Study to Help Understand the Action of the Drug Etanercept for the Adult Patient With Psoriasis

"All subjects will administer etanercept 50 mg twice weekly subcutaneously (2 injections of 25 mg etanercept SC within 1 hour twice weekly) for the first 12 weeks of study.~Subjects randomized to the continuous therapy arm will then receive 50 mg once weekly SC (2 injections of 25 mg etanercept SC within 1 hour once weekly) for weeks 13 through 24. Subjects randomized to the intermittent therapy arm will be assessed for response. Those who achieve a responder status on the PGA (PGA score £ 2 and improved from baseline) at week 12 will discontinue therapy. Upon relapse of PGA responder status, etanercept will be administered 50 mg once weekly SC (2 injections of 25 mg etanercept SC within 1 hour once weekly) through week 24."