Subject had previously received systemic or biologic anti-IL-12 therapy

Subject cannot discontinue systemic therapies and/or topical therapies for the treatment of psoriasis and cannot avoid UVB or PUVA phototherapy

Subject is taking or requires oral or injectable corticosteroids

Subject considered by the investigator, for any reason, to be an unsuitable candidate for the study

Female subject who is pregnant or breast-feeding or considering becoming pregnant

Efficacy and Safety of ABT-874 in Subjects With Moderate to Severe Chronic Plaque Psoriasis