Background There is significant unmet need in patients with ankylosing spondylitis (AS) who have inadequate response or intolerance to anti-tumour necrosis factor (TNF) treatment. Secukinumab, an anti-interleukin-17A monoclonal antibody, significantly improved signs and symptoms of AS in the MEASURE 2 study (NCT01649375).

Methods Subjects with active AS (N=219) received secukinumab (150 or 75 mg) or placebo at baseline, weeks 1, 2, 3 and 4, and every 4 weeks thereafter. Randomisation was stratified by prior anti-TNF use: anti-TNF-naive or inadequate response/intolerance to one anti-TNF (anti-TNF-IR). The primary endpoint was Assessment of SpondyloArthritis International Society criteria (ASAS) 20 at week 16.

Results At week 16, 68.2% of anti-TNF-naive subjects treated with secukinumab 150 mg achieved ASAS20 compared with 31.1% treated with placebo (p<0.001). In the anti-TNF-IR group, 50.0% of subjects treated with secukinumab 150 mg achieved an ASAS20 response compared with 24.1% treated with placebo (p<0.05). Numerically greater improvements were observed with secukinumab than with placebo for most secondary endpoints. Clinical responses were sustained through week 52.

Conclusions Secukinumab 150 mg provided sustained improvements in signs and symptoms of AS in anti-TNF-naive and anti-TNF-IR subjects through 52 weeks of therapy.

Trial registration number NCT01649375.