A Study Comparing Upadacitinib (ABT-494) to Placebo in Participants With Active Psoriatic Arthritis Who Have a History of Inadequate Response to at Least One Biologic Disease Modifying Anti-Rheumatic Drug

Inclusion Criteria:

• Clinical diagnosis of PsA with symptom onset at least 6 months prior to theScreening Visit and fulfillment of the Classification Criteria for PsA (CASPAR)criteria

• Participant has active disease at Baseline defined as >= 3 tender joints (based on 68 joint counts) and >= 3 swollen joints (based on 66 joint counts) at Screening andBaseline Visits

• Diagnosis of active plaque psoriasis or documented history of plaque psoriasis

• Participant has had an inadequate response (lack of efficacy after a minimum 12 weekduration of therapy) or intolerance to treatment with at least 1 bDMARD.

Exclusion Criteria:

• Prior exposure to any Janus Kinase (JAK) inhibitor (including but not limited toruxolitinib, tofacitinib, baricitinib, and filgotinib)

• Current treatment with > 2 non-biologic DMARDs or use of DMARDs other thanMethotrexate (MTX), Sulfasalazine (SSZ), Leflunomide (LEF), apremilast,Hydroxychloroquine (HCQ), bucillamine or iguratimod or use of MTX in combinationwith LEF at Baseline.

• History of fibromyalgia, any arthritis with onset prior to age 17 years, or currentdiagnosis of inflammatory joint disease other than PsA (including, but not limitedto rheumatoid arthritis, gout, overlap connective tissue diseases, scleroderma,polymyositis, dermatomyositis, systemic lupus erythematosus). Prior history ofreactive arthritis or axial spondyloarthritis including ankylosing spondylitis andnon-radiographic axial spondyloarthritis is permitted if documentation of change indiagnosis to PsA or additional diagnosis of PsA is made. Prior history offibromyalgia is permitted if documentation of change in diagnosis to PsA ordocumentation that the diagnosis of fibromyalgia was made incorrectly.