Psoriatic arthritis (PsA) is a long-term inflammatory disease that affects the joints and skin.
The purpose of this study is to check how safe zasocitinib is, how well it is tolerated and how well it works in adults with PsA over a longer period of time.
Adults who completed the 1-year (52-week) treatment period in one of the parent studies (TAK-279-PsA-3001 \[NCT06671483\] or TAK-279-PsA-3002 \[NCT06671496\]) may be able to join this continuation study (also called long-term extension or LTE study). All participants in this continuation study, will receive zasocitinib (lower or higher dose), once a day (QD).
Each participant can be in this study for approximately 2 years (108 weeks). This includes a treatment period of up to 2 years (104 weeks) and a 1-month (4-week) follow-up period to monitor a participant's health.