General Information

Elitek (rasburicase) is a recombinant urate oxidase developed for the prevention and treatment of hyperuricemia in subjects receiving chemotherapy. Rapid destruction of cancer cells can result in the release of uric acid into the blood. Rasburicase acts by converting uric acid to alantoin, which can be excreted by the kidney.

Elitek is specifically indicated for the initial management of plasma uric acid levels in adults with leukemia, lymphoma, and solid tumor malignancies who are receiving anti-cancer therapy expected to result in tumor lysis syndrome and subsequent elevations of plasma uric acid.

Elitek is supplied as a solution for intravenous infusion. The recommended initial dose is 0.2 mg/kg as a 30 minute infusion daily for up to five days. Dosing beyond five days or for more than one course is not recommended.

Mechanism of Action

Elitek (rasburicase) is a recombinant urate oxidase developed for the prevention and treatment of hyperuricemia in subjects receiving chemotherapy. Rapid destruction of cancer cells can result in the release of uric acid into the blood. Rasburicase acts by converting uric acid to alantoin, which can be excreted by the kidney.

Side Effects

Adverse events associated with the use of Elitek may include, but are not limited to, the following:

• Vomiting
• Fever
• Nausea
• Headache
• Abdominal pain
• Constipation
• Diarrhea
• Mucositis
• rash

The Elitek drug label comes with a Black Box warning of the increased risk for hypersensitivity reactions, hemolysis, methemoglobinemia and interference with uric acid measurement associated with the use of Elitek.

Clinical Trial Results

The FDA approval of Elitek in adults was based on a multi-center, open-label, randomized, parallel group comparative phase III trial comparing Elitek to oral allopurinol, standard of care. The subjects received one of three treatments: intravenous Elitek (rasburicase) alone daily for 5 days, intravenous Elitek daily for day 1 to day 3 followed by oral allopurinol daily for day 3 to day 5, and oral allopurinol alone daily for 5 days. The daily dose of Elitek was 0.20 mg/kg, while that of allopurinol was 300 mg. Results showed that in patients treated with Elitek alone or followed by oral allopurinol, uric acid levels were less than or equal to 2.0 mg/dL in 96% of patients (at 4 hours of the day 1 dose). In the patients treated with Elitek alone, the the plasma uric acid (PUA) response rate was 87%, higher than that seen with patients treated with oral allopurinol alone at 66% (p=0.0009), while those treated with Elitek/oral allopurinol had a PUA response rate of 78%. Treatment was generally well tolerated.