Tumor necrosis factor–⍺ is a key mediator in the pathogenesis of psoriasis. Infliximab is a monoclonal antibody that specifically binds to tumor necrosis factor-⍺, blocking its biologic activity.

The purpose of this study was to access the efficacy and safety of infliximab induction therapy for patients with severe plaque psoriasis.

In this multicenter, double-blind, placebo-controlled trial, 249 patients with severe plaque psoriasis were randomly assigned to receive intravenous infusions of either 3 or 5 mg/kg of infliximab or placebo given at weeks 0, 2, and 6. The primary end point was the proportion of patients who achieved at least 75% improvement in Psoriasis Area and Severity Index score from baseline at week 10. At week 26, patients whose Physician Global Assessment indicated moderate or severe disease were eligible for a single intravenous infusion of their assigned treatment to assess the safety of retreatment after a 20-week, treatment-free interval.

At week 10, 72% of patients treated with infliximab (3 mg/kg) and 88% of patients treated with infliximab (5 mg/kg) achieved a 75% or greater improvement from baseline in Psoriasis Area and Severity Index score compared with 6% of patients treated with placebo (P < .001). Improvement was observed in both infliximab groups as early as 2 weeks. Overall, 63%, 78%, and 79% of patients in the placebo, 3-, and 5-mg/kg groups, respectively, reported one or more adverse events.

Infliximab treatment resulted in a rapid and significant improvement in the signs and symptoms of psoriasis. Infliximab was generally well tolerated.