Identification

Name
Letrozole
Accession Number
DB01006  (APRD01066)
Type
Small Molecule
Groups
Approved, Investigational
Description

Letrozole, or CGS 20267, is an oral non-steroidal type II aromatase inhibitor first described in the literature in 1990.1,5,8,9 It is a third generation aromatase inhibitor like exemestane and anastrozole, meaning it does not significantly affect cortisol, aldosterone, and thyroxine.2

Letrozole was granted FDA approval on 25 July 1997.8

Structure
Thumb
Synonyms
  • Letrozol
  • Letrozole
External IDs
CGS 20267 / CGS-20267
Product Images
Prescription Products
NameDosageStrengthRouteLabellerMarketing StartMarketing End
Co LetrozoleTabletOralCobalt LaboratoriesNot applicableNot applicableCanada
FemaraTablet, film coated2.5 mg/1OralNovartis Pharmaceuticals Corporation1997-07-31Not applicableUs
FemaraTablet, film coated2.5 mg/1OralPhysicians Total Care, Inc.2005-02-10Not applicableUs
Femara 2.5mgTabletOralNovartis1997-09-02Not applicableCanada
LetrozoleTabletOralMeliapharm Inc2011-08-292014-06-25Canada
LetrozoleTabletOralTEVA Canada Limited2010-04-282013-12-10Canada
LetrozoleTabletOralPro Doc Limitee2013-02-14Not applicableCanada
LetrozoleTabletOralActavis Pharma Company2010-04-282018-06-18Canada
Letrozole SunTabletOralTaro Pharmaceuticals, Inc.Not applicableNot applicableCanada
Letrozole TabletsTabletOralFresenius KabiNot applicableNot applicableCanada
Additional Data Available
  • Application Number
    Application Number

    A unique ID assigned by the FDA when a product is submitted for approval by the labeller.

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  • Product Code
    Product Code

    A governmentally-recognized ID which uniquely identifies the product within its regulatory market.

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Generic Prescription Products
NameDosageStrengthRouteLabellerMarketing StartMarketing End
Accel-letrozole Tablets USPTabletOralAccel Pharma IncNot applicableNot applicableCanada
Ach-letrozoleTabletOralAccord Healthcare Inc2010-05-03Not applicableCanada
Ag-letrozoleTabletOralAngita Pharma Inc.Not applicableNot applicableCanada
Apo-letrozoleTabletOralApotex Corporation2012-06-11Not applicableCanada
Auro-letrozoleTabletOralAuro Pharma Inc2013-06-122015-04-24Canada
Bio-letrozoleTabletOralBiomed Pharma2013-02-12Not applicableCanada
Ccp-letrozoleTabletOralCellchem Pharmaceuticals Inc.2017-07-24Not applicableCanada
Dom-letrozoleTabletOralDominion PharmacalNot applicableNot applicableCanada
Ipg-letrozoleTabletOralMarcan Pharmaceuticals IncNot applicableNot applicableCanada
Jamp-letrozoleTabletOralJamp Pharma Corporation2011-09-30Not applicableCanada
Additional Data Available
  • Application Number
    Application Number

    A unique ID assigned by the FDA when a product is submitted for approval by the labeller.

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  • Product Code
    Product Code

    A governmentally-recognized ID which uniquely identifies the product within its regulatory market.

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Mixture Products
NameIngredientsDosageRouteLabellerMarketing StartMarketing End
Kisqali Femara Co-packLetrozole (2.5 mg/1) + Ribociclib (200 mg/1)OralNovartis Pharmaceuticals Corporation2017-05-04Not applicableUs
Kisqali Femara Co-packLetrozole (2.5 mg/1) + Ribociclib (200 mg/1)OralNovartis Pharmaceuticals Corporation2017-05-04Not applicableUs
Kisqali Femara Co-packLetrozole (2.5 mg/1) + Ribociclib (200 mg/1)OralNovartis Pharmaceuticals Corporation2017-05-04Not applicableUs
Categories
UNII
7LKK855W8I
CAS number
112809-51-5
Weight
Average: 285.3027
Monoisotopic: 285.101445377
Chemical Formula
C17H11N5
InChI Key
HPJKCIUCZWXJDR-UHFFFAOYSA-N
InChI
InChI=1S/C17H11N5/c18-9-13-1-5-15(6-2-13)17(22-12-20-11-21-22)16-7-3-14(10-19)4-8-16/h1-8,11-12,17H
IUPAC Name
4-[(4-cyanophenyl)(1H-1,2,4-triazol-1-yl)methyl]benzonitrile
SMILES
N#CC1=CC=C(C=C1)C(N1C=NC=N1)C1=CC=C(C=C1)C#N

Pharmacology

Indication

Letrozole is indicated to treat postmenopausal women with hormone receptor (HR) positive early breast cancer, postmenopausal women with early breast cancer who have periviously been treated with tamoxifen, and postmenopausal women with HR+ or unknown advanced breast cancer.8 Letrozole, given with ribociclib, is indicated to treat pre, peri, and postmenopausal women with HR+ and human epidermal growth factor 2 (HER2) negative advanced or metastatic breast cancer.9

Associated Conditions
Pharmacodynamics

Letrozole is an aromatase inhibitor used in the treatment of breast cancer. Aromatase inhibitors work by inhibiting the action of the enzyme aromatase, which converts androgens into estrogens by a process called aromatization. As breast tissue is stimulated by estrogens, decreasing their production is a way of suppressing recurrence of the breast tumor tissue.

Letrozole is a third generation type II aromatase inhibitor used to treat estrogen dependant breast cancers.8 It has a long duration of action as it has a half life of over 42 hours in breast cancer patients.2,4,8 Patients should be counselled regarding the risk of interstitial lung disease, pneumonitis, QT prolongation, elevated transaminase levels, neutropenia, and embryo-fetal toxicity.8

Mechanism of action

Letrozole is a non-steroidal type II aromatase inhibitor.5 It blocks the active site, and therefore the electron transfer chain of CYP19A1.5 This competitive inhibition prevents the conversion of androgens to estrogen.5 This action leads to a reduction in uterine weight and elevated leuteinizing hormone.8 In postmenopausal women, the action of aromatase is responsible for the majority of estrogen production.8 With reduced availability of estrogen, estrogen-dependant tumors regress.8 Third generation aromatase inhibitors do not significantly affect cortisol, aldosterone, and thyroxine levels.2

TargetActionsOrganism
ACytochrome P450 19A1
antagonist
Humans
Additional Data Available
Adverse Effects

Comprehensive structured data on known drug adverse effects with statistical prevalence. MedDRA and ICD10 ids are provided for adverse effect conditions and symptoms.

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Additional Data Available
Contraindications

Structured data covering drug contraindications. Each contraindication describes a scenario in which the drug is not to be used. Includes restrictions on co-administration, contraindicated populations, and more.

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Additional Data Available
Blackbox Warnings

Structured data representing warnings from the black box section of drug labels. These warnings cover important and dangerous risks, contraindications, or adverse effects.

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Absorption

Letrozole is 99.9% orally bioavailable.2 A 2.5mg oral dose reaches a Cmax of 104nmol/L with a Tmax of 8.10h, and an AUC of 7387nmol*h/L.4

Volume of distribution

The volume of distribution of letrozole is 1.87L/kg.2

Protein binding

Letrozole is 60% bound to proteins.2,4 55% is bound to albumin.2

Metabolism

Letrozole is metabolized by CYP2A6 to a ketone analog metabolite, which is further metabolized by CYP3A4 and CYP2A6 to 4,4'-(hydroxymethylene)dibenzonitrile.[A33288] 4,4'-(hydroxymethylene)dibenzonitrile is glucuronidated by UGT2B7.3

Route of elimination

Letrozole is 90% eliminated in the urine.8 75% of the dose is recovered as a glucuronide metabolite, 9% is in the form of the ketone and carbinol metabolites, and 6% is recovered in urine as unchanged letrozole.8

Half life

The terminal elimination half life of letrozole is approximately 42h in healthy volunteers, but longer in breast cancer patients.2,4,8

Clearance

The average clearance after a single dose of letrozole was 1.52L/h and at steady state was 1.20L/h.4

Toxicity

Overdose data in humans is not readily available, however 1 reported case was not associated with serious adverse reactions.8 Animal studies do not report serious adverse effects with high dose treatment.6 Patients experiencing and overdose should be treated with symptomatic and supportive measures.8

Oral doses over 2000mg/kg were associated with reduced motor activity, ataxia, dyspnea, and death in mice and rats.8

Affected organisms
  • Humans and other mammals
Pathways
Not Available
Pharmacogenomic Effects/ADRs
Not Available

Interactions

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.
DrugInteraction
(R)-warfarinThe metabolism of (R)-warfarin can be decreased when combined with Letrozole.
(S)-WarfarinThe metabolism of (S)-Warfarin can be decreased when combined with Letrozole.
AbataceptThe metabolism of Letrozole can be increased when combined with Abatacept.
AcenocoumarolThe metabolism of Acenocoumarol can be decreased when combined with Letrozole.
AcetaminophenThe metabolism of Acetaminophen can be decreased when combined with Letrozole.
AcipimoxThe risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Letrozole is combined with Acipimox.
AdalimumabThe metabolism of Letrozole can be increased when combined with Adalimumab.
AfelimomabThe metabolism of Letrozole can be increased when combined with Afelimomab.
AlbendazoleThe metabolism of Albendazole can be decreased when combined with Letrozole.
Alendronic acidThe risk or severity of myopathy, rhabdomyolysis, and myoglobinuria can be increased when Alendronic acid is combined with Letrozole.
Additional Data Available
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    Extended Description

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  • Severity
    Severity

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Food Interactions
  • Take with or without food. Food slows absorption without decreasing the quantity absorbed.

References

Synthesis Reference

Peter MacDonald, Ettore Bigatti, Pierluigi Rossetto, Zvi Harel, "Process for the preparation of letrozole." U.S. Patent US20070066831, issued March 22, 2007.

US20070066831
General References
  1. Bhatnagar AS, Hausler A, Schieweck K, Lang M, Bowman R: Highly selective inhibition of estrogen biosynthesis by CGS 20267, a new non-steroidal aromatase inhibitor. J Steroid Biochem Mol Biol. 1990 Dec 20;37(6):1021-7. doi: 10.1016/0960-0760(90)90460-3. [PubMed:2149502]
  2. Bhatnagar AS: The discovery and mechanism of action of letrozole. Breast Cancer Res Treat. 2007;105 Suppl 1:7-17. doi: 10.1007/s10549-007-9696-3. Epub 2007 Oct 3. [PubMed:17912633]
  3. Precht JC, Schroth W, Klein K, Brauch H, Krynetskiy E, Schwab M, Murdter TE: The letrozole phase 1 metabolite carbinol as a novel probe drug for UGT2B7. Drug Metab Dispos. 2013 Nov;41(11):1906-13. doi: 10.1124/dmd.113.053405. Epub 2013 Aug 21. [PubMed:23965986]
  4. Pfister CU, Martoni A, Zamagni C, Lelli G, De Braud F, Souppart C, Duval M, Hornberger U: Effect of age and single versus multiple dose pharmacokinetics of letrozole (Femara) in breast cancer patients. Biopharm Drug Dispos. 2001 Jul;22(5):191-7. doi: 10.1002/bdd.273. [PubMed:11745921]
  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]
  6. Schieweck K, Bhatnagar AS, Batzl C, Lang M: Anti-tumor and endocrine effects of non-steroidal aromatase inhibitors on estrogen-dependent rat mammary tumors. J Steroid Biochem Mol Biol. 1993 Mar;44(4-6):633-6. doi: 10.1016/0960-0760(93)90270-7. [PubMed:8476774]
  7. Dave N, Chow LM, Gudelsky GA, LaSance K, Qi X, Desai PB: Preclinical pharmacological evaluation of letrozole as a novel treatment for gliomas. Mol Cancer Ther. 2015 Apr;14(4):857-64. doi: 10.1158/1535-7163.MCT-14-0743. Epub 2015 Feb 18. [PubMed:25695958]
  8. FDA Approved Drug Products: Femara Letrozole Oral Tablets [Link]
  9. FDA Approved Drug Products: Kisquali Femara Co-Pack Letrozole and Ribociclib Succinate Oral Tablets [Link]
External Links
Human Metabolome Database
HMDB0015141
KEGG Drug
D00964
KEGG Compound
C08163
PubChem Compound
3902
PubChem Substance
46504610
ChemSpider
3765
BindingDB
13061
RxNav
72965
ChEBI
6413
ChEMBL
CHEMBL1444
ZINC
ZINC000003778874
Therapeutic Targets Database
DAP000626
PharmGKB
PA450196
RxList
RxList Drug Page
Drugs.com
Drugs.com Drug Page
Wikipedia
Letrozole
ATC Codes
L02BG04 — Letrozole
AHFS Codes
  • 10:00.00 — Antineoplastic Agents
FDA label
Download (112 KB)

Clinical Trials

Clinical Trials
PhaseStatusPurposeConditionsCount
0CompletedBasic ScienceBreast Cancer1
0CompletedTreatmentInfertility / Polycystic Ovaries Syndrome2
0Not Yet RecruitingScreeningInfertility1
0RecruitingBasic ScienceBreast Cancer1
0RecruitingBasic ScienceNeoplasms, Brain1
0RecruitingBasic ScienceOvarian Cancer1
0RecruitingTreatmentBreast Cancer2
0RecruitingTreatmentEndometrial Endometrioid Adenocarcinoma1
0RecruitingTreatmentEstrogen Receptor Positive Breast Cancer / Estrogen Receptor-Positive Breast Cancer1
0RecruitingTreatmentMalignant Neoplasm of Female Breast1
0TerminatedTreatmentBreast Cancer1
1Active Not RecruitingOtherAdvanced Breast Cancer1
1Active Not RecruitingTreatmentAdvanced Malignant Solid Neoplasm / Breast Cancer / Estrogen Receptor Positive / HER2/Neu Positive / One to five years postmenopausal / Premenopausal / Progesterone Receptor Positive / Recurrent Breast Carcinoma / Refractory Breast Carcinoma / Refractory Hormone Receptor Positive Breast Carcinoma / Stage IIIA Breast Cancer AJCC v7 / Stage IIIB Breast Cancer AJCC v7 / Stage IIIC Breast Cancer AJCC v7 / Stage IV Breast Cancer AJCC v6 and v7 / Tumors, Solid1
1Active Not RecruitingTreatmentBreast Cancer1
1Active Not RecruitingTreatmentCancer, Advanced / Lung Cancer Non-Small Cell Cancer (NSCLC) / Mesothelioma, Malignant / Metastatic Breast Cancer / Metastatic Cancers / Non-Hodgkin's Lymphoma (NHL)1
1Active Not RecruitingTreatmentEstrogen Receptor Positive Breast Cancer / Estrogen Receptor-Positive Breast Cancer / HER2 Negative Breast Cancer / HER2-Negative Breast Cancer / Invasive Ductal Breast Carcinoma / Progesterone Receptor Positive Breast Cancer / Progesterone Receptor-positive Breast Cancer / Recurrent Breast Cancer / Stage IV Breast Cancer1
1Active Not RecruitingTreatmentHormone Receptor Positive, HER2-negative, Advanced Breast Cancer1
1Active Not RecruitingTreatmentNeoplasms, Breast1
1Active Not RecruitingTreatmentNon-Hodgkin's Lymphoma (NHL) / Solid Cancers1
1CompletedNot AvailableHealthy Volunteers2
1CompletedBasic ScienceTumors, Solid1
1CompletedOtherAdvanced or Metastatic Breast Cancer1
1CompletedPreventionHealthy, no Evidence of Disease / Lobular Breast Carcinoma In Situ1
1CompletedTreatmentBreast Cancer3
1CompletedTreatmentBreast Cancer / Metastatic Breast Cancer, Locally Advanced Breast Cancer1
1CompletedTreatmentFocus of Study1
1CompletedTreatmentHealthy Volunteers2
1CompletedTreatmentMcCune Albright Syndrome / McCune-Albright Syndrome / Polyostotic Fibrous Dysplasia / Puberty, Precocious1
1CompletedTreatmentMetastatic Breast Cancer1
1CompletedTreatmentMetastatic or Locally-advanced Unresectable Breast Cancer1
1Not Yet RecruitingOtherUterine Leiomyomas1
1Not Yet RecruitingTreatmentAdvanced Breast Cancer / Tumors, Solid1
1RecruitingOtherHealthy Volunteers1
1RecruitingTreatmentAnatomic Stage III Breast Cancer AJCC v8 / Anatomic Stage IIIA Breast Cancer AJCC v8 / Anatomic Stage IIIB Breast Cancer AJCC v8 / Anatomic Stage IIIC Breast Cancer AJCC v8 / Anatomic Stage IV Breast Cancer AJCC v8 / Estrogen Receptor Positive / HER2/Neu Negative / Invasive Breast Carcinoma / Prognostic Stage III Breast Cancer AJCC v8 / Prognostic Stage IIIA Breast Cancer AJCC v8 / Prognostic Stage IIIB Breast Cancer AJCC v8 / Prognostic Stage IIIC Breast Cancer AJCC v8 / Prognostic Stage IV Breast Cancer AJCC v8 / Recurrent Breast Carcinoma1
1RecruitingTreatmentBreast Cancer2
1RecruitingTreatmentBreast Cancer / Tumors, Solid1
1RecruitingTreatmentBreast Neoplasm Female1
1RecruitingTreatmentCastration Resistant Prostate Cancer (CRPC) / Castration-Resistant Prostate Cancer (CRPC) / Hormone Receptor Positive Advanced Breast Cancer / Human Epidermal Receptor 2 Negative Advanced Breast Cancer / Metastatic Breast Cancer1
1RecruitingTreatmentMalignant Neoplasm of Female Breast1
1RecruitingTreatmentNeoplasms / Neoplasms, Breast1
1TerminatedTreatmentBreast Cancer2
1TerminatedTreatmentEstrogen Receptor Positive Breast Cancer / Estrogen Receptor-Positive Breast Cancer / HER2 Negative Breast Cancer / HER2-Negative Breast Cancer / Progesterone Receptor Positive Breast Cancer / Progesterone Receptor-positive Breast Cancer / Stage II Breast Cancer / Stage IIIA Breast Cancer1
1WithdrawnTreatmentBreast Cancer1
1WithdrawnTreatmentSymptomatic or Large Uterine Fibroids1
1, 2Active Not RecruitingTreatmentBreast Cancer2
1, 2Active Not RecruitingTreatmentMetastatic Breast Cancer1
1, 2CompletedNot AvailableBreast Cancer1
1, 2CompletedTreatmentAndrogen Deficiency / BMI >30 kg/m2 / Insulin Resistance / Metabolic Diseases / Type 2 Diabetes Mellitus1
1, 2CompletedTreatmentBreast Cancer2
1, 2CompletedTreatmentOvarian Stimulation1
1, 2Not Yet RecruitingTreatmentAdvanced Solid Tumors / Neoplasms, Breast1
1, 2Not Yet RecruitingTreatmentHER2 Positive Breast Cancers / Metastatic Breast Cancer / One to five years postmenopausal1
1, 2RecruitingTreatmentAdvanced Breast Cancer1
1, 2RecruitingTreatmentAnatomic Stage I Breast Cancer AJCC v8 / Anatomic Stage IA Breast Cancer AJCC v8 / Anatomic Stage IB Breast Cancer AJCC v8 / Anatomic Stage II Breast Cancer AJCC v8 / Anatomic Stage IIA Breast Cancer AJCC v8 / Anatomic Stage IIB Breast Cancer AJCC v8 / Anatomic Stage III Breast Cancer AJCC v8 / Anatomic Stage IIIA Breast Cancer AJCC v8 / Anatomic Stage IIIB Breast Cancer AJCC v8 / Anatomic Stage IIIC Breast Cancer AJCC v8 / Anatomic Stage IV Breast Cancer AJCC v8 / Estrogen Receptor Positive / HER2/Neu Negative / MKI67 Positive / One to five years postmenopausal / Prognostic Stage I Breast Cancer AJCC v8 / Prognostic Stage IA Breast Cancer AJCC v8 / Prognostic Stage IB Breast Cancer AJCC v8 / Prognostic Stage IIA Breast Cancer AJCC v8 / Prognostic Stage IIB Breast Cancer AJCC v8 / Prognostic Stage III Breast Cancer AJCC v8 / Prognostic Stage IIIA Breast Cancer AJCC v8 / Prognostic Stage IIIB Breast Cancer AJCC v8 / Prognostic Stage IIIC Breast Cancer AJCC v8 / Prognostic Stage IV Breast Cancer AJCC v81
1, 2RecruitingTreatmentBreast Cancer3
1, 2RecruitingTreatmentHER2 Positive Breast Cancers / Metastatic Breast Cancer1
1, 2SuspendedTreatmentEarly Breast Cancer / Estrogen Receptor Positive / HER2/Neu Negative / Invasive Breast Carcinoma / Multifocal Breast Carcinoma / One to five years postmenopausal / Progesterone Receptor Positive / Stage IA Breast Cancer / Stage IB Breast Cancer / Stage II Breast Cancer / Stage IIA Breast Cancer / Stage IIB Breast Cancer / Stage III Breast Cancer / Stage IIIA Breast Cancer / Stage IIIB Breast Cancer / Stage IIIC Breast Cancer / Stage IV Breast Cancer1
1, 2TerminatedTreatmentBreast Cancer1
2Active Not RecruitingBasic ScienceBreast Cancer1
2Active Not RecruitingPreventionBreast Cancer / Osteoporosis1
2Active Not RecruitingTreatmentAdvanced, Persistent, or Recurrent Endometrial Cancer1
2Active Not RecruitingTreatmentBreast Cancer9
2Active Not RecruitingTreatmentBreast Cancer / Breast Cancer Stage II / Breast Cancer Stage III / HER2 Positive Breast Cancers / Malignant Neoplasm of Female Breast1
2Active Not RecruitingTreatmentBreast Cancer / Cancer of the Breast / Carcinoma, Breast / Malignant Tumor of Breast1
2Active Not RecruitingTreatmentBreast Cancer / Cancer of the Breast / Neoplasms, Breast1
2Active Not RecruitingTreatmentBreast Cancer / Carcinoma, Breast / Tumors, Breast1
2Active Not RecruitingTreatmentBreast Cancer / Hormone Receptor Positive Tumor / Human Epidermal Growth Factor 2 Negative Carcinoma of Breast1
2Active Not RecruitingTreatmentCongenital Adrenal Hyperplasia (CAH)1
2Active Not RecruitingTreatmentEarly-Stage Breast Carcinoma / Hormone Receptor Positive Tumor1
2Active Not RecruitingTreatmentEndometrial Cancer3
2Active Not RecruitingTreatmentEstrogen Receptor Negative / Estrogen Receptor Positive / HER2/Neu Negative / Progesterone Receptor Negative / Progesterone Receptor Positive / Stage IV Breast Cancer / Triple-Negative Breast Carcinoma1
2Active Not RecruitingTreatmentEstrogen Receptor Positive Breast Cancer / Estrogen Receptor-Positive Breast Cancer / HER2 Negative Breast Cancer / HER2-Negative Breast Cancer / Progesterone Receptor Positive Breast Cancer / Progesterone Receptor-positive Breast Cancer / Recurrent Breast Cancer / Stage IIIA Breast Cancer / Stage IIIB Breast Cancer / Stage IIIC Breast Cancer / Stage IV Breast Cancer1
2Active Not RecruitingTreatmentEstrogen Receptor Positive Breast Cancer / Estrogen Receptor-Positive Breast Cancer / HER2/Neu Negative / Stage IV Breast Cancer AJCC v6 and v71
2Active Not RecruitingTreatmentEstrogen Receptor Positive / One to five years postmenopausal / RB1 Positive / Recurrent Fallopian Tube Carcinoma / Recurrent Ovarian Carcinoma / Recurrent Primary Peritoneal Carcinoma / Recurrent Uterine Corpus Carcinoma1
2Active Not RecruitingTreatmentFibrolamellar Carcinoma / Fibrolamellar Liver Cancer1
2Active Not RecruitingTreatmentHormone Receptor Positive Breast Cancer1
2Active Not RecruitingTreatmentMetastatic Breast Cancer2
2Active Not RecruitingTreatmentNeoadjuvant Operable Breast Cancer1
2Active Not RecruitingTreatmentNeoplasms, Breast2
2Active Not RecruitingTreatmentReccurent/Metastatic Solid Tumor Disease1
2CompletedDiagnosticBreast Cancer1
2CompletedPreventionBreast Cancer5
2CompletedSupportive CareDuctal Carcinoma In Situ / Early Breast Cancer / Estrogen Receptor Positive Breast Cancer / Estrogen Receptor-Positive Breast Cancer / Progesterone Receptor Positive Breast Cancer / Progesterone Receptor-positive Breast Cancer / Stage II Breast Cancer / Stage IIIA Breast Cancer / Stage IIIB Breast Cancer / Stage IIIC Breast Cancer1
2CompletedSupportive CareEarly Breast Cancer / Joint Pain / Musculoskeletal Complications / Pain / Recurrent Breast Cancer / Stage II Breast Cancer / Stage IIIA Breast Cancer / Stage IIIB Breast Cancer / Stage IIIC Breast Cancer1
2CompletedTreatmentAnatomic Stage IV Breast Cancer AJCC v8 / Breast Cancer / Estrogen Receptor Positive / KIT Positive / One to five years postmenopausal / PDGFR Positive / Progesterone Receptor Positive / Prognostic Stage IV Breast Cancer AJCC v81
2CompletedTreatmentBreast Cancer19
2CompletedTreatmentEndocrine Sensitive HER2+/HR+ Breast Cancer1
2CompletedTreatmentEndometrial Cancer2
2CompletedTreatmentEstrogen Receptor Positive Breast Cancer / Estrogen Receptor-negative Breast Cancer / Estrogen Receptor-Positive Breast Cancer / HER2 Positive Breast Cancers / Progesterone Receptor Positive Breast Cancer / Progesterone Receptor-negative Breast Cancer / Progesterone Receptor-positive Breast Cancer / Stage IA Breast Cancer / Stage IB Breast Cancer / Stage II Breast Cancer / Stage IIIA Breast Cancer1
2CompletedTreatmentHighly Endocrine Responsive Operable Breast Cancer1
2CompletedTreatmentInfertility2
2CompletedTreatmentInvasive Breast Cancer1
2CompletedTreatmentLeiomyosarcomas1
2CompletedTreatmentLymphangioleiomyomatosis1
2CompletedTreatmentMetastatic Breast Cancer7
2CompletedTreatmentNeoplasms, Breast4
2CompletedTreatmentNeoplasms / Neoplasms, Breast1
2CompletedTreatmentOvarian Endometrioid Adenocarcinoma / Ovarian Seromucinous Carcinoma / Ovarian Serous Cystadenocarcinoma / Ovarian Serous Surface Papillary Adenocarcinoma / Recurrent Fallopian Tube Carcinoma / Recurrent Ovarian Carcinoma / Recurrent Ovarian Germ Cell Tumor / Recurrent Primary Peritoneal Carcinoma / Undifferentiated Ovarian Carcinoma1
2CompletedTreatmentOvarian Response1
2CompletedTreatmentPostmenopausal Women With Advanced Breast Cancer3
2CompletedTreatmentPregnancy1
2CompletedTreatmentRecurrent and Metastatic Endometrial Cancer1
2CompletedTreatmentSevere and Recurrent Endometriosis1
2Not Yet RecruitingTreatmentAnovulatory cycle / Polycystic Ovaries Syndrome1
2Not Yet RecruitingTreatmentBreast Diseases / HER2 Positive Breast Cancers / Hormone Receptor Positive Malignant Neoplasm of Breast / Hormone Receptor Positive Tumor / Malignant Neoplasm of Female Breast / Metastatic Breast Cancer2
2Not Yet RecruitingTreatmentEarly Breast Cancer1
2Not Yet RecruitingTreatmentEndometrial Cancer1
2Not Yet RecruitingTreatmentMedical; Abortion, Fetus1
2Not Yet RecruitingTreatmentMetastatic Breast Cancer1
2RecruitingBasic ScienceBreast Cancer1
2RecruitingOtherBreast Cancer1
2RecruitingOtherHR+ HER2 Breast Cancer1
2RecruitingPreventionEndometriosis / Ovarian Hyperstimulation1
2RecruitingTreatmentAbortions spontaneous / Missed Abortion1
2RecruitingTreatmentAdvanced Breast Cancer / Breast Cancer / Hormone Receptor Positive Tumor / Human Epidermal Growth Factor 2 Negative Carcinoma of Breast1
2RecruitingTreatmentAnatomic Stage I Breast Cancer AJCC v8 / Anatomic Stage IA Breast Cancer AJCC v8 / Anatomic Stage IB Breast Cancer AJCC v8 / Anatomic Stage II Breast Cancer AJCC v8 / Anatomic Stage IIA Breast Cancer AJCC v8 / Anatomic Stage IIB Breast Cancer AJCC v8 / Anatomic Stage III Breast Cancer AJCC v8 / Anatomic Stage IIIA Breast Cancer AJCC v8 / Anatomic Stage IIIB Breast Cancer AJCC v8 / Anatomic Stage IIIC Breast Cancer AJCC v8 / Early-Stage Breast Carcinoma / Invasive Breast Carcinoma / Prognostic Stage I Breast Cancer AJCC v8 / Prognostic Stage IA Breast Cancer AJCC v8 / Prognostic Stage IB Breast Cancer AJCC v8 / Prognostic Stage II Breast Cancer AJCC v8 / Prognostic Stage IIA Breast Cancer AJCC v8 / Prognostic Stage IIB Breast Cancer AJCC v8 / Prognostic Stage III Breast Cancer AJCC v8 / Prognostic Stage IIIA Breast Cancer AJCC v8 / Prognostic Stage IIIB Breast Cancer AJCC v8 / Prognostic Stage IIIC Breast Cancer AJCC v81
2RecruitingTreatmentAnatomic Stage IV Breast Cancer AJCC v8 / Estrogen Receptor Positive / HER2/Neu Negative / Metastatic Breast Carcinoma / Metastatic Malignant Neoplasm in the Bone / Progesterone Receptor Positive / Prognostic Stage IV Breast Cancer AJCC v81
2RecruitingTreatmentAnatomic Stage IV Breast Cancer AJCC v8 / Metastatic Breast Carcinoma / Prognostic Stage IV Breast Cancer AJCC v81
2RecruitingTreatmentBreast Cancer12
2RecruitingTreatmentBreast Cancer / Cancer of the Breast / Carcinoma, Breast1
2RecruitingTreatmentBreast Cancer / Estrogen Receptor Positive Tumor / HER2 Positive Breast Cancers1
2RecruitingTreatmentBreast Cancer / Hormone Receptor Positive Tumor1
2RecruitingTreatmentBreast Cancer / Invasive Breast Cancer2
2RecruitingTreatmentEarly Breast Cancer / Hormone Receptor Positive Tumor1
2RecruitingTreatmentEarly-Stage Breast Carcinoma / Estrogen Receptor Positive Tumor1
2RecruitingTreatmentEndometrial Cancer1
2RecruitingTreatmentEndometrial Cancer / Ovarian Cancer1
2RecruitingTreatmentEndometrial Carcinoma / Malignant Neoplasms of Female Genital Organs1
2RecruitingTreatmentEstrogen Receptor Positive / HER2/Neu Negative / Metastatic Breast Carcinoma / One to five years postmenopausal / Recurrent Breast Carcinoma / Stage IV Breast Cancer1
2RecruitingTreatmentHER2 Positive Breast Cancers / Metastatic Breast Cancer1
2RecruitingTreatmentInfertility1
2RecruitingTreatmentLow Grade Endometrial Stromal Sarcoma1
2RecruitingTreatmentLow Grade Serous Carcinoma1
2RecruitingTreatmentMetastatic Breast Cancer4
2RecruitingTreatmentNeoplasms, Breast3
2RecruitingTreatmentOvarian Cancer1
2RecruitingTreatmentUterine Cervical Neoplasms1
2RecruitingTreatmentTo Evaluate Letrozole as a Modality for Minimal Ovarian Stimulation in ICSI Cycles 1
2TerminatedNot AvailableEarly Breast Cancer1
2TerminatedTreatmentAdvanced Breast Cancer (Phase 1b) / Early Breast Cancer (Phase 2)1
2TerminatedTreatmentBreast Cancer8
2TerminatedTreatmentCarcinoma, Breast1
2TerminatedTreatmentEndocrine Breast Diseases / Neoplasms Metastasis / Neoplasms, Breast1
2TerminatedTreatmentEstrogen Receptor Positive Breast Cancer / Estrogen Receptor-Positive Breast Cancer / HER2 Negative Breast Cancer / HER2-Negative Breast Cancer / Stage II Breast Cancer / Stage IIIA Breast Cancer / Stage IIIB Breast Cancer / Stage IIIC Breast Cancer1
2TerminatedTreatmentFallopian Tube Cancer / Malignant Peritoneal Neoplasm / Ovarian Cancer1
2TerminatedTreatmentHormone-sensitive Metastatic Breast Cancer1
2TerminatedTreatmentLeiomyosarcomas / Uterine Neoplasms1
2TerminatedTreatmentMedical Abortion, Complete or Unspecified, Without Complication1
2TerminatedTreatmentNeoplasms, Breast2
2Unknown StatusPreventionBreast Cancer / One to five years postmenopausal1
2Unknown StatusTreatmentBreast Cancer2
2Unknown StatusTreatmentBreast Cancer / Hormone-Sensitive Breast Cancer1
2Unknown StatusTreatmentER Positive, HER2 Negative Breast Cancer1
2WithdrawnTreatmentBreast Cancer2
2WithdrawnTreatmentBreast Cancer / Breast Cancer Stage II / Breast Cancer Stage III1
2WithdrawnTreatmentFallopian Tube Cancer / Malignant Peritoneal Neoplasm / Ovarian Cancer1
2, 3Active Not RecruitingNot AvailableHealthy Volunteers / Idiopathic Hypogonadotropic Hypogonadism / Olfacto genital dysplasia1
2, 3Active Not RecruitingTreatmentHormone Receptor Positive HER-2 Negative Breast Cancer / HR+ HER2 Negative Breast Cancer1
2, 3Active Not RecruitingTreatmentInflammatory Breast Cancer (IBC) / Invasive Ductal Breast Carcinoma / Mucinous Breast Cancer / Tubular Breast Carcinoma1
2, 3Active Not RecruitingTreatmentLow Grade Ovarian Serous Adenocarcinoma / Micropapillary Serous Carcinoma / Ovarian Serous Adenocarcinoma / Primary Peritoneal Serous Adenocarcinoma / Recurrent Low Grade Ovarian Serous Adenocarcinoma / Recurrent Ovarian Carcinoma / Recurrent Primary Peritoneal Carcinoma / Recurrent Primary Peritoneal Serous Adenocarcinoma1
2, 3CompletedOtherPolycystic Ovaries Syndrome1
2, 3CompletedTreatmentAbortions spontaneous1
2, 3CompletedTreatmentBreast Cancer1
2, 3CompletedTreatmentComplete Miscarriage1
2, 3CompletedTreatmentConstitutional Delay of Growth and Puberty1
2, 3CompletedTreatmentInfertility2
2, 3CompletedTreatmentMetastatic Breast Cancer1
2, 3CompletedTreatmentUterine Malignancies1
2, 3CompletedTreatmentThe Efficacy of Aromatase Inhibitor vs. Gonadotrpins Releasing Hormone Agonists in Treating Premenopausal Women With Uterine Adenomyosis1
2, 3Not Yet RecruitingTreatmentBreast Cancer1
2, 3Not Yet RecruitingTreatmentBreast Cancer / Cancer treatment / Endocrine Breast Diseases1
2, 3RecruitingPreventionBreast Cancer1
2, 3TerminatedTreatmentBreast Cancer1
3Active Not RecruitingPreventionBrca1 Mutation Carrier / Brca2 Mutation Carrier / Breast Cancer / Hereditary Breast/Ovarian Cancer (brca1, brca2)1
3Active Not RecruitingTreatmentAdvanced Metastatic Breast Cancer1
3Active Not RecruitingTreatmentAdvanced, Metastatic Breast Cancer1
3Active Not RecruitingTreatmentBreast Adenocarcinoma / Estrogen Receptor and/or Progesterone Receptor Positive / Stage IA Breast Cancer AJCC v7 / Stage IB Breast Cancer AJCC v7 / Stage IIA Breast Cancer AJCC v6 and v7 / Stage IIB Breast Cancer AJCC v6 and v7 / Stage IIIB Breast Cancer AJCC v71
3Active Not RecruitingTreatmentBreast Cancer11
3Active Not RecruitingTreatmentDuctal Breast Carcinoma In Situ / Invasive Breast Carcinoma / Multicentric Breast Carcinoma / Multifocal Breast Carcinoma / Synchronous Bilateral Breast Carcinoma1
3Active Not RecruitingTreatmentInvasive Breast Carcinoma / Recurrent Breast Carcinoma / Stage III Breast Cancer AJCC v6 / Stage IV Breast Cancer AJCC v6 and v71
3Active Not RecruitingTreatmentMetastatic Breast Cancer2
3Active Not RecruitingTreatmentNeoplasms, Breast2
3CompletedPreventionBreast Cancer1
3CompletedPreventionNeoplasms, Breast / Osteoporosis1
3CompletedSupportive CareBreast Cancer / Osteoporosis1
3CompletedTreatmentAdvanced Breast Cancer Female1
3CompletedTreatmentAdvanced Metastatic Breast Cancer1
3CompletedTreatmentAzoospermia, Nonobstructive / Oligozoospermia1
3CompletedTreatmentBMI >30 kg/m2 / Hypogonadotrophic Hypogonadism1
3CompletedTreatmentBone Loss / Breast Cancer1
3CompletedTreatmentBreast Cancer13
3CompletedTreatmentHormone Sensitive Resected Primary Breast Cancer in Postmenopausal Women1
3CompletedTreatmentIdiopathic Short Stature (ISS)1
3CompletedTreatmentInfertility2
3CompletedTreatmentMalignant Neoplasm of Female Breast1
3CompletedTreatmentNeoplasms, Breast1
3CompletedTreatmentNeoplasms, Breast / Neoplasms, Hormone-Dependent1
3CompletedTreatmentOne to five years postmenopausal / Osteoporosis1
3CompletedTreatmentPolycystic Ovarian Syndrome1
3CompletedTreatmentPolycystic Ovaries Syndrome / Pregnancy1
3CompletedTreatmentPregnancy / Unexplained Infertility1
3CompletedTreatmentTranssexualism1
3CompletedTreatmentUnexplained Infertility1
3Not Yet RecruitingPreventionOvarian Hyperstimulation Syndrome1
3Not Yet RecruitingTreatmentAbdominal wall neoplasm / Fallopian Tube Neoplasms / Ovarian Neoplasm Epithelial1
3Not Yet RecruitingTreatmentOvarian Epithelial Cancer1
3Not Yet RecruitingTreatmentTubal Pregnancy1
3RecruitingTreatmentAdvanced Breast Cancer1
3RecruitingTreatmentBreast Cancer5
3RecruitingTreatmentBreast Neoplasm Female1
3RecruitingTreatmentCancer Metastatic1
3RecruitingTreatmentEstrogen Receptor Positive Breast Cancer / HER2 Positive Breast Cancers1
3RecruitingTreatmentFemale Infertility1
3RecruitingTreatmentInduction of Ovulation1
3RecruitingTreatmentInfertility3
3RecruitingTreatmentLow Grade Ovarian Serous Adenocarcinoma / Primary Peritoneal Low Grade Serous Adenocarcinoma / Stage II Ovarian Cancer AJCC v8 / Stage IIA Ovarian Cancer AJCC v8 / Stage IIB Ovarian Cancer AJCC v8 / Stage III Ovarian Cancer AJCC v8 / Stage IIIA Ovarian Cancer AJCC v8 / Stage IIIA1 Ovarian Cancer AJCC v8 / Stage IIIA2 Ovarian Cancer AJCC v8 / Stage IIIB Ovarian Cancer AJCC v8 / Stage IIIC Ovarian Cancer AJCC v8 / Stage IV Ovarian Cancer AJCC v8 / Stage IVA Ovarian Cancer AJCC v8 / Stage IVB Ovarian Cancer AJCC v8 / TP53 Negative1
3RecruitingTreatmentMetastatic Breast Cancer1
3RecruitingTreatmentNeoadjuvant Therapy1
3RecruitingTreatmentPolycystic Ovaries Syndrome2
3RecruitingTreatmentSubfertility1
3TerminatedOtherBreast Cancer1
3TerminatedTreatmentNeoplasms Metastasis / Neoplasms, Breast1
3TerminatedTreatmentNeoplasms, Breast / Neoplasms, Hormone-Dependent2
3TerminatedTreatmentOperable Breast Neoplasms1
3Unknown StatusTreatmentBreast Cancer3
3WithdrawnTreatmentBreast Cancer1
4Active Not RecruitingPreventionFertility / Neoplasms, Breast1
4Active Not RecruitingTreatmentBreast Cancer / Infertility1
4Active Not RecruitingTreatmentInvestigative Techniques / Reproductive Techniques / Reproductive Techniques, Assisted1
4CompletedBasic ScienceFertility1
4CompletedDiagnosticESTROGENS/RIFAMPIN [VA Drug Interaction] / Ovarian Cysts / Ovulatory Dysfunction1
4CompletedPreventionBreast Cancer1
4CompletedPreventionOvarian Hyperstimulation Syndrome1
4CompletedTreatmentBreast Cancer5
4CompletedTreatmentHormono-depending Adjuvant Breast Cancer1
4CompletedTreatmentInfertility1
4CompletedTreatmentInfertility Indicated for ICSI1
4CompletedTreatmentInfertility / Polycystic Ovarian Syndrome1
4CompletedTreatmentInfertility / Polycystic Ovaries Syndrome1
4CompletedTreatmentLeiomyomas / Uterine Leiomyomas1
4CompletedTreatmentLocally Advanced Breast Cancer (LABC)1
4CompletedTreatmentLocally Advanced Metastatic Breast Cancer / Locally Advanced or Metastatic Breast Cancer / Metastatic Breast Cancer / Postmenopausal Women1
4Not Yet RecruitingSupportive CareMyoma;Uterus1
4Not Yet RecruitingTreatmentBreast Cancer1
4Not Yet RecruitingTreatmentFemale Infertility / IVF / Ovulatory Dysfunction / Polycystic Ovaries Syndrome1
4Not Yet RecruitingTreatmentMissed Abortion2
4Not Yet RecruitingTreatmentSubfertility1
4RecruitingHealth Services ResearchBMI >30 kg/m21
4RecruitingPreventionBreast Neoplasm Malignant Female1
4RecruitingTreatmentAnovulatory cycle1
4RecruitingTreatmentEarly Breast Cancer1
4RecruitingTreatmentImplantation, Embryo1
4RecruitingTreatmentMetastatic Breast Cancer1
4RecruitingTreatmentNeoplasms, Breast1
4RecruitingTreatmentPolycystic Ovarian Syndrome1
4RecruitingTreatmentShort Stature1
4TerminatedTreatmentMetastatic Breast Cancer2
4TerminatedTreatmentNeoplasms, Breast1
4Unknown StatusTreatmentBreast Cancer1
4Unknown StatusTreatmentPoor Responders Undergoing IVF1
4Unknown StatusTreatmentIs to Identify Biomarkers That Could Predict the Efficacy of an Adjuvant Letrozol Treatment in Postmenopausal Breast Cancer Patients1
4WithdrawnTreatmentHER2/Neu Negative / Invasive Breast Carcinoma / One to five years postmenopausal / Stage 0 Breast Cancer / Stage IA Breast Cancer1
4WithdrawnTreatmentInfertility1
Not AvailableActive Not RecruitingNot AvailableBreast Cancer2
Not AvailableActive Not RecruitingTreatmentNeoplasms, Breast1
Not AvailableCompletedNot AvailableBMI >30 kg/m21
Not AvailableCompletedNot AvailableBMI >30 kg/m2 / Breast Cancer / Joint Pain1
Not AvailableCompletedNot AvailableBreast Cancer1
Not AvailableCompletedNot AvailableBreast Cancer / Joint Pain / Pain1
Not AvailableCompletedNot AvailableInfertility1
Not AvailableCompletedNot AvailableJoint Pain1
Not AvailableCompletedNot AvailableMetastatic Breast Cancer1
Not AvailableCompletedBasic ScienceBreast Cancer1
Not AvailableCompletedHealth Services ResearchOvarian Follicle1
Not AvailableCompletedHealth Services ResearchPolycystic Ovaries Syndrome1
Not AvailableCompletedOtherHealthy Volunteers1
Not AvailableCompletedOtherInfertility1
Not AvailableCompletedPreventionBreast Cancer / Osteoporosis1
Not AvailableCompletedTreatmentBreast Cancer1
Not AvailableCompletedTreatmentEndometrial Carcinoma1
Not AvailableCompletedTreatmentEndometriosis1
Not AvailableCompletedTreatmentInfertility1
Not AvailableCompletedTreatmentInfertility Poly Cystic Ovary1
Not AvailableCompletedTreatmentMale Breast Cancer / Recurrent Breast Cancer / Stage IV Breast Cancer2
Not AvailableCompletedTreatmentPolycystic Ovaries Syndrome3
Not AvailableCompletedTreatmentPoor Responders1
Not AvailableEnrolling by InvitationNot AvailableBreast Cancer1
Not AvailableNo Longer AvailableNot AvailableAdvanced Breast Cancer (Female)1
Not AvailableNot Yet RecruitingTreatmentART1
Not AvailableNot Yet RecruitingTreatmentExtrauterine Pregnancy1
Not AvailableNot Yet RecruitingTreatmentInduction of Abortion1
Not AvailableNot Yet RecruitingTreatmentInfertility1
Not AvailableNot Yet RecruitingTreatmentInfertility / Polycystic Ovaries Syndrome1
Not AvailableNot Yet RecruitingTreatmentIntrauterine Insemination / Unexplained Infertility1
Not AvailableRecruitingNot AvailableHR+ HER2- Men, Pre/Postmenopausal Advanced Breast Cancer1
Not AvailableRecruitingBasic ScienceBreast Cancer1
Not AvailableRecruitingBasic ScienceNeoplasms1
Not AvailableRecruitingTreatmentBreast Cancer1
Not AvailableRecruitingTreatmentFemale Infertility Due to Nonimplantation of Ovum1
Not AvailableRecruitingTreatmentInfertility / Intrauterine Insemination1
Not AvailableRecruitingTreatmentNeoplasms Metastasis / Neoplasms, Breast1
Not AvailableRecruitingTreatmentPolycystic Ovarian Syndrome / Subfertility1
Not AvailableUnknown StatusNot AvailableArthritis / Joint Pain / Neoplasms, Breast / Polymorphism, Genetic1
Not AvailableUnknown StatusNot AvailableBreast Cancer / Hypoxia1
Not AvailableUnknown StatusNot AvailableLow Responders / Mild to Moderate Male Factor Infertility / Primary Infertility / Secondary Infertility1
Not AvailableUnknown StatusTreatmentComplete Abortion1
Not AvailableUnknown StatusTreatmentInfertility2
Not AvailableUnknown StatusTreatmentPolycystic Ovarian Syndrome1
Not AvailableUnknown StatusTreatmentPolycystic Ovaries Syndrome2

Pharmacoeconomics

Manufacturers
  • Novartis pharmaceuticals corp
  • Mylan pharmaceuticals inc
Packagers
  • Kaiser Foundation Hospital
  • Novartis AG
  • Physicians Total Care Inc.
Dosage forms
FormRouteStrength
TabletOral
TabletOral2.5 mg/1
Tablet, coatedOral2.5 mg/1
Tablet, film coatedOral2.5 mg/1
Prices
Unit descriptionCostUnit
Femara 2.5 mg tablet16.87USD tablet
DrugBank does not sell nor buy drugs. Pricing information is supplied for informational purposes only.
Patents
Patent NumberPediatric ExtensionApprovedExpires (estimated)
US4978672No1990-12-182011-06-03Us
US8685980No2014-04-012030-05-25Us
US9193732No2015-11-242031-11-09Us
US8415355No2013-04-092031-02-19Us
US8324225No2012-12-042028-06-17Us
US9416136No2016-08-162029-08-20Us
US8962630No2015-02-242029-12-09Us
US9868739No2018-01-162031-11-09Us
Additional Data Available
  • Filed On
    Filed On

    The date on which a patent was filed with the relevant government.

    Learn more

Properties

State
Solid
Experimental Properties
PropertyValueSource
melting point (°C)184-185 °CFDA Label
logP2.5Dave N, et al. 2015
Predicted Properties
PropertyValueSource
Water Solubility0.0799 mg/mLALOGPS
logP1.86ALOGPS
logP2.94ChemAxon
logS-3.6ALOGPS
pKa (Strongest Basic)2.17ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count4ChemAxon
Hydrogen Donor Count0ChemAxon
Polar Surface Area78.29 Å2ChemAxon
Rotatable Bond Count3ChemAxon
Refractivity94.47 m3·mol-1ChemAxon
Polarizability29.59 Å3ChemAxon
Number of Rings3ChemAxon
Bioavailability1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleNoChemAxon
MDDR-like RuleNoChemAxon
Predicted ADMET features
PropertyValueProbability
Human Intestinal Absorption+0.9965
Blood Brain Barrier+0.9737
Caco-2 permeable+0.6347
P-glycoprotein substrateNon-substrate0.8391
P-glycoprotein inhibitor INon-inhibitor0.8087
P-glycoprotein inhibitor IINon-inhibitor0.9147
Renal organic cation transporterNon-inhibitor0.5908
CYP450 2C9 substrateNon-substrate0.7898
CYP450 2D6 substrateNon-substrate0.9116
CYP450 3A4 substrateNon-substrate0.6843
CYP450 1A2 substrateNon-inhibitor0.8374
CYP450 2C9 inhibitorNon-inhibitor0.9071
CYP450 2D6 inhibitorNon-inhibitor0.923
CYP450 2C19 inhibitorInhibitor0.8993
CYP450 3A4 inhibitorInhibitor0.6451
CYP450 inhibitory promiscuityHigh CYP Inhibitory Promiscuity0.7027
Ames testNon AMES toxic0.6371
CarcinogenicityNon-carcinogens0.8926
BiodegradationNot ready biodegradable0.9864
Rat acute toxicity1.9916 LD50, mol/kg Not applicable
hERG inhibition (predictor I)Weak inhibitor0.9261
hERG inhibition (predictor II)Non-inhibitor0.8817
ADMET data is predicted using admetSAR, a free tool for evaluating chemical ADMET properties. (23092397)

Spectra

Mass Spec (NIST)
Not Available
Spectra
SpectrumSpectrum TypeSplash Key
Predicted GC-MS Spectrum - GC-MSPredicted GC-MSNot Available
Predicted MS/MS Spectrum - 10V, Positive (Annotated)Predicted LC-MS/MSNot Available
Predicted MS/MS Spectrum - 20V, Positive (Annotated)Predicted LC-MS/MSNot Available
Predicted MS/MS Spectrum - 40V, Positive (Annotated)Predicted LC-MS/MSNot Available
Predicted MS/MS Spectrum - 10V, Negative (Annotated)Predicted LC-MS/MSNot Available
Predicted MS/MS Spectrum - 20V, Negative (Annotated)Predicted LC-MS/MSNot Available
Predicted MS/MS Spectrum - 40V, Negative (Annotated)Predicted LC-MS/MSNot Available
LC-MS/MS Spectrum - LC-ESI-QFT , negativeLC-MS/MSsplash10-001i-0090000000-0fbd577a32ff572f7368
LC-MS/MS Spectrum - LC-ESI-QFT , negativeLC-MS/MSsplash10-001i-0190000000-dfcab9af789387521571
LC-MS/MS Spectrum - LC-ESI-QFT , negativeLC-MS/MSsplash10-0006-0390000000-dbc68fd6017abe6e8adc
LC-MS/MS Spectrum - LC-ESI-QFT , negativeLC-MS/MSsplash10-00kf-0490000000-c3fc389848a06a012234
LC-MS/MS Spectrum - LC-ESI-QFT , negativeLC-MS/MSsplash10-014l-0690000000-38ba597054b02b136ab6
LC-MS/MS Spectrum - LC-ESI-QFT , negativeLC-MS/MSsplash10-00kf-1980000000-13a8827cbc5c1b36a14f
LC-MS/MS Spectrum - LC-ESI-QFT , negativeLC-MS/MSsplash10-00kf-3940000000-e01d63313ef1cfa7477a
LC-MS/MS Spectrum - LC-ESI-QFT , negativeLC-MS/MSsplash10-014i-9410000000-83b93aed0756bd41adaf
LC-MS/MS Spectrum - LC-ESI-QFT , negativeLC-MS/MSsplash10-014i-9100000000-d1757f8c218d5dcc4809
LC-MS/MS Spectrum - LC-ESI-QFT , positiveLC-MS/MSsplash10-014i-0090000000-791121bd513899b7dfc0
LC-MS/MS Spectrum - LC-ESI-QFT , positiveLC-MS/MSsplash10-014i-0090000000-eb3996846ea4f036ccca
LC-MS/MS Spectrum - LC-ESI-QFT , positiveLC-MS/MSsplash10-014i-0390000000-a57ce4cfb24ba743c54b
LC-MS/MS Spectrum - LC-ESI-QFT , positiveLC-MS/MSsplash10-0006-0950000000-303d99867511fe3a013b
LC-MS/MS Spectrum - LC-ESI-QFT , positiveLC-MS/MSsplash10-0006-0930000000-77e720374927be5113ef
LC-MS/MS Spectrum - LC-ESI-QFT , positiveLC-MS/MSsplash10-0006-0920000000-4a93d8e76eb7d0d59481
LC-MS/MS Spectrum - LC-ESI-QFT , positiveLC-MS/MSsplash10-03du-0910000000-8ad9f37884e8686ef7ba
LC-MS/MS Spectrum - LC-ESI-QFT , positiveLC-MS/MSsplash10-03dr-2900000000-2274a3adb5e486f57001
LC-MS/MS Spectrum - LC-ESI-QFT , positiveLC-MS/MSsplash10-03dr-6900000000-74d56231c43250bc65ca
MS/MS Spectrum - , positiveLC-MS/MSsplash10-014i-0490000000-7868daa9f0ec9ebda34a

Taxonomy

Description
This compound belongs to the class of organic compounds known as diphenylmethanes. These are compounds containing a diphenylmethane moiety, which consists of a methane wherein two hydrogen atoms are replaced by two phenyl groups.
Kingdom
Organic compounds
Super Class
Benzenoids
Class
Benzene and substituted derivatives
Sub Class
Diphenylmethanes
Direct Parent
Diphenylmethanes
Alternative Parents
Benzonitriles / Triazoles / Heteroaromatic compounds / Nitriles / Azacyclic compounds / Organopnictogen compounds / Hydrocarbon derivatives
Substituents
Diphenylmethane / Benzonitrile / Heteroaromatic compound / 1,2,4-triazole / Azole / Azacycle / Organoheterocyclic compound / Nitrile / Carbonitrile / Organic nitrogen compound
Molecular Framework
Aromatic heteromonocyclic compounds
External Descriptors
nitrile, triazoles (CHEBI:6413)

Targets

Details
1. Cytochrome P450 19A1
Kind
Protein
Organism
Humans
Pharmacological action
Yes
Actions
Antagonist
General Function
Oxygen binding
Specific Function
Catalyzes the formation of aromatic C18 estrogens from C19 androgens.
Gene Name
CYP19A1
Uniprot ID
P11511
Uniprot Name
Aromatase
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. Ebert AD, Bartley J, David M, Schweppe KW: [Aromatase inhibitors--theoretical concept and present experiences in the treatment of endometriosis]. Zentralbl Gynakol. 2003 Jul-Aug;125(7-8):247-51. [PubMed:14505258]
  3. Long BJ, Jelovac D, Handratta V, Thiantanawat A, MacPherson N, Ragaz J, Goloubeva OG, Brodie AM: Therapeutic strategies using the aromatase inhibitor letrozole and tamoxifen in a breast cancer model. J Natl Cancer Inst. 2004 Mar 17;96(6):456-65. [PubMed:15026471]
  4. Murphy MJ Jr: Molecular Action and Clinical Relevance of Aromatase Inhibitors. Oncologist. 1998;3(2):129-130. [PubMed:10388095]
  5. FDA Approved Drug Products: Femara Letrozole Oral Tablets [Link]
  6. FDA Approved Drug Products: Kisquali Femara Co-Pack Letrozole and Ribociclib Succinate Oral Tablets [Link]

Enzymes

Kind
Protein
Organism
Humans
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
Uniprot Name
Aromatase
Molecular Weight
57882.48 Da
References
  1. Azria D, Larbouret C, Cunat S, Ozsahin M, Gourgou S, Martineau P, Evans DB, Romieu G, Pujol P, Pelegrin A: Letrozole sensitizes breast cancer cells to ionizing radiation. Breast Cancer Res. 2005;7(1):R156-63. doi: 10.1186/bcr969. Epub 2004 Dec 7. [PubMed:15642164]
  2. Trosken ER, Fischer K, Volkel W, Lutz WK: Inhibition of human CYP19 by azoles used as antifungal agents and aromatase inhibitors, using a new LC-MS/MS method for the analysis of estradiol product formation. Toxicology. 2006 Feb 15;219(1-3):33-40. doi: 10.1016/j.tox.2005.10.020. Epub 2005 Dec 5. [PubMed:16330141]
  3. Dowsett M, Jones A, Johnston SR, Jacobs S, Trunet P, Smith IE: In vivo measurement of aromatase inhibition by letrozole (CGS 20267) in postmenopausal patients with breast cancer. Clin Cancer Res. 1995 Dec;1(12):1511-5. [PubMed:9815951]
  4. FDA Approved Drug Products: Femara Letrozole Oral Tablets [Link]
  5. FDA Approved Drug Products: Kisquali Femara Co-Pack Letrozole and Ribociclib Succinate Oral Tablets [Link]
Kind
Protein
Organism
Humans
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 react...
Gene Name
CYP3A4
Uniprot ID
P08684
Uniprot Name
Cytochrome P450 3A4
Molecular Weight
57342.67 Da
References
  1. Jeong S, Woo MM, Flockhart DA, Desta Z: Inhibition of drug metabolizing cytochrome P450s by the aromatase inhibitor drug letrozole and its major oxidative metabolite 4,4'-methanol-bisbenzonitrile in vitro. Cancer Chemother Pharmacol. 2009 Oct;64(5):867-75. doi: 10.1007/s00280-009-0935-7. Epub 2009 Feb 7. [PubMed:19198839]
  2. Bhatnagar AS: The discovery and mechanism of action of letrozole. Breast Cancer Res Treat. 2007;105 Suppl 1:7-17. doi: 10.1007/s10549-007-9696-3. Epub 2007 Oct 3. [PubMed:17912633]
  3. FDA Approved Drug Products: Femara Letrozole Oral Tablets [Link]
  4. FDA Approved Drug Products: Kisquali Femara Co-Pack Letrozole and Ribociclib Succinate Oral Tablets [Link]
Kind
Protein
Organism
Humans
Pharmacological action
Unknown
Actions
Substrate
Inhibitor
General Function
Steroid hydroxylase activity
Specific Function
Exhibits a high coumarin 7-hydroxylase activity. Can act in the hydroxylation of the anti-cancer drugs cyclophosphamide and ifosphamide. Competent in the metabolic activation of aflatoxin B1. Const...
Gene Name
CYP2A6
Uniprot ID
P11509
Uniprot Name
Cytochrome P450 2A6
Molecular Weight
56501.005 Da
References
  1. Jeong S, Woo MM, Flockhart DA, Desta Z: Inhibition of drug metabolizing cytochrome P450s by the aromatase inhibitor drug letrozole and its major oxidative metabolite 4,4'-methanol-bisbenzonitrile in vitro. Cancer Chemother Pharmacol. 2009 Oct;64(5):867-75. doi: 10.1007/s00280-009-0935-7. Epub 2009 Feb 7. [PubMed:19198839]
  2. Raunio H, Rautio A, Gullsten H, Pelkonen O: Polymorphisms of CYP2A6 and its practical consequences. Br J Clin Pharmacol. 2001 Oct;52(4):357-63. [PubMed:11678779]
  3. Borrie AE, Rose RV, Choi YH, Perera FE, Read N, Sexton T, Lock M, Vandenberg TA, Hahn K, Dinniwell R, Younus J, Logan D, Potvin K, Yaremko B, Yu E, Lenehan J, Welch S, Tyndale RF, Teft WA, Kim RB: Letrozole concentration is associated with CYP2A6 variation but not with arthralgia in patients with breast cancer. Breast Cancer Res Treat. 2018 Nov;172(2):371-379. doi: 10.1007/s10549-018-4910-z. Epub 2018 Aug 9. [PubMed:30094551]
  4. Bhatnagar AS: The discovery and mechanism of action of letrozole. Breast Cancer Res Treat. 2007;105 Suppl 1:7-17. doi: 10.1007/s10549-007-9696-3. Epub 2007 Oct 3. [PubMed:17912633]
  5. FDA Approved Drug Products: Femara Letrozole Oral Tablets [Link]
  6. FDA Approved Drug Products: Kisquali Femara Co-Pack Letrozole and Ribociclib Succinate Oral Tablets [Link]
Kind
Protein
Organism
Humans
Pharmacological action
Unknown
Actions
Inhibitor
General Function
Steroid hydroxylase activity
Specific Function
Responsible for the metabolism of a number of therapeutic agents such as the anticonvulsant drug S-mephenytoin, omeprazole, proguanil, certain barbiturates, diazepam, propranolol, citalopram and im...
Gene Name
CYP2C19
Uniprot ID
P33261
Uniprot Name
Cytochrome P450 2C19
Molecular Weight
55930.545 Da
References
  1. FDA Approved Drug Products: Femara Letrozole Oral Tablets [Link]
  2. FDA Approved Drug Products: Kisquali Femara Co-Pack Letrozole and Ribociclib Succinate Oral Tablets [Link]
Kind
Protein
Organism
Humans
Pharmacological action
Unknown
Actions
Substrate
General Function
Glucuronosyltransferase activity
Specific Function
UDPGT is of major importance in the conjugation and subsequent elimination of potentially toxic xenobiotics and endogenous compounds.Its unique specificity for 3,4-catechol estrogens and estriol su...
Gene Name
UGT2B7
Uniprot ID
P16662
Uniprot Name
UDP-glucuronosyltransferase 2B7
Molecular Weight
60694.12 Da
References
  1. Precht JC, Schroth W, Klein K, Brauch H, Krynetskiy E, Schwab M, Murdter TE: The letrozole phase 1 metabolite carbinol as a novel probe drug for UGT2B7. Drug Metab Dispos. 2013 Nov;41(11):1906-13. doi: 10.1124/dmd.113.053405. Epub 2013 Aug 21. [PubMed:23965986]

Carriers

Kind
Protein
Organism
Humans
Pharmacological action
Unknown
Actions
Binder
General Function
Toxic substance binding
Specific Function
Serum albumin, the main protein of plasma, has a good binding capacity for water, Ca(2+), Na(+), K(+), fatty acids, hormones, bilirubin and drugs. Its main function is the regulation of the colloid...
Gene Name
ALB
Uniprot ID
P02768
Uniprot Name
Serum albumin
Molecular Weight
69365.94 Da
References
  1. Bhatnagar AS: The discovery and mechanism of action of letrozole. Breast Cancer Res Treat. 2007;105 Suppl 1:7-17. doi: 10.1007/s10549-007-9696-3. Epub 2007 Oct 3. [PubMed:17912633]

Transporters

Kind
Protein
Organism
Humans
Pharmacological action
Unknown
Actions
Substrate
General Function
Xenobiotic-transporting atpase activity
Specific Function
Energy-dependent efflux pump responsible for decreased drug accumulation in multidrug-resistant cells.
Gene Name
ABCB1
Uniprot ID
P08183
Uniprot Name
Multidrug resistance protein 1
Molecular Weight
141477.255 Da
References
  1. Miyajima M, Kusuhara H, Takahashi K, Takashima T, Hosoya T, Watanabe Y, Sugiyama Y: Investigation of the effect of active efflux at the blood-brain barrier on the distribution of nonsteroidal aromatase inhibitors in the central nervous system. J Pharm Sci. 2013 Sep;102(9):3309-19. doi: 10.1002/jps.23600. Epub 2013 May 27. [PubMed:23712697]

Drug created on June 13, 2005 07:24 / Updated on July 08, 2020 06:58

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