A Multicenter, Randomized, Double-blind, Placebo-controlled Trial of Golimumab, a Fully Human Anti-TNFa MonoclonalAntibody, Administered Subcutaneously in Subjects With Active Psoriatic Arthritis

The purpose of this study is to evaluate the safety and efficacy (improvement of signs and symptoms) of subcutaneous (under the skin) injections of golimumab for the treatment of active psoriatic arthritis (PsA). Efficacy will be measured by reduction in the signs and symptoms of active PsA, including effects on joint pain and swelling, changes on x-ray related to joint damage, psoriasis skin lesions, physical function, and quality of life.