Pegloticase for treating refractory chronic gout

Gout is a metabolic disorder of excess uric acid accumulation that manifests clinically as inflammatory arthritis, chronic arthropathy and the formation of deposits of uric acid known as tophi. A primary objective of gout management is to reduce the excess urate burden by regular use of drugs that reduce serum urate levels. Conventional urate-lowering drugs available in the U.S. are allopurinol, febuxostat and probenecid. Some patients are intolerant to or unresponsive to urate-lowering therapies and, therefore, are said to have refractory gout. Recently, a polyethylene glycol-conjugated uricase, pegloticase, was approved for treating refractory gout. In recent clinical trials, pegloticase normalized plasma urate levels, reduced the size of tophi, and improved functional status and quality of life in patients with refractory disease. Immunogenicity to pegloticase is associated with loss of urate-lowering response and the risk of infusion reactions. Pegloticase is effective in treating hyperuricemia and the clinical manifestations of gout in patients who cannot be adequately managed with conventional therapy.