Elitek® is indicated for the initial management of plasma
uric acid levels in pediatric and adult patients with leukemia, lymphoma, and solid
tumor malignancies who are receiving anti-cancer therapy expected to result in tumor
lysis and subsequent elevation of plasma uric acid. ELITEK is indicated for
only a single course of treatment.
Tumor Lysis Syndrome Risk Factors
Spontaneous occurrence of tumor lysis syndrome (TLS) has been reported in pediatric patients with hematologic
malignancies, particularly Burkitt's lymphoma.11 In general, tumor lysis syndrome (TLS) develops within the first 24 to
48 hours after the initial dose of chemotherapy. The signs and symptoms of TLS may
last for 5 to 7 days.10
The exact incidence of tumor lysis syndrome (TLS) is unknown. In patients with non-Hodgkin's lymphoma,
the incidence of TLS has been reported to be as high as 40%.5 However, with routine use of preventative measures,
the incidence and severity of TLS may have decreased over the past several years.10
Risk Factors for Tumor Lysis Syndrome5,10
- Large tumor burden
- Tumors with high growth rate
- Cancers that are very sensitive to chemotherapy
- White blood cell count (WBC) ≥ 50,000
- Elevated LDH ≥ 2 x ULN
- Elevated uric acid
- Preexisting renal impairment
- Dehydration
- Acute renal failure developing after treatment
The occurrence, severity, and duration of TLS are influenced by tumor type, chemosensitivity,
tumor burden, timing and intensity of chemotherapy, and the patient's condition
with respect to hydration, acid-base status, and renal function.10,12
IMPORTANT SAFETY INFORMATION INCLUDING BOXED WARNING
Important Safety Information
BOXED WARNINGS
Anaphylaxis:
ELITEK can cause severe 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 pre-chilled tubes containing heparin and immediately immerse
and maintain sample in an ice water bath. Assay plasma samples within 4 hours of
collection.
Among the 347 (265 pediatric; 82 adult) patients for whom all adverse reactions
regardless of severity were assessed in Studies 1, 2 and 3, as well as an uncontrolled
safety trial, the most frequently observed adverse reactions (incidence ≥10%) were
vomiting (50%), fever (46%), nausea (27%), headache (26%), abdominal pain (20%),
constipation (20%), diarrhea (20%), mucositis (15%), and rash (13%).
Among the 275 adult patients in Study 4, hypersensitivity reactions occurred in
4.3% of patients treated with the ELITEK alone and 1.1% of patients treated
with the ELITEK/oral allopurinol combination. Hypersensitivity reactions
included arthralgia, injection site irritation, peripheral edema, and rash. The
most common Grade 3 or 4 adverse reactions regardless of relationship to study drug
in the 3 arms of Study 4 (ELITEK alone; ELITEK combined with oral
allopurinol; oral allopurinol alone) were sepsis (5.4%; 6.5%; 4.4%), hypophosphatemia
(4.3%; 6.5%; 6.6%), anxiety (3.3%; 0%; 0%), abdominal pain (3.3%; 4.3%; 2.2%), hyperbilirubinemia
(3.3%; 2.2%; 4.4%), and increased alanine aminotransferase (3.3%; 4.3%; 2.2%), respectively.
The following serious adverse reactions occurred with a difference in incidence
of greater than or equal to 2% in patients receiving ELITEK compared to patients
receiving oral allopurinol in randomized studies (Study 1 and Study 4): pulmonary
hemorrhage, respiratory failure, supraventricular arrhythmias, ischemic coronary
artery disorders, and abdominal and gastrointestinal infections.
Indication
ELITEK® is indicated for the initial management of plasma
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. ELITEK is indicated for
only a single course of treatment.
Please see accompanying full Prescribing Information, including Boxed
WARNING.