This study is a randomized (the study drug is assigned by chance), double-blind (neither physician nor the patient knows the treatment that the patient receives), parallel-group (each group of patients will be treated at the same time), multicenter study to evaluate the effectiveness and safety of CNTO 1275 compared to placebo in the treatment of patients with active psoriatic arthritis. Patients will be randomized in 1:1 ratio to 1 of 2 treatment groups (CNTO 1275 63 mg and placebo). Patients will be randomly assigned to receive study medication up to Week 12 and will be followed through Week 36 to monitor safety and efficacy. Patients randomly assigned to placebo will crossover to receive CNTO 1275 63 mg at Weeks 12 and 16. Patients randomly assigned to CNTO 1275 will receive placebo at Weeks 12 and 16 to maintain the blind. The duration of participation for an individual patient in the study will be up to 36 weeks.
The purpose of this study is to evaluate the effectiveness and safety of CNTO 1275 (ustekinumab) in patients with psoriatic arthritis.