Korean Post-marketing Surveillance for Xeljanz XR

This is a post-marketing surveillance study in Korea monitoring the real-world safety and effectiveness of Xeljanz XR (tofacitinib extended-release), a medication used to treat rheumatoid arthritis, psoriatic arthritis, and ankylosing spondylitis. Researchers collect data on how the drug performs outside of clinical trial conditions. **You may be eligible if...** - You are an adult (18+) being prescribed Xeljanz XR for rheumatoid arthritis, psoriatic arthritis, or ankylosing spondylitis according to the approved Korean labeling - You have had an inadequate response or intolerance to prior standard treatments (e.g., methotrexate or other DMARDs) - You have provided written informed consent - You may also be eligible if you are switching from the regular Xeljanz 5mg tablet to the XR formulation **You may NOT be eligible if...** - You are allergic to any ingredient of Xeljanz XR - You are in a special caution group (age 65+, cardiovascular risk, or cancer risk) and no other treatments have been tried first - You are pregnant or nursing Talk to your doctor to see if this trial is right for you.