Comparison of fixed versus traditional weight-based dosing of rasburicase in a pediatric population

The American Society of Clinical Oncology guidelines recommend rasburicase for the treatment of pediatric patients with hyperuricemia at risk of tumor lysis syndrome (TLS) using a weight-based dose of 0.1-0.2 mg/kg once daily for 1-7 days. However, there has been a trend in practice due to recent data showing benefit using a fixed-dose approach. The purpose of this study was to evaluate the efficacy and safety between fixed and weight-based dosing of rasburicase in a pediatric population.

This was a retrospective chart review of 48 patients from January 1, 2007 to August 31, 2016 at Children's National Health System. Patients less than 18 years old with a documented diagnosis of a malignancy and baseline uric acid level were included; patients less than 30 kg at the time of rasburicase administration were excluded.

The primary endpoint of this study was the treatment success of normalization of uric acid level (<5 mg/dl) within 24 hr of rasburicase administration. Eighty-three percent of patients had success with normalization of uric acid post rasburicase dose. Eighty-five percent of patients had success in the weight-based group compared to eighty-one percent in the fixed-dose group (P = 0.715). Mean percent reduction of uric acid at 24 hr was relatively similar between both groups (94% vs. 89%).

Our results suggest that a fixed-dose strategy of rasburicase is both safe and effective in reducing uric acid levels in the pediatric patient population. A fixed dose of rasburicase 6 mg is a cost-effective treatment option for TLS.