A Randomized, Double-blind, Placebo-controlled Clinical Study of the Oral IL-12/23 Inhibitor, STA-5326 Mesylate, Administered to Patients With Rheumatoid Arthritis to Determine Safety, Tolerability, Pharmacokinetic and Synovial Tissue Outcomes

It is not fully clear how rheumatoid arthritis originates and develops, but it is understood that multiple genetic and environmental factors interact to trigger its onset. The immune system attacks the joint synovium, which damages the cartilage and bone in the joint by increasing the number of inflammatory cells and forming new blood vessels in the joint space. STA-5326 mesylate inhibits the production of IL-12 and IL-23 and therefore may inhibit Th-1 cytokine production. A reduction in the Th-1 response has the potential to minimize or eliminate joint damage caused by the immune response in rheumatoid arthritis. This study is designed to assess whether the proposed mechanism of action is associated with a reduction in inflammation in the synovium of patients who have rheumatoid arthritis.