I. Health Net Approved Indications and Usage Guidelines: A. Psoriatic Arthritis: 1. Diagnosis of Active Psoriatic Arthritis; AND 2. Confirmed by a Rheumatologist or Dermatologist; AND 3. Failure or clinically significant adverse effects to MTX unless contraindicated. B. Plaque Psoriasis: 1. Diagnosis of chronic moderate to severe plaque psoriasis; AND 2. Prescribed by a Dermatologist or Rheumatologist; AND 3. Failure or clinically significant adverse effects to ONE of the following therapies either alone or in combination, unless contraindicated: i. Methotrexate up to a dose of 15-20 mg/week; OR ii. If methotrexate is contraindicated, failure or clinically significant adverse effects to PUVA Therapy or UVB, or cyclosporine or acitretin. II. Authorization Limit: 6 months or to member's renewal date, whichever is longer.