Two 12-week phase III double-blind, placebo-controlled trials, PHOENIX 1 (N = 766) and PHOENIX 2 (N = 1,230) evaluated the efficacy and safety of ustekinumab in patients with moderate-severe psoriasis. Regimens ranged from two 45-mg or 90-mg ustekinumab s.c. doses at week 0 and 4, then 45 mg or 90 mg every 12 weeks or placebo. The primary endpoint for both studies was the percentage of patients achieving a 75% or greater decrease from baseline in the Psoriasis Area and Severity Index (PASI-75) at week 12. After 12 weeks both studies had a placebo crossover period until week 28. In both studies psoriasis improved significantly at week 12 after 45 ...