A Study of Safety and Effectiveness of Ustekinumab (CNTO 1275) in Patients With Moderate to Severe Plaque-type Psoriasis

This is a randomized (patients are assigned to different treatments based on chance), double blind (neither the patient nor the physician knows whether medication or placebo \[an inactive substance that is compared with a medication to test whether the medication has a real effect in a clinical study\] is being taken, or at what dosage), parallel-group (each group of patients are treated at the same time), multicenter study to determine the effectiveness and safety of two different doses of ustekinumab administered subcutaneously (under the skin) as compared with placebo in patients with moderate to severe plaque-type psoriasis (the most common type of psoriasis). 766 patients will be randomized to Group 1 (ustekinumab 45 mg), Group 2 (ustekinumab 90 mg) and Group 3 (placebo) at Week 0. The study was designed to evaluate the effectiveness and safety of 2 dose regimens of ustekinumab: (1) 45 mg at Weeks 0 and 4 followed by 45 mg every 12 weeks maintenance therapy (treatment designed to help the original primary treatment succeed) and (2) 90 mg at Weeks 0 and 4 followed by 90 mg every 12 weeks maintenance therapy. The study will consist of 4 periods: (1) Placebo-controlled portion of study \[Week 0 to Week 12\] during which the safety and effectiveness of 2 doses (45mg and 90mg) of ustekinumab will be compared to placebo; (2) Placebo crossover and active treatment portion of study \[Week 12 to Week 40\] during which patients randomized to receive placebo at Week 0 will crossover to receive ustekinumab, and all patients will receive active treatment; (3) Randomized withdrawal portion of study \[beginning at Week 40\] during which patients who received ustekinumab \[45mg or 90mg every 12 weeks\] at Week 0 and are responding to it, will be randomized either to placebo or continued maintenance therapy with ustekinumab; and (4) Long-term extension \[from Week 52 to Week 264 (ie, 5 years)\] period during which the safety and effectiveness of ustekinumab long-term use will be evaluated in patients.