# Exemestane

Source: https://onco.cc/drugs/exemestane/  
OnCo record `exemestane` (Treatment). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Exemestane is a steroidal aromatase inhibitor, the partner of everolimus and the agent tested with ovarian suppression in young women.

## Summary

Exemestane is a steroidal aromatase inactivator: it binds aromatase irreversibly as a 'suicide' substrate, permanently disabling the enzyme that makes oestrogen from androgens in postmenopausal women. It is used in hormone receptor-positive breast cancer after failure of a non-steroidal aromatase inhibitor, as the partner of everolimus (BOLERO-2), and with ovarian function suppression in premenopausal women (TEXT). In the combined SOFT and TEXT analysis, exemestane plus OFS improved 12-year disease-free survival over tamoxifen plus OFS (80.5% versus 75.9%, HR 0.79) without an overall survival difference. It is taken as 25 mg once daily after a meal and is generic. Whether its steroidal structure gives a real advantage after non-steroidal AI failure is not settled. For a newcomer, exemestane is the aromatase inhibitor most often chosen when another one has stopped working.

## Fields

- Kind: Treatment
- Status: approved
- Last checked: 2026-09-07
- Brand: Aromasin
- Modality: Small-molecule steroidal aromatase inactivator
- Mechanism: Irreversible 'suicide' inactivation of aromatase.
- Approvals: US 1999: Advanced breast cancer after tamoxifen; US 2005: Adjuvant after 2-3 years of tamoxifen
- Dosing: Oral; 25 mg once daily after a meal

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Exemestane
- FDA label (DailyMed): https://dailymed.nlm.nih.gov/dailymed/search.cfm?query=Exemestane

## Connected records

- cancers: [High-risk early HR-positive breast cancer](https://onco.cc/cancers/hr-positive-early-high-risk/), [HR-positive / HER2-negative breast cancer](https://onco.cc/cancers/breast-hr-positive/), [HR-positive metastatic breast cancer after CDK4/6 inhibitors](https://onco.cc/cancers/hr-positive-metastatic-post-cdk46/)
- technologies: [Acupuncture for aromatase-inhibitor joint pain](https://onco.cc/technologies/acupuncture-aromatase-inhibitor-arthralgia/), [Acupuncture for hot flushes on endocrine therapy](https://onco.cc/technologies/acupuncture-hot-flushes/), [Antiandrogens for hair: spironolactone, finasteride, dutasteride](https://onco.cc/technologies/hair-antiandrogens-alopecia/), [Bone loss caused by cancer treatment, and what rebuilds it](https://onco.cc/technologies/cancer-treatment-bone-loss/), [Dietitian-led weight-loss programmes in HR-positive breast cancer](https://onco.cc/technologies/dietitian-led-weight-loss-breast/), [Endocrine therapy (SERMs, AIs, SERDs)](https://onco.cc/technologies/endocrine-therapy/), [Menopause brought on by cancer treatment, and the options for it](https://onco.cc/technologies/menopause-after-cancer-treatment/), [Minoxidil for persistent chemotherapy- and endocrine-therapy hair loss](https://onco.cc/technologies/minoxidil-chemotherapy-alopecia/), [Vaginal oestrogen after breast cancer: what the evidence says, and where it disagrees](https://onco.cc/technologies/vaginal-oestrogen-after-breast-cancer/)
- targets: [Aromatase (CYP19A1)](https://onco.cc/targets/aromatase/), [Estrogen receptor (ERα)](https://onco.cc/targets/estrogen-receptor/)
- companies: [Pfizer (incl. Seagen)](https://onco.cc/companies/pfizer/)
- trials: [A Study of Camizestrant in ER+/HER2- Early Breast Cancer After at Least 2 Years of Standard Adjuvant Endocrine Therapy](https://onco.cc/trials/nct05774951/), [A Study of Elacestrant Versus Standard Endocrine Therapy in Women and Men With ER+,HER2-, Early Breast Cancer With High Risk of Recurrence](https://onco.cc/trials/nct06492616/), [A Study of Imlunestrant Versus Standard Endocrine Therapy in Participants With Early Breast Cancer](https://onco.cc/trials/nct05514054/), [A Study of MK-5684 in People With Certain Solid Tumors (MK-5684-015/OMAHA-015)](https://onco.cc/trials/nct06979596/), [BOLERO-2](https://onco.cc/trials/bolero-2/), [evERA](https://onco.cc/trials/evera/), [First-in-Human Study of Tersolisib (STX-478) as Monotherapy and in Combination With Other Antineoplastic Agents in Participants With Advanced Solid Tumors](https://onco.cc/trials/nct05768139/), [OP-1250 (Palazestrant) vs. Standard of Care for the Treatment of ER+/HER2- Advanced Breast Cancer](https://onco.cc/trials/nct06016738/), [Ovarian Suppression Evaluating Subcutaneous Leuprolide Acetate in Breast Cancer](https://onco.cc/trials/nct04906395/), [Phase 1/2 Study to Evaluate EP0062 as Monotherapy and in Combination in Patients With Advanced or Metastatic AR+/HER-2-/ER+ Breast Cancer](https://onco.cc/trials/nct05573126/), [Phase IIIb Study of Ribociclib + ET in Early Breast Cancer](https://onco.cc/trials/nct05827081/), [Sirolimus for Injection (Albumin-bound) in Combination With Endocrine Therapy for HR+/HER2- Advanced/Metastatic Breast Cancer Patients Who Have Failed Standard Therapy](https://onco.cc/trials/nct06957379/), [SOFT & TEXT](https://onco.cc/trials/soft-text/), [Study of Belzutifan (MK-6482) Plus Fulvestrant for ER+/HER2- Metastatic Breast Cancer (MK-6482-029/LITESPARK-029)](https://onco.cc/trials/nct06428396/)
- terms: [Endocrine-therapy-induced alopecia](https://onco.cc/terms/alopecia-endocrine-therapy/), [Ovarian function suppression (OFS)](https://onco.cc/terms/ovarian-function-suppression/)
- drugs: [Aminoglutethimide](https://onco.cc/drugs/aminoglutethimide/), [Anastrozole](https://onco.cc/drugs/anastrozole/), [Formestane](https://onco.cc/drugs/formestane/)
- roadmaps: [Hormonal therapy roadmap: removing the ovaries → tamoxifen → oral degraders switched by a blood test](https://onco.cc/roadmaps/hormonal-therapy-roadmap/)

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JSON: https://onco.cc/api/v1/entities/exemestane.json