Uric acid is the waste product from broken down purines, which are chemicals present in cells and certain foods. These high levels of uric acid, known as hyperuricemia, lead to the formation of uric acid crystals in the joints called tophi, prompting pain and swelling. The second approach is to address the underlying cause of the disease, which is the accumulation of uric acid in the body. Lingdolinurad managed to bring serum uric acid levels down to 5 mg/dl and 4 mg/dl. PRX-115 converts uric acid into allantoin, a harmless molecule that is easily removed through urine, reducing the risk of uric acid forming clumps.