Evaluation of the Effect of Topiroxostat on Renal Function in Patients with Hyperuricemia: STOP-C Study, a Retrospective Observational Cohort Study

BACKGROUND: Serum uric acid-lowering therapy is associated with maintaining renal function. OBJECTIVE: We aimed to retrospectively evaluate renal function and serum uric acid in patients with hyperuricemia who received topiroxostat for over a year. METHODS: Medical records of patients from 1 January, 2015 to 31 October, 2019 in our hospital were used. From the medical records, data of 100 patients with hyperuricemia treated with topiroxostat were extracted (67:33 male:female). The primary endpoints were changes in serum creatinine level and estimated glomerular filtration rate at 12 months after topiroxostat administration. The secondary endpoints were changes in serum creatinine, serum uric acid, and estimated glomerular filtration rate before and after topiroxostat administration. RESULTS: The study mainly involved elderly individuals (77.2 ± 9.5 years). Forty-four patients administered uric acid-lowering drugs were switched to topiroxostat. After 12 months, the serum creatinine level and estimated glomerular filtration rate showed no significant changes from baseline; however, the serum uric acid level significantly decreased. The estimated glomerular filtration rate significantly decreased during the 6 months before topiroxostat administration (p < 0.001), but showed no significant change at 6 months after topiroxostat administration (p = 0.849). CONCLUSIONS: This study revealed that topiroxostat use not only reduced the serum uric acid level but also maintained renal function in elderly patients with hyperuricemia in daily clinical practice.