- Males or females, aged >= 18 years at time of consent.
- Have a diagnosis of Psoriatic arthritis (PsA) of >= 6 months
- Meet the Classification Criteria of PsA (CASPAR) at time of screening
- Must not have been adequately treated with a a traditional non-biologic disease
modifying anti-rheumatic drug (DMARD).
- Concurrent treatment with methotrexate, leflunomide, or sulfasalazine allowed and
- Must not have taken a biologic Tumour Necrosis Factor Inhibitor
- Must have 3 or more swollen joints AND 3 or more tender joints
- Must have active psoriasis skin lesions
- Have non-plaque forms of psoriasis, eg erythrodermic, guttate or pustular, with the
exception of nail psoriasis which is allowed
- Pregnant or breast feeding, females of child-bearing potential not using highly
- New York Heart Association Class III and IV congestive heart failure
- History of hypersensitivity or infusion reaction to biologic agents
- Infection with HIV, hepatitis B virus, hepatitis C virus, or other chronic infection