Anti-tumor necrosis factor alpha agents are among the most effective therapies for rheumatoid arthritis (RA). However, their optimal use is yet to be determined. This 12-month double-blind study attempted remission induction using standard therapy with or without infliximab in patients with early, poor-prognosis RA. The primary end point was synovitis (measured by magnetic resonance imaging [MRI]). Clinical observations continued to 24 months.
All patients had fewer than 12 months of symptoms. Assessments included full metrologic evaluation, laboratory tests, radiographs, functional evaluation using the Health Assessment Questionnaire (HAQ), and quality of life measurement using the RA Quality of Life (RAQoL) questionnaire. MRI was performed at 0, 4, 14, and 54 weeks; MR images were scored blindly. Patients received methotrexate (MTX) and were randomized to receive either infliximab or placebo for 12 months.
Twenty patients were recruited (mean age 52 years, mean symptom duration 6 months, mean C-reactive protein level 42 mg/liter, and 65% rheumatoid factor positive). At 1 year, all MRI scores were significantly better, with no new erosions in the infliximab plus MTX group; a greater percentage of infliximab plus MTX-treated patients fulfilled the American College of Rheumatology (ACR) 50% and 70% improvement criteria (78% versus 40% in the placebo plus MTX group and 67% versus 30%, respectively) and had a greater functional benefit (P < 0.05 for all comparisons). Importantly, at 1 year after stopping induction therapy, response was sustained in 70% of the patients in the infliximab plus MTX group, with a median Disease Activity Score in 28 joints (DAS28) of 2.05 (remission range). At 2 years, there were no significant between-group differences in the DAS28, ACR response, or radiographic scores, but differences in the HAQ and RAQoL scores were maintained (P < 0.05).
Remission induction with infliximab plus MTX provided a significant reduction in MRI evidence of synovitis and erosions at 1 year. At 2 years, functional and quality of life benefits were sustained, despite withdrawal of infliximab therapy. These data may have significant implications for the optimal use of expensive biologic therapies.