The purpose of this protocol is to determine the single-dose pharmacokinetics and immunogicity of BMS-188667 administered as a 1 hour intravenous infusion with extended pharmacokinetic sampling. Safety of all subjects will be assessed in a double blind fashion through the inclusion of placebo controls at each dose level.

Inclusion Criteria:

• Subjects required to have a know diagnosis of psoriasis vulgaris involving 5-49% of total body surface area (BSA) for at least six months prior to randomization.
• Subjects clinically insignificant abnormal laboratory or ECG test results who were otherwise healthy and met all remaining eligibility criteria.

Exclusion Criteria:

• Evidence of active bacterial or viral infections at the time of enrollment, including any history of or clinical evidence of infection with Human Immunodeficiency virus (HIV) Hepatitis B or Hepatitis C.
• Any underlying metabolic, hematologic, pulmonary, cardiac, renal hepatic, infectious, psychiatric or gastrointestional condition, which in the opinion of the investigator, placed the subject at unacceptable risk from participation in a study with potentially immunosuppresive therapy.