Inclusion Criteria:
1. Able and willing to give written informed consent prior to any study related procedures and to comply with the requirements of the study protocol
2. Male and female subjects between 18 and 75 years old
3. Diagnosis of moderate to severe types I and II plaque psoriasis (Type I : symptoms onset before 40 years old; Type II: symptoms onset after 40 years old), with at least 6 months of duration
4. Documented moderate to severe plaque psoriasis based on Psoriasis Area and Severity Index (PASI) score \>10
5. Subjects naïve to adalimumab therapy
6. Subject must be evaluated for active and latent tuberculosis (TB) infection by using a Purified Protein Derivative (PPD) skin test, chest x-ray (posterior to anterior (PA) and lateral views) and a detailed review of the subject's medical history. This screening must be negative
7. A negative pregnancy test (serum human chorionic gonadotrophin) for women of childbearing potential prior to start of study treatment. (Non-childbearing potential is defined as postmenopausal for at least 1 year or surgically sterile \[bilateral tubal ligation, bilateral oophorectomy or hysterectomy\])
8. Able and willing to self-administer subcutaneous injections or have available a suitable person to administer subcutaneous injections
9. Subject is judged to be in generally good health as determined by the investigator
Exclusion Criteria:
1. Prior treatment with any investigational agent within 30 days, or five half-lives of the product, which ever is longer. Subject has been treated with any investigational drug of chemical or biologic nature within a minimum of 30 days or five half lives (whichever is longer) of the drug prior to study entry (Baseline Visit)
2. Subject has other active skin diseases or skin infections (bacterial, fungal, or viral) that may interfere with the evaluation of psoriasis or compromise the subject's safety
3. Subject has a history of dysplasia, malignancy (including lymphoma and leukemia), or lymphoproliferative disease other than: a. Successfully and completely treated non-metastatic squamous or basal cell carcinoma of the skin with no recurrence within the last five years. b. Localized carcinoma in situ of the cervix or cervical dysplasia, with no recurrence within the last five years
4. Persistent or recurrent infections or severe infections requiring hospitalization or treatment with intravenous (IV) antibiotics, IV antivirals, or IV antifungals within 30 days, or oral antibiotics, oral antivirals or oral antifungals within 14 days prior to Baseline Visit
5. Other medical conditions: uncontrolled diabetes, unstable ischemic heart disease, congestive heart failure New York Heart Association (NYHA) III-IV, recent stroke (within three months), chronic leg ulcer and any other condition (e.g., indwelling urinary catheter) which, in the opinion of the investigator, may place the subject at risk
6. Previous diagnosis or signs highly indicative of central nervous system demyelinating diseases (e.g., optic neuritis, ataxia, apraxia)
7. History of listeriosis, histoplasmosis, chronic or active Hepatitis B infection, human immunodeficiency virus (HIV) infection, immunodeficiency syndrome, chronic recurring infections or active TB
8. Female subjects who are pregnant or breast-feeding
9. History of clinically significant drug or alcohol abuse in the last year
10. Subject started receiving a new topical therapy within the last four weeks prior to the Baseline visit for areas other than the palms, soles of feet, axilla and groin
11. Subject started being treated with ultraviolet B (UVB) phototherapy, within the last four weeks prior to the Baseline visit
12. Subject was treated with psoralen ultraviolet A (PUVA) phototherapy within the last four weeks prior to the Baseline visit
13. Subject has been initiated on a new systemic agent within the last four weeks prior to the Baseline visit
14. Patients with history of atopy
15. Patients with any other autoimmune disease such as systemic lupus erythematosus (SLE) , Sdx Sjögren, vasculitis etc
16. Known hypersensitivity to the excipients of adalimumab as stated in the label
17. Female subjects who are pregnant or breast-feeding or considering becoming pregnant during the study
18. Subject is considered by the investigator, for any reason, to be an unsuitable candidate for the study
19. Subject with any prior exposure to Tysabri (natalizumab), or Orencia (abatacept)
20. Subjects with positive immunologic test for hepatitis A, B or C (Positive test of any of the following: hepatitis A viral antibody immunoglobulin M (HAV-IgM), hepatitis B surface antigen (HBsAg) or hepatitis C virus antibody (HCV Ab)
21. Subjects with a positive immunologic test for HIV determined by enzyme-linked immunosorbent assay (ELISA) method
