David Borenstein, MD Executive Editor theSpineCommunity
Biologic therapy is indicated for the treatment of ankylosing spondylitis (AS) has been demonstrated to improve outcomes and is now standard of care. However, a frequently asked question from patients is “how long do I need to take this medicine?” A recent study suggests that unless there is a specific reason to halt therapy, prolonged biologic therapy measured in years can have beneficial effects on the prevention of spinal fusion.
The answer is “it depends on what you are measuring.” Within a few doses of biologic therapy, markers of inflammation, elevated ESR and CRP levels can normalize. Patients’ clinical symptoms improve with less morning stiffness and improved function. Can the same be said for the radiographic changes associated with AS in the spine? The answer is no.
Maas and colleagues reported on a Dutch study of 210 AS patients who had regular x-ray tests every 2 years over an 8 year span while taking TNF-alpha inhibitors. Patients demonstrated improvement in disease activity measures as soon as therapy was started. As far as radiographic changes were noted, a linear progression of spinal changes was noted during the first 4 years. However, a delay in progression was noted in year 6 and persisted through year 8.
Patients with more severe disease also ingested NSAIDs for a longer period of time. The use of NSAIDs could have some synergistic effect with slowing progression of new bone formation.
Biologic therapy has a beneficial effect on AS patients who have more inflammatory disease as measured by elevated ESR and CRP and more radiographic damage when diagnosed. The benefits of biologic therapy on bone formation may take a number of years to develop. The duration of biologic therapy should be discussed between a patient and their physician. This study suggests that unless there is a specific reason to halt therapy, prolonged biologic therapy measured in years can have beneficial effects on the prevention of spinal fusion.
Maas F, Arends S, Brouwer E et a. Reduction in spinal radiographic progression in ankylosing spondylitis patients receiving prolonged treatment with TNF-alpha inhibitors. Arthritis Care Res DOI: 10.1002/acr.23097