The rationale for this study is to investigate whether in psoriatic arthritis (PsA) patients in stable remission a reduction or complete discontinuation of immunosuppressive therapy can be achieved in a treat-to-target approach while maintaining in remission. Due to the lack of reliable data that answers the question of how to safely reduce medication in which patients, this study will test a pragmatic treatment algorithm that can be applied in clinical practice and that offers a gradual reduction with escape strategies in order to facilitate the maintenance of remission.