Efficacy and Safety of Duvakitug as Maintenance Therapy in Participants with Moderately to Severely Active Ulcerative Colitis: A Phase 3, Randomized, Placebo-Controlled Study

The primary objective of this study is to evaluate the efficacy of duvakitug as maintenance therapy compared to placebo in participants with moderately to severely active ulcerative colitis (5). The secondary objectives include:

• Assessment of efficacy using multiple measures of disease activity.
• Evaluation of the safety of duvakitug compared to placebo (4).
• Analysis of pharmacokinetics (6) and immunogenicity.
• Assessment of the safety of long-term administration of duvakitug.

This study involves a total of 467 patients diagnosed with ulcerative colitis. The study population includes both male and female participants, including vulnerable populations. Eligible participants are aged between 18 and 80 years, although individuals aged 16 to less than 18 years may be included where locally permissible if they meet the criteria for Tanner stage 5. The cohort consists of individuals who achieved clinical response and completed endoscopy at the conclusion of the SUNSCAPE-1 study. The primary objective is to evaluate the efficacy of duvakitug as maintenance therapy compared to a placebo in those with moderately to severely active disease.

This multicenter, multinational, randomized, double-blind, placebo-controlled, Phase 3 study is designed to evaluate the efficacy and safety of duvakitug as maintenance therapy in individuals with moderately to severely active ulcerative colitis. Participants will receive either duvakitug via subcutaneous injection or a matched placebo. The primary objective is to assess the proportion of participants achieving clinical remission as measured by the modified Mayo Score. Secondary endpoints include endoscopic improvement, histologic endoscopic mucosal improvement, and the incidence of treatment-emergent adverse events. The study includes a pivotal maintenance sub-study and an open-label extension sub-study. Participants must have achieved clinical response and completed endoscopy at the end of the prior induction period to be eligible for the maintenance cohort. The total study duration is estimated to extend through August 2033.

The experimental medication, duvakitug, is administered as a solution for injection via subcutaneous injection. The specified dosage for this test product is 00 mg.

The comparator treatment consists of a matched placebo designed to be identical to the experimental medication. This placebo is utilized for comparison in participants with moderately to severely active ulcerative colitis.

The efficacy of duvakitug in participants with moderately to severely active ulcerative colitis is assessed through several endpoints. The primary endpoint is the proportion of participants achieving clinical remission as measured by the modified Mayo Score.

Secondary efficacy parameters include:

• Proportion of participants with endoscopic improvement or endoscopic remission.
• Proportion of participants achieving histologic endoscopic mucosal improvement.
• Proportion of participants with corticosteroid-free clinical remission.
• Proportion of participants with no bowel urgency.
• Change from baseline in the PROMIS-Fatigue Short Form 7a T-score.
• Proportion of participants achieving maintenance of clinical remission in a subset that achieved remission at the end of the induction period.
• Proportion of participants with no abdominal pain as evaluated by the Numerical Rating Scale.
• Change from baseline in the Inflammatory Bowel Disease Questionnaire total score.
• Incidence of ulcerative colitis-related hospitalizations.
• Proportion of participants with symptomatic remission based on the stool-frequency sub score and rectal bleeding sub score.
• Proportion of participants achieving clinical remission and no steroid use from baseline to the time of endpoint analysis.
• Serum concentration of duvakitug measured over time.
• Incidence of anti-drug antibodies against duvakitug.