A Phase 3 Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Efficacy and Safety of Tulisokibart in Participants with Moderately to Severely Active Ulcerative Colitis

The primary objective is to evaluate the efficacy of tulisokibart compared to placebo in participants with moderately to severely active ulcerative colitis, as assessed by the proportion of participants achieving clinical remission per Modified Mayo Score at Week 12 and Week 52. 5

Secondary objectives include:

• Evaluation of safety and tolerability. 4
• Assessment of efficacy through endoscopic improvement, endoscopic remission, and histologic-endoscopic mucosal improvement at various time points. 5
• Evaluation of clinical response and clinical remission according to the partial modified Mayo score. 5
• Measurement of symptomatic outcomes, including bowel urgency and abdominal pain. 5
• Assessment of quality of life via the Inflammatory Bowel Disease Questionnaire and fatigue levels using the Functional Assessment of Chronic Illness Therapy – Fatigue score. 5
• Evaluation of corticosteroid-free clinical remission at Week 52. 5
• Analysis within a diagnostic assay positive subpopulation. 5

The study involves a total of 512 patients diagnosed with ulcerative colitis. The study population includes both males and females between the ages of 18 and 80 years. Eligible participants must have had symptoms for at least 3 months and present with moderately to severely active disease. Inclusion requires a body weight of at least 40 kg and a documented inadequate response, loss of response, corticosteroid dependence, or intolerance to specific prior treatments. For those of childbearing potential, strict contraceptive requirements or abstinence must be maintained to prevent pregnancy. The primary objectives are:

• To evaluate the efficacy of tulisokibart compared to placebo as assessed by the proportion of participants achieving clinical remission per Modified Mayo Score at Week 12.
• To evaluate the efficacy of tulisokibart compared to placebo as assessed by the proportion of participants achieving clinical remission per Modified Mayo Score at Week 52.

This Phase 3, randomized, double-blind, placebo-controlled program is designed to evaluate the efficacy and safety of tulisokibart in individuals with moderately to severely active ulcerative colitis. The methodology compares the administration of tulisokibart via intravenous use or subcutaneous use against a placebo. The primary objective is to assess the proportion of participants achieving clinical remission according to the Modified Mayo Score at Week 12 and Week 52. The study procedures involve an initial screening visit to determine eligibility based on clinical history, weight, and disease activity. Following randomization, participants undergo scheduled assessments to monitor endoscopic improvement, histologic-endoscopic mucosal improvement, and other secondary endpoints. The total duration of participant involvement is centered around the 52-week evaluation period. Early termination from the study may occur due to adverse events or discontinuation of the study intervention.

The experimental medication consists of tulisokibart, which is provided as a concentrate for solution for infusion intended for intravenous use. Additionally, tulisokibart is available as a solution for injection in pre-filled injector for subcutaneous use.

A placebo to MK-7240 is administered as a comparator treatment in the study of participants with ulcerative colitis.

The efficacy of tulisokibart in participants with ulcerative colitis will be evaluated using several parameters. The primary endpoints consist of the proportion of participants achieving clinical remission as measured by the Modified Mayo Score at Week 12 and Week 52.

Secondary efficacy assessments include the following:

• The percentage of participants achieving clinical response per Modified Mayo Score or partial Modified Mayo Score at Week 12 and Week 2.
• The percentage of participants achieving endoscopic improvement or endoscopic remission at Week 12 and Week 52.
• The percentage of participants achieving histologic-endoscopic mucosal improvement at Week 12 and Week 52, as well as histologic-endoscopic remission at Week 12 and Week 52.
• The percentage of participants achieving corticosteroid-free clinical remission per Modified Mayo Score at Week 52.
• The percentage of participants achieving sustained clinical remission at both Week 12 and Week 52, or sustained endoscopic improvement at both Week 12 and Week 52.
• Patient-reported outcomes, including the percentage of participants reporting no bowel urgency or no abdominal pain at Week 12 and Week 52.
• Remission rates assessed via the Inflammatory Bowel Disease Questionnaire at Week 12 and Week 52.
• Changes from baseline in the Functional Assessment of Chronic Illness Therapy - Fatigue score at Week 12 and Week 52.
• Specific assessments for diagnostic assay positive participants regarding clinical remission and endoscopic improvement at Week 12 and Week 52.