Asparaginase Escherichia coli



Asparaginase Escherichia coli is an asparaginase enzyme from E. coli used as part of treatment regimens for acute lymphoblastic leukemias.

Brand Names
Rylaze, Spectrila
Generic Name
Asparaginase Escherichia coli
DrugBank Accession Number

Asparaginase derived from Escherichia coli (L-asparagine amidohydrolase, EC is an enzyme responsible for the metabolism of L-asparagine, by catalyzing L-asparagine into L-aspartic acid and ammonia. It also facilitates the production of oxaloacetate which is needed for general cellular metabolism. Asparaginase from E. coli has clinically shown to exhibit antitumor actions in models of leukaemias 1,2. L-asparaginase of E. coli is marketed under several different trade names, including Elspar, for the treatment of acute lymphoblastic leukemia (ALL) as part of a multi-agent chemotherapeutic regimen. It is available as intramuscular or intravenous injections. Therapeutic L-asparaginase from E. coli works by depleting the levels of non-essential amino acid, asparagine, in lymphoblastic leukemic cells thus promoting apoptotic cell death 3. For patients who develop hypersensitivity to E. coli-derived formulations of L-asparaginase, the use of PEGylated or non-PEGylated Asparaginase Erwinia chrysanthemi is recommended 3.

Approved, Investigational
Biologic Classification
Protein Based Therapies
Other protein based therapies
Protein Structure
Protein Chemical Formula
Protein Average Weight
Not Available
>sp|P00805|ASPG2_ECOLI L-asparaginase 2 OS=Escherichia coli (strain K12) GN=ansB PE=1 SV=2
Download FASTA Format
  • Asparaginase
  • Asparaginase (E. coli)
  • Colaspase
  • Escherichia coli L-asparaginase
  • L-asparaginase
  • L-asparagine amidohydrolase



Indicated as a component of a multi-agent chemotherapeutic regimen for the treatment of patients with acute lymphoblastic leukemia (ALL).5

Reduce drug development failure rates
Build, train, & validate machine-learning models
with evidence-based and structured datasets.
See how
Build, train, & validate predictive machine-learning models with structured datasets.
See how
Associated Conditions
Contraindications & Blackbox Warnings
Prevent Adverse Drug Events Today
Tap into our Clinical API for life-saving information on contraindications & blackbox warnings, population restrictions, harmful risks, & more.
Learn more
Avoid life-threatening adverse drug events with our Clinical API
Learn more

In clinical trials of patients with previously untreated, standard-risk ALL, administration of asparaginase resulted in a decrease of plasma asparagine levels from average of 41 μM to less than 3 μM Label. The native asparaginase in whom plasma enzyme activity before treatment was greater than 0.1 International Units/mL Label. 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 Label. Native E. coli asparaginase results in asparagine depletion in 14 to 23 days following administration 3.

Mechanism of action

Asparagine is a non-essential amino acid that maintains DNA, RNA and protein synthesis and promotes cell growth. While healthy and normal cells are capable of obtaining asparagine via dietary intake or synthesizing the asparagine from aspartate via asparagine synthetase activity, lymphoblastic leukemic cells lack the asparagine synthetase enzyme and cannot produce asparagine de novo 3. Thus, leukemic cells rely on exogenous source of asparagine for protein synthesis and cell survival 3. L-asparagine from E. coli serves to deplete plasma levels of asparagine in leukemic cells by converting L-asparagine to L-aspartic acid and ammonia 3, leading to reduced reduced DNA, RNA and protein synthesis; inhibition of cell growth; and ultimately the activation of apoptotic cell-death mechanisms 3. Normal cells, however, are able to synthesize asparagine and thus are affected less by the rapid depletion produced by treatment with the enzyme asparaginase Label.


In a study in patients with metastatic cancer and leukemia, daily intravenous administration of L-asparaginase derived from E. coli resulted in a cumulative increase in plasma levels. Following intramuscular injection in patients with metastatic cancer and leukemia, peak plasma levels of asparaginase was achieved 14 to 24 hours post-dosing Label.

Peak asparaginase activity of native E. coli asparaginase can be observed in 24 to 48 hours following administration 3.

Volume of distribution

Apparent volume of distribution was slightly greater than the plasma volume. Asparaginase levels in cerebrospinal fluid were less than 1% of concurrent plasma levels 3.

Protein binding

Not Available

Not Available
Route of elimination

Not Available


Plasma half life of L-asparagine derived from E. coli following intravenous injection was 8-30 hrs Label. Plasma half-life was 34 to 49 hours after intramuscular injection Label. Half-life (mean ± SD) of native E. coli asparaginase is approximately 1.28 ± 0.35 days 3.


Not Available

Adverse Effects
Improve decision support & research outcomes
With structured adverse effects data, including: blackbox warnings, adverse reactions, warning & precautions, & incidence rates. View sample adverse effects data in our new Data Library!
See the data
Improve decision support & research outcomes with our structured adverse effects data.
See a data sample

No studies assessing the mutagenic or carcinogenic potential of E. coli L-asparagine have been conducted. In the Ames assay, no mutagenic effect was demonstrated when tested against Salmonella typhimurium strains Label. No studies have been performed on impairment of fertility Label. Following a single, intravenous injection of 12,500 to 50,000 International Units L-asparagine/kg in rabbits, edema and necrosis of pancreatic islets were observed. The clinical relevance of this finding is unclear as it does not indicate pancreatitis Label.

Not Available
Pharmacogenomic Effects/ADRs
Not Available


Drug Interactions
This information should not be interpreted without the help of a healthcare provider. If you believe you are experiencing an interaction, contact a healthcare provider immediately. The absence of an interaction does not necessarily mean no interactions exist.
AllantoinThe therapeutic efficacy of Allantoin can be increased when used in combination with Asparaginase Escherichia coli.
AmbroxolThe risk or severity of methemoglobinemia can be increased when Asparaginase Escherichia coli is combined with Ambroxol.
ArticaineThe risk or severity of methemoglobinemia can be increased when Asparaginase Escherichia coli is combined with Articaine.
BenzocaineThe risk or severity of methemoglobinemia can be increased when Asparaginase Escherichia coli is combined with Benzocaine.
Benzyl alcoholThe risk or severity of methemoglobinemia can be increased when Asparaginase Escherichia coli is combined with Benzyl alcohol.
BupivacaineThe risk or severity of methemoglobinemia can be increased when Asparaginase Escherichia coli is combined with Bupivacaine.
ButacaineThe risk or severity of methemoglobinemia can be increased when Asparaginase Escherichia coli is combined with Butacaine.
ButambenThe risk or severity of methemoglobinemia can be increased when Asparaginase Escherichia coli is combined with Butamben.
CapsaicinThe risk or severity of methemoglobinemia can be increased when Asparaginase Escherichia coli is combined with Capsaicin.
CarbamazepineThe therapeutic efficacy of Carbamazepine can be increased when used in combination with Asparaginase Escherichia coli.
Identify potential medication risks
Easily compare up to 40 drugs with our drug interaction checker.
Get severity rating, description, and management advice.
Learn more
Food Interactions
No interactions found.


Drug product information from 10+ global regions
Our datasets provide approved product information including:
dosage, form, labeller, route of administration, and marketing period.
Access now
Access drug product information from over 10 global regions.
Access now
Brand Name Prescription Products
NameDosageStrengthRouteLabellerMarketing StartMarketing EndRegionImage
ElsparInjection, powder, lyophilized, for solution10000 [iU]/1Intramuscular; IntravenousLundbeck Inc.1978-01-102013-07-18US flag
KidrolasePowder, for solution10000 unit / vialIntramuscular; IntravenousJazz Pharmaceuticals France Sas1974-12-312021-07-07Canada flag
RylazeInjection20 mg/1mLIntramuscularJazz Pharmaceuticals, Inc.2021-06-30Not applicableUS flag
SpectrilaInjection, powder, for solution10000 UIntravenousMedac Gesellschaft Fuer Klinische Spezialpraeparate Mb H2016-09-08Not applicableEU flag
SpectrilaInjection, powder, for solution10000 UIntravenousMedac Gesellschaft Fuer Klinische Spezialpraeparate Mb H2016-09-08Not applicableEU flag


ATC Codes
L01XX02 — Asparaginase
Drug Categories
Chemical TaxonomyProvided by Classyfire
Not Available
Organic Compounds
Super Class
Organic Acids
Carboxylic Acids and Derivatives
Sub Class
Amino Acids, Peptides, and Analogues
Direct Parent
Alternative Parents
Not Available
Not Available
Molecular Framework
Not Available
External Descriptors
Not Available
Affected organisms
  • Humans and other mammals

Chemical Identifiers

CAS number


Synthesis Reference

Masao Nambu, "Process for producing immobilized L-asparaginase preparations for the therapy of leukemia." U.S. Patent US4617271, issued January, 1977.

General References
  1. Roberts J, Prager MD, Bachynsky N: The antitumor activity of Escherichia coli L-asparaginase. Cancer Res. 1966 Oct;26(10):2213-7. [Article]
  2. Boyse EA, Old LJ, Campbell HA, Mashburn LT: Suppression of murine leukemias by L-asparaginase. Incidence of sensitivity among leukemias of various types: comparative inhibitory activities of guinea pig serum L-asparaginase and Escherichia coli L-asparaginase. J Exp Med. 1967 Jan 1;125(1):17-31. [Article]
  3. Asselin B, Rizzari C: Asparaginase pharmacokinetics and implications of therapeutic drug monitoring. Leuk Lymphoma. 2015;56(8):2273-80. doi: 10.3109/10428194.2014.1003056. Epub 2015 Mar 11. [Article]
  4. UniProtKB - V6FYV8 (V6FYV8_ECOLX): E. coli L-asparaginase, type II FASTA sequence [Link]
  5. FDA Approved Drug Products: Elspar (asparaginase) for intravenous or intramuscular injection [Link]
PubChem Substance
RxList Drug Page Drug Page
FDA label
Download (176 KB)

Clinical Trials

Clinical Trials
4CompletedTreatmentAcute Lymphobkastic Leukemia1
4CompletedTreatmentAcute Lymphoblastic Leukaemias (ALL)5
4CompletedTreatmentLeukemia, Lymphocytic, Acute, Adult5
4CompletedTreatmentLymphoblastic Lymphoma1
4Unknown StatusTreatmentAcute Lymphoblastic Leukemia (ALL)1
4Unknown StatusTreatmentPeripheral T-Cell Lymphoma (PTCL)1
3Active Not RecruitingTreatmentAcute Lymphoblastic Leukaemias (ALL) / Acute Undifferentiated Leukemia (AUL) / T-cell Childhood Acute Lymphoblastic Leukemia1
3Active Not RecruitingTreatmentAcute Lymphoblastic Leukaemias (ALL) / Adult B Lymphoblastic Lymphoma / Ann Arbor Stage I B Lymphoblastic Lymphoma / Ann Arbor Stage II B Lymphoblastic Lymphoma / B-cell Childhood Acute Lymphoblastic Leukemia / Childhood B Acute Lymphoblastic Leukemia With t(9;22)(q34.1;q11.2); BCR-ABL1 / Childhood B Lymphoblastic Lymphoma / Down Syndrome (DS) / Hypodiploid B Acute Lymphoblastic Leukemia / Philadelphia Chromosome Positive (Ph+)1
3Active Not RecruitingTreatmentAcute Lymphoblastic Leukaemias (ALL) / B Acute Lymphoblastic Leukemia, Philadelphia Chromosome Negative1
3Active Not RecruitingTreatmentAcute Myeloid Leukemia / Down Syndrome (DS) / Myelodysplastic Syndrome / Myeloid Leukemia Associated With Down Syndrome / Myeloproliferative Neoplasms (MPNs)1


Not Available
  • Lundbeck Inc.
  • Merck & Co.
  • Prescript Pharmaceuticals
Dosage Forms
Injection, powder, lyophilized, for solutionIntramuscular; Intravenous10000 [iU]/1
Injection, powder, for solutionParenteral
Powder, for solutionIntramuscular; Intravenous10000 unit / vial
Injection, powder, lyophilized, for solutionIntramuscular; Intrathecal; Intravenous10000 IU
Injection, powder, for solution
Injection, powder, lyophilized, for solutionIntravenous10000 iu
Injection, powder, for solutionIntravenous10000 iu
Powder10000 iu/1vial
InjectionIntramuscular20 mg/1mL
Injection, powder, for solutionIntravenous10000 U
Unit descriptionCostUnit
Elspar 10000 unit vial74.6USD vial
DrugBank does not sell nor buy drugs. Pricing information is supplied for informational purposes only.
Not Available


Experimental Properties
hydrophobicity0.059Not Available
isoelectric point4.67Not Available


Build, predict & validate machine-learning models
Use our structured and evidence-based datasets to unlock new
insights and accelerate drug research.
Learn more
Use our structured and evidence-based datasets to unlock new insights and accelerate drug research.
Learn more
Small molecule
Pharmacological action
  1. Overington JP, Al-Lazikani B, Hopkins AL: How many drug targets are there? Nat Rev Drug Discov. 2006 Dec;5(12):993-6. [Article]
  2. Imming P, Sinning C, Meyer A: Drugs, their targets and the nature and number of drug targets. Nat Rev Drug Discov. 2006 Oct;5(10):821-34. [Article]
  3. Wetzler M, Sanford BL, Kurtzberg J, DeOliveira D, Frankel SR, Powell BL, Kolitz JE, Bloomfield CD, Larson RA: Effective asparagine depletion with pegylated asparaginase results in improved outcomes in adult acute lymphoblastic leukemia: Cancer and Leukemia Group B Study 9511. Blood. 2007 May 15;109(10):4164-7. Epub 2007 Jan 30. [Article]
  4. Wenner KA, Vieira Pinheiro JP, Escherich G, Wessalowski R, Jorch N, Wolff J, Stehn M, Kohlschutter A, Boos J, Janka-Schaub GE: Asparagine concentration in plasma after 2,500 IU/m(2) PEG-asparaginase i.v. in children with acute lymphoblastic leukemia. Klin Padiatr. 2005 Nov-Dec;217(6):321-6. [Article]
  5. Appel IM, Pinheiro JP, den Boer ML, Lanvers C, Reniers NC, Boos J, Pieters R: Lack of asparagine depletion in the cerebrospinal fluid after one intravenous dose of PEG-asparaginase: a window study at initial diagnosis of childhood ALL. Leukemia. 2003 Nov;17(11):2254-6. [Article]


Pharmacological action
General Function
Serine-type endopeptidase inhibitor activity
Specific Function
Major thyroid hormone transport protein in serum.
Gene Name
Uniprot ID
Uniprot Name
Thyroxine-binding globulin
Molecular Weight
46324.12 Da

Drug created at June 13, 2005 13:24 / Updated at December 06, 2023 02:33