This study looks at how well a new drug, **JNJ-88545223**, works to treat **Psoriatic Arthritis (PsA)**, a condition causing joint pain and skin issues. The study compares JNJ-88545223 to a **placebo**, which is a harmless pill with no active medicine, to see if it helps improve joint and skin health. **Key Points:** - The study requires adults with active PsA for at least 3 months. Participants should have at least 3 swollen and 3 tender joints, along with active skin issues due to PsA. - Women who can have children must have a negative pregnancy test before starting the study. Participants should not have other severe health issues or allergies to JNJ-88545223. - People with nonplaque forms of psoriasis or certain other health conditions can't join. The study will check for a history of severe allergies or recent cancer. If you have any of these conditions and want to join, please discuss with your doctor to see if this study is right for you. This study aims to find better treatments for PsA to improve life quality.