Secukinumab, an Interleukin-17A Inhibitor, in Ankylosing Spondylitis

BACKGROUND: Secukinumab is an anti-interleukin-17A monoclonal antibody that has been shown to control the symptoms of ankylosing spondylitis in a phase 2 trial. We conducted two phase 3 trials of secukinumab in patients with active ankylosing spondylitis. METHODS: In two double-blind trials, we randomly assigned patients to receive secukinumab or placebo. In MEASURE 1, a total of 371 patients received intravenous secukinumab (10 mg per kilogram of body weight) or matched placebo at weeks 0, 2, and 4, followed by subcutaneous secukinumab (150 mg or 75 mg) or matched placebo every 4 weeks starting at week 8. In MEASURE 2, a total of 219 patients received subcutaneous secukinumab (150 mg or 75 mg) or matched placebo at baseline; at weeks 1, 2, and 3; and every 4 weeks starting at week 4. At week 16, patients in the placebo group were randomly reassigned to subcutaneous secukinumab at a dose of 150 mg or 75 mg. The primary end point was the proportion of patients with at least 20% improvement in Assessment of Spondyloarthritis International Society (ASAS20) response criteria at week 16. RESULTS: In MEASURE 1, the ASAS20 response rates at week 16 were 61%, 60%, and 29% for subcutaneous secukinumab at doses of 150 mg and 75 mg and for placebo, respectively (P<0.001 for both comparisons with placebo); in MEASURE 2, the rates were 61%, 41%, and 28% for subcutaneous secukinumab at doses of 150 mg and 75 mg and for placebo, respectively (P