Intensive Serum Urate Lowering With Oral Urate-Lowering Therapy for Erosive Gout: A Randomized Double-Blind Controlled Trial

Abstract

Objective: To determine whether a therapeutic approach of intensive serum urate lowering results in improved bone erosion scores in patients with erosive gout.

Methods: We undertook a 2-year, double-blind randomized controlled trial of 104 participants with erosive gout who were receiving serum urate-lowering therapy orally and who had serum urate levels of ≥0.30 mmoles/liter at baseline. Participants were randomly assigned to either an intensive serum urate target of <0.20 mmoles/liter or a standard target of <0.30 mmoles/liter (considered the standard according to rheumatology guidelines). Oral serum urate-lowering therapy was titrated to target using a standardized protocol (with the maximum approved doses of allopurinol, probenecid, febuxostat, and benzbromarone). The primary end point was the total computed tomography (CT) bone erosion score. Outcome Measures in Rheumatology (OMERACT) gout core outcome domains were secondary end points.

Results: Although the serum urate levels were significantly lower in the intensive target group compared to the standard target group over the study period (P = 0.002), fewer participants in the intensive target group achieved the randomized serum urate target level by year 2 (62% versus 83% of patients in the standard target group; P < 0.05). The intensive target group required higher doses of allopurinol (mean ± SD 746 ± 210 mg/day versus 497 ± 186 mg/day; P < 0.001) and received more combination therapy (P = 0.0004) compared to the standard target group. We observed small increases in CT bone erosion scores in both serum urate target groups over 2 years, with no between-group difference (P = 0.20). OMERACT core outcome domains (gout flares, tophi, pain, patient's global assessment of disease activity, health-related quality of life, and activity limitation) improved in both groups over 2 years, with no between-group differences. Adverse event and serious adverse event rates were similar between the groups.

Conclusion: Compared to a serum urate target of <0.30 mmoles/liter, more intensive serum urate lowering is difficult to achieve with an oral urate-lowering therapy. Intensive serum urate lowering leads to a high medication burden and does not improve bone erosion scores in patients with erosive gout.