BACKGROUND: In previous studies, etanercept significantly improved plaque psoriasis and was well tolerated. OBJECTIVES: To examine further the efficacy and safety of etanercept and to assess maintenance of treatment effect after dose reduction of etanercept. METHODS: In this multicentre 24-week study in the U.S.A., Canada and Western Europe, patients were at least 18 years old; had active, clinically stable plaque psoriasis involving at least 10% of body surface area; had a minimum Psoriasis Area and Severity Index (PASI) of 10 at screening; and had received or were a candidate to receive systemic psoriasis therapy or phototherapy. During the first 12 weeks of the study, patients were randomly assigned to receive by subcutaneous injection etanercept twice weekly (BIW) at a dose of 50 mg or 25 mg, or placebo BIW in a double-blind fashion. During the second 12 weeks, all patients received etanercept 25 mg BIW. The primary endpoint was a 75% or greater improvement from baseline in PASI (PASI 75) at 12 weeks. RESULTS: Five hundred and eighty-three subjects were randomized and received at least one dose of study drug. At week 12, a PASI 75 was achieved by 49% of patients in the etanercept 50 mg BIW group, 34% in the 25 mg BIW group, and 3% in the placebo group (P