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Identification
NameExemestane
Accession NumberDB00990  (APRD00144)
TypeSmall Molecule
GroupsApproved, Investigational
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
Synonyms
6-Methyleneandrosta-1,4-diene-3,17-dione
Exemestane
Exemestano
Exemestanum
External Identifiers Not Available
Approved Prescription Products
NameDosageStrengthRouteLabellerMarketing StartMarketing End
Act Exemestanetablet25 mgoralActavis Pharma Company2012-07-26Not applicableCanada
Aromasintablet25 mg/1oralPharmacia and Upjohn Company1999-10-21Not applicableUs
Aromasintablet25 mgoralPfizer Canada Inc2000-08-17Not applicableCanada
Aromasintablet25 mg/1oralPhysicians Total Care, Inc.2005-06-29Not applicableUs
Exemestanetablet, sugar coated25 mg/1oralGreenstone LLC2011-04-01Not applicableUs
Gd-exemestanetablet25 mgoralGenmed A Division Of Pfizer Canada IncNot applicableNot applicableCanada
Med-exemestanetablet25 mgoralGeneric Medical Partners Inc2013-12-02Not applicableCanada
Mylan-exemestanetablet25 mgoralMylan Pharmaceuticals UlcNot applicableNot applicableCanada
Teva-exemestanetablet25 mgoralTeva Canada Limited2013-10-01Not applicableCanada
Approved Generic Prescription Products
NameDosageStrengthRouteLabellerMarketing StartMarketing End
Apo-exemestanetablet25 mgoralApotex Inc2014-05-01Not applicableCanada
Exemestanetablet, film coated25 mg/1oralRoxane Laboratories, Inc2011-04-01Not applicableUs
Exemestanetablet25 mg/1oralAmerican Health Packaging2015-03-31Not applicableUs
Exemestanetablet25 mg/1oralAlvogen Inc.2014-07-25Not applicableUs
Approved Over the Counter ProductsNot Available
Unapproved/Other Products Not Available
International Brands
NameCompany
ExemestanceNot Available
Brand mixturesNot Available
SaltsNot Available
Categories
UNIINY22HMQ4BX
CAS number107868-30-4
WeightAverage: 296.4034
Monoisotopic: 296.177630012
Chemical FormulaC20H24O2
InChI KeyInChIKey=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
IUPAC Name
(1S,2R,10R,11S,15S)-2,15-dimethyl-8-methylidenetetracyclo[8.7.0.0²,⁷.0¹¹,¹⁵]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
Taxonomy
DescriptionThis compound belongs to the class of organic compounds known as androgens and derivatives. These are 3-hydroxylated C19 steroid hormones. They are known to favor the development of masculine characteristics. They also show profound effects on scalp and body hair in humans.
KingdomOrganic compounds
Super ClassLipids and lipid-like molecules
ClassSteroids and steroid derivatives
Sub ClassAndrostane steroids
Direct ParentAndrogens and derivatives
Alternative Parents
Substituents
  • Androgen-skeleton
  • Oxosteroid
  • 17-oxosteroid
  • 3-oxosteroid
  • 3-oxo-delta-1,4-steroid
  • Delta-1,4-steroid
  • Cyclic ketone
  • Ketone
  • Hydrocarbon derivative
  • Organooxygen compound
  • Carbonyl group
  • Aliphatic homopolycyclic compound
Molecular FrameworkAliphatic homopolycyclic compounds
External Descriptors
Pharmacology
IndicationFor the treatment of advanced breast cancer in postmenopausal women whose disease has progressed following tamoxifen therapy.
PharmacodynamicsAromatase 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 actionBreast 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.
Related Articles
Absorption42%
Volume of distributionNot Available
Protein binding90% (mainly α1-acid glycoprotein and albumin)
Metabolism

Hepatic

Route of eliminationNot Available
Half life24 hours
ClearanceNot Available
ToxicityConvulsions
Affected organisms
  • Humans and other mammals
PathwaysNot Available
SNP Mediated EffectsNot Available
SNP Mediated Adverse Drug ReactionsNot Available
ADMET
Predicted ADMET features
PropertyValueProbability
Human Intestinal Absorption+1.0
Blood Brain Barrier+0.9778
Caco-2 permeable+0.7992
P-glycoprotein substrateSubstrate0.5589
P-glycoprotein inhibitor IInhibitor0.8974
P-glycoprotein inhibitor IINon-inhibitor0.6749
Renal organic cation transporterNon-inhibitor0.6499
CYP450 2C9 substrateNon-substrate0.8764
CYP450 2D6 substrateNon-substrate0.9115
CYP450 3A4 substrateSubstrate0.7167
CYP450 1A2 substrateNon-inhibitor0.8552
CYP450 2C9 inhibitorNon-inhibitor0.9224
CYP450 2D6 inhibitorNon-inhibitor0.9373
CYP450 2C19 inhibitorNon-inhibitor0.751
CYP450 3A4 inhibitorNon-inhibitor0.8309
CYP450 inhibitory promiscuityLow CYP Inhibitory Promiscuity0.8276
Ames testNon AMES toxic0.9483
CarcinogenicityNon-carcinogens0.9245
BiodegradationNot ready biodegradable0.9539
Rat acute toxicity1.7582 LD50, mol/kg Not applicable
hERG inhibition (predictor I)Weak inhibitor0.76
hERG inhibition (predictor II)Non-inhibitor0.7791
ADMET data is predicted using admetSAR, a free tool for evaluating chemical ADMET properties. (23092397 )
Pharmacoeconomics
Manufacturers
  • Pharmacia and upjohn co
Packagers
Dosage forms
FormRouteStrength
Tabletoral25 mg/1
Tabletoral25 mg
Tablet, film coatedoral25 mg/1
Tablet, sugar coatedoral25 mg/1
Prices
Unit descriptionCostUnit
Aromasin 25 mg tablet13.77USD tablet
DrugBank does not sell nor buy drugs. Pricing information is supplied for informational purposes only.
Patents
Patent NumberPediatric ExtensionApprovedExpires (estimated)
CA2409059 No2006-04-182021-04-25Canada
US4808616 No1994-04-012011-04-01Us
Properties
StateSolid
Experimental Properties
PropertyValueSource
melting point155.13 °CNot Available
water solubilityNon-solubleNot Available
logP3.7Not Available
Predicted Properties
PropertyValueSource
Water Solubility0.00683 mg/mLALOGPS
logP2.67ALOGPS
logP3.87ChemAxon
logS-4.6ALOGPS
pKa (Strongest Acidic)19.96ChemAxon
pKa (Strongest Basic)-5ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count2ChemAxon
Hydrogen Donor Count0ChemAxon
Polar Surface Area34.14 Å2ChemAxon
Rotatable Bond Count0ChemAxon
Refractivity89.03 m3·mol-1ChemAxon
Polarizability33.71 Å3ChemAxon
Number of Rings4ChemAxon
Bioavailability1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
Spectra
Mass Spec (NIST)Not Available
SpectraNot Available
References
Synthesis Reference

Kevin Kunnen, Nathan W. Stehle, Scot W. Weis, John M. Pascone, Richard J. Pariza, Scott G. Van Ornum, Paul Zizelman, “Exemestane and Its Intermediates and Methods of Making the Same.” U.S. Patent US20080234505, issued September 25, 2008.

US20080234505
General References
  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:17307102 ]
  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:19436613 ]
  3. Untch M, Jackisch C: Exemestane in early breast cancer: a review. Ther Clin Risk Manag. 2008 Dec;4(6):1295-304. [PubMed:19337436 ]
  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:20360896 ]
  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:18728707 ]
External Links
ATC CodesL02BG06
AHFS Codes
  • 10:00.00
PDB EntriesNot Available
FDA labelDownload (74.6 KB)
MSDSNot Available
Interactions
Drug Interactions
Drug
AripiprazoleThe serum concentration of Aripiprazole can be decreased when it is combined with Exemestane.
BexaroteneThe serum concentration of Exemestane can be decreased when it is combined with Bexarotene.
BosentanThe serum concentration of Exemestane can be decreased when it is combined with Bosentan.
CarbamazepineThe serum concentration of Exemestane can be decreased when it is combined with Carbamazepine.
ChlorotrianiseneThe therapeutic efficacy of Exemestane can be decreased when used in combination with Chlorotrianisene.
DabrafenibThe serum concentration of Exemestane can be decreased when it is combined with Dabrafenib.
DeferasiroxThe serum concentration of Exemestane can be decreased when it is combined with Deferasirox.
EnzalutamideThe serum concentration of Exemestane can be decreased when it is combined with Enzalutamide.
EstradiolThe therapeutic efficacy of Exemestane can be decreased when used in combination with Estradiol.
Estrone sulfateThe therapeutic efficacy of Exemestane can be decreased when used in combination with Estropipate.
FosphenytoinThe serum concentration of Exemestane can be decreased when it is combined with Fosphenytoin.
HydrocodoneThe serum concentration of Hydrocodone can be decreased when it is combined with Exemestane.
MethadoneThe serum concentration of Methadone can be increased when it is combined with Exemestane.
MitotaneThe serum concentration of Exemestane can be decreased when it is combined with Mitotane.
NimodipineThe serum concentration of Nimodipine can be decreased when it is combined with Exemestane.
PhenobarbitalThe serum concentration of Exemestane can be decreased when it is combined with Phenobarbital.
PhenytoinThe serum concentration of Exemestane can be decreased when it is combined with Phenytoin.
PrimidoneThe serum concentration of Exemestane can be decreased when it is combined with Primidone.
RifabutinThe serum concentration of Exemestane can be decreased when it is combined with Rifabutin.
RifampicinThe serum concentration of Exemestane can be decreased when it is combined with Rifampicin.
RifapentineThe serum concentration of Exemestane can be decreased when it is combined with Rifapentine.
SaxagliptinThe serum concentration of Saxagliptin can be decreased when it is combined with Exemestane.
SiltuximabThe serum concentration of Exemestane can be decreased when it is combined with Siltuximab.
St. John's WortThe serum concentration of Exemestane can be decreased when it is combined with St. John's Wort.
TocilizumabThe serum concentration of Exemestane can be decreased when it is combined with Tocilizumab.
Food Interactions
  • High-fat meals increase plasma exemestane concentrations by approximately 40%.

Targets

Kind
Protein
Organism
Human
Pharmacological action
yes
Actions
inhibitor
General Function:
Oxygen binding
Specific Function:
Catalyzes the formation of aromatic C18 estrogens from C19 androgens.
Gene Name:
CYP19A1
Uniprot ID:
P11511
Molecular Weight:
57882.48 Da
References
  1. Chen X, Ji ZL, Chen YZ: TTD: Therapeutic Target Database. Nucleic Acids Res. 2002 Jan 1;30(1):412-5. [PubMed:11752352 ]
  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. doi: 10.1186/1476-4598-8-109. [PubMed:19930708 ]
  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:19436613 ]
  4. Untch M, Jackisch C: Exemestane in early breast cancer: a review. Ther Clin Risk Manag. 2008 Dec;4(6):1295-304. [PubMed:19337436 ]
  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. doi: 10.1038/sj.bjc.6604868. Epub 2009 Jan 20. [PubMed:19156139 ]
  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:20360896 ]
  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:18728707 ]
  8. Brueggemeier RW: Update on the use of aromatase inhibitors in breast cancer. Expert Opin Pharmacother. 2006 Oct;7(14):1919-30. [PubMed:17020418 ]
  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:15814851 ]

Enzymes

Kind
Protein
Organism
Human
Pharmacological action
unknown
Actions
substrate
General Function:
Vitamin d3 25-hydroxylase activity
Specific Function:
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 xenobiot...
Gene Name:
CYP3A4
Uniprot ID:
P08684
Molecular Weight:
57342.67 Da
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:19436613 ]
  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. doi: 10.1093/nar/gkp970. Epub 2009 Nov 24. [PubMed:19934256 ]
Kind
Protein
Organism
Human
Pharmacological action
unknown
Actions
inhibitor
General Function:
Oxygen binding
Specific Function:
Catalyzes the formation of aromatic C18 estrogens from C19 androgens.
Gene Name:
CYP19A1
Uniprot ID:
P11511
Molecular Weight:
57882.48 Da
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. doi: 10.1093/nar/gkp970. Epub 2009 Nov 24. [PubMed:19934256 ]
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Drug created on June 13, 2005 07:24 / Updated on September 16, 2013 17:12