Safety and Efficacy Study of PEG-uricase in the Treatment of Hyperuricemic Patients With Symptomatic Gout

The primary objective of each of the studies is to demonstrate superiority in the response rate (control of uric acid levels to below 6 mg/dL) in the PEG-uricase treatment groups compared to the placebo-control group. While reduction or resolution of tophi have been reported in the setting of prolonged urate-lowering therapy, there is photographic and additional anecdotal evidence from the Phase 2 PEG-uricase study of resolution or significant reduction of tophi after 3 months of therapy. Therefore, an assessment of changes in tophi over time will be conducted through the use of digital photographs obtained in a standardized manner from all subjects during the study. The effect on other clinical outcomes, including quality of life, health-related disability measures, gout flares and the number of swollen and tender joints will also be compared between the treatment groups and control group. Subjects will be randomized to one of the three treatment arms in a 2:2:1 ratio: 8 mg PEG-uricase every 2 weeks; 8 mg PEG-uricase every 4 weeks; or placebo. All subjects will receive an intravenous infusion (PEG-uricase or placebo) every two weeks in order to maintain the blind throughout the study. Study duration is approximately 26 weeks, including two weeks for screening and 24 weeks (6 months) of treatment.