Treatment with adalimumab is appropriate for this patient with ankylosing spondylitis, a form of spondyloarthritis that predominantly affects the axial skeleton. Inflammatory back pain is a hallmark feature, manifesting as pain and stiffness in the spine that is worse after immobility and better with use. Symptoms are prominent in the morning and can be symptomatic during the night. Buttock pain is common and correlates with sacroiliitis. Fusion of the spine may occur over time, leading to rigidity and kyphosis. Exercise to preserve range of motion and strengthen the spine extensor muscles to prevent kyphosis is essential. Physical therapy may be indicated to assist patients in developing a home exercise routine. NSAIDs are considered first-line therapy for symptomatic patients. If the patient does not adequately respond to a minimum of two different trials of NSAIDs used at least 4 weeks total, the Assessment of SpondyloArthritis international Society/European League Against Rheumatism (ASAS/EULAR) guidelines recommend treatment with a tumor necrosis factor (TNF)-α inhibitor. This patient has not adequately responded to either naproxen or indomethacin; therefore, a TNF-α inhibitor such as adalimumab is appropriate. The currently available TNF-α inhibitors appear to be equally effective when compared with placebo. Response is rapid, often within the first 6 weeks of therapy. Patients who do not respond to one agent may respond to an alternative. Because long-term safety is unknown, TNF-α inhibitors remain second-line therapy to NSAIDs.
Nonbiologic disease-modifying antirheumatic drugs (DMARDs) such as methotrexate and sulfasalazine have not been demonstrated to be efficacious for axial disease but may be considered for peripheral arthritis.
Rituximab is a biologic DMARD used to treat moderate to severe rheumatoid arthritis in combination with methotrexate in patients who have had an inadequate response to TNF-α inhibitor therapy and is also used in ANCA-associated vasculitis. There is no evidence showing benefit of this agent in ankylosing spondylitis.