What are the signs and symptoms of tumor lysis syndrome (TLS)?

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

What lab tests are needed to diagnose laboratory tumor lysis syndrome (TLS)?

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.

Are people with rising uric acid levels at risk for tumor lysis syndrome (TLS)?

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

Who is at risk for tumor lysis syndrome (TLS)?

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.

What is the mechanism of action for ELITEK® (rasburicase)?

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

Can ELITEK® (rasburicase) help protect people with baseline hyperuricemia who are at high risk for tumor lysis syndrome (TLS)?

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). View the efficacy of ELITEK in adult patients. View ELITEK Safety Profile. *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. 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).

Can ELITEK® (rasburicase) help protect people who are at high risk for tumor lysis syndrome (TLS) from rising uric acid levels?

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). View the efficacy of ELITEK in adult patients.See how ELITEK was studied in adult patients. View ELITEK Safety Profile. 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. 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).

How is ELITEK® (rasburicase) administered?

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. 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. Learn more about the dosing and administration of ELITEK.

Is there financial assistance for patients being treated with ELITEK® (rasburicase)?

CareASSIST by Sanofi for ELITEK offers resources and support for your eligible patients. These include access and reimbursement within the insurance landscape, financial assistance that can help mitigate the cost of ELITEK, and resource support for both patients and caregivers. If your patients have commercial insurance, they may qualify for the CareASSIST Copay Program and pay as little as $0 out of pocket for ELITEK. See the full scope of CareASSIST offerings.

FAQs | ELITEK® (rasburicase)

Q: Who is at risk for tumor lysis syndrome (TLS)?

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.

Q: What is ELITEK® (rasburicase)?

ELITEK is a recombinant urate-oxidase approved by the FDA for the initial management of uric acid 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. ELITEK is indicated only for a single course of treatment.

Q: What is the mechanism of action for ELITEK® (rasburicase)?

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

Expand all | Collapse all

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
Learn more about TLS risk here.
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
Learn more about laboratory testing for TLS here.
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

View TLS risk factors for more information.
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
View TLS risk factors for more information.
ELITEK is a recombinant urate-oxidase approved by the FDA for the initial management of uric acid in pediatric and adult patients with leukemia, lymphoma, and solid tumor malignancies who are receiving anticancer therapy plasma uric acid. ELITEK is indicated only for a single course of treatment.³⁰
Contact an ELITEK representative to learn more.
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
Learn more about the mechanism of action for ELITEK here.
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

View the efficacy of ELITEK in adult patients.

View ELITEK Safety Profile.

*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

See how ELITEK was studied in adult patients.

View the efficacy of ELITEK in adult patients.

View ELITEK Safety Profile.

*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
Learn more about ELITEK in pediatric patients.
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
Learn more about the dosing and administration of ELITEK.
CareASSIST by Sanofi Genzyme for ELITEK offers resources and support for your eligible patients. These include access and reimbursement within the insurance landscape, financial assistance that can help mitigate the cost of ELITEK, and resource support for both patients and caregivers.

If your patients have commercial insurance, they may qualify for the CareASSIST Copay Program and pay as little as $0 out of pocket for ELITEK.
See the full scope of CareASSIST offerings.

References: 1. Cortes J, Moore JO, Maziarz RT, et al. Control of plasma uric acid in adults at risk for tumor lysis syndrome: efficacy and safety of rasburicase alone and rasburicase followed by allopurinol compared with allopurinol alone—results of a multicenter phase III study. J Clin Oncol. 2010;28(27):4207-4213. 2. Referenced with permission from the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines^®) for B-Cell Lymphomas. V.4.2022. ©National Comprehensive Cancer Network, Inc. 2022. All rights reserved. Accessed August 26, 2022. To view the most recent and complete version of the guideline, go online to NCCN.org. NCCN makes no warranties of any kind whatsoever regarding use in any way. 3. Edeani A, Shirali A. Chapter 4: Tumor Lysis Syndrome. Onco-Nephrology Curriculum. American Society of Nephrology. 2016. https://www.asnonline.org/education/distancelearning/curricula/onco/Chapter4.pdf. Accessed August 26, 2022. 4. Cairo MS. Prevention and treatment of hyperuricemia in hematological malignancies. Clin Lymphoma. 2002;3(S1)S26-S31. 5. Venclexta [prescribing information]. East Windsor, NJ: Acrotech Biopharma LLC; 2020. 6. Imbruvica [prescribing information]. Horsham, PA: Janssen Biotech, Inc.; 2020. 7. Yescarta [prescribing information]. Santa Monica, CA: Kite Pharma, Inc; 2022. 8. Revlimid [prescribing information]. Summit, NJ: Celgene Corporation; 2021. 9. Bendeka [prescribing information]. Parsippany, NJ: Teva Pharmaceuticals; 2021. 10. Gleevec [prescribing information]. East Hanover, NJ: Novartis Pharmaceuticals Corporation; 2022. 11. Gazyva [prescribing information]. South San Francisco, CA: Genentech, Inc.; 2022. 12. Thalomid [prescribing information]. Summit, NJ: Celgene Corporation; 2021. 13. Marqibo [prescribing information]. East Windsor, NJ: Acrotech Biopharma LLC; 2020. 14. Sprycel [prescribing information]. Princeton, NJ: Bristol-Myers Squibb Company; 2021. 15. Pomalyst [prescribing information]. Summit, NJ: Celgene Corporation; 2021. 16. Doxorubicin hydrochloride [prescribing information]. New York, NY: Pfizer Labs; 2013. 17. Tasigna [prescribing information]. East Hanover, NJ: Novartis Pharmaceuticals Corporation; 2021. 18. Rituxan [prescribing information]. South San Francisco, CA: Genentech, Inc.; 2021. 19. Adcetris [prescribing information]. Bothell, WA: Seagen Inc.; 2022. 20. Ninlaro [prescribing information]. Cambridge, MA: Millennium Pharmaceuticals, Inc.; 2021. 21. Tibsovo [prescribing information]. Boston, MA: Servier Pharmaceuticals LLC; 2021. 22. Kyprolis [prescribing information]. Thousand Oaks, CA: Onyx Pharmaceuticals, Inc.; 2021. 23. Goldman SC, Holcenberg JS, Finkelstein JZ, et al. A randomized comparison between rasburicase and allopurinol in children with lymphoma or leukemia at high risk for tumor lysis. Blood. 2001;97:2998-3003. 24. Istodax [prescribing information]. Summit, NJ: Celgene Corporation; 2021. 25. Blincyto [prescribing information]. Thousand Oaks, CA: Amgen Inc.; 2022. 26. Polivy [prescribing information]. South San Francisco, CA: Genentech, Inc.; 2020. 27. Kymriah [prescribing information]. East Hanover, NJ: Novartis Pharmaceuticals Corporation; 2022. 28. Referenced with permission from the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines^®) for Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma. V.3.2022. ©National Comprehensive Cancer Network, Inc. 2022. All rights reserved. Accessed July 8, 2022. To view the most recent and complete version of the guideline, go online to NCCN.org. NCCN makes no warranties of any kind whatsoever regarding their content, use or application and disclaims any responsibility for their application or use in any way. 29. Wilson FP, Berns JS. Onco-nephrology: tumor lysis syndrome. Clin J Am Soc Nephrol. 2012;7(10):1730-1739. 30. ELITEK [prescribing information]. Bridgewater, NJ: sanofi-aventis U.S. LLC. 31. Ueng S. Rasburicase (Elitek): a novel agent for tumor lysis syndrome. Proc (Bayl Univ Med Cent). 2005;18(3):275-279. 32. Goldman SC, Holcenberg JS, Finkelstein JZ, et al. A randomized comparison between rasburicase and allopurinol in children with lymphoma or leukemia at high risk for tumor lysis. Blood. 2001;97:2998-3003.

INDICATION

ELITEK is indicated for the 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. ELITEK is indicated only for a single course of treatment.

IMPORTANT SAFETY INFORMATION

WARNING: HYPERSENSITIVITY REACTIONS, HEMOLYSIS, METHEMOGLOBINEMIA, AND INTERFERENCE WITH URIC ACID MEASUREMENTS

Hypersensitivity Reactions: ELITEK can cause serious and fatal hypersensitivity reactions including anaphylaxis. Immediately and permanently discontinue ELITEK in patients who experience a serious hypersensitivity reaction.
Hemolysis: Do not administer ELITEK to patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Immediately and permanently discontinue ELITEK in patients developing hemolysis. Screen patients at higher risk for G6PD deficiency (e.g., patients of African or Mediterranean ancestry) prior to starting ELITEK.
Methemoglobinemia: ELITEK can result in methemoglobinemia in some patients. Immediately and permanently discontinue ELITEK in patients developing methemoglobinemia.
Interference with Uric Acid Measurements: ELITEK enzymatically degrades uric acid in blood samples left at room temperature. Collect blood samples in prechilled tubes containing heparin and immediately immerse and maintain sample in an ice water bath. Assay plasma samples within 4 hours of collection.

CONTRAINDICATIONS

ELITEK is contraindicated in patients with a history of anaphylaxis or severe hypersensitivity to rasburicase or in patients with development of hemolytic reactions or methemoglobinemia with rasburicase. ELITEK is contraindicated in individuals deficient in glucose-6-phosphate dehydrogenase (G6PD).

ADVERSE REACTIONS

Most common adverse reactions (incidence ≥20%), when used concomitantly with anticancer therapy, are vomiting, nausea, fever, peripheral edema, anxiety, headache, abdominal pain, constipation, diarrhea, hypophosphatemia, pharyngolaryngeal pain, and increased alanine aminotransferase.

USE IN SPECIFIC POPULATIONS

Pregnancy: Consider the benefits and risks of ELITEK and possible risks to the fetus when prescribing ELITEK to a pregnant woman
Lactation: Because of the potential for serious adverse reactions in the breastfed child, advise patients that breastfeeding is not recommended during treatment with ELITEK and for 2 weeks after the last dose

Please see full Prescribing Information, including Boxed WARNING.

MAT-US-2020415-v2.0-08/2022

Last Updated: August 2022-08-01