OBJECTIVE: High magnetic resonance imaging (MRI)-detected inflammation is associated with greater progression and poorer outcomes in rheumatoid arthritis (RA). This analysis aimed to determine if baseline MRI inflammation was related to clinical response and remission in the Assessing Very Early Rheumatoid arthritis Treatment (AVERT) study.

METHODS: AVERT was a phase IIIb, randomized, controlled trial with a 12-month, double-blind treatment period enrolling patients with early (≤2 years' duration), anti-citrullinated peptide-positive methotrexate (MTX)-naive RA. In this post hoc analysis, patients in the abatacept plus MTX (n = 114) and MTX (n = 111) arms with available MRI results were stratified into low and high baseline MRI inflammation groups based on previously developed cutoffs of synovitis and osteitis on unilateral hand-wrist contrast-enhanced MRI. Simplified Disease Activity Index (SDAI) remission (≤3.3), Clinical Disease Activity Index (CDAI) remission (≤2.8), Boolean remission, and Disease Activity Score in 28 joints using the C-reactive protein level (<2.6) were assessed.

RESULTS: Overall, 100 of 225 patients (44.4%) had high baseline MRI inflammation. In patients with high baseline MRI inflammation, a significantly greater proportion achieved remission at 12 months with abatacept plus MTX versus MTX across SDAI (45.1% versus 16.3%; P = 0.0022), CDAI (47.1% versus 20.4%; P = 0.0065), and Boolean indices (39.2% versus 16.3%; P = 0.0156). In patients with low baseline MRI inflammation, remission rates were not significantly different with abatacept plus MTX versus MTX (SDAI: 39.7% versus 32.3%; P = 0.4961).

CONCLUSION: In seropositive, MTX-naive patients with early RA and presence of objectively measured high inflammation by MRI, indicating poor prognosis, remission rates were higher with abatacept plus MTX treatment versus MTX.