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Identification
Name Exemestane
Accession Number DB00990 (APRD00144)
Type small molecule
Groups approved
Description

Exemestane is an oral steroidal aromatase inhibitor used in the adjuvant treatment of hormonally-responsive (also called hormone-receptor-positive, estrogen-responsive) breast cancer in postmenopausal women. It acts as a false substrate for the aromatase enzyme, and is processed to an intermediate that binds irreversibly to the active site of the enzyme causing its inactivation.
Structure Thumb
Download: MOL | SDF | SMILES | InChI
Display: 2D Structure | 3D Structure
Synonyms
  • exemestane
  • Exemestano [INN-Spanish]
  • Exemestanum [INN-Latin]
Brand names
  • Aromasin
  • Exemestance
Brand name mixtures Not Available
Categories
  • Antineoplastic Agents
  • Aromatase Inhibitors
CAS number 107868-30-4
Weight Average: 296.4034
Monoisotopic: 296.177630012
Chemical Formula C20H24O2
InChI Key InChIKey=BFYIZQONLCFLEV-DAELLWKTSA-N
InChI
InChI=1S/C20H24O2/c1-12-10-14-15-4-5-18(22)20(15,3)9-7-16(14)19(2)8-6-13(21)11-17(12)19/h6,8,11,14-16H,1,4-5,7,9-10H2,2-3H3/t14-,15-,16-,19+,20-/m0/s1
Plain Text
IUPAC Name
(1S,2R,10R,11S,15S)-2,15-dimethyl-8-methylidenetetracyclo[8.7.0.0^{2,7}.0^{11,15}]heptadeca-3,6-diene-5,14-dione
SMILES
[H][C@@]12CCC(=O)[C@@]1(C)CC[C@@]1([H])[C@@]2([H])CC(=C)C2=CC(=O)C=C[C@]12C
Plain Text
Mass Spec Not Available
Taxonomy
Kingdom Organic
Classes
  • Steroids and Steroid Derivatives
Substructures
  • Steroids and Steroid Derivatives
  • Carbonyl Compounds
  • Alkanes and Alkenes
  • Isoprenes
  • Ketones
Pharmacology
Indication For the treatment of advanced breast cancer in postmenopausal women whose disease has progressed following tamoxifen therapy.
Pharmacodynamics Aromatase is an enzyme that converts hormones to estrogen in the body's adrenal glands. The aromatase inhibitors (AIs) are drugs that reduce estrogen levels by blocking the action of aromatase in the adrenal glands. The selective AIs (SAIs) selectively reduce levels of estrogen without interfering with levels of other steroid hormones that are produced by the adrenal gland. Drugs in this class include anastrozole (Arimidex ™), letrozole (Femara ™) and exemestane (Aromasin ™).
Mechanism of action Breast cancer cell growth may be estrogen-dependent. Aromatase (exemestane) is the principal enzyme that converts androgens to estrogens both in pre- and postmenopausal women. While the main source of estrogen (primarily estradiol) is the ovary in premenopausal women, the principal source of circulating estrogens in postmenopausal women is from conversion of adrenal and ovarian androgens (androstenedione and testosterone) to estrogens (estrone and estradiol) by the aromatase enzyme in peripheral tissues. Estrogen deprivation through aromatase inhibition is an effective and selective treatment for some postmenopausal patients with hormone-dependent breast cancer. Exemestane is an irreversible, steroidal aromatase inactivator, structurally related to the natural substrate androstenedione. It acts as a false substrate for the aromatase enzyme, and is processed to an intermediate that binds irreversibly to the active site of the enzyme causing its inactivation, an effect also known as "suicide inhibition". Exemestane significantly lowers circulating estrogen concentrations in postmenopausal women, but has no detectable effect on the adrenal biosynthesis of corticosteroids or aldosterone. This reduction in serum and tumor concentrations of estrogen delays tumor growth and disease progression. Exemestane has no effect on other enzymes involved in the steroidogenic pathway up to a concentration at least 600 times higher than that inhibiting the aromatase enzyme.
Absorption 42%
Volume of distribution Not Available
Protein binding 90% (mainly α1-acid glycoprotein and albumin)
Metabolism

Hepatic
Route of elimination Not Available
Half life 24 hours
Clearance Not Available
Toxicity Convulsions
Affected organisms
  • Humans and other mammals
Pathways Not Available
Pharmacoeconomics
Manufacturers
  • Pharmacia and upjohn co
Packagers
Dosage forms
Form Route Strength
Tablet Oral
Prices
Unit description Cost Unit
Aromasin 25 mg tablet 13.77 USD tablet
Patents
Country Patent Number Approved Expires
United States 4808616 1994-04-01 2011-04-01
Canada 2409059 2006-04-18 2021-04-25
Properties
State solid
Melting point 155.13oC
Experimental Properties
Property Value Source
water solubility Non-soluble PhysProp
logP 3.7 PhysProp
Predicted Properties
Property Value Source
water solubility 6.83e-03 g/l ALOGPS
logP 2.67 ALOGPS
logP 3.87 ChemAxon Molconvert
logS -4.64 ALOGPS
pKa ChemAxon Molconvert
hydrogen acceptor count 2 ChemAxon Molconvert
hydrogen donor count 0 ChemAxon Molconvert
polar surface area 34.14 ChemAxon Molconvert
rotatable bond count 0 ChemAxon Molconvert
refractivity 89.03 ChemAxon Molconvert
polarizability 33.71 ChemAxon Molconvert
References
Synthesis Reference Not Available
General Reference
  1. Coombes RC, Kilburn LS, Snowdon CF, Paridaens R, Coleman RE, Jones SE, Jassem J, Van de Velde CJ, Delozier T, Alvarez I, Del Mastro L, Ortmann O, Diedrich K, Coates AS, Bajetta E, Holmberg SB, Dodwell D, Mickiewicz E, Andersen J, Lonning PE, Cocconi G, Forbes J, Castiglione M, Stuart N, Stewart A, Fallowfield LJ, Bertelli G, Hall E, Bogle RG, Carpentieri M, Colajori E, Subar M, Ireland E, Bliss JM: Survival and safety of exemestane versus tamoxifen after 2-3 years’ tamoxifen treatment (Intergroup Exemestane Study): a randomised controlled trial. Lancet. 2007 Feb 17;369(9561):559-70. Pubmed
  2. Robinson A: A review of the use of exemestane in early breast cancer. Ther Clin Risk Manag. 2009 Feb;5(1):91-8. Epub 2009 Mar 26. Pubmed
  3. Untch M, Jackisch C: Exemestane in early breast cancer: a review. Ther Clin Risk Manag. 2008 Dec;4(6):1295-304. Pubmed
  4. Abrial C, Durando X, Mouret-Reynier MA, Thivat E, Bayet-Robert M, Nayl B, Dubray P, Pomel C, Chollet P, Penault-Llorca F: Role of neo-adjuvant hormonal therapy in the treatment of breast cancer: a review of clinical trials. Int J Gen Med. 2009 Jul 30;2:129-40. Pubmed
  5. Nabholtz JM: Long-term safety of aromatase inhibitors in the treatment of breast cancer. Ther Clin Risk Manag. 2008 Feb;4(1):189-204. Pubmed
External Links
Resource Link
KEGG Drug D00963 Link_out
KEGG Compound C08162 Link_out
PubChem Compound 60198 Link_out
PubChem Substance 46508243 Link_out
ChemSpider 54278 Link_out
ChEBI 4953 Link_out
ChEMBL 4953 Link_out
Therapeutic Targets Database DAP000625 Link_out
Drug Product Database 2242705 Link_out
RxList http://www.rxlist.com/cgi/generic3/exemest.htm Link_out
Drugs.com http://www.drugs.com/cdi/exemestane.html Link_out
Wikipedia http://en.wikipedia.org/wiki/Exemestane Link_out
ATC Codes
  • L02BG06
AHFS Codes
  • 10:00.00
PDB Entries Not Available
FDA label show (74.6 KB)
MSDS Not Available
Interactions
Drug Interactions
Drug Interaction
Food Interactions
  • High-fat meals increase plasma exemestane concentrations by approximately 40%.
Targets

1. Cytochrome P450 19A1

Pharmacological action: yes
Actions: inhibitor

Catalyzes the formation of aromatic C18 estrogens from C19 androgens

Organism class: human
UniProt ID: P11511 Link_out
Gene: CYP19A1 Link_out
Protein Sequence: FASTA
Gene Sequence: FASTA
SNPs: SNPJam Report Link_out

References:
  1. Chen X, Ji ZL, Chen YZ: TTD: Therapeutic Target Database. Nucleic Acids Res. 2002 Jan 1;30(1):412-5. Pubmed
  2. Koutras A, Giannopoulou E, Kritikou I, Antonacopoulou A, Evans TR, Papavassiliou AG, Kalofonos H: Antiproliferative effect of exemestane in lung cancer cells. Mol Cancer. 2009 Nov 24;8:109. Pubmed
  3. Robinson A: A review of the use of exemestane in early breast cancer. Ther Clin Risk Manag. 2009 Feb;5(1):91-8. Epub 2009 Mar 26. Pubmed
  4. Untch M, Jackisch C: Exemestane in early breast cancer: a review. Ther Clin Risk Manag. 2008 Dec;4(6):1295-304. Pubmed
  5. Barnadas A, Gil M, Gonzalez S, Tusquets I, Munoz M, Arcusa A, Prieto L, Margeli-Vila M, Moreno A: Exemestane as primary treatment of oestrogen receptor-positive breast cancer in postmenopausal women: a phase II trial. Br J Cancer. 2009 Feb 10;100(3):442-9. Epub 2009 Jan 20. Pubmed
  6. Abrial C, Durando X, Mouret-Reynier MA, Thivat E, Bayet-Robert M, Nayl B, Dubray P, Pomel C, Chollet P, Penault-Llorca F: Role of neo-adjuvant hormonal therapy in the treatment of breast cancer: a review of clinical trials. Int J Gen Med. 2009 Jul 30;2:129-40. Pubmed
  7. Nabholtz JM: Long-term safety of aromatase inhibitors in the treatment of breast cancer. Ther Clin Risk Manag. 2008 Feb;4(1):189-204. Pubmed
  8. Brueggemeier RW: Update on the use of aromatase inhibitors in breast cancer. Expert Opin Pharmacother. 2006 Oct;7(14):1919-30. Pubmed
  9. Brueggemeier RW, Hackett JC, Diaz-Cruz ES: Aromatase inhibitors in the treatment of breast cancer. Endocr Rev. 2005 May;26(3):331-45. Epub 2005 Apr 6. Pubmed
Enzymes

1. Cytochrome P450 3A4

Actions: substrate

Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway. It performs a variety of oxidation reactions (e.g. caffeine 8-oxidation, omeprazole sulphoxidation, midazolam 1'-hydroxylation and midazolam 4- hydroxylation) of structurally unrelated compounds, including steroids, fatty acids, and xenobiotics. The enzyme also hydroxylates etoposide

UniProt ID: P08684 Link_out
Gene: CYP3A4
Protein Sequence: FASTA
Gene Sequence: FASTA
SNPs: SNPJam Report Link_out

References:
  1. Robinson A: A review of the use of exemestane in early breast cancer. Ther Clin Risk Manag. 2009 Feb;5(1):91-8. Epub 2009 Mar 26. Pubmed
  2. Preissner S, Kroll K, Dunkel M, Senger C, Goldsobel G, Kuzman D, Guenther S, Winnenburg R, Schroeder M, Preissner R: SuperCYP: a comprehensive database on Cytochrome P450 enzymes including a tool for analysis of CYP-drug interactions. Nucleic Acids Res. 2010 Jan;38(Database issue):D237-43. Epub 2009 Nov 24. Pubmed

2. Cytochrome P450 19A1

Actions: inhibitor

Catalyzes the formation of aromatic C18 estrogens from C19 androgens

UniProt ID: P11511 Link_out
Gene: CYP19A1 Link_out
Protein Sequence: FASTA
Gene Sequence: FASTA
SNPs: SNPJam Report Link_out

References:
  1. Preissner S, Kroll K, Dunkel M, Senger C, Goldsobel G, Kuzman D, Guenther S, Winnenburg R, Schroeder M, Preissner R: SuperCYP: a comprehensive database on Cytochrome P450 enzymes including a tool for analysis of CYP-drug interactions. Nucleic Acids Res. 2010 Jan;38(Database issue):D237-43. Epub 2009 Nov 24. Pubmed
Comments
Drug created on June 13, 2005 07:24 / Updated on April 19, 2011 15:07

This project is supported by Genome Alberta & Genome Canada, a not-for-profit organization that is leading Canada's national genomics strategy with $600 million in funding from the federal government. This project is also supported in part by GenomeQuest, Inc., an enterprise genomic information company serving the life science community.