A Study to Evaluate Infliximab in Subjects With Moderate-to-Severe Psoriasis Not Responding to Standard or Biologic Therapy (Study P04612)

Inclusion Criteria: * \>=18 to 75 years of age, of either gender, and of any race. * Psoriasis covering at least 10% of total body surface area (BSA) and PASI \>=12 at Screening and Baseline. * Diagnosis of moderate-to-severe psoriasis at least 6 months prior the screening. * Eligible to infliximab who have failed at least 1 of the following: corticosteroids, methotrexate (MTX), systemic retinoids, cyclosporine, psoralen-ultraviolet A (PUVA), ultraviolet B (UVB) phototherapy, and/or biologics (etanercept or efalizumab). * Eligible according to tuberculosis (TB) eligibility assessment, screening and early detection of reactivation rules. * Chest x-ray within 3 months prior to Screening with no evidence of malignancy, infection, or fibrosis. * Screening and Baseline tests (complete blood count \[CBC\], blood chemistry, and urinalysis) must be within protocol-specified parameters. * Free of significant disease that could interfere with study evaluations. * Willing to give written informed consent and able to adhere to protocol visits and procedures. * Women of childbearing potential and all men must be using adequate birth control and must continue to do so for 6 months after receiving the last dose of study medication. * Females of childbearing potential must have a negative serum pregnancy test at Screening and a negative urine pregnancy test at Baseline. Exclusion Criteria: * Standard concomitant psoriasis therapies. * Active or latent TB. * History of chronic infectious disease, opportunistic infection, or serious infection within 2 months of enrollment. * History of lymphoproliferative disease. * Malignancy in past 5 years (except treated basal cell carcinoma \[BCC\]). * Treatment with tumor necrosis factor (TNF) antagonists within previous 6 weeks. * Current drug-induced psoriasis. * Females who are pregnant or nursing and females and males who are planning pregnancy within 6 months from the last infusion of infliximab. * Previously treated with infliximab. * Concomitant diagnosis of congestive heart failure (CHF) including medically-controlled asymptomatic subjects. * History of chronic or recurrent infectious disease. * Have or have had a serious infection or have been hospitalized or received intravenous antibiotics for an infection during the 2 months prior to Screening. * Have or have had an opportunistic infection within 6 months prior to Screening.