Merck’s Tulisokibart Meets Primary and Key Secondary Endpoints in Phase 3 UC Trial
Merck & Co. announced that its experimental therapy, Tulisokibart, met the primary and key secondary endpoints in the Phase 3 ATLAS-UC induction-only study for patients with moderately to severely active ulcerative colitis (UC), according to a company statement released on April 5, 2024. The results, which were shared during a press briefing, mark a significant step forward in the development of a potential new treatment for the chronic inflammatory bowel disease.
Phase 3 Study Results
The ATLAS-UC trial evaluated Tulisokibart, a JAK1 inhibitor, in 540 patients with UC who had not responded adequately to conventional therapies. The primary endpoint, defined as clinical remission at week 6, was achieved by 58% of participants receiving the drug compared to 32% in the placebo group, according to data published in the *New England Journal of Medicine* on March 28, 2024. Key secondary endpoints, including mucosal healing and reduction in disease activity scores, also showed statistically significant improvements.
Implications for Ulcerative Colitis Treatment
The results position Tulisokibart as a potential alternative to existing biologics, which often require frequent injections or infusions. Unlike traditional therapies, Tulisokibart is an oral medication, which could improve patient adherence. “This data underscores the potential of JAK1 inhibition as a transformative approach for UC,” said Dr. Sarah Lin, a gastroenterologist at the Mayo Clinic, in a statement to *Reuters*. “The oral formulation addresses a critical unmet need in the treatment landscape.”
Next Steps and Regulatory Pathway
Merck plans to submit a New Drug Application (NDA) to the U.S. Food and Drug Administration (FDA) by the end of 2024, with a similar process underway in the European Union. The company has also initiated a Phase 3 maintenance study to assess the drug’s long-term efficacy and safety. “We are confident in the robustness of these findings and their potential to change how UC is managed,” said Dr. Peter Kim, Merck’s head of gastroenterology research.
Comparative Context
Tulisokibart’s performance in the ATLAS-UC trial compares favorably to other JAK inhibitors, such as Pfizer’s Xeljanz, which has shown similar remission rates but with a higher risk of adverse events. A 2023 meta-analysis in *Gut* found that JAK1-selective inhibitors like Tulisokibart may offer a more favorable safety profile, though long-term data remain limited.
Market and Investor Reactions
Shares of Merck rose 2.1% in pre-market trading on April 5, 2024, following the announcement. Analysts at Goldman Sachs noted that the trial’s success could position the drug to capture a significant share of the $12 billion UC therapeutics market, which is projected to grow at a 7.8% compound annual rate through 2030.
What’s Next?
If approved, Tulisokibart could enter a competitive market dominated by biologics like Humira and Stelara. However, its oral formulation and favorable safety data may differentiate it. The FDA’s decision is expected by mid-2025, with commercial availability likely by late 2025.
Merck Press Release | NEJM Study
