SAT0078 Which cdmard strategy is most effective in newly diagnosed seronegative rheumatoid arthritispatients; post-hoc analysis of the treach study
Authors: N. Luurssen-Masurel, A. E. A.M. Weel, J.M.W. Hazes, P.H.P. de Jong
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background</h3> The disease spectrum of rheumatoid arthritis (RA) is heterogeneous. Literature suggests that these different disease subsets could be treated differently, with less aggressive treatment for rheumatoid factor and anti-citrullinated protein antibody negative RA patients ("seronegative RA"). Current treatment guidelines, however, do not take this into account since evidence is lacking. Especially, data about standardised treatment strategies in seronegative patients are needed. <h3>Objectives</h3> To compare 1 year clinical efficacy of 4 different initial treatment strategies in newly diagnosed, seronegative RA patients, according to the 2010 criteria. <h3>Methods</h3> For this post-hoc analysis data of the tREACH trial (stratified, single-blinded, randomised clinical trial) were used. Eligible patients, for the tREACH, were stratified into 3 probability tertiles (low, intermediate and high) according to their likelihood of progressing to persistent arthritis based upon the prediction model of Visser. For this analysis we selected all seronegative RA patients, of whom respectively 81% and 19% were in the intermediate and high stratum. Patients received 1 of the following 4 initial treatment strategies, which were based upon the tREACH randomization within each stratum (figure 1): [A] triple DMARD combination therapy (MTX 25 mg/wk.+SASP 2 gr/day+HCQ 400 mg/day+GCs (intramuscular or an oral tapering scheme, starting with 15 mg/day), [B] MTX 25 mg/wk.±GCs orally starting with 15 mg/day, [C] HCQ 400 mg/day and [D] GCs orally starting with 15 mg/day. Treatment strategies were 'tightly controlled', with patients being examined every 3 months. Treatment decisions were based upon the original Disease Activity Score (DAS) threshold for low disease activity (DAS &lt;2.4). Primary outcomes were DAS and functional ability, measured with the Health Assessment Questionnaire (HAQ), over time, using a linear mixed model (LMM). In our final model we corrected for baseline DAS and HAQ and visser score, which is a confounder by indication on forehand. <h3>Results</h3> 162 patients were grouped into treatment arms A (n=17), B (n=64), C (n=40) or D (n=41). Patients were mostly female (67%) with an average symptom duration of 161 days (95% CI: 146–175). At baseline the average visser score was 4 out of 13 (IQR 4–5). The difference in visser score was mainly due to the difference in erosions (figure 1A). Figure 1B and C show the DAS and HAQ over time per treatment arm. Our corrected LMM showed that there was no significant difference between treatment arms for DAS over time. After 3 months 56%, 38%, 35% and 69% respectively treated with A, B, C and D had an active disease (DAS≥2.4), and thus needed a treatment intensification (P0.003 for C versus D). However, after 1 year there was no difference between DAS over all treatment arms. HAQ over time did differ between treatment arms. Patients who received HCQ showed a better functional ability over time compared to patients receiving 1 of the other treatments (C versus respectively B (β=−0.18, p0.000), D (β=−0.14, p0.004) and A (β=−0.17, p0.016) ). <h3>Conclusions</h3> This research supports current hypothesis that seronegative RA patients can be treated with less aggressive treatment with similar efficacy. <h3>Disclosure of Interest</h3> None declared