Tumor necrosis factor (TNF) inhibitors decrease spinal radiographic advancement in individuals suffering from radiographic axial spondyloarthritis that might be partially uncoupled from their impact on Ankylosing Spondylitis Disease Activity Score (ASDAS) inflammation.

A prospective cohort study (ALBERTA FORCAST) was carried out to determine if TNF inhibitors affect spinal radiographic advancement in individuals suffering from axial spondyloarthritis and if this is coupled with their impact on inflammation.

The study incorporated 314 subjects having axial spondyloarthritis meeting the modified New York criteria. With the aid of the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS), the spine radiographs carried out every two years up to 10 years were scored by two central readers.

Assessment of the indirect impact of TNF inhibitors on mSASSS was done using generalized estimating equations by assessing the interaction between TNF inhibitors and ASDAS at the beginning of each two‐year interval (t). If vital, the link between ASDAS at t and mSASSS at end of the interval (t+1) was examined in (1) participants treated with TNF inhibitors in all visits; (2) some visits, and (3) never treated. Furthermore, the link between TNF inhibitors at t and mSASSS at t+1 (adjusting for ASDAS at t) was also evaluated (direct effect).

A gradient was witnessed for the impact of ASDAS at t on mSASSS at t+1, with an elevated advancement in individuals never treated with TNF inhibitors in comparison with individuals continuously treated (indirect effect). The TNF inhibitors were also found to directly slow advancement as treated individuals had on average 0.85 mSASSS‐units less on t+1 in comparison with those not treated.

In radiographic axial spondyloarthritis patients, the use of TNF inhibitors minimizes spinal radiographic advancement.