To Study the Use of Humanized CD25 in Preventing the Relapse of Psoriasis Vulgaris

Inclusion Criteria

Male or female patients with chronic psoriasis vulgaris (disease stable or worsening for > 6 months). Patients age 16 - 21 will be considered on a case to case basis.

For those patients under the age of 18, parental consent will be obtained.

Extensive skin involvement.
Scale, thickness, and erythema in individual psoriasis lesions of at least moderate intensity.
Psoriasis treated with emollients only for 2 weeks prior to treatment
Patients with active psoriatic arthritis, if accompanied by psoriasis vulgaris involving more than 5% of the body surface.
Patients that are appropriate for treatment with UVB.

Exclusion Criteria:

Positive serology for HIV, Hepatitis B, or Hepatitis C.
Positive β-HCG titer. For women of childbearing potential, unwillingness or inability to use a contraceptive device during this study if negative for β-HCG.
Guttate psoriasis, pustular psoriasis, or whole body erythroderma.
Active infection or persistent fever of unknown origin.
Major concurrent illness, which could worsen following treatment with anti-TAC.