TNF inhibitors and radiographic progression in axSpA Save

A remaining challenge for clinicians is the ability to delay, if not completely stop, structural progression in patients with axial spondyloarthritis (ax-Spa), whether they are diagnosed with radiographic (r-axSpa) or non-radiographic (nr-axSpA) disease.

Data from observational studies have recently suggested that tumor necrosis factor inhibitors (TNFi) might retard spinal progression in patients with ax-SpA if treatment was started at an early stage and sustained in time, but whether a similar trend would apply to sacro-iliac joints (SIJ) radiographic progression, remains unknown.

To answer this question, Torgutalp et al. in abstract 0451 have used data from the German Spondyloarthritis Inception Cohort (GESPIC). They have analysed radiographic outcomes from 301 patients (166 with nr-axSpA, symptom duration ≤5 years and 135 with r-axSpA, symptom duration ≤10 years) with a total of 737 2-year radiographic intervals.

The longitudinal association between radiographic sacroiliitis progression and treatment with TNFi was analysed using longitudinal generalized estimating equations analysis. More specifically, they investigated the change in the sacroiliitis sum score defined as the difference between the mean SIJ radiographic score assessed by 2 trained readers in successive sets of plain radiographs.

The main findings are summarized as follows: over the follow-up period, almost 1 patient out of 3 (28.9%) received at least one TNFi. They were able to show that patients receiving ≥12 months TNFi over a previous period of 2 years was associated with a lower progression of the sacroiliitis sum score compared to not receiving TNFi. This result appears robust as validated through different statistical models. 

This study indicates that treatment with TNFi is associated to lower SIJ radiographic progression in a long term axSpa inception cohort. These data support the concept of early treatment intensification strategies and tight disease control in axSpA.

Figure: The change in sacroiliitis sum scores over two years in patients with axial spondyloarthritis treated vs non-treated with TNFi at least 12 months in the previous 2-year radiographic intervals.