Objective: To examine the association of radiographic progression and disease activity states in patients with rheumatoid arthritis (RA) treated with methotrexate with or without infliximab.
Methods: Patients (n=1049) with active RA for ≤T3 years and no prior methotrexate treatment were randomly assigned (4:5:5) to receive methotrexate plus placebo or methotrexate plus infliximab 3 or 6 mg/kg at weeks 0, 2, and 6, and every 8 weeks thereafter through week 46. Disease activity was classified by the simplified disease activity index (SDAI) score as remission (≤3.3), low (>3.3 to ≤T11), moderate (>11 to „T26), high (>26). Radiographic progression was measured as change from baseline to week 54 in total Sharp score (TSS).
Results: At weeks 14 and 54, more patients receiving methotrexate plus infliximab than methotrexate plus placebo were in remission (10.7% vs. 2.8% week 14; 21.3% vs. 12.3% week 54; p<0.001 for both). Methotrexate plus placebo halted radiographic progression only if patients achieved remission within 3 months, while methotrexate plus infliximab also halted or minimised progression in patients with low or moderate activity, respectively. Patients with persistently high disease activity levels had much less progression of joint damage if treated with methotrexate plus infliximab versus methotrexate monotherapy. However, even with infliximab plus methotrexate there was a direct relationship between disease activity and radiographic changes, although the slope was deflected when compared to methotrexate monotherapy.
Conclusion: With methotrexate, joint damage progresses even at low and moderate disease activity levels, while methotrexate plus infliximab inhibits radiographic progression across all disease activity states.