SAT0419 DAS-28 Score is Useful to Evaluate the Effect of Biologicals on Articular Involvement in Primary SjÖgren's Syndrome
Authors: R.V. Moerman, S. Arends, P. Meiners, A. Vissink, F.K.L. Spijkervet, F.G.M. Kroese, E. Brouwer, H. Bootsma
Journal: Annals of the Rheumatic Diseases (2015)

<h3>Background</h3> Arthralgia and arthritis are common features of disease activity in patients with primary Sjögren9s syndrome (pSS) with prevalence rates of 45-50% and 15-35%, respectively. Disease Activity Score including 28 joints (DAS-28) has been developed and validated to monitor disease activity in patients with rheumatoid arthritis, but it is also used in other auto-immune diseases. This extrapolation of indications is very relevant in the current scientific debate on comparability of the efficacy of biologicals and biosimilars. <h3>Objectives</h3> To evaluate the usefulness of DAS-28<sub>ESR</sub> in pSS patients treated with rituximab or abatacept. <h3>Methods</h3> pSS patients treated with rituximab or abatacept within our previously reported studies<sup>1,2</sup> were selected based on DAS-28<sub>ESR</sub> of ≥3.2 at baseline. Eighteen patients treated with rituximab (1000 mg, days 1 and 15) were evaluated at baseline and at weeks 16, 24, 36, 48 and 60 after treatment. Thirteen patients treated with abatacept infusions (∼10 mg/kg of body weight, days 1, 15 and 29 and every 4 weeks thereafter) were evaluated at baseline and at weeks 4, 12, 24 (on treatment), 36 and 48 weeks (off treatment). All patients fulfilled the revised American-European Consensus Group criteria for pSS and were ACPA antibody negative. Generalized estimating equations were used to analyse DAS-28<sub>ESR</sub> over time within both treatment groups. P&lt;0.05 was considered statistically significant. <h3>Results</h3> At baseline, the median DAS-28<sub>ESR</sub> score was 3.7 and 4.5 in the rituximab and abatacept treatment studies, respectively. Following rituximab treatment, DAS28<sub>ESR</sub> decreased significantly up to 48 weeks and returned to baseline values at week 60 (Figure 1A). In abatacept treated patients, DAS-28<sub>ESR</sub> decreased significantly up to 24 weeks and returned to baseline values at week 36 (Figure 1B). The proportion of patients with any degree of activity (score ≥1) in the articular domain of the EULAR Sjögren9s Syndrome Disease Activity Index (ESSDAI) are shown in Figure 1. <h3>Conclusions</h3> To our knowledge, this is the first analysis using DAS-28<sub>ESR</sub> to evaluate the disease activity in patients with pSS. The present results indicate that DAS-28<sub>ESR</sub> can be used to evaluate biologic therapies in trials with pSS patients. DAS-28<sub>ESR</sub> has a good sensitivity to change and is valuable to monitor disease activity in pSS. Moreover, DAS-28<sub>ESR</sub> score has comparable course over time with the articular domain of the ESSDAI score. Summarized, DAS-28<sub>ESR</sub> is useful not only in patients with RA, but also in patients with pSS. This is of particular relevance for the extrapolation of indications and comparison of biosimilars in the treatment of auto-immune diseases. <h3>References</h3> Responsiveness of disease activity indices ESSPRI and ESSDAI in patients with primary Sjögren9s syndrome treated with rituximab. Meiners PM, Arends S, Brouwer E, et al. Ann Rheum Dis. 2012 Aug;71(8):1297-302. Abatacept treatment reduces disease activity in early primary Sjögren9s syndrome (open-label proof of concept ASAP study). Meiners PM, Vissink A, Kroese FGM, et al. Ann Rheum Dis. 2014 Jul;73(7):1393-6. <h3>Disclosure of Interest</h3> None declared