P074 Real-world use of benzbromarone in individuals with gout: a retrospective cohort study

Background/Aims Gout is the most common inflammatory arthritis worldwide, affecting 2.5% of the UK population. There are only two licensed urate-lowering therapies (ULTs) in the UK, allopurinol and febuxostat - both of which are xanthine oxidase inhibitors (XOIs). Other ULTs, such as the uricosuric agent benzbromarone, can only be prescribed off-licence by hospital specialists, and real-world data on its use are limited. Our aim was to evaluate the use, effectiveness, and safety of benzbromarone across three large hospital sites over a 10-year period. Methods Data were collected retrospectively for all patients prescribed benzbromarone for gout between May 2015 and May 2025 across three hospital sites in South-East London. Data collection included demographics, comorbidities, previous ULTs, use of combination ULTs, clinical outcomes, adverse events and treatment duration. Results Over a 10-year period, 32 patients (mean age 55.8 years; 84% male) were prescribed benzbromarone across three hospital sites. 21/32 (65%) patients had documented tophaceous disease; 28/32 (88%) had prior documented XOI therapy, of whom all 28 had received allopurinol and 16 (50%) had received febuxostat. The primary documented reason for discontinuing XOIs was intolerance or side effects. Chronic kidney disease was present in 17 (53%) benzbromarone-treated patients, with liver disease in 4 (13%) patients. The median prescribed benzbromarone dose was 75mg daily. Of 32 treated patients, 14 (44%) discontinued benzbromarone with a median treatment duration of 290 days; most commonly due to supply issues or side effects not thought to be directly attributable to the drug. Benzbromarone was generally well-tolerated otherwise. One patient developed a mild drug sensitivity reaction, which resolved after cessation of the medication. No cases of hepatic failure or new nephrolithiasis were observed. Of 18 (56%) patients who remained on long-term benzbromarone, 9 (50%) achieved target serum urate levels (<360 µmol/L), with a median dose of 100mg once daily and median time-to-target of 129 days. An additional 5 (28%) patients were documented as undergoing ongoing dose titration. Combination therapy with benzbromarone and a XOI was used in 7 patients; 6 (86%) of whom subsequently discontinued benzbromarone, primarily due to inefficacy or supply issues. Only one patient on combination therapy achieved a urate <360 µmol/L. Conclusion This study provides real-world data on benzbromarone use in the NHS, supporting its utility in the management of patients with gout intolerant of, or unresponsive to, XOIs. Benzbromarone was generally well-tolerated and effective when titrated appropriately, with few medication-attributable adverse effects observed. Despite this, almost half discontinued therapy, most often due to supply barriers rather than safety concerns. Combination therapy with XOIs appeared safe, though efficacy data were limited. These findings underscore the limited ULT options available in the UK and highlight the need for broader access to alternative ULTs to optimise patient outcomes. Disclosure W. Han: None. R. Byng-Maddick: Honoraria; R.BM. has received honoraria from UCB. M.D. Russell: Honoraria; MD.R. has received honoraria from Menarini.