A Phase 3b, Multicenter, Randomized, Placebo-Controlled, Double Blind, Double-Dummy, Study of the Efficacy and Safety of Apremilast (CC-10004), Etanercept, and Placebo, in Subjects With Moderate to Severe Plaque Psoriasis

Inclusion Criteria:

- Males or females, ≥ 18 years of age

- Diagnosis of chronic, moderate to severe plaque psoriasis for at least 12 months
prior to Screening, and a candidate for phototherapy and/or systemic (including
etanercept) therapy

- Had an inadequate response, intolerance, or contraindication to at least 1
conventional systemic agent for the treatment of psoriasis.

- No prior exposure to biologics for treatment of psoriatic arthritis or psoriasis

Exclusion Criteria:

- Other than psoriasis, history of any clinically significant and uncontrolled systemic
diseases; any condition, including the presence of laboratory abnormalities, which
would place the subject at unacceptable risk if he/she were to participate in the
study.

- Pregnant or breast feeding.

- Have failed more than 3 systemic agents for treatment of psoriasis.

- History of allergy to any component of the investigational product (IP), including
human immunoglobulin (Ig) proteins or allergy to etanercept.

- Hepatitis B surface antigen or anti-hepatitis C antibody positive at Screening.

- Latent, active tuberculosis (TB) or inadequately treated TB; nontuberculous
mycobacterial infection or opportunistic infection (eg, cytomegalovirus, Pneumocystis
carinii, aspergillosis, Clostridium difficile).

- Have a history of, or ongoing, chronic or recurrent infectious disease

- Have received, or are expected to receive, any live virus or bacterial vaccination
within 3 months before first administration of IP, or through Week 20 during the
study.

- Had a Bacillus Calmette-Guérin (BCG) vaccination within 1 year prior to screening.

- History of positive human immunodeficiency virus (HIV), or have congenital or
acquired immunodeficiency (eg, common variable immunodeficiency disease).

- Active substance abuse or a history of substance abuse within 6 months prior to
Screening.

- Malignancy or history of malignancy, except for treated [ie, cured] basal cell or
squamous cell in situ skin carcinomas and cervical intraepithelial neoplasia [CIN] or
carcinoma in situ of the cervix with no evidence of recurrence within the previous 5
years.

- Psoriasis flare or rebound within 4 weeks prior to Screening.

- Topical therapy within 2 weeks of randomization or systemic therapy for psoriasis
within 4 weeks prior to randomization

- Use of phototherapy within 4 weeks prior to randomization or prolonged sun exposure
or use of tanning booths or other ultraviolet (UV) light sources.

- Any investigational drug within 4 weeks prior to randomization, or 5
pharmacokinetic/pharmacodynamic half lives, if known (whichever is longer).

- Prior treatment with apremilast or etanercept.