CRP and Sacroiliac arthritis: Clinical and imaging criteria: Active PsA (DISCOVER-1: ≥3 swollen joints, ≥3 tender joints, CRP ≥0.3 mg/dL despite standard therapies; DISCOVER-2: ≥5 swollen joints, ≥5 tender joints, CRP ≥ 0.6 mg/dL despite standard therapies) with current or past sacroiliitis on imaging as assessed by the local investigator.