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Hormone · Profile

Exemestane

Aromasin · Steroidal AI

Hormone ManagementApproved
MW
296.4g/mol
Formula
C20H24O2

Exemestane is a steroidal aromatase inhibitor that irreversibly inactivates the aromatase enzyme, primarily produced in peripheral tissues, and is used in the management of hormone-sensitive breast cancer. Researchers primarily study exemestane for its efficacy in reducing estrogen levels and improving outcomes in premenopausal women with estrogen/progesterone receptor-positive early breast cancer. Key findings from the combined SOFT and TEXT trials indicated that exemestane, when used alongside ovarian function suppression, significantly improved disease-free survival and distant recurrence-free interval compared to tamoxifen plus ovarian suppression. Current research continues to explore the long-term benefits and optimal patient selection for exemestane, highlighting its clinical relevance in the evolving landscape of breast cancer therapy.

Overview

Übersicht

Exemestane, also known by its trade name Aromasin, is a synthetic steroidal aromatase inhibitor used in hormone management. It is chemically classified as a steroidal agent and is primarily utilized in the treatment of estrogen receptor-positive breast cancer in postmenopausal women. Exemestane is distinct from non-steroidal aromatase inhibitors due to its steroidal structure, which may confer additional benefits in terms of bone and lipid metabolism. Researchers have extensively studied its efficacy in both adjuvant and advanced breast cancer settings. Exemestane's primary physiological role is to reduce estrogen levels by irreversibly binding to the aromatase enzyme, thereby inhibiting the conversion of androgens to estrogens. This mechanism is particularly beneficial in estrogen-dependent breast cancer, where lowering estrogen levels can impede cancer progression. Clinical trials such as the SOFT and TEXT trials have demonstrated exemestane's effectiveness in improving disease-free survival and distant recurrence-free intervals when combined with ovarian suppression in premenopausal women. The mechanism of action involves the irreversible inactivation of the aromatase enzyme, leading to a substantial reduction in circulating estrogen levels. This action is achieved by binding to the substrate binding site of the enzyme, effectively blocking estrogen synthesis. Pharmacokinetically, exemestane has an oral bioavailability that is subject to first-pass metabolism, with a half-life of approximately 24 hours. It is metabolized primarily by the liver and excreted via urine. Clinically, exemestane is approved for use in the treatment of breast cancer in postmenopausal women, particularly following tamoxifen therapy. It is available by prescription and is recognized for its favorable tolerability profile compared to other endocrine therapies.

Chemical profile

Chemische Struktur

Chemical structure of Exemestane
FormelC20H24O2
Molekulargewicht296.4g/mol
CAS-Nummer107868-30-4
PubChem CID60198
Mechanism

Wirkmechanismus

Exemestane acts by irreversibly binding to the aromatase enzyme, leading to its inactivation. This prevents the conversion of androgens to estrogens, resulting in decreased estrogen levels and subsequent reduction in estrogen-dependent tumor growth.

Mechanism

Signalweg

Exemestane is a steroidal aromatase inhibitor that irreversibly binds to the aromatase enzyme, inhibiting the conversion of androgens to estrogens, thereby reducing estrogen levels in the body. This action primarily affects estrogen receptor-positive (ER+) breast cancer cells, leading to decreased activation of estrogen receptor signaling pathways, which are crucial for tumor growth and proliferation. While the precise downstream signaling pathways affected by this reduction in estrogen are not fully understood, the inhibition of aromatase contributes to altered cellular processes such as cell cycle regulation and apoptosis in hormone-sensitive breast cancer.

Half-Life & Pharmacokinetics

POOral

Approximately 24 hours

Exemestane undergoes extensive first-pass metabolism, which affects its oral bioavailability.

Storage

Temperature

Store at room temperature (15-30C)

Light

Protect from light

Form

Tablets are stable under recommended storage conditions

Notes

Keep in original packaging to protect from moisture and light.

Solubility

Löslichkeit

Exemestane is poorly soluble in water but shows better solubility in organic solvents such as ethanol.

Legal Status

🇩🇪DE

Exemestane is a prescription-only medication (verschreibungspflichtig) in Germany.

🇺🇸US

Exemestane is FDA-approved for the treatment of breast cancer and requires a prescription.

🇦🇺AU

In Australia, exemestane is classified as a Schedule 4 (S4) prescription-only medicine.

🇬🇧UK

Exemestane is a prescription-only medicine (POM) in the UK, regulated by the MHRA.

Legal status information is provided for general reference only and may not reflect the most current regulatory changes. Always verify with official government sources before making any decisions.

Open Questions

Offene Forschungsfragen

Current evidence is limited regarding the long-term overall survival benefits of exemestane compared to tamoxifen in premenopausal women, particularly in high-risk subgroups. Further research is needed to clarify the optimal sequencing and combination of exemestane with other endocrine therapies, as well as to investigate its efficacy and safety in diverse populations, including those with varying tumor characteristics and treatment histories. Additionally, larger randomized controlled trials are necessary to assess the long-term effects of exemestane on quality of life and the management of adverse events, especially in patients receiving ovarian suppression.

79 Research Publications

3,855

Total Citations

46

Human/RCT

3.9

Avg. Influence

2020

Latest

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Filter
#01

Adjuvant exemestane with ovarian suppression in premenopausal breast cancer.

Pagani Olivia, et al. · The New England journal of medicine · 2014

HumanInfluence30.0
706
The study demonstrated that adjuvant treatment with exemestane plus ovarian suppression resulted in significantly improved disease-free survival compared to tamoxifen plus ovarian suppression in premenopausal women with hormone-receptor-positive early breast cancer.

Key findings

  1. 01Exemestane plus ovarian suppression significantly reduced the risk of cancer recurrence compared to tamoxifen plus ovarian suppression.
  2. 02The 5-year disease-free survival rate was 91.1% for the exemestane group.
  3. 03Overall survival rates were similar between the two treatment groups.
#02

Tailoring Adjuvant Endocrine Therapy for Premenopausal Breast Cancer.

Francis Prudence A, et al. · The New England journal of medicine · 2018

HumanInfluence32.0
557
Researchers observed that premenopausal women with breast cancer receiving exemestane plus ovarian suppression had significantly lower recurrence rates compared to those receiving tamoxifen plus ovarian suppression.

Key findings

  1. 01Exemestane plus ovarian suppression resulted in lower recurrence rates than tamoxifen plus ovarian suppression.
  2. 02Tamoxifen plus ovarian suppression improved survival rates compared to tamoxifen alone.
  3. 03Higher rates of side effects were observed in groups receiving ovarian suppression.
#03

Adjuvant tamoxifen and exemestane in early breast cancer (TEAM): a randomised phase 3 trial.

HumanInfluence17.0
373
The study demonstrated no significant difference in disease-free survival between exemestane monotherapy and sequential tamoxifen followed by exemestane in postmenopausal women with hormone-receptor-positive early breast cancer.
#04

Adjuvant Exemestane With Ovarian Suppression in Premenopausal Breast Cancer: Long-Term Follow-Up of the Combined TEXT and SOFT Trials.

HumanInfluence8.0
125
The study demonstrated that adjuvant exemestane plus ovarian function suppression significantly improved disease-free survival and distant recurrence-free interval compared to tamoxifen plus ovarian function suppression in premenopausal women with hormone receptor-positive early breast cancer.
#05

ESR1 Mutations and Overall Survival on Fulvestrant versus Exemestane in Advanced Hormone Receptor-Positive Breast Cancer: A Combined Analysis of the Phase III SoFEA and EFECT Trials.

Turner Nicholas C, et al. · Clinical cancer research : an official journal of the American Association for Cancer Research · 2020

HumanInfluence5.0
121
The study demonstrated that patients with ESR1 mutations had inferior progression-free and overall survival when treated with exemestane compared to fulvestrant in advanced hormone receptor-positive breast cancer.

Key findings

  1. 01Fulvestrant and exemestane were compared in patients who progressed on prior therapy.
  2. 02The study involved analyzing serum and plasma samples from hundreds of patients.
  3. 03The trials aimed to improve treatment options for metastatic breast cancer.
#06

Aromatase inhibitors: are there differences between steroidal and nonsteroidal aromatase inhibitors and do they matter?

ReviewInfluence3.0
116
Researchers observed that switching between steroidal and nonsteroidal aromatase inhibitors may yield modest clinical benefits, indicating partial noncross-resistance between the classes of inhibitors.
#07

Sequential treatment with exemestane and non-steroidal aromatase inhibitors in advanced breast cancer.

HumanInfluence2.0
90
The study demonstrated that exemestane is active after prior failure of non-steroidal aromatase inhibitors, confirming partial non-cross resistance between steroidal and non-steroidal agents.
#08

Exemestane (FCE 24304), a new steroidal aromatase inhibitor.

HumanInfluence1.0
90
The study demonstrated that exemestane effectively reduces estrogen levels in postmenopausal women, with a minimal effective dose of 5 mg.
#09

Endocrine and clinical endpoints of exemestane as neoadjuvant therapy.

HumanInfluence1.0
80
The study demonstrated that exemestane significantly reduced aromatization and tumor volume in postmenopausal women with estrogen receptor-rich tumors during neoadjuvant therapy.
#10

Exemestane, a new steroidal aromatase inhibitor of clinical relevance.

ReviewInfluence3.0
79
Researchers observed that exemestane, a novel steroidal aromatase inhibitor, is a well-tolerated hormonal therapy for postmenopausal patients with advanced breast cancer that has become refractory to standard hormonal therapies.

Clinical Trials (21)

Preclinical
Phase I
Phase II
Phase III
Approved

21

Total Trials

21,227

Total Enrolled

Data Analysis for Drug Repurposing for Effective Alzheimer's Medicines (DREAM)- Anastrozole vs Exemestane/Letrozole

NCT05635357COMPLETED
Sponsor

Brigham and Women's Hospital

Enrollment

16,989

Started

2022

Primary outcome

Time to dementia onset

Breast Cancer

ExclUsive endocRine Therapy Or Radiation theraPy for Women Aged ≥70 Years Early Stage Breast Cancer

NCT04134598Phase 3ACTIVE_NOT_RECRUITING
Sponsor

Azienda Ospedaliero-Universitaria Careggi

Enrollment

926

Started

2021

Primary outcome

Patient reported outcome measures (PROM) HRQoL as assessed by European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ) C30

Breast Cancer

Fulvestrant and EVerolimus Plus EXemestane in Metastatic Breast Cancer

NCT02404051Phase 3UNKNOWN
Sponsor

Consorzio Oncotech

Enrollment

745

Started

2015

Primary outcome

Progression-free survival (PFS1)

Metastatic Breast CancerBreast CancerHormone Receptor Positive TumorHuman Epidermal Growth Factor 2 Negative Carcinoma of BreastLocally Advanced Malignant Neoplasm

Study of Faslodex +/- Concomitant Arimidex v Exemestane Following Progression on Non-steroidal Aromatase Inhibitors

NCT00253422Phase 3COMPLETED
Sponsor

Institute of Cancer Research, United Kingdom

Enrollment

698

Started

2004

Primary outcome

Progression-free Survival

Breast Cancer

OP-1250 (Palazestrant) vs. Standard of Care for the Treatment of ER+/HER2- Advanced Breast Cancer

NCT06016738Phase 3RECRUITING
Sponsor

Olema Pharmaceuticals, Inc.

Enrollment

510

Started

2023

Primary outcome

Dose-Selection Part: Incidence of adverse events

Breast CancerAdvanced Breast CancerMetastatic Breast CancerER Positive Breast CancerHER2 Negative Breast Carcinoma

Aromasin Vs Arimidex Study As Initial Hormonal Therapy In Postmenopausal Women With Advanced/Recurrent Breast Cancer

NCT00143390Phase 3COMPLETED
Sponsor

Pfizer

Enrollment

298

Started

2005

Primary outcome

Time to Progression (TTP) - Expert Evaluation Committee Assessment

Breast Neoplasms

Multicenter Follow Up Study Of Subjects Who Participated In An Original Protocol Of Exemestane Vs. Megestrol Acetate In Postmenopausal Women With Metastatic Breast Cancer

NCT01237327Phase 3COMPLETED
Sponsor

Pfizer

Enrollment

84

Started

2001

Primary outcome

Overall Survival

Metastatic Breast Cancer

Letrozole, Anastrozole, Exemestane, or Tamoxifen Citrate in Treating Postmenopausal Women With Breast Cancer

NCT00893061Phase 3COMPLETED
Sponsor

Centre Oscar Lambret

Enrollment

44

Started

2009

Primary outcome

Changes in verbal episodic memory performance after 6 months of treatment, using the Rey Auditory Verbal Learning Test

Breast Cancer

Efficacy and Safety Study of Enzalutamide in Combination With Exemestane in Patients With Advanced Breast Cancer

NCT02007512Phase 2COMPLETED
Sponsor

Pfizer

Enrollment

247

Started

2013

Primary outcome

Progression Free Survival (PFS): Intent-to-Treat (ITT) Population By Interactive Web Recognition System (IWRS)

Breast Cancer

Study of Belzutifan (MK-6482) Plus Fulvestrant for ER+/HER2- Metastatic Breast Cancer (MK-6482-029/LITESPARK-029)

NCT06428396Phase 2RECRUITING
Sponsor

Merck Sharp & Dohme LLC

Enrollment

120

Started

2024

Primary outcome

Progression-free Survival (PFS)

Metastatic Breast Cancer

Open Label, Multicenter, Randomized, Controlled Study of IM or Oral Exemestane (Aromasin) in Postmenopausal Women

NCT00040014Phase 2TERMINATED
Sponsor

Pfizer

Enrollment

100

Started

2002

Primary outcome

To determine the pharmacodynamic equivalence at steady state of the IM formulation of exemestane with the oral formulation in terms of plasma estrone sulphate inhibitory effect in postmenopausal women with advanced breast cancer.

Breast Neoplasms

Exemestane As Treatment In Neoadjuvant Setting For Operable Breast Cancer Patients

NCT00174343Phase 2COMPLETED
Sponsor

Pfizer

Enrollment

46

Started

2001

Primary outcome

To evaluate clinical and pathologic response rates following primary hormonal therapy by exemestane (Aromasin®)

Breast Neoplasms

Neoadjuvant Chemo-endocrine Therapy and Immunotherapy for Pre-menopausal Luminal B Breast Cancer Patients

NCT04659551Phase 2COMPLETED
Sponsor

Istituto Oncologico Veneto IRCCS

Enrollment

43

Started

2017

Primary outcome

pathological complete response (pCR)

Breast Cancer

Exemestane in Combination With Fulvestrant in Postmenopausal Women With Hormone Sensitive Advanced Breast Cancer

NCT00201864Phase 2COMPLETED
Sponsor

Ohio State University Comprehensive Cancer Center

Enrollment

40

Started

2005

Primary outcome

Time to Progression (TTP) in Women With Hormone Responsive Advanced Breast Cancer Treated With Combination of Exemestane and Fulvestrant.

Breast Cancer

Exemestane in Treating Patients With Complex Atypical Hyperplasia of the Endometrium/Endometrial Intraepithelial Neoplasia or Low Grade Endometrial Cancer

NCT03300557Phase 2COMPLETED
Sponsor

National Cancer Institute (NCI)

Enrollment

40

Started

2017

Primary outcome

Change in Tumor Proliferation

Atypical HyperplasiaEndometrial Atypical Hyperplasia/Endometrioid Intraepithelial NeoplasiaEndometrial CarcinomaFIGO Grade 1 Endometrial Endometrioid AdenocarcinomaFIGO Grade 2 Endometrial Endometrioid Adenocarcinoma

Preoperative Hormone Therapy for Postmenopausal Women With ER+ Clinical Stage T2-4 Tumors

NCT01831076Phase 2COMPLETED
Sponsor

University of Colorado, Denver

Enrollment

36

Started

2002

Primary outcome

Overall Response Rate as Measured by Clinical Exam, Standard Imaging, and Surgical Pathology Findings

Breast CancerStage II Breast CancerStage III Breast Cancer

Exemestane in Treating Postmenopausal Women With Stage IV Breast Cancer

NCT00810797Phase 2COMPLETED
Sponsor

City of Hope Medical Center

Enrollment

36

Started

2008

Primary outcome

Progression-free Survival

Breast Cancer

Neoadjuvant Tucidinostat and Exemestane in Early Breast Cancer

NCT04465097Phase 2COMPLETED
Sponsor

First Affiliated Hospital, Sun Yat-Sen University

Enrollment

30

Started

2020

Primary outcome

objective response rate (ORR) evaluated by MRI

Breast Cancer

Pembrolizumab and Doxorubicin Hydrochloride or Anti-Estrogen Therapy in Treating Patients With Triple-Negative or Hormone Receptor-Positive Metastatic Breast Cancer

NCT02648477Phase 2COMPLETED
Sponsor

City of Hope Medical Center

Enrollment

30

Started

2016

Primary outcome

Number of Participants With Overall Response

Estrogen Receptor NegativeEstrogen Receptor PositiveHER2/Neu NegativeProgesterone Receptor NegativeProgesterone Receptor PositiveStage IV Breast CancerTriple-Negative Breast Carcinoma

Phase Ib Trial of LEE011 With Everolimus (RAD001) and Exemestane in the Treatment of Hormone Receptor Positive HER2 Negative Advanced Breast Cancer

NCT01857193Phase 1COMPLETED
Sponsor

Novartis Pharmaceuticals

Enrollment

132

Started

2013

Primary outcome

Dose Escalation: Incidence of Dose Limiting Toxicity (DLT)

Breast Cancer

Study to Evaluate Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Alobresib (Formerly GS-5829) in Adults With Advanced Solid Tumors and Lymphomas and in Combination With Exemestane or Fulvestrant in Adults With Estrogen Receptor Positive Breast Cancer

NCT02392611Phase 1COMPLETED
Sponsor

Gilead Sciences

Enrollment

33

Started

2015

Primary outcome

Number of Participants Experiencing Dose Limiting Toxicities (DLTs)

Solid Tumors and Lymphomas

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This page is for informational and research purposes only. All information is based on published scientific literature and does not constitute medical advice, diagnosis, or treatment recommendations. Many substances listed may not be approved for human use and may be subject to drug regulation laws (e.g., AMG in Germany, FDA in the US). PepStack does not encourage the use of any substance on humans. Always consult a qualified healthcare professional before making any health-related decisions. Use of this information is entirely at your own risk. PepStack assumes no liability for the accuracy, completeness, or timeliness of the content provided. Full disclaimer