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.
HYPERURICEMIA
Hyperuricemia (abnormal elevation of serum uric acid levels) is the single most common abnormality seen in patients with TLS who
develop severe metabolic abnormalities which may lead to acute renal failure. Ultimately, if left untreated, hyperuricemia and TLS
can lead to acute kidney failure9,12.
Destroyed tumor cells release their intracellular contents, inducing electrolytes,
nucleic acids, proteins, and their metabolites into the circulation at a more rapid
rate than the kidneys are able to remove them, leading to metabolic abnormalities
that can cause renal failure.3,5-7,12 The purines released undergo
accelerated catabolism, resulting in increased uric acid,13
which is soluble at physiologic pH (7.4). At acidic pH, uric acid crystals can form
and deposit in the kidneys, joints, and other soft tissues. When uric acid crystals
form in the renal tubules and collecting ducts, where the normal urine pH is around
5.0, obstruction, inflammation, and/or damage to the kidney tissues may occur.10 When uric acid crystals deposit in the joints, they can
cause joint pain and inflammation.10
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.