Plasma uric acid concentrations during 24 hours after first dose of study drug for individual patients with uric acid levels more than 8 mg/dL at time 0.

Squares (solid lines) denote individual patients who received rasburicase and stars (dashed lines) allopurinol. Hyperuricemic patients who received rasburicase (n = 10) all achieved a plasma uric acid level less than 8 mg/dL within 4 hours of first drug dose. None of the hyperuricemic allopurinol patients (n = 5) achieved control by 4 hours.