A Study Evaluating the Efficacy of Secukinumab 300mg in Chinese Adults With Active Ankylosing Spondylitis

Inclusion Criteria: * Participant with a clinical diagnosis of ankylosing spondylitis (AS) and meeting the modified New York criteria for AS. * Participant must have baseline disease activity as defined by having a Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score \>= 4 and a Patient's Assessment of ●Total Back Pain score \>= 4 based on a 0 - 10 numeric rating scale (NRS) at the Screening and Baseline visits. * Participant has had an inadequate response to at least two nonsteroidal anti-inflammatory drugs (NSAIDs) over an at least 4-week period in total at maximum recommended or tolerated doses, or participant has an intolerance to or contraindication for NSAIDs as defined by the Investigator. * If entering the study on concomitant methotrexate (MTX), leflunomide, sulfasalazine (SSZ), and/or hydroxychloroquine, participant must be on a stable dose of MTX (\<= 25 mg/week) and/or SSZ (\<= 3 g/day) and/or hydroxychloroquine (\<= 400 mg/day) or leflunomide (\<= 20 mg/day) for at least 28 days prior to the Baseline visit. A combination of up to two background conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs) is allowed except the combination of MTX and leflunomide. * If entering the study on concomitant oral corticosteroids, participant must be on a stable dose of prednisone (\<= 10 mg/day), or oral corticosteroid equivalents, for at least 14 days prior to the Baseline visit. * If entering the study on concomitant NSAIDs, tramadol, combinati…