On August 26, 2019, the FDA approved a new indication for ixekizumab (Taltz; Eli Lilly) for the treatment of patients with active ankylosing spondylitis (AS). Ixekizumab has received previous FDA approval for the treatment of patients with moderate-to-severe plaque psoriasis who are candidates for systemic therapy or phototherapy, as well as for the treatment of patients with active psoriatic arthritis.
This latest approval was based on data from 2 randomized, placebo-controlled, phase 3 clinical trials of 657 adult patients with active AS (COAST-V and COAST-W). The COAST-V trial (N = 341) evaluated ixekizumab in patients who had not previously received treatment with biologic disease-modifying antirheumatic drugs, whereas the COAST-W trial (N = 316) evaluated the drug in patients with an inadequate response or intolerance to tumor necrosis factor inhibitors. The primary end point of both trials was a 40% Assessment of Spondyloarthritis International Society (ASAS40) response by week 16.
Patients treated with ixekizumab in both studies achieved statistically significant and clinically meaningful improvement in signs and symptoms, as defined by ASAS40 response compared with those receiving placebo.
In COAST-V, 48% of patients receiving ixekizumab achieved ASAS40, compared with 18% of those receiving placebo (P <.0001). In COAST-W, 25% of patients receiving ixekizumab achieved ASAS40 compared with 13% of those receiving placebo (P <.05).
The most common (>1%) adverse effects associated with the use of ixekizumab are injection-site reactions, upper respiratory tract infections, nausea, and tinea infections.
The recommended dose of ixekizumab for the treatment of AS is 160 mg by subcutaneous injection (two 80-mg injections) at week 0, followed by 80 mg every 4 weeks.