FAQs

TLS is caused by a massive release of intracellular contents into peripheral blood that results in metabolic derangements, including hyperuricemia, hyperkalemia, hyperphosphatemia, and hypocalcemia.¹
TLS associated with hyperuricemia may lead to serious clinical complications, including acute renal failure, cardiac arrhythmias, loss of muscle control, seizures, or death.²

To diagnose TLS, test for 2 or more of the following abnormalities within 3 days before to 7 days after initiation of cancer treatment: uric acid ≥8 mg/dL or 25% increase from baseline; potassium ≥6 mEq/dL or 25% increase from baseline; phosphate ≥6.5 mg/dL (children), ≥4.5 mg/dL (adults), or 25% increase from baseline; calcium ≥25% decrease from baseline.³

In a retrospective analysis of 1198 patients with hematologic malignancies treated with inpatient chemotherapy, the risk of TLS increased with rising uric acid levels⁴:

• Patients with high uric acid levels (>8.0 mg/dL) had an 85.7% risk of developing TLS. Compared to patients with medium uric acid levels (4.0-8.0 mg/dL), there was a relative risk increase of 3.7 (95% CI: 2.6-5.2), P<0.001⁴
• Patients with medium uric acid levels (4.0-8.0 mg/dL) had a 23.4% risk of developing TLS. Compared to patients with low uric acid levels (<4.0 mg/dL), there was a relative risk increase of 5.5 (95% CI: 3-10), P<0.001⁴

There are a variety of factors that can put patients at risk of developing TLS. If your patients have hematologic malignancies, received certain anticancer agents associated with developing TLS, demonstrate rising uric acid levels, or have other factors such as an elevated white blood cell count or bulky disease, they may be at an increased risk for TLS.^2,5-29

ELITEK is a recombinant urate-oxidase approved by the FDA for the initial management of uric acid levels in pediatric and adult patients with leukemia, lymphoma, and solid tumor malignancies who are receiving anticancer therapy expected to result in tumor lysis and subsequent elevation of plasma uric acid. Limitations of Use: ELITEK is indicated only for a single course of treatment.³⁰

ELITEK is a recombinant urate-oxidase that catalyzes enzymatic oxidation of poorly soluble uric acid into an inactive and more soluble metabolite (allantoin).³⁰
Unlike allopurinol, ELITEK is the only antihyperuricemic agent that has the mechanism to clear existing uric acid.³¹

In a phase 3 trial comparing ELITEK and allopurinol in adults,* 18% of patients were hyperuricemic (>7.5 mg/dL) at baseline. ELITEK given prophylactically maintained normal uric acid levels (≤7.5 mg/dL) from Day 3 to Day 7 in 90% of patients with baseline hyperuricemia, while 53% of patients taking allopurinol maintained normal uric acid levels over the same time period (P=0.015).¹

*ELITEK was studied in a randomized, multicenter, open-label, phase 3 study in adult patients (N=275) with leukemia, lymphoma, and solid tumor malignancies at risk for hyperuricemia and TLS. The primary endpoint for the pivotal study was the response rate, defined as the proportion of adult patients with plasma uric acid levels maintained at ≤7.5 mg/dL between 3 and 7 days after initiation of antihyperuricemic treatment.^1,30
Results were consistent with the overall patient population (primary endpoint): 87% (n=92) of patients receiving ELITEK prophylactically maintained uric acid levels ≤7.5 mg/dL vs 66% (n=91) of patients receiving allopurinol (P=0.001). ELITEK + allopurinol maintained normal uric acid in 78% (n=92) of patients (P=NS vs allopurinol).¹

In a phase 3 trial comparing ELITEK and allopurinol in adults,* 92% of patients were at high risk for TLS at baseline. ELITEK given prophylactically maintained normal uric acid levels (≤7.5 mg/dL) from Day 3 to Day 7 in 89% of high-risk patients, while 68% of patients taking allopurinol maintained normal uric acid levels over the same time period (P=0.001).¹

*ELITEK was studied in a randomized, multicenter, open-label, phase 3 study in adult patients (N=275) with leukemia, lymphoma, and solid tumor malignancies at risk for hyperuricemia and TLS. The primary endpoint for the pivotal study was the response rate, defined as the proportion of adult patients with plasma uric acid levels maintained at ≤7.5 mg/dL between 3 and 7 days after initiation of antihyperuricemic treatment.^1,30
Results were consistent with the overall patient population (primary endpoint): 87% (n=92) of patients receiving ELITEK prophylactically maintained uric acid levels ≤7.5 mg/dL vs 66% (n=91) of patients receiving allopurinol (P=0.001). ELITEK + allopurinol maintained normal uric acid in 78% (n=92) of patients (P=NS vs allopurinol).¹

ELITEK is approved for use in pediatric patients. The safety and effectiveness of ELITEK have been established in pediatric patients ages 1 month to 17 years for initial management of plasma uric acid levels in patients with leukemia, lymphoma, and solid tumor malignancies who are receiving anticancer therapy expected to result in tumor lysis and subsequent elevation of plasma uric acid.^30,32

The recommended dose for ELITEK is 0.2 mg/kg once daily. ELITEK is not indicated for dosing beyond 5 days or administration of more than 1 course. Do not administer as an intravenous bolus.³⁰
ELITEK is available in 2 vial sizes: 1.5 mg and 7.5 mg. Administer ELITEK as an intravenous infusion only. Inject the calculated dose of reconstituted ELITEK solution into an infusion bag containing the appropriate volume of 0.9% sterile sodium chloride to achieve a final total volume of 50 mL. DO NOT use filters during infusion of reconstituted ELITEK drug product. Infuse over 30 minutes through a separate IV line or flush line with at least 15 mL of normal saline prior to and after ELITEK infusion.³⁰