Adalimumab is a fully human, recombinant, monoclonal IgG1 antibody specific for the cytokine tumour necrosis factor-α. It is approved for the treatment of various inflammatory disorders, including severe non-radiographic axial spondyloarthritis (axSpA). The clinical efficacy of adalimumab (40 mg administered subcutaneously every other week) in adult patients meeting the Assessment of SpondyloArthritis international Society (ASAS) criteria for axSpA but not the modified New York criteria for ankylosing spondylitis (AS) has been demonstrated in the pivotal phase III, randomized, double-blind, placebo-controlled ABILITY-1 trial (n = 192 randomized). In ABILITY-1, adalimumab was effective in improving the signs and symptoms of non-radiographic axSpA in patients who had active disease despite treatment with NSAIDs or who were intolerant to, or had a contraindication for, NSAIDs. Compared with placebo, a significantly greater proportion of patients receiving adalimumab 40 mg every other week achieved an ASAS 40 response after 12 weeks of treatment (primary endpoint). Furthermore, adalimumab significantly decreased inflammation in the spine and sacroiliac joints, as measured by MRI, and improved spondyloarthritic and general measures of health-related quality of life at 12 weeks. Efficacy of adalimumab was sustained over the longer term, according to data at 68 weeks from an open-label extension of ABILITY-1. Adalimumab was generally well tolerated in clinical trials of non-radiographic axSpA; the adverse event profile was similar to that in patients with AS or other approved indications.