The purpose of this research study is to see how well (compared to placebo) Enbrel® (etanercept) 50 mg twice a week for 12 weeks affects plaque psoriasis of the hands and/or feet (palmoplantar psoriasis).

This multicenter investigation is a 12 week, double-blind, randomized trial of etanercept, 50 mg twice weekly versus placebo in subjects with palmoplantar psoriasis (PPP). Subjects who meet the eligibility criteria will be randomized to either 50 mg etanercept twice weekly or placebo. Subcutaneous injections will occur twice weekly at approximately the same time of day over the 12-week treatment period. The primary efficacy endpoint will be assessed after 12 weeks of treatment. At the end of the first 12 weeks, all patients (both treatment and placebo arms) will be treated with etanercept 50 mg twice a week (BIW) for an additional 12 weeks.

Inclusion Criteria:

• Moderate to severe palmar plantar psoriasis based on physician's global assessment (PGA).
• Between 18 and 70 years of age
• Negative urine pregnancy test at screening and at baseline
• Sexually active men and women of child-bearing potential must agree to use a medically accepted form of contraception (birth control) during the exclusionary medicine wash-out period and throughout the study.
• Ability to self inject study drug or have a designee who can do so
• Capable of understanding and giving written voluntary informed consent

Exclusion Criteria:

• Previous treatment with Enbrel® (etanercept) or similar drugs
• Receipt of investigational drugs or "biologics" within 4 weeks of the screening visit.
• Evidence of skin conditions (e.g. eczema) other than psoriasis that would interfere with evaluations of the study medication.
• Receipt of any biologic medication within the previous 6 months that resulted in a decreased white blood cell count (cells to help fight infections)
• Ultraviolet light treatment (e.g. UVB, PUVA) within one month prior to study drug initiation.
• Receipt of immune-suppressing drugs other than Rheumatrex® (methotrexate) or Soriatane® (acetretin) within 4 weeks prior to the first dose of study drug. Medications you would not be allowed to take during this study include for example, Cytoxan® (cyclosporine), Imuran® (azathioprine), or Sulfazine® (sulfasalazine). If you remain on Rheumatrex® (methotrexate) (≤25 mg/week) or Soriatane® (acitretin) (≤50 mg/day), you must be considered to have inadequate disease control in the opinion of the investigator based on physician's global assessment. You must have been on a stable dose of systemic treatment for at least 1 month prior to the start of the study medication. You will be required to maintain a stable dose of the systemic treatment throughout the study.
• Use of topical steroids in the past 14 days unless they have been used for longer than 14 days and the severity of disease allows entry into study.
• Systemic steroid use (prednisone, etc).
• Prior or concurrent use of Cytoxan® (cyclophosphamide).
• Elevated liver tests; red blood cell count less than normal; decreased platelet count (cells to help with blood clotting); decreased white blood cell count (cells to fight infection); kidney insufficiency
• Any severe adverse event, infection or abnormal laboratory value at the time of the screening visit that would preclude participation in the study
• Presence of a severe infection, less than 30 days prior to the screening visit or between the screening visit and the first dose of study drug
• Pregnant or breast-feeding females.
• Significant concurrent medical diseases including: Uncompensated congestive heart failure (heart is unable to pump as normal): Myocardial infarction (heart attack) within 12 months of screening period; Unstable or stable angina pectoris (chest pains related to your heart); Uncontrolled high blood pressure
• Severe lung disease requiring medical or oxygen therapy
• History of cancer (other than surgically removed skin cancer and in situ cervical cancer) within 5 years of the screening visit
• History of tuberculosis
• Known to be HIV positive
• Rheumatoid arthritis
• Any neurologic demyelinating disease (such as multiple sclerosis or any neurologic disease causing loss of sensation or loss of normal movement) or seizure disorder
• Current or history of psychiatric disease that would interfere with ability to comply with the study protocol or give informed consent.
• History of alcohol or drug abuse.
• Not up-to-date with all immunizations in agreement with the current immunization guidelines
• Significant exposure to the varicella virus (chicken pox)
• Guttate or generalized pustular psoriasis
• Surgery or trauma within a month of baseline considered by the investigator to represent a significant risk or interfere with patient evaluation.

Adverse event data were collected over a 28 week period.