• Number (Percent) of Patients Who Achieve a Physician Global Assessment (PGA) Score of Minimal (1) or Clear (0) [ Time Frame: Week 10 ] [ Designated as safety issue: No ]
  Patients who did not have a PGA score at Week 10 will be treated as not having achieved a PGA score of minimal (1) or clear (0) at Week 10. Specifically, treatment failures prior to Week 10 will be classified as not having a minimal (1) or clear (0).
  
  

• Number (Percent) of Patients Achieved Psoriasis Area Activity Index (PASI) 50 Response [ Time Frame: Weeks 10 ] [ Designated as safety issue: No ]
  A PASI 50 responder is defined as a patient who has achieved at least a 50% improvement in the overall PASI score from baseline. PASI is an index used for assessing and grading the severity of psoriatic lesions and their response to therapy. The PASI produces a numeric score that can range from 0 to 72.
  
  
• Number (Percent) of Patients Achieved Psoriasis Area Activity Index (PASI) 50 Response [ Time Frame: Week 26 ] [ Designated as safety issue: No ]
  

The most common form of psoriasis is plaque-type psoriasis, which is characterized by recurrent flaring of thickened, red, scaly patches of skin. Although psoriasis is usually not life threatening, these physical discomforts combined with the potential psychological effects of the disease may interfere with everyday activities and negatively impact an individual's quality of life. Many therapies are available for psoriasis; however, with limited effectiveness and significant toxicity. Infliximab is an antibody made in a laboratory. Antibodies are proteins that fight other substances in the body that may cause infections or diseases. A substance called "tumor necrosis factor" (TNF) naturally occurs in the body. TNF is related to the itchy patches of skin (or plaques) of psoriasis. Infliximab stops the TNF from working. Other studies have shown that stopping the TNF may reduce the plaques. To address the unmet medical need for effective chronic therapies, TNFalpha blockers have recently been used to treat patients with moderate to severe plaque psoriasis. Etanercept also works by stopping the TNF, but in a different way than infliximab. This multi-center, open-label study is designed to test whether or not patients with plaque psoriasis who have not responded well to etanercept treatment may benefit from treatment with infliximab. Key effectiveness measurements will include the time to onset of symptom improvement and health-related quality of life. Safety will be assessed throughout the study. Two weeks after their last dose of etanercept, all eligible patients will receive open-label 5 mg/kg infliximab infusions at Weeks 0, 2, 6, 14, and 22.