Ixekizumab in Psoriatic Arthritis After Inadequate Response to TNF Inhibitors



Title: Ixekizumab for the treatment of patients with active psoriatic arthritis and an inadequate response to tumour necrosis factor inhibitors: results from the 24-week randomised, double-blind, placebo-controlled period of the SPIRIT-P2 phase 3 trial

Nash, P. et al.


 

What You Need to Know:

In patients with active psoriatic arthritis previously unresponsive to treatment with tumor necrosis factor inhibitors, ixekizumab, a monoclonal antibody that targets interleukin-17A, is safe as well as effective at improving the signs and symptoms of the disease when administered every 2 or 4 weeks.

Trial Design:

  • Randomized, double-blind, placebo-controlled, phase 3 study (SPIRIT-P2) evaluated the safety and efficacy of ixekizumab in patients ≥18 years old with a confirmed diagnosis of psoriatic arthritis for ≥6 months and an inadequate response or intolerance to tumor necrosis factor inhibitors
  • Included patients from 109 centers in 10 countries
  • 363 patients randomly assigned (1:1:1) to subcutaneous injections of 80 mg ixekizumab every 4 weeks, every 2 weeks following a starting dose of 160mg, or placebo
  • Primary endpoint: proportion of patients with 20% improvement according to the American College of Rheumatology response criteria (ACR-20) measured at week 24

Key Outcomes:

  • 53% of patients receiving ixekizumab every 4 weeks (65/122) at week 24 and 48% of patients receiving ixekizumab every 2 weeks (59/123) attained ACR-20 vs 20% of patients receiving placebo (23/118)
  • Effect size vs placebo reported as 33.8% (95% CI: 22.4, 45.2; P<0.0001) for patients receiving ixekizumab every 4 weeks and 28.5% (95% CI: 17.1, 39.8; P<0.0001) for patients receiving ixekizumab every 2 weeks
  • Serious adverse events at week 24: reported in 3% of patients receiving ixekizumab every 4 weeks, 7% of patients receiving ixekizumab every 2 weeks, and 3% of patients receiving placebo
  • Infections: reported in 39% of patients receiving ixekizumab every 4 weeks, 38% of patients receiving ixekizumab every 2 weeks, and 30% of patients receiving placebo
  • Serious infections occurred in 2% of ixekizumab given every 2 weeks group