Trial results for guselkumab (Tremfya) in participants with moderately to severely active ulcerative colitis were posted on ClinicalTrials.gov on 2025-12-09. The study demonstrated that 27.6% of participants receiving guselkumab achieved clinical remission at Week 12, compared to 6.5% for those on placebo, with an adjusted treatment difference of 21.1% (p=0.001).
Background
The study evaluated the efficacy of guselkumab in participants diagnosed with moderately to severely active ulcerative colitis (UC).
Trial design
The study (NCT05528510) was a Phase 3 trial with an enrollment of 418 participants. The study investigated guselkumab therapy in participants with moderately to severely active ulcerative colitis. The purpose was to evaluate the efficacy, including clinical remission, of guselkumab subcutaneous induction compared to placebo.
Key results
The trial results demonstrated significant differences between the guselkumab and placebo groups across multiple efficacy endpoints.
- For "Percentage of Participants in Clinical Remission at Week 12": 6.5% of participants in the placebo group achieved remission, compared to 27.6% in the Combined Guselkumab 400 mg group. The adjusted treatment difference was 21.1% (95.0% CI: 14.5 to 27.6), with a p-value of 0.001.
- For "Percentage of Participants in Symptomatic Remission at Week 12": 20.9% of participants in the placebo group achieved remission, compared to 51.3% in the Combined Guselkumab 400 mg group. The adjusted treatment difference was 30.4% (95.0% CI: 21.6 to 39.2), with a p-value of 0.001.
- For "Percentage of Participants With Endoscopic Improvement at Week 12": 12.9% of participants in the placebo group showed improvement, compared to 37.3% in the Combined Guselkumab 400 mg group. The adjusted treatment difference was 24.3% (95.0% CI: 16.6 to 31.9), with a p-value of 0.001.
- For "Percentage of Participants in Clinical Response at Week 12": 34.5% of participants in the placebo group achieved response, compared to 65.6% in the Combined Guselkumab 400 mg group. The adjusted treatment difference was 31.0% (95.0% CI: 21.6 to 40.5), with a p-value of 0.001.
- For "Percentage of Participants With Histologic-endoscopic Mucosal Improvement at Week 12": 10.8% of participants in the placebo group showed improvement, compared to 30.5% in the Combined Guselkumab 400 mg group. The adjusted treatment difference was 19.6% (95.0% CI: 12.4 to 26.9), with a p-value of 0.001.
- For "Percentage of Participants in Clinical Remission at Week 24": 9.4% of participants in the placebo group achieved remission, compared to 35.3% in the Guselkumab 400 mg q4w - Guselkumab 100 mg q8w group. The adjusted treatment difference was 25.9% (95.0% CI: 16.7 to 35.1), with a p-value of 0.001.
What this means
The results indicate that guselkumab significantly improved clinical remission, symptomatic remission, endoscopic improvement, clinical response, and histologic-endoscopic mucosal improvement in participants with moderately to severely active ulcerative colitis compared to placebo. The consistent and statistically significant differences observed across multiple endpoints at both Week 12 and Week 24 suggest that guselkumab could be an effective treatment option for this patient population.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for study NCT05528510, titled "A Study of Guselkumab Therapy in Participants With Moderately to Severely Active Ulcerative Colitis," were posted on 2025-12-09 on clinicaltrials.gov.