Study to Evaluate Safety and Effectiveness of Oral Apremilast (CC-10004) in Patients With Moderate to Severe Plaque Psoriasis.

Inclusion Criteria:

1. Males or females, ≥ 18 years of age at the time of signing the informed consent
document

2. Diagnosis of chronic plaque psoriasis for at least 12 months prior to Screening

a. Have moderate to severe plaque psoriasis at Screening and Baseline

3. Must meet all laboratory criteria

4. Females of childbearing potential (FCBP) must have a negative pregnancy test at
Screening and Baseline. FCBP who engage in activity in which conception is possible
must use 2 forms of contraception as described by the Study Doctor while on study
medication and for at least 28 days after taking the last dose of study medication

5. Male subjects (including those who have had a vasectomy) who engage in activity in
which conception is possible must use barrier contraception (latex condom or any
nonlatex condom NOT made out of natural [animal] membrane [eg, polyurethane]) while on
study medication and for a least 28 days after the last dose of study medication.

Exclusion Criteria:

1. Other than psoriasis, history of any clinically significant (as determined by the
Investigator) or other major uncontrolled disease.

2. Pregnant or breast feeding

3. History of allergy to any component of the study drug

4. Hepatitis B surface antigen positive at Screening

5. Anti-hepatitis C antibody positive at Screening

6. Active tuberculosis (TB) or a history of incompletely treated TB

7. Clinically significant abnormality on 12-Lead ECG at Screening

8. Clinically significant abnormal chest x-ray

9. History of positive human immunodeficiency virus (HIV), or have congenital or acquired
immunodeficiency

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

11. Bacterial infections requiring treatment with oral or injectable antibiotics, or
significant viral or fungal infections, within 4 weeks of Screening

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

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

14. Evidence of skin conditions that would interfere with clinical assessments

15. Topical therapy within 2 weeks of randomization

16. Systemic therapy for psoriasis within 4 weeks prior to randomization

17. Use of phototherapy within 4 weeks prior to randomization (ie, UVB, PUVA)

18. Adalimumab, etanercept, infliximab, or certolizumab pegol within 12 weeks prior to
randomization

19. Alefacept, briakinumab, or ustekinumab within 24 weeks prior to randomization

20. Use of any investigational drug within 4 weeks prior to randomization

21. Prolonged sun exposure or use of tanning booths or other ultraviolet (UV) light
sources

22. Prior treatment with apremilast