Abstract： Objective::Ixekizumab is a high-affinity monoclonal antibody that selectively targets interleukin-17A and is approved for treating moderate-to-severe psoriasis. This phase 3, multicenter, randomized, double-blind, placebo-controlled trial (NCT03364309; registered December 6, 2017) evaluated the safety and efficacy of ixekizumab in Chinese patients with moderate-to-severe psoriasis.Methods::438 patients were randomized 2:2:1 to 80 mg ixekizumab every 2 weeks (IXE Q2W, n = 176), 80 mg ixekizumab every 4 weeks (IXE Q4W, n = 174), or placebo ( n = 88). Efficacy was assessed by evaluating the static Physician’s Global Assessment score of 0 or 1 (sPGA [0,1]) and Psoriasis Area and Severity Index (PASI) 75/90/100 responses, and nonresponder imputation was used for handling missing data. The safety profile was evaluated by assessing treatment emergent adverse events (AEs) and serious AEs. Results::At week 12, the sPGA (0,1) response rates were 3.4%, 79.9%, and 86.4% in the placebo, IXE Q4W, and IXE Q2W groups, respectively. The PASI 75/90/100 response rates were 8.0%/2.3%/0.0%, 87.4%/75.9%/29.3%, and 93.8%/82.4%/33.0% in the placebo, IXE Q4W, and IXE Q2W groups, respectively. Ixekizumab led to rapid PASI 50 responses, as early as week 1, whereas PASI 75 and sPGA (0,1) responses were observed from week 2. sPGA (0,1) and sPGA (0) responses were maintained through week 60 in a higher proportion of patients receiving IXE Q4W vs. placebo. The safety profile was consistent with previous studies of ixekizumab in psoriasis. Conclusion::Ixekizumab showed a rapid onset of action and high efficacy that was maintained through 60 weeks and was well tolerated with no unexpected AEs, in Chinese patients with moderate-to-severe plaque psoriasis.