Inclusion Criteria:  Diagnosis of Ankylosing Spondylitis (AS) fulfilling the modified New York criteria Active axial disease at Screening and Baseline defined by a Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score ≥ 4 and Total Back Pain ≥ 4 Failed prior treatment with at least 2 NSAIDs for at least 4 weeks each Participant has never received a biologic therapy eg, tumor necrosis factor (TNF) antagonist or monoclonal antibody [mAb] against IL-17A (biologic naive main study), or have taken more than one biologic therapy (biologic-failure substudy) for the treatment of AS  Exclusion Criteria:  Radiographic evidence of total ankylosis of the spine Clinically significant back pain caused by diseases other than AS Concurrent treatment or treatment within the 6 months prior to Baseline with cell depleting biologic agents Participation in any study of an investigational drug, including those for COVID-19 History of malignancy Oral corticosteroids (prednisone or equivalent) > 10 mg/day systemically for ≥ 2 weeks prior to Baseline Visit