Background Radiological structural changes in the sacroiliac joint (SIJ) over time in non-radiographic axial spondyloarthrits (nr-axSpA) can be evaluated by measuring the progression from non-radiographic to radiographic damage status according to modified New York (mNY) criteria but also with other more sensitive methods.1,2 However, the question remains whether anti-tumor necrosis factor therapy can prevent this structural progression, particularly in patients with nr-axSpA.
Objectives To evaluate radiographic progression in SIJ after 2 years of etanercept (ETN) treatment in nr-axSpA according to different outcome measures.
Methods Study design: 104-week follow-up of patients enrolled in the EMBARK trial who received ETN either from baseline (active treatment arm) or week 12 (placebo [PBO] arm). Patients: Active nr-axSpA refractory to ≥2 NSAIDs. Study drug: ETN 50 mg once a week. Outcome measures: Pelvic X-rays were performed at both baseline and week 104. After anonymization, 3 trained readers evaluated the films blinded to chronology using the 0–4 grade scale of the mNY radiographic criteria for each (left and right) SIJ. Statistical analysis: X-rays from patients who completed the 104-week study were assessed. For continuous variables (e.g., total score from 0 to 8 for the left and right SIJ according to mNY grading), the mean score from the 3 readers was evaluated (bias was possible because readers knew that all patients were previously considered to have nr-axSpA); for binary variables (e.g., change from non-radiographic to radiographic axSpA, worsening of ≥1 grade in ≥1 SIJ and an absolute final value of ≥2 in the worsened joint), the score agreed upon by ≥2 readers was used for analysis.
Results Of 215 randomized patients, 169 completed the open-label period at 104 weeks; 161 patients had X-rays available at both baseline and week 104. Only 1 patient was found to have satisfied mNY criteria for radiographic SIJ damage (ie, at least bilateral grade II or unilateral grade III) at baseline. Of 160 patients with mNY negative scores at baseline, none became mNY positive at week 104. The mean score (SD) for the total (left and right) SIJ (scale, 0–8) was 0.87 (0.83) at baseline and 0.88 (0.85) at week 104 (change, 0.01 [0.15]; P=0.386). No patients had both worsening of ≥1 grade in ≥1 SIJ and an absolute final value of ≥2 in the worsened joint.
Conclusions This study suggests that, whatever the outcome measure, no structural radiological progression in the SIJ occurred after 2 years of etanercept treatment in patients with nr-axSpA. Given this study's limitations, eg, lack of controls and inclusion of completers only, it is unclear whether this is an effect of etanercept. Additional studies using X-rays and MRI of the SIJ should be conducted to further address this question.
Van der Linden S, et al. Arthritis Rheum. 1984;27:361–8.
Dougados M, et al. Arthritis Rheum. 2014;66(suppl 11):S234–5.
Disclosure of Interest M. Dougados Grant/research support from: Pfizer, AbbVie, UCB, Merck, Eli-Lilly, Sanofi, Consultant for: Pfizer, AbbVie, UCB, Merck, Eli-Lilly, Sanofi, W. Maksymowych Grant/research support from: AbbVie, Consultant for: AbbVie, Amgen, Boehringer Ingelheim, Eli Lilly, Janssen Pharmaceutica, L.P, Pfizer, UCB, D. van der Heijde Consultant for: AbbVie, Amgen, Astellas, AstraZeneca, BMS, Celgene, Daiichi, Eli-Lilly, Galapagos, Janssen, Merck, Novartis, Pfizer, Roche, Sanofi-Aventis, UCB, Employee of: Director of Imaging Rheumatology bv., R. Pedersen Shareholder of: Pfizer, Employee of: Pfizer, R. Bonin Shareholder of: Pfizer, Employee of: Pfizer, I. Logeart Shareholder of: Pfizer, Employee of: Pfizer, J. Bukowski Shareholder of: Pfizer, Employee of: Pfizer, H. Jones Shareholder of: Pfizer, Employee of: Pfizer