Data from two Phase II double-blind, placebo-controlled clinical trials suggest that inhibition of interleukin-17 (IL-17) may be an effective and targeted therapy for psoriasis. The IL-17 receptor-specific antibody brodalumab (AMG 827; Amgen) and the IL-17A-specific monoclonal antibody ixekizumab (LY2439821; Eli Lilly) were given subcutaneously at a range of doses to patients with moderate-to-severe plaque psoriasis for 10 or 16 weeks, respectively. At week 12, at least 76% of patients who received the antibodies had an improvement of ≥75% in their psoriasis area-and-severity index (PASI) score (except for those who received the lowest drug dose). Treated patients had improved PASI scores as early as week 1, indicating that these antibodies have a rapid onset of action. Neutropenia of grade 2 or higher was reported in a very small percentage of patients (<2%), but neither trial was large enough or of long enough duration to assess uncommon adverse events.