Ixekizumab provides superior efficacy compared with ustekinumab over 52 weeks of treatment: Results from IXORA-S, a phase 3 study

© 2018 Background: Biologics targeting interleukin 17A (IL-17A) allow for rapid clearance of psoriatic plaques, with a clinically favorable safety profile. Objectives: To compare the safety and efficacy of ixekizumab, an IL-17A antagonist, with the safety and efficacy of the IL-12/23 inhibitor ustekinumab through 52 weeks of treatment in the head-to-head trial IXORA-S. Methods: Patients were randomized to ixekizumab (n = 136) or ustekinumab (n = 166) and dosed per the approved labels. After 1 year, efficacy was assessed via improvements in Psoriasis Area and Severity Index (PASI) score (with PASI 90 indicating a 90% or greater improvement from baseline PASI score) and a static Physician's Global Assessment (sPGA) response of either 0 or 0 or 1, with dropouts counted as nonresponders. Safety analyses included treatment-emergent adverse events (AEs). Results: At week 52, significantly more ixekizumab-treated patients (P <.01) reported PASI 90 (104 [76.5%]), an sPGA response of 0 (72 [52.9%]), or an sPGA response of 0 or 1 (110 [82.1%]) responses than did ustekinumab-treated patients (PASI 90, 98 [59.0%]; sPGA response of 0, 60 [36.1%]; and sPGA response of 0 or 1, 108 [65.1%]). Treatment-emergent AEs, serious AEs, and discontinuation rates were not different between the treatment groups. Injection site reactions occurred more frequently in the ixekizumab-treated group (ixekizumab, 22 [16.3%]; ustekinumab, 2 [1.2%]) (P <.001). Limitations: This study was not designed to compare safety end points related to rare events. Conclusions: Compared with ustekinumab, ixekizumab showed superior efficacy and comparable safety outcomes through 52 weeks of treatment.