• The primary endpoint is the proportion of patients who achieve >= 75% improvement in the psoriasis area-and-severity index from baseline at Week 12.
  

• Major secondary endpoints are the proportions of patients with clear or minimal disease at Week 12 by Physician Global Assessment, the improvement in the Dermatology Life Quality Index, and benefit:risk profile of maintenance therapy.
  

Although numerous therapeutic options exist for the treatment of psoriasis, significant unmet medical needs for effective therapies with limited toxicity and side effects. Preclinical studies and early phase clinical studies suggest that interleukins-12 and -23, two molecules that are part of the communication network in the immune system, may play an important role in psoriasis. This is a randomized (patients are assigned different treatments based on chance), double blind (neither the patient nor the physician knows whether drug or placebo is being taken, or at what dosage), parallel-group, multicenter study to determine the effectiveness and safety of two different doses of CNTO 1275 administered subcutaneously (under the skin) as compared with placebo in patients with moderate to severe plaque-type psoriasis (the most common type of psoriasis). The hypothesis is that CNTO 1275 will be more effective in treatment of psoriasis than placebo, that the improvement in psoriasis will result in an improved quality of life for treated patients and that CNTO 1275 will be generally well tolerated. Patients will be randomized to long term extension of the study during which subjects will continue to receive treatment with CNTO 1275 and will be followed for a total of up to 264 weeks from the initial (week 0) administration of study agent. This study will remain blinded through the Week 76 database lock.

The dose of CNTO 1275 will be 45 or 90 mg administered subcutaneously at weeks 0 and 4 weeks then every 12 weeks thereafter. For patients who partially respond to the starting regimen, the dosing interval may be adjusted to every 8 weeks.