GRAPPA Research Projects: Development of Criteria for Axial Psoriatic Arthritis and Definitions of Complex-to-Manage...

At the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) 2025 congress, 2 major research initiatives in psoriatic disease were highlighted: (1) the Axial Involvement in Psoriatic Arthritis (AXIS) study, and (2) the GRAPPA consensus definitions for complex-to-manage psoriatic arthritis (C2M-PsA) and treatment-refractory PsA (TR-PsA). The AXIS study, jointly led by Assessment of SpondyloArthritis international Society (ASAS) and GRAPPA, aims to establish internationally accepted classification criteria for axial PsA. In its recently completed phase, 409 patients were recruited across 41 centers in 19 countries. A comprehensive imaging and clinical dataset were collected and analyzed. The next phase will construct and validate a PsA-specific classification instrument to support future research. In parallel, GRAPPA developed consensus definitions for C2M-PsA and TR-PsA through a transparent, multistakeholder process. C2M-PsA refers to patients with persistent symptoms despite appropriate treatment, often complicated by comorbidities or overlapping conditions. TR-PsA is defined by failure to respond to multiple therapies and by confirmed persistent inflammation. These definitions were endorsed by 95% of GRAPPA members and are supported by practical checklists for clinical use. These initiatives represent a significant advancement in PsA research, offering clinicians structured tools to improve patient stratification, guide treatment decisions, and enhance personalized care.