Male or Female participants 5 to \< 18 years of age at the time of randomization.
Participant must have a confirmed diagnosis of juvenile psoriatic arthritis (JPsA) according to the International League of Associations for Rheumatology (ILAR) Edmonton Revision (Petty, 2001) classification criteria of at least 6 months duration:
* Arthritis and psoriasis, OR
* Arthritis with at least 2 of the following:
* Dactylitis
* Nail pitting or onycholysis
* Psoriasis in a first-degree relative
Active disease: at least 3 active joints.
Inadequate response (at least 2 months) or intolerance to ≥ 1 disease-modifying anti-rheumatic drugs (DMARD), (which may include methotrexate \[MTX\] or biologic agents).
You may not be if
Exclusions per ILAR Edmonton Revision (Edmonton, 2001) criteria for JPsA include:
* Arthritis in an HLA-B27-positive male with arthritis onset after 6 years of age
* Ankylosing spondylitis, sacroiliitis with inflammatory bowel disease, Reiter's syndrome, acute anterior uveitis, or a history of one of these disorders in a first-degree relative
* History of IgM rheumatoid factor on at least 2 occasions at least 3 months apart
* Presence of systemic juvenile idiopathic arthritis (JIA).
Rheumatic autoimmune disease other than psoriatic arthritis (PsA), including, but not limited to: systemic lupus erythematosus, mixed connective tissue disease, scleroderma, polymyositis, or fibromyalgia.
Prior history of or current inflammatory joint disease other than PsA (eg, gout, reactive arthritis, rheumatoid arthritis, ankylosing spondylitis, Lyme disease).
