A Study of Brodalumab in Subjects With Axial Spondyloarthritis (axSpA)

Inclusion Criteria: * Subject with age at onset \<45 years and continuous chronic back pain for ≥ 3 months fulfills the ASAS classification criteria of axial spondyloarthritis (with the exception of the Crohn's disease) * Subject has Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score ≥ 4 at screening and enrollment * Subject has spinal pain score (BASDAI question #2) ≥ 4 at screening and enrollment * Subject has had adequate therapy with non-steroidal anti-inflammatory drugs (oral NSAIDs) for back pain for at least 3 months with inadequate treatment response before enrollment Exclusion Criteria: * Complete ankylosis (fusion) of the spine * Subject with active ongoing inflammatory diseases other than axSpA that might confound the evaluation of Brodalumab therapy, including reactive arthritis, spondyloarthritis associated with inflammatory bowel disease, SAPHO syndrome (pustulotic arthro-osteitis), fibromyalgia, ankylosing spinal hyperostosis, osteitis condensans ilii, spondylosis deformans, or osteoarthritis sacroiliac joint disease * Subject has a prior history of \>1 anti-tumor necrosis factor (TNF) therapy * Subject has a history or evidence of suicidal ideation (severity of 4 or 5) or any suicidal behavior based on an assessment with the Columbia-Suicide Severity Rating Scale (C-SSRS) at enrollment * Subject has a history or evidence of a psychiatric disorder, alcohol and/or substance abuse * Subject has severe depression based on a total score of ≥ 15 on the Patient Health Questionnaire-8 (PHQ-8) at enrollment (note: subjects with a total score of 10 to 14 on the PHQ-8 should be referred to a mental health care professional)