Researchers are looking for new ways to treat radiographic axial spondyloarthritis (r-axSpA). R-axSpA is a type of arthritis that causes pain, stiffness, and inflammation (swelling) in the spine and joints in the pelvis (hip bone). Radiographic means the damage it causes can be seen on X-rays.

This study will help find out if a study medicine called tulisokibart can treat symptoms of r-axSpA. Researchers will look at different doses of tulisokibart.

Researchers want to know if at least one of the study doses of tulisokibart works better than a placebo to improve r-axSpA symptoms. A placebo looks like the study medicine but has no study medicine in it. Using a placebo helps researchers better understand the effects of the study medicine.