FRI0199 In patients with established RA, abatacept efficacy is independent of baseline annual radiographic progression rate

Background In the Phase III, double-blind, placebo (PBO)-controlled AIM study, abatacept (ABA)+ MTX significantly inhibited structural damage progression vs PBO+MTX in pts with established RA and inadequate response to MTX.1Sustained inhibition of radiographic progression was seen up to yr 5.2 Previous data in pts with early RA showed a benefit of ABA in pts with faster progression.3 Objectives To assess clinical outcomes at 1 yr according to annual radiographic progression rate (ARPR) by quartile at baseline (BL) in pts with established RA in AIM. Methods BL characteristics were similar between ABA 10 mg/kg+MTX (n=433) and PBO+MTX (n=219). ARPR was defined as total Genant-modified Sharpscore divided by disease duration. Pts were categorized into four quartiles according to ARPR at BL (Q1: ≤2.78; Q2: 2.78 to ≤4.64; Q3: 4.64 to ≤8.04; Q4: >8.04). For each quartile, treatment benefit was assessed post hoc by outcomes: DAS28(CRP)-derived criteria (remission