THU0095 IMPACT OF BASELINE EROSION SCORE ON RESPONSE TO TREATMENT AND FUTURE RADIOLOGICAL DAMAGE IN AVERT-2, A RANDOMISED PHASE IIIB STUDY OF ABATACEPT IN MTX-NAÏVE, ANTI-CITRULLINATED PROTEIN ANTIBODY–POSITIVE (ACPA+) PATIENTS WITH EARLY RA

Abstract

Background: Bone erosions are associated with poor prognosis in patients (pts) with RA. They can be associated with subclinical inflammation and independently predict future radiological damage.1 The Phase IIIb Assessing Very Early RA Treatment (AVERT)-2 (NCT02504268) trial evaluated abatacept (ABA)+MTX in MTX-naive, ACPA+ pts with early RA.2 Objectives: To explore the impact of baseline (BL) X-ray erosion scores (ES) on clinical response and future radiological damage over 1 yr in different groups of pts from AVERT-2. Methods: BL and Wk 52 X-ray data were evaluated using Sharp/van der Heijde score. SDAI remission rates (RRs; ≤3.3), unadjusted mean changes from BL (CfB) and duration of/time to sustained remission over 52 wks were evaluated. Radiographic progression was assessed at Wk 52 using CfB in ES. A range of BL ES cut-offs were evaluated to highlight key findings through comparison of pts with low and high ES. Results: Of 994 pts in the study, 964 (97%) had BL (median 2.0, interquartile range [IQR] 0.5–5.1) and 792 (80%) had BL and Wk 52 (median 2.5, IQR 1.0–6.5) ES. Results in Table 1 are based on ES cut-offs of 2 and 5, resulting in 53% and 75%, respectively, of pts in low ES groups. In pts who received ABA+MTX, those with low ES had higher SDAI RRs over 52 wks vs pts with high ES. The relationship was more pronounced for higher cut-offs. This was not observed with ABA placebo+MTX (MTX). Greater reduction of mean CfB in SDAI was achieved in pts with high vs low ES who received ABA+MTX. This was not observed with MTX. Pts who received ABA+MTX had longer duration and shorter time to sustained SDAI remission vs MTX. With ABA+MTX, pts with low ES had longer duration and shorter time to sustained SDAI remission vs high ES. This was not observed with MTX. Mean CfB in ES at Wk 52 was lower in the ABA+MTX arm vs the MTX arm. ABA seemed to equally protect pts with low and high ES; with MTX, pts with high ES had higher mean CfB in ES at Wk 52 than pts with low ES. Conclusion: This erosion-based stratification of the AVERT-2 early seropositive RA population emphasizes the importance of treating pts prior to the accumulation of erosive disease. Abatacept+MTX led to higher SDAI RRs in pts with low vs high ES and provided further protection vs MTX alone against future radiological damage in pts with high ES. Additional statistical modelling and adjustment for confounding factors at BL is warranted.