Background Several studies have demonstrated that TNFi are efficient in non-radiographic axial spondyloarthritis (Nr-AxSpA). Intriguingly, few investigations have directly compared ankylosing spondylitis (AS) patients with Nr-AxSpA patients, and fewer still have compared rates of response to first line TNFi treatment.

Objectives The purpose of this study, which involved a tertiary care cohort, was to (i) evaluate baseline characteristics of Nr-AxSpA and AS treated by TNFi; (ii) assess the response to first-line TNFi treatment; (iii) compare drug-survival duration and rates.

Methods Inclusion criteria were patients with axial SpA who initiated first-line TNFi treatment between April 2001 and July 2014 and were followed up for at least 3 months. Efficacy criteria were an improvement of at least 2 points (on a 0 – 10 scale) or a 50% improvement in BASDAI. Baseline characteristics, responses at 12 months, and drug survival were compared between AS and Nr-AxSpA.

Results A total of 361 patients were included in the study (AS: n=263; Nr-AxSpA: n=98). AS patients were more often male (65.02% vs. 45.92%; p=0.001) and had longer symptom durations (11.71±9.52 vs. 7.34±9.30; p<0.001). Median levels of acute-phase reactants (CRP and ESR) were significantly higher in AS patients (p<0.001 for both). Median BASDAI scores at first line TNFi initiation were not higher in Nr-AxSpA patients than in AS patients (59 [49-70] vs. 60 [50-70]; p=0.73). BASDAI 20 and BASDAI 50 response rates at 12 months were not statistically different between AS patients and Nr-AxSpA patients (74.58% vs. 64.58%; p=0.19 and 61.02% vs. 50.00%; p=0.19 respectively). No statistically significant difference in terms of survival was observed between AS and Nr-AxSpA patients (p=1.00).

Conclusions Treatment response, drug survival and patient outcome in our study were similar in patients with AS and Nr-AxSpA after first line TNFi initiation.

References

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2. Sieper J, van der Heijde D, Dougados M, Mease PJ, Maksymowych WP, Brown MA, et al. Efficacy and safety of adalimumab in patients with non-radiographic axial spondyloarthritis: results of a randomised placebo-controlled trial (ABILITY-1). Ann Rheum Dis 2013;72:815-22.

3. Kiltz U, Baraliakos X, Karakostas P, Igelmann M, Kalthoff L, Klink C, et al. Do patients with non-radiographic axial spondyloarthritis differ from patients with ankylosing spondylitis? Arthritis Care Res (Hoboken) 2012;64:1415–22.

Disclosure of Interest J. Corli Grant/research support from: Pfizer, R.-M. Flipo Grant/research support from: Pfizer, P. Philippe: None declared, A. Bera-Louville: None declared, C. Wibaux: None declared, J. Paccou Grant/research support from: Pfizer