The purpose of this study is to learn more about the immune response to etanercept produced using a modified process in patients with plaque psoriasis.

This is a multicenter, open-label, single-arm phase 4 study in patients with plaque psoriasis who are etanercept-naïve and who are not receiving methotrexate therapy. The study will consist of a screening period of up to 30 days, a 24-week treatment period and a 30-day follow-up period for safety. Etanercept dosing will follow the recommended label dosing for patients with plaque psoriasis.

Inclusion Criteria:

• Subject is ≥ 18 years of age at time of screening.
• Subject is a candidate for systemic therapy or phototherapy in the opinion of the investigator.
• Subject has involved body surface area (BSA) ≥ 10%, static physician global assessment (sPGA) ≥ 3, and Psoriasis Area and Severity Index (PASI) ≥ 10 at screening and at baseline.
• Subject is naïve to etanercept.
• Subject is a candidate for treatment with etanercept in the opinion of the investigator in addition to the caring physician's intent to initiate treatment with etanercept, as applicable.
• Subject is able to self-inject etanercept or have a designee who can do so.
• Subject has not used methotrexate within 4-weeks from the first dose of etanercept.
• Subject has a negative test for hepatitis B surface antigen, hepatitis B core antibody and hepatitis C antibody.
• Subject has no known history of active tuberculosis.
• Subject has a negative test for tuberculosis during screening
• Subject, if female and not at least 2 years postmenopausal or history of hysterectomy, bilateral salpingectomy, or bilateral oophorectomy, has a negative serum pregnancy test ≤ 4 weeks from starting etanercept and a negative urine pregnancy test at baseline (day 1).

Exclusion Criteria:

• Subject has active erythrodermic, pustular, guttate psoriasis, or medication induced psoriasis, or other skin conditions at the time of the screening visit (e.g., eczema) that would interfere with evaluations of the effect of investigational product on psoriasis.
• Subject has any uncontrolled, clinically significant systemic disease (e.g., renal failure, heart failure, hypertension, pulmonary or liver disease, diabetes, anemia).
• Myocardial infarction or unstable angina pectoris within the last year.
• Major chronic inflammatory disease or connective tissue disease other than psoriasis and/or psoriatic arthritis.
• Multiple sclerosis or any other demyelinating disease.
• Active malignancy, including evidence of cutaneous basal or squamous cell carcinoma or melanoma, Merkel cell carcinoma, or history of cancer (other than fully resected and surgically cured cutaneous basal cell and squamous cell carcinoma) within 5 years before the first dose of etanercept. If malignancy occurred more than 5 years ago, documentation of disease-free state since treatment is required.
• Known history of alcoholic hepatitis or immunodeficiency syndromes including human Immunodeficiency virus (HIV) infection.
• Subject has any active infection (including chronic or localized infections) for which anti-infectives were indicated within 4 weeks prior to first dose of etanercept.
• Subject has a serious infection, defined as requiring hospitalization or intravenous (IV) anti-infectives within 8 weeks prior to first dose of etanercept.
• Any condition that, in the opinion of the investigator, might cause this study to be detrimental to the subject.
• Subject has any condition that could, in the opinion of the investigator, compromise the subject's ability to give written consent and/or comply with the study procedures, such as a history of substance abuse or a psychiatric condition.