The interleukin 1 inhibitor rilonacept in treatment of chronic gouty arthritis: results of a placebo-controlled, monosequence crossover, non-randomised, single-blind pilot study

Background: Recent studies suggest that blockade of the NLRP3 (cryopyrin) inflammasome interleukin 1 beta (IL1 beta) pathway may offer a new treatment strategy for gout. Objective: To explore the potential utility of rilonacept (IL1 Trap) in patients with chronic active gouty arthritis in a proof-of-concept study. Methods: This 14-week, multicentre, non-randomised, single-blind, monosequence crossover study of 10 patients with chronic active gouty arthritis included a placebo run-in (2 weeks), active rilonacept treatment (6 weeks) and a 6-week post-treatment follow-up. Results: Rilonacept was generally well tolerated. No deaths and no serious adverse events occurred during the study. One patient withdrew owing to an injection-site reaction. Patients' self-reported median pain visual analogue scale scores significantly decreased from week 2 (after the placebo run-in) to week 4 (2 weeks of rilonacept) (5.0 to 2.8; p < 0.049), with sustained improvement at week 8 (1.3; p < 0.049); 5 of 10 patients reported at least a 75% improvement. Median symptom-adjusted and severity-adjusted joint scores were significantly decreased. High-sensitivity C-reactive protein levels fell significantly. Conclusions: This proof-of-concept study demonstrated that rilonacept is generally well tolerated and may offer therapeutic benefit in reducing pain in patients with chronic refractory gouty arthritis, supporting the need for larger, randomised, controlled studies of IL1 antagonism such as with rilonacept for this clinical indication.