Maksymowych WP, et al. - The goal of the study described in this paper was to assess the effect on structural lesions observed on MRI in the sacroiliac joints (SIJ) at 12 weeks in patients with non-radiographic axial spondyloarthritis (nr-axSpA) receiving etanercept or placebo in EMBARK (Effect of Etanercept on Symptoms and Objective Inflammation in nr-axSpA, a 104-week study). It was concluded that the treatment with etanercept was related to the significantly greater reduction in erosions and increase in backfill at 3 months compared with placebo, consistent with a very early reparative response to antitumour necrosis factor therapy. The effect on disease progression in spondyloarthritis ought to be considered further.