Merck has announced a significant expansion of its clinical development program for tulisokibart (MK-7240), an investigational monoclonal antibody targeting the inflammatory mediator TL1A. Reported by Drugs.com, in October 2025, the company began three new Phase 2b trials to assess tulisokibart’s safety and efficacy in patients with moderate to severe hidradenitis suppurativa (HS), radiographic axial spondyloarthritis (r-axSpA, also known as ankylosing spondylitis), and rheumatoid arthritis (RA). Together, these global trials aim to enroll over 640 participants, reflecting Merck’s commitment to developing new therapies for immune-mediated inflammatory diseases in both rheumatology and dermatology.
Expanding Clinical Impact Across Diseases
These three new studies (NCT06956235 for HS, NCT07133633 for r-axSpA, and NCT07176390 for RA) bring tulisokibart’s total clinical footprint to six diseases. Tulisokibart is already being studied in Phase 3 trials for two types of inflammatory bowel disease—ulcerative colitis (UC) and Crohn’s disease (CD)—as well as in a Phase 2 trial for systemic sclerosis-associated interstitial lung disease (SSc-ILD). According to Dr. Aileen Pangan, vice president and head of immunology at Merck Research Laboratories, these trials underscore Merck’s drive to address the significant burdens faced by patients with immune-driven inflammatory conditions.
Understanding the Target Diseases
- Hidradenitis suppurativa (HS): A chronic skin disorder causing painful nodules and abscesses in areas like the armpits and groin, affecting up to 0.8% of people.
- Radiographic axial spondyloarthritis (r-axSpA): Also called ankylosing spondylitis, this form of arthritis causes inflammation and pain in the spine and pelvis, with changes visible on X-rays. It affects up to 1% of the population.
- Rheumatoid arthritis (RA): A chronic autoimmune disease leading to joint inflammation and pain, as well as complications in organs throughout the body. Globally, RA affects 17.9 million people and its prevalence is rising.
About Tulisokibart
Tulisokibart is a humanized monoclonal antibody designed to bind both soluble and membrane-bound TL1A, a protein implicated in inflammation and tissue fibrosis. By targeting TL1A, tulisokibart may help inhibit inflammatory pathways, particularly those driving diseases like IBD and potentially alter the course of disease by reducing fibrosis. This mechanism is the focus of Merck’s strategy to develop more effective therapies for a broad range of immune-mediated diseases.
Merck’s Vision in Immunology
Merck’s research efforts are centered on innovative targets such as TL1A and CD30L, aiming to shift treatment paradigms for immune-mediated inflammatory diseases. The company is leveraging its scientific expertise to discover and develop therapies that improve patients’ lives. With tulisokibart, Merck is reinforcing its longstanding commitment to advancing new options for conditions with significant unmet medical needs.
Looking Forward
As Merck continues to broaden tulisokibart’s clinical development, the company emphasizes that the future of immune disease therapy lies in understanding novel biological pathways and delivering targeted treatments to patients worldwide.
