elspar (ASPARAGINASE) powder, for solution
|FULL PRESCRIBING INFORMATION: CONTENTS*|
Elspar is indicated as a component of a multi-agent chemotherapeutic regimen for the treatment of patients with acute lymphoblastic leukemia (ALL).
The recommended dose of Elspar is 6,000 International Units/m2 intramuscularly (IM) or intravenously (IV) three times a week.
When Elspar is administered IM, the volume at a single injection site should be limited to 2 mL. If a volume greater than 2 mL is to be administered, two injection sites should be used.
When administered IV, give Elspar over a period of not less than thirty minutes through the side arm of an infusion of Sodium Chloride Injection or Dextrose Injection 5% (D5W).
For IM administration, reconstitute Elspar by adding 2 mL Sodium Chloride Injection to the 10,000 unit vial. Withdraw volume of reconstituted Elspar containing calculated dose into sterile syringe.
For IV administration, reconstitute Elspar by adding 5 mL Sterile Water for Injection or Sodium Chloride Injection to the 10,000 unit vial. Withdraw volume of reconstituted Elspar containing calculated dose into sterile syringe.
Use reconstituted Elspar within eight hours
Parenteral drug products should be inspected visually for particulate matter, cloudiness or discoloration prior to administration, whenever solution and container permit. If any of these are present, discard the solution. However, occasionally, a very small number of gelatinous fiber-like particles may develop on standing. Filtration through a 5.0 micron filter during administration will remove the particles with no resultant loss in potency.
10,000 International Units as lyophilized powder in single-use vial.
Serious allergic reactions to Elspar or other Escherichia coli-derived L-asparaginases
Serious thrombosis with prior L-asparaginase therapy
Pancreatitis with prior L-asparaginase therapy
Serious hemorrhagic events with prior L-asparaginase therapy
Serious allergic reactions can occur in patients receiving Elspar. The risk of serious allergic reactions is higher in patients with prior exposure to Elspar or other Escherichia coli-derived L-asparaginases. Observe patients for one hour after administration of Elspar in a setting with resuscitation equipment and other agents necessary to treat anaphylaxis (for example, epinephrine, oxygen, intravenous steroids, antihistamines). Discontinue Elspar in patients with serious allergic reactions.
Serious thrombotic events, including sagittal sinus thrombosis can occur in patients receiving Elspar. Discontinue Elspar in patients with serious thrombotic events.
Pancreatitis, in some cases fulminant or fatal, can occur in patients receiving Elspar. Evaluate patients with abdominal pain for evidence of pancreatitis. Discontinue Elspar in patients with pancreatitis.
Glucose intolerance can occur in patients receiving Elspar. In some cases, glucose intolerance is irreversible. Monitor serum glucose.
Increased prothrombin time, increased partial thromboplastin time, and hypofibrinogenemia can occur in patients receiving Elspar. CNS hemorrhages have been observed. Monitor coagulation parameters at baseline and periodically during and after treatment. Initiate treatment with fresh-frozen plasma to replace coagulation factors in patients with severe or symptomatic coagulopathy.
The following serious adverse reactions occur with Elspar treatment [see Warnings and Precautions (5)]:
Anaphylaxis and serious allergic reactions
The most common adverse reactions with Elspar are allergic reactions (including anaphylaxis), hyperglycemia, pancreatitis, central nervous system (CNS) thrombosis, coagulopathy, hyperbilirubinemia, and elevated transaminases.
The adverse reactions included in this section were identified in single-arm clinical trials in which Elspar was administered as part of a multi-agent regimen or from spontaneous post-marketing reports or published literature.
Because these adverse events were identified in clinical trials that were not designed to isolate the adverse effects of Elspar or were reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
Serious Adverse Reactions
Anaphylaxis and serious allergic reactions. Allergic reactions have occurred with the first dose and with subsequent doses of Elspar. The risk of serious allergic reactions appears to be higher in patients with prior exposure to Elspar or other Escherichia coli-derived L-asparaginases.
Serious thrombosis, including sagittal sinus thrombosis
Pancreatitis, in some cases fulminant or fatal
Glucose intolerance, in some cases irreversible
Coagulopathy, including increased prothrombin time, increased partial thromboplastin time, and decreased fibrinogen, protein C, protein S and antithrombin III. CNS hemorrhages have been reported.
Central Nervous System effects including coma, seizures, and hallucinations.
Common Adverse Reactions
Azotemia, liver function abnormalities, including hyperbilirubinemia, and elevated transaminases.
As with all therapeutic proteins, there is a potential for immunogenicity, defined as development of binding and/or neutralizing antibodies to the product.
Elspar is a bacterial protein and can elicit antibodies in patients treated with the drug. In 2 prospectively designed clinical trials (N=59 and 24), approximately one quarter of the patients developed antibodies that bound to Elspar as measured by enzyme-linked immunosorbent assays (ELISA).1,2 Clinical hypersensitivity reactions to Elspar in studies were common ranging from 32.5%3 to 75%.1 In these studies, concomitant medications and dosing schedules varied. Patients with hypersensitivity reactions were more likely to have antibodies than those without hypersensitivity reactions.1 Hypersensitivity reactions have been associated with increased clearance of Elspar.4 Incidence of antibody formation was lower upon first administration of Elspar than second administration.1,2 The frequency of antibody formation in adults relative to children is unknown. There is insufficient information to comment on neutralizing antibodies; however, higher levels of antibody correlated with a decrease in asparaginase activity.2
The detection of antibody formation is highly dependent on the sensitivity and specificity of the assay, and the observed incidence of antibody positivity in an assay may be influenced by several factors including sample handling, concomitant medications and underlying disease. Therefore, comparison of the incidence of antibodies to Elspar with the incidence of antibodies to other products may be misleading.
No formal drug interaction studies between Elspar and other drugs have been performed.
Pregnancy Category C. In mice and rats Elspar has been shown to retard the weight gain of mothers and fetuses when given in doses of more than 1000 International Units/kg (approximately equivalent to the recommended human dose, when adjusted for total body surface area). Resorptions, gross abnormalities and skeletal abnormalities were observed. The intravenous administration of 50 or 100 International Units/kg (approximately equivalent to 10 to 20% of the recommended human dose, when adjusted for total body surface area) to pregnant rabbits on Day 8 and 9 of gestation resulted in dose dependent embryotoxicity and gross abnormalities. There are no adequate and well-controlled studies in pregnant women. Elspar should be given to a pregnant woman only if clearly needed.
It is not known whether Elspar is excreted in human milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants from ELSPAR, a decision should be made to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.
[See Clinical Studies (14.1)]
Clinical studies of Elspar did not include sufficient numbers of subjects aged 65 and older to determine whether they respond differently from younger subjects.
Elspar (asparaginase) contains the enzyme L-asparagine amidohydrolase, type EC-2, derived from Escherichia coli. Elspar activity is expressed in terms of International Units according to the recommendation of the International Union of Biochemistry. One International Unit of asparaginase is defined as that amount of enzyme required to generate 1 µmol of ammonia per minute at pH 7.3 and 37°C. The specific activity of Elspar is at least 225 International Units per milligram of protein.
Elspar is provided as a sterile, white lyophilized plug or powder. Each vial contains 10,000 International Units of asparaginase and 80 mg of mannitol.
The mechanism of action of Elspar is thought to be based on selective killing of leukemic cells due to depletion of plasma asparagine. Some leukemic cells are unable to synthesize asparagine due to a lack of asparagine synthetase and are dependent on an exogenous source of asparagine for survival. Depletion of asparagine, which results from treatment with the enzyme L-asparaginase, kills the leukemic cells. Normal cells, however, are less affected by the depletion due to their ability to synthesize asparagine.
The relationship between asparaginase activity and asparagine levels has been studied in clinical trials. In previously untreated, standard-risk ALL patients treated with native asparaginase in whom plasma enzyme activity was greater than 0.1 International Units/mL, plasma asparagine levels decreased from a pretreatment average level of 41 μM to less than 3 μM. In this study, cerebrospinal fluid asparagine levels in patients treated with asparaginase decreased from 2.8 μM (pretreatment) to 1.0 μM and 0.3 μM at day 7 and day 28 of induction, respectively.2
In a study5 in patients with metastatic cancer and leukemia, daily intravenous administration of L-asparaginase resulted in a cumulative increase in plasma levels. Plasma half-life varied from 8 to 30 hours. Apparent volume of distribution was slightly greater than the plasma volume. Asparaginase levels in cerebrospinal fluid were less than 1% of concurrent plasma levels.
In a study6 in which patients with leukemia and metastatic cancer received intramuscular L-asparaginase, peak plasma levels of asparaginase were reached 14 to 24 hours after dosing. Plasma half-life was 34 to 49 hours.
No long-term carcinogenicity studies in animals have been performed with Elspar.
No relevant studies addressing mutagenic potential have been conducted. Elspar did not exhibit a mutagenic effect when tested against Salmonella typhimurium strains in the Ames assay.
No studies have been performed on impairment of fertility.
Edema and necrosis of pancreatic islets were observed in rabbits following a single, intravenous injection of 12,500 to 50,000 International Units Elspar/kg (approximately equivalent to 25 to 100-fold the recommended human dose, when adjusted for total body surface area). These changes were not reflective of pancreatitis, and were not observed in rabbits following a single intravenous injection of 1000 International Units/kg (approximately equivalent to two times the recommended human dose, when adjusted for total body surface area).
Elspar was evaluated in an open-label, multi-center, single-arm study in which 823 patients less than 16 years of age with previously untreated acute lymphoblastic or acute undifferentiated leukemia received Elspar as a component of multi-agent chemotherapy for induction of first remission. Elspar was administered at a dose of 6,000 International Units/m2 intramuscularly 3 times a week for a total of 9 doses.7 Of 815 evaluable patients, 758 (93%) achieved a complete remission. In a previous study, in a similar patient population, which utilized an initial induction chemotherapy regimen containing the same agents without Elspar, 429 of 499 (86%) patients achieved a complete remission.
Wang, B.; Relling, M.V.; Storm, M.C.; Woo, M.H.; Ribeiro, R.; Pui, C.H.; Hak, L.J.: Evaluation of immunologic crossreaction of antiasparaginase antibodies in acute lymphoblastic leukemia (ALL) and lymphoma patients, Leukemia 17: 1583-1588, 2003.
Avramis, V.I.; Sencer, S.; Periclou, A.P.; Sather, H.; Bostrom, B.C.; Cohen, L.J.; Ettinger, A.G.; Ettinger, L.J.; Franklin, J.; Gaynon, P.S.; Hilden, J.M.; Lange, B.; Majlessipour, F.; Mathew, P.; Needle, M.; Neglia, J.; Reaman, G.; Holcenberg, J.S.: A randomized comparison of native Escherichia coli asparaginase and polyethylene glycol conjugated asparaginase for treatment of children with newly diagnosed standard-risk acute lymphoblastic leukemia: a Children’s Cancer Group study, Blood 99: 1986-1994, 2002.
Woo, M.H.; Hak, L.J.; Storm, M.C.; Sandlund, J.T.; Ribeiro, R.C.; Rivera, G.K.; Rubnitz, J.E.; Harrison, P.L.; Wang, B.; Evans, W.E.; Pui, C.H.; Relling, M.V.: Hypersensitivity or development of antibodies to asparaginase does not impact treatment outcome of childhood acute lymphoblastic leukemia, J. Clin. Oncol. 18(7): 1525-1532, Apr. 2000.
Asselin, B.L.: The three asparaginases: Comparative pharmacology and optimal use in childhood leukemia, Adv. Exp. Med. Biol. 457: 621-629, 1999.
Ho, D.H.W.; Thetford, B.S.; Carter, C.J.K.; Frei, E., III: Clinical pharmacologic studies of L-asparaginase, Clin. Pharmacol. Ther. 11: 408-417, May-June 1970.
Ho, D.H.W.; Yap, H.Y.; Brown, N.; Benjamin, R.S.; Friereich, E.J.; Blumenschein, G.R.; Bodey, G.P.: Clinical pharmacology of intramuscularly administered L-asparaginase, J. Clin. Pharmacol. 21: 72-78, Feb-Mar. 1981.
Ortega, J.A.; Nesbit, M.E.; Donaldson, M.H.; Hittle, R.E.; Weiner, J.; Karon, M.; Hammond, D.: L-asparaginase, vincristine and prednisone for induction of first remission in acute lymphocytic leukemia, Cancer Research 37: 535-540, Feb. 1977.
10,000 International Units as lyophilized powder in single dose vial individually packaged in a carton.
Storage and Handling
Keep vials refrigerated at 2-8°C (36-46°F).
Elspar does not contain a preservative. Store unused, reconstituted solution at 2-8°C (36-46°C) and discard after eight hours, or sooner if it becomes cloudy.
Patients should be informed of the possibility of serious allergic reactions, including anaphylaxis, and advised to immediately report any swellings or difficulty breathing.
Patients should be advised to immediately report any severe headache. Arm or leg swelling, acute shortness of breath, and chest pain also should be reported immediately.
Patients should be advised to immediately report any severe abdominal pain.
Patients should be advised to report excessive thirst or any increase in the volume or frequency of urination.
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Data are from FDA and U.S. National Library of Medicine.