Anakinra for the treatment of acute gout flares: a randomized, double-blind, placebo-controlled, active-comparator, non-inferiority trial

OBJECTIVES: To evaluate the efficacy and safety of anakinra in treating acute gout flares in a randomized, double-blind, placebo-controlled, active comparator, non-inferiority (NI) trial. METHODS: Patients with a crystal-proven acute gout flare were randomized (1: 1) to treatment with anakinra or treatment as usual (free choice: either colchicine, naproxen or prednisone). The primary end point was the change in pain between baseline and the averaged pain score on days 2-4 measured on a five-point rating scale. NI of anakinra would be established if the upper bound of the 95% CI of the numeric difference in changed pain scores between treatment groups did not exceed the NI limit of 0.4 in favour of treatment as usual, in the per-protocol (PP) and intention-to-treat (ITT) populations, assessed in an analysis of covariance model. Secondary outcomes included safety assessments, improvement in pain, swelling, tenderness and treatment response after 5 days, assessed using linear mixed models and binary logistic regression models. RESULTS: Forty-three patients received anakinra and 45 treatment as usual. Anakinra was non-inferior (mean difference; 95% CI) to treatment as usual in both the PP (-0.13; -0.44, 0.18) and ITT (-0.18; -0.44, 0.08) populations. No unexpected or uncommon (serious) adverse events were observed in either treatment arm. Analyses of secondary outcomes showed that patients in both groups reported similar significant reductions in their gout symptoms. CONCLUSION: Efficacy of anakinra was shown to be non-inferior to treatment as usual for the treatment of acute gout flares, suggesting that anakinra is an effective treatment alternative for acute gout flares. TRIAL REGISTRATION: Het Nederlands Trial Register, www.trialregister.nl, NTR5234.