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

Abstract

Objective: To compare 2 years of radiographic sacroiliac joint (SIJ) changes in patients with recent onset axial spondyloarthritis (axSpA) receiving etanercept in a clinical trial (EMBARK) to similar patients not receiving biologics in a cohort study (DESIR).

Methods: Endpoints were changes at week 104 per the modified New York (mNY) grading system in total SIJ score (primary endpoint) and net percentage of patients with progression defined three ways. Treatment effect was analysed with and without adjustment for baseline covariates.

Results: At 104 weeks, total SIJ score improved in the etanercept group (n=154, adjusted least-squares mean change: -0.14) and worsened in the control group (n=182, change: 0.08). The adjusted difference between groups (etanercept minus control) was -0.22 (95% CI -0.38 to -0.06), p=0.008. The net percentage of patients with progression was significantly lower in the etanercept versus the control group for two of three binary endpoints: -1.9% versus 1.6% (adjusted difference for etanercept minus control: -4.7%,95% CI -9.9 to 0.5, p=0.07) for change in mNY criteria; -1.9% versus 7.8% (adjusted difference: -18.2%,95% CI -30.9 to -5.6, p=0.005) for change ≥1 grade in ≥1 SIJ; and -0.6% versus 6.7% (adjusted difference: -16.4%,95% CI -27.9 to -5.0, p=0.005) for change ≥1 grade in ≥1 SIJ, with shift from 0 to 1 or 1 to 0 considered no change.

Conclusion: Despite the slow radiographic SIJ progression rate over 2 years in axSpA, this study suggests a lower rate of progression in the SIJ with etanercept than without anti-tumour necrosis factor therapy.

Trial registration numbers: NCT01258738, NCT01648907; Post-results.

Keywords: anti-tnf; spondyloarthritis; treatment.

Conflict of interest statement

Competing interests: MD reports grants and personal fees from Pfizer, AbbVie, UCB, Merck, Lilly, Janssen and Novartis during the conduct of the study. WPM reports grants and personal fees from AbbVie and Pfizer, personal fees from Janssen, Lilly, Novartis, Merck and UCB outside the submitted work. RGL reports personal fees from AbbVie and BioClinica outside the submitted work. JFB, HJ, IL, RP and BV are employees of, and own stock in Pfizer. RB was an employee of Pfizer at the time the article was written. AS is an employee of inVentiv Health and was contracted by Pfizer to provide statistical support for the development of this paper. DvdH reports personal fees from AbbVie, Amgen, Astellas, AstraZeneca, Bristol Meyers Squibb, Boehringer Ingelheim, Celgene, Daiichi, Galapagos,Glaxo-Smith-Kline, Janssen, Merck, Novartis, Pfizer, Regeneron, Roche, Sanofi, Takeda and UCB outside the submitted work; and is director of Imaging Rheumatology BV. RL, AM, PC and MdH have no competing interests to declare.

© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Figures

Figure 1

Cumulative probability of change in sacroiliac joint (SIJ) radiography score from baseline to week 104 for the control and etanercept cohorts, average of the readers.

Figure 2

Net percent of patients with progression (number of patients with worsening minus the number of patients with improvement, divided by the study population) from baseline to week 104 in each study group for the three binary endpoints: (A) change in modified New York (mNY) criteria, adjusted analysis and (B) unadjusted analysis; (C) change of ≥1 grade in ≥1 sacroiliac joint (SIJ), adjusted analysis and (D) unadjusted analysis; and (E) change of ≥1 grade in ≥1 SIJ with shift from 0 to 1 and from 1 to 0 considered no change, adjusted analysis and (F) unadjusted analysis.