Merck reported a positive Phase 3 result for tulisokibart, an anti-TL1A antibody acquired through its $10.8 billion Prometheus deal, in an ulcerative colitis induction-only study. The company said the therapy met the primary endpoint of clinical remission at week 12 without identifying safety concerns. Merck positioned tulisokibart as the first anti-TL1A antibody to show positive clinical remission outcomes after 12 weeks in the specific patient population studied, with detailed results planned for upcoming congress and regulator discussions. The drug is being evaluated across additional inflammatory indications, including Crohn’s disease and other immune-mediated diseases. The readout adds incremental clinical validation to a newer inflammation class, while also sharpening the competitive landscape against existing UC mechanisms such as IL-23 inhibitors, JAK inhibitors, and integrin therapies. For investors, it increases the probability that the Prometheus asset will contribute meaningfully to Merck’s long-term immunology portfolio.