additional action to block the CD64 receptor. However, this needs to be tested in a direct comparison trial.