A Double Blind Study in Pediatric Subjects With Chronic Plaque Psoriasis, Studying Adalimumab vs. Methotrexate

Inclusion Criteria:

1. Subject is ≥ 4 years and < 18 years of age;
2. Subject weighs ≥ 13 kg;
3. Subject must have failed to respond to topical therapy;

4. Subject must need systemic treatment to control his/her disease and meet one of the following:

   • Physician's Global Assessment (PGA) ≥ 4
   • Body surface area (BSA) involved > 20%
   • Very thick lesions with BSA > 10% - Psoriasis Area and Severity Index (PASI) > 20

   • PASI > 10 and at least one of the following:

     • Active psoriatic arthritis unresponsive to non-steroid anti-inflammatory drugs (NSAIDs)
     • Clinically relevant facial involvement
     • Clinically relevant genital involvement * Clinically relevant hand and/or foot involvement
     • Children's Dermatology Life Quality Index (CDLQI) > 10
5. If subject is < 12 years of age and resides in a geographic region where heliotherapy is practical, subject must have failed to respond, be intolerant, or have a contraindication to heliotherapy, or is not a suitable candidate for heliotherapy;
6. If ≥12 years of age, subject must have failed to respond, be intolerant, or have a contraindication to phototherapy, or is not a suitable candidate for phototherapy;
7. Subject must have a clinical diagnosis of psoriasis for at least 6 months as determined by the subject's medical history and confirmation of diagnosis through physical examination by the Investigator; 8. Subject must have stable plaque psoriasis for at least 2 months prior to Baseline

Exclusion Criteria:

1. Prior biologic use other than prior treatment with etanercept;
2. Treatment with etanercept therapy within 4 weeks prior to the Baseline visit;
3. Methotrexate (MTX) use within the past year or prior MTX use at any time where the subject did not respond, or did not tolerate MTX;
4. Contraindication for treatment with MTX during the study;
5. Erythrodermic Ps, generalized or localized pustular Ps, medication-induced or medication exacerbated Ps or new onset guttate Ps;
6. Infection(s) requiring treatment with intravenous (IV) anti-infectives within 30 days prior to the Baseline Visit or oral anti-infectives within 14 days prior to the Baseline Visit;
7. Treatment of Ps with topical therapies such as corticosteroids, vitamin D analogs, or retinoids within 7 days prior to the Baseline visit;
8. Treatment of Ps with UVB phototherapy, excessive sun exposure, or the use of tanning beds within 7 days prior to the Baseline visit;
9. Treatment of Ps with PUVA phototherapy, non-biologic systemic therapies for the treatment of Ps, or systemic therapies known to improve Ps within 14 days prior to the Baseline visit;