Background AVERT (Assessing Very Early Rheumatoid arthirits Treatment) is a Phase IIIb, randomized, active-controlled trial to evaluate the efficacy and safety of abatacept (ABA) in combination with methotrexate (+ MTX) in patients (pts) with early RA.

Objectives To assess joint damage progression by magnetic resonance imaging (MRI) in pts with early RA from the AVERT study who were treated with ABA + MTX or ABA monotherapy, compared with MTX alone.

Methods MTX-naïve, anti-CCP2+ pts with early RA (active synovitis in ≥2 joints for ≥8 weeks, DAS28 (CRP) >3.2 and onset of symptoms within ≤2 yrs) were included. Pts were randomized to 12 mths of weekly SC ABA 125 mg + MTX, ABA 125 mg monotherapy or MTX alone. Pts with DAS28 (CRP) <3.2 at Mth 12 entered a 12-mth withdrawal period with no treatment. All pts with protocol-defined flare after Mth 15 could receive open-label ABA + MTX. Gadolinium-enhanced MRI of the dominant hand-wrist was performed on all pts at baseline and at Mths 6, 12, 18 and 24. Changes from baseline in synovitis, osteitis and bone erosion MRI scores were assessed up to Month 18 in this analysis.

Results During the 12-mth treatment period, benefits in synovitis, osteitis and erosion scores were numerically greater for ABA + MTX than for MTX alone; while numerically greater benefits were observed in synovitis and osteitis scores for ABA monotherapy than for MTX alone (Table 1). A post hoc analysis of pts who maintained DAS28 (CRP) <2.6 to Mth 18 after treatment withdrawal did not show evidence of MRI progression compared to Mth 12 in those pts.

Conclusions Consistent with the clinical outcomes of the AVERT study in pts with early RA with high disease activity, there were greater reductions in MRI outcomes with abatacept treatment in combination with MTX than with MTX alone. MRI changes with abatacept monotherapy treatment were intermediate between abatacept in combination with MTX and MTX treatment alone.

Disclosure of Interest C. Peterfy Shareholder of: Spire Sciences Inc., Synarc Inc., Consultant for: AbbVie, Inc., Amgen Inc., Articulinx, AstraZeneca, Bristol-Myers Squibb, Five Prime Therapeutics, Genentech, Hoffmann-La Roche, Inc., Lilly USA, LLC, Medimmune, Merck Pharmaceuticals, Moximed, Novartis Pharmaceuticals Corporation, Novo Nordisk, Plexxikon, Pfizer Inc, Sanofi, Salix-Santarus, Samsung, UCB, Inc., Employee of: Spire Sciences Inc., G. Burmester Grant/research support: BMS, AbbVie, Pfizer, Medimmune, Novartis, Roche, UCB, Lilly, Consultant for: BMS, AbbVie, Pfizer, MSD, Medimmune, Roche, UCB, Speakers bureau: BMS, AbbVie, Pfizer, MSD, Roche, UCB, V. Bykerk Grant/research support: Amgen, Pfizer, BMS, Janssen, UCB, Roche/Genentech, B. Combe Grant/research support: Pfizer, Roche-Chugai, Speakers bureau: BMS, Merck, Pfizer, Roche-Chugai, UCB, D. Furst Grant/research support: AbbVie, Actelion, Amgen, BMS, Gilead, GSK, NIH, Novartis, Pfizer, Roche/Genentech, UCB, Consultant for: AbbVie, Actelion, Amgen, BMS, Janssen, Gilead, GSK, NIH, Novartis, Pfizer, Roche/Genentech, UCB, Speakers bureau: AbbVie, Actelion, UCB, T. Huizinga Grant/research support: EU & Dutch Arthritis Foundation, Consultant for: Abbott Laboratories, Biotest AG, Bristol-Myers Squibb, Crescendo Bioscience, Inc, Novartis Pharmaceuticals Corporation, Pfizer Inc, Roche, sanofi-aventis, Schering-Plough, UCB, Inc., Eli Lilly, Speakers bureau: Abbott Laboratories, Biotest AG, Bristol-Myers Squibb, Novartis Pharmaceuticals Corporation, Pfizer Inc, Roche, sanofi-aventis, Schering-Plough, C. Karyekar Employee of: BMS, D. Wong Employee of: BMS, P. Conaghan Grant/research support: Centocor Research and Development, Inc., Pfizer Inc., Speakers bureau: AbbVie, BMS, Janssen, Pfizer, Roche, UCB, P. Emery Grant/research support: AbbVie, BMS, Merck, Pfizer, Roche, Consultant for: AbbVie, BMS, Merck, Pfizer, Roche, Takeda

DOI 10.1136/annrheumdis-2014-eular.1524