ABOUT CHRONIC TOPHACEOUS GOUT Symptoms of gout are caused by the body's response to the presence of high uric acid levels which can lead to the formation of urate crystals in the joints and surrounding tissue, which form when uric acid levels in the blood are elevated (a condition called hyperuricemia). The longer hyperuricemia persists, the higher the risk of developing gout. Symptoms of gout may include painful flares, pain or swelling in the joints (known as "gouty arthritis") or deposits of urate crystals under the skin, called "tophi." In cases of severe debilitating chronic tophaceous gout, these symptoms have a major influence on patient health due to the frequency and severity of episodes. Although most cases of gout can be controlled with conventional urate-lowering therapy, uric acid levels may remain high and symptoms persist despite treatment efforts, even at maximum medically appropriate doses.ABOUT KRYSTEXXAKRYSTEXXA ® (pegloticase) is a PEGylated uric acid specific enzyme for administration by intravenous infusion. The active substance pegloticase is a covalent conjugate of uricase produced by a genetically modified strain of Escherichia coli and monomethoxypoly (ethylene glycol). KRYSTEXXA was approved in the US in September 2010. KRYSTEXXA is indicated in the US for the treatment of chronic gout in adult patients refractory to conventional therapy. KRYSTEXXA is not recommended for the treatment of asymptomatic hyperuricemia. IMPORTANT SAFETY INFORMATION The following information is provided in both the US and European prescribing information. KRYSTEXXA ® is not indicated for the treatment of asymptomatic hyperuricemia. Patients who are at risk of having a condition known as G6PD deficiency should be screened by their physician prior to starting therapy with KRYSTEXXA. Discontinue oral urate-lowering therapies before instituting KRYSTEXXA and do not institute oral urate-lowering therapy while the patient is on KRYSTEXXA therapy.