Evaluation of the efficacy and safety of a novel xanthine oxidase inhibitor, tigulixostat, in gout patients with hyperuricemia: Design of the EURELIA 1 and EURELIA 2 studies

Background: Gout is a chronic disease of monosodium urate crystal deposition caused by elevated serum urate (SU). Gout may progress from acute episodic attacks to a disabling chronic deforming arthropathy. Allopurinol and febuxostat are the most widely prescribed urate-lowering drugs, however, these agents have potential adverse events and are seldom titrated to achieve a target SU level. Tigulixostat is a novel non-purine selective xanthine oxidase inhibitor for gout with hyperuricemia which has demonstrated potent in vitro and in vivo urate lowering activity and is being further investigated in humans for regulatory approvals. Methods: The Phase 3 program for tigulixostat consists of two clinical trials: EURELIA 1 and EURELIA 2. EURELIA 1 is a randomized, multi-regional, double-blind, parallel-group, placebo-controlled study to assess the safety and efficacy of 6 months of tigulixostat (100, 200, or 300 mg) in gout patients with hyperuricemia (n = 350). EURELIA 2 is a randomized, multi-regional, double-blind, double-dummy, parallel-group, active comparator (allopurinol titrated up to 800 mg) and placebo-controlled study to assess the safety and efficacy of tigulixostat (100, 200, or 300 mg) up to 12 months in gout patients with hyperuricemia (n = 2542). The primary endpoint for both studies is to determine the proportion of patients with SU levels <6.0 mg/dL sustained at for 3 months (Months 4, 5, and 6). Conclusions: EURELIA 1 and EURELIA 2 studies will be able to adequately determine the efficacy and safety of tigulixostat compared to both placebo and allopurinol. Trial registration number: For EURELIA 1, the clinicaltrials.gov identifier is NCT05586958. For EURELIA 2, the clinicaltrials.gov identifier is NCT05586971 and the EU CT number is 2022–501421–20-00. The sponsor for both trials is LG Chem, Ltd. (Seoul, South Korea).