A Study to Evaluate the Long-term Safety, Tolerability and Efficacy of Bimekizumab in Subjects With Active Axial Spondyloarthritis Including Ankylosing Spondylitis and Nonradiographic Axial Spondyloarthritis

The purpose of the study is to demonstrate the long-term safety, tolerability and efficacy of bimekizumab in patients with active axial spondyloarthritis (axSpA, also known as radiographic axSpa (r-axSpA)) including ankylosing spondylitis (AS) and nonradiographic axial spondyloarthritis (nr-axSpa).

Inclusion Criteria: * Study participant is considered reliable and capable of adhering to the protocol (eg, able to understand and complete questionnaires), visit schedule, and medication intake according to the judgement of the Investigator * In the opinion of the Investigator, the study participant is expected to benefit from participation in this extension study * Study participant completed AS0010 (NCT03928704) or AS0011 (NCT03928743) Exclusion Criteria: * Female study participants who plan to become pregnant during the study or within 20 weeks following final dose of Investigational Medicinal Product (IMP). Male study participants who are planning a partner pregnancy during the study or within 20 weeks following the final dose * Study participants who meet any withdrawal criteria in AS0010 or AS0011. For any study participant with an ongoing serious adverse event (SAE), or a history of serious infections (including hospitalizations) in the feeder study, the Medical Monitor must be consulted prior to the study participant's entry into AS0014 * Study participant has a positive or indeterminate interferon gamma release assay (IGRA) in AS0010 or AS0011, unless appropriately evaluated and treated