To investigate the possibility of achieving partial remission (PR) in patients with nonradiographic axial spondyloarthritis (nr-axSpA) versus ankylosing spondylitis (AS) treated with anti-tumor necrosis factor (TNF)-α antagonists, such as adalimumab (ADA), etanercept (ETN), and infliximab (IFX), in a real clinical practice setting. The Assessment of SpondyloArthritis international Society (ASAS) 20, ASAS40, and Ankylosing Spondylitis Disease Activity Score were also calculated.
A retrospective study was conducted in patients with axSpA treated with ADA, ETN, and IFX from 2000 to 2013. All patients fulfilled the ASAS or the modified New York criteria. PR was reached when the score was < 20 mm (on a visual analog scale of 0-100 mm) in each of these domains: (1) patient global assessment, (2) pain, (3) function, and (4) inflammation.
A total of 321 patients with axSpA were treated. Among them, 62 were nr-axSpA while the remaining 259 were AS. Log-rank test to compare survival curves showed that the probability of obtaining PR in nr-axSpA and AS during treatment with anti-TNF-α was not significantly different. At 12 weeks of exposure to the first anti-TNF-α drug, PR was achieved in 7 patients with nr-axSpA (11.3%) and in 68 patients with AS (26.2%).
Our results, obtained from clinical practice, showed that PR is an achievable target of anti-TNF-α treatment in nr-axSpA. The PR rate, as a reliable indicator of sustained effectiveness, is similar in nr-axSpA and in AS.