The occurrence of multiple treatment switches in axial spondyloarthritis. Results from five Nordic rheumatology registries

Characteristics of difficult-to-treat axial spondyloarthritis: Results of a real-world multicentric study

OBJECTIVE

The EULAR task force recently published the difficult-to-treat RA (D2T RA) definition, however, a definition of D2T axSpA is still lacking and limitations in this definition exist. The objectives were to study the characteristics of D2T axSpA patients using the EULAR definition and to study a subgroup of patients with a predefined more stringent definition including a temporal criterion.

METHODS

A multicentric retrospective study was performed. D2T axSpA was defined as failure of≥2 b/tsDMARDs with different mechanism of action. Very D2T axSpA was defined as failure of≥2 b/tsDMARDs in less than 2 years of follow-up. D2T and Very D2T axSpA patients were compared to non-D2T (nD2T) axSpA patients.

RESULTS

Three hundred and eleven axSpA patients were included: 88 D2T axSpA (28.3%) and 223 non-D2T (nD2T) axSpA (71.7%). Peripheral involvement was more prevalent in the D2T group (34.9 vs. 21.4%; P=0.015). BASDAI level at baseline was higher in the D2T group (63.7±16.5 vs. 58.8±14.7; P=0.015). Fibromyalgia was found to be more frequent in the D2T group vs nD2T group (P<0.001). Twelve patients (3.8%) were categorized as very D2T axSpA. Compared to nD2T, Very D2T patients had a higher CRP level at baseline (42.0±31.3 vs. 17.8±23.1; P=0.010). IBD prevalence at baseline was higher in the very D2T group (41.7 vs. 3.1%; P<0.001). None of the very D2T patients presented a fibromyalgia.

CONCLUSION

D2T axSpA was associated with higher disease activity, peripheral involvement, extra-musculoskeletal manifestations and fibromyalgia. Very D2T patients represented a minim proportion of patients after applying a more stringent definition including a temporal criterion of 2 years and might be independent from fibromyalgia.

Difficult-to-treat axial spondyloarthritis is associated with psoriasis, peripheral involvement and comorbidities: results of an observational nationwide study

OBJECTIVES

To determine the cumulative incidence and identify the factors associated with difficult-to-treat axial spondyloarthritis (D2T-axSpA) in French patients newly benefiting from the French 'long-term illness' (LTI) social security scheme for axial spondyloarthritis (axSpA).

METHODS

This national cohort study was based on the French National Medico-Administrative Database, SNDS, which contains data on hospitalisation, LTI and outpatient care consumption. All French patients newly receiving LTI benefits for ankylosing spondylitis (AS) between 2010 and 2013 were included in the study. In France, LTI is required to access biological/targeted synthetic DMARDs (b/tsDMARDs). The follow-up period ended on 31 December 2018. So-called D2T-axSpA was defined as the failure of three b/tsDMARDs or of two b/tsDMARDs with different modes of action. Comorbidities and extra-musculoskeletal manifestations were identified using previously described algorithms. Characteristics were compared between patients with D2T-axSpA and patients with non-D2T-axSpA who had received at least one b/tsDMARD with bivariate and multivariate analysis using logistic regression. Incidence rates of major cardiovascular event (MACE) and death were compared using competitive risk analysis.

RESULTS

22 932 patients were included. 10 798 (47.08%) patients received at least one bDMARD. None received tsDMARD. During follow-up, 2115 patients were classified as having D2T-axSpA, representing 19.59% of patients who received at least one bDMARD. In multivariate analysis, D2T-axSpA was significantly associated with female gender, peripheral involvement, psoriasis, hypertension and depression (p<0.001 for each case). There was no difference in the incidence of MACE (p=0.92) or death (p=0.87).

CONCLUSION

D2T-axSpA affects one in five patients exposed to bDMARDs in this national cohort. D2T-axSpA is more common in women and patients with peripheral involvement and/or comorbidities.