Etanercept May Slow Radiographic Sacroiliac Joint Progression in Axial Spondyloarthritis

In patients with recent-onset axial spondyloarthritis (axSpA), the long-term use of etanercept may result in a lower rate of radiographic progression in the sacroiliac joint, according to the results of a study published in Annals of the Rheumatic Diseases.

Sacroiliac joint changes in patients enrolled in the EMBARK clinical trial (ClinicalTrials.gov identifier: NCT01258738) in which they were treated with the anti-tumor necrosis factor (TNF) agent etanercept for a period of 2 years, were compared with those from participants in the DESIR study (ClinicalTrials.gov identifier: NCT01648907), in which the participants did not receive biologic therapy. The primary end point was change in total sacroiliac joint score at 104 weeks, according to the modified New York (mNY) grading system. A patient’s sacroiliac joint score was obtained by adding the scores of both sacroiliac joints (0 to 4 per sacroiliac joint; range, 0 to 8); thus, the change could range from –8 to +8. Binary end points included the net percentage of patients with progression, defined in 3 different ways.

At 104 weeks, the total sacroiliac joint score improved in the etanercept arm (n=154; adjusted least squares mean change, –0.14) and worsened in the control arm (n=182; change, 0.08). The adjusted difference between the groups was –0.22; (95% CI, –0.38 to –0.06; P =.008).

The net percentage of patients with progression was significantly lower for patients treated with etanercept than controls for 2 of the 3 binary end points: change ≥1 grade in at least 1 sacroiliac joint: –1.9% vs 7.8% (adjusted difference: –18.2%; 95% CI, –30.9 to –5.6; P =.005); and change ≥1 grade in at least 1 sacroiliac joint, with shift from 0 to 1 or from 1 to 0 considered to be no change: –0.6% vs 6.7% (adjusted difference: –16.4%; 95% CI, –27.9 to –5.0; P =.005). No significant difference in mNY criteria was detected: –1.9% vs 1.6% (adjusted difference for etanercept minus control: –4.7%; 95% CI, –9.9 to 0.5; P =.07).

The investigators concluded that, regardless of the slow radiographic sacroiliac joint progression rate in axSpA reported over 2 years, these findings suggest a lower rate of progression in the sacroiliac joint among etanercept-treated patients vs those receiving no anti-TNF therapy. Although the data are encouraging, further studies are warranted to confirm the validity of these outcome measures and to assess the structural effects of different treatments in the sacroiliac joint with the use of advanced imaging techniques.

Several of the study’s authors received support from Pfizer, which manufactures etanercept.

Reference

Dougados M, Maksymowych WP, Landewé RB, et al. Evaluation of the change in structural radiographic sacroiliac joint damage after 2 years of etanercept therapy (EMBARK trial) in comparison to a contemporary control cohort (DESIR cohort) in recent onset axial spondyloarthritis [published online September 29, 2017]. Ann Rheum Dis. doi: 10.1136/annrheumdis-2017-212008