Exemestane

Breast cancer cell growth may be estrogen-dependent. Aromatase is the principal enzyme that converts androgens to estrogens both in pre- and postmenopausal women.

• Exemestane tablets are an aromatase inhibitor indicated for: adjuvant treatment of postmenopausal women with estrogen-receptor positive early breast cancer who have received two to three years of tamoxifen and are switched to exemestane tablets for completion of a total of five consecutive years of adjuvant hormonal therapy ( 14.1 ). treatment of advanced breast cancer in postmenopausal women whose disease has progressed following tamoxifen therapy ( 14.2 ).ICD-10: C50.919

• Exemestane tablets are contraindicated in patients with a known hypersensitivity to the drug or to any of the excipients. Patients with a known hypersensitivity to the drug or to any of the excipients ( 4 ).contraindicated

Recommended Dose: One 25 mg tablet once daily after a meal ( 2.1 ). 2.1 Recommended Dose The recommended dose of exemestane tablets in early and advanced breast cancer is one 25 mg tablet once daily after a meal. adjuvant treatment of postmenopausal women with estrogen-receptor positive early breast cancer who have received two to three years of tamoxifen and are switched to exemestane tablets for completion of a total of five consecutive years of adjuvant hormonal therapy. the treatment of advanced breast cancer in postmenopausal women whose disease has progressed following tamoxifen therapy. 2.2 Dose Modifications Concomitant use of strong CYP 3A4 inducers decreases exemestane exposure. For patients receiving exemestane tablets with a strong CYP 3A4 inducer such as rifampicin or phenytoin, the recommended dose of exemestane tablets is 50 mg once daily after a meal [see Drug Interactions (7) and Clinical Pharmacology (12.3) ].

Reductions in bone mineral density (BMD) over time are seen with exemestane use ( 5.1 ). Routine assessment of 25-hydroxy vitamin D levels prior to the start of aromatase inhibitor treatment should be performed ( 5.2 ). Embryo-Fetal Toxicity: Can cause fetal harm. Advise females of reproductive potential of the potential risk to a fetus and to use effective contraception ( 5.6 , 8.1 , 8.3 ). 5.1 Reductions in Bone Mineral Density (BMD) Reductions in bone mineral density (BMD) over time are seen with exemestane use. Table 1 describes changes in BMD from baseline to 24 months in patients receiving exemestane compared to patients receiving tamoxifen (IES) or placebo (027). Concomitant use of bisphosphonates, vitamin D supplementation, and calcium was not allowed. Table 1. Percent Change in BMD from Baseline to 24 months, Exemestane vs. Control 1 IES 027 BMD Exemestane N=29 Tamoxifen 1 N=38 Exemestane N=59 Placebo 1 N=65 Lumbar spine (%) -3.1 -0.2 -3.5 -2.4 Femoral neck (%) -4.2 -0.3 -4.6 -2.6 During adjuvant treatment with exemestane, women with osteoporosis or at risk of osteoporosis should have their bone mineral density formally assessed by bone densitometry at the commencement of treatment. Monitor patients for bone mineral density loss and treat as appropriate. 5.2 Vitamin D Assessment Routine assessment of 25-hydroxy vitamin D levels prior to the start of aromatase inhibitor treatment should be performed, due to the high prevalence of vitamin D deficiency in women with early breast cancer (EBC).

The following clinically significant adverse reactions are described elsewhere in the labeling: Reductions in Bone Mineral Density (BMD) [see Warnings and Precautions (5.1) ] Early breast cancer: Adverse reactions occurring in ≥10% of patients in any treatment group (exemestane tablets vs. tamoxifen) were hot flushes (21% vs. 20%), fatigue (16% vs. 15%), arthralgia (15% vs. 9%), headache (13% vs. 11%), insomnia (12% vs. 9%), and increased sweating (12% vs. 10%). Discontinuation rates due to AEs were similar between exemestane tablets and tamoxifen (6% vs. 5%). Incidences of cardiac ischemic events (myocardial infarction, angina, and myocardial ischemia) were exemestane tablets 1.6%, tamoxifen 0.6%. Incidence of cardiac failure: exemestane tablets 0.4%, tamoxifen 0.3% ( 6 , 6.1 ). Advanced breast cancer: Most common adverse reactions were mild to moderate and included hot flushes (13% vs. 5%), nausea (9% vs. 5%), fatigue (8% vs. 10%), increased sweating (4% vs. 8%), and increased appetite (3% vs. 6%) for exemestane tablets and megestrol acetate, respectively ( 6 , 6.1 ). To report SUSPECTED ADVERSE REACTIONS, contact Breckenridge Pharmaceutical, Inc. at 1-800-367-3395 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trial Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.

Lactation: Advise not to breastfeed ( 8.2 ). 8.1 Pregnancy Risk Summary Based on findings in animal studies and its mechanism of action , exemestane tablets can cause fetal harm when administered to a pregnant woman [see Clinical Pharmacology (12.1) ] . Limited human data from case reports are insufficient to inform a drug-associated risk. In animal reproduction studies, administration of exemestane to pregnant rats and rabbits caused increased incidence of abortions, embryo-fetal toxicity, and prolonged gestation with abnormal or difficult labor [see Data ] . Advise pregnant women of the potential risk to a fetus. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. In the US general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively. Data Animal Data In animal reproduction studies in rats and rabbits, exemestane caused embryo-fetal toxicity, and was abortifacient. Radioactivity related to 14 C-exemestane crossed the placenta of rats following oral administration of 1 mg/kg exemestane. The concentration of exemestane and its metabolites was approximately equivalent in maternal and fetal blood.

Metabolism

Following oral administration to healthy postmenopausal women, plasma concentrations of exemestane decline polyexponentially with a mean terminal half-life of about 24 hours. The pharmacokinetics of exemestane are dose proportional after single (10 to 200 mg) or repeated oral doses (0.5 to 50 mg).

Clinical trials have been conducted with exemestane given as a single dose to healthy female volunteers at doses as high as 800 mg and daily for 12 weeks to postmenopausal women with advanced breast cancer at doses as high as 600 mg. These dosages were well tolerated. There is no specific antidote to overdosage and treatment must be symptomatic. General supportive care, including frequent monitoring of vital signs and close observation of the patient, is indicated. A male child (age unknown) accidentally ingested a 25-mg tablet of exemestane. The initial physical examination was normal, but blood tests performed 1 hour after ingestion indicated leucocytosis (WBC 25000/mm 3 with 90% neutrophils). Blood tests were repeated 4 days after the incident and were normal. No treatment was given. In mice, mortality was observed after a single oral dose of exemestane of 3200 mg/kg, the lowest dose tested (about 640 times the recommended human dose on a mg/m 2 basis).

• Oct 21, 1999NDANDA020753Pfizer
• Jul 26, 2017ANDAANDA209208Upsher Smith Labs
• Apr 27, 2018ANDAANDA210323Cipla
• Oct 3, 2018ANDAANDA202602Zydus Pharms
• Feb 21, 2019ANDAANDA211031Breckenridge
• Apr 13, 2020ANDAANDA213547Qilu
• May 20, 2022ANDAANDA216454Eugia Pharma

1. 1Fatigue2,20510%
2. 2Malignant Neoplasm Progression1,7958.5%
3. 3Arthralgia1,7038.1%
4. 4Nausea1,6928.0%
5. 5Diarrhoea1,6818.0%
6. 6Dyspnoea1,3916.6%
7. 7Pain1,1225.3%
8. 8Asthenia1,0715.1%
9. 9Headache1,0615.0%
10. 10Malaise1,0605.0%
11. 11Cough1,0194.8%
12. 12Vomiting9824.7%
13. 13Disease Progression9664.6%
14. 14Death9314.4%
15. 15Neoplasm Progression9244.4%

The 10 most recently updated of 386 ClinicalTrials.gov registrations naming Exemestane as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

• Testing Whether Hormone Therapy With Ribociclib is as Effective as Chemotherapy Followed by Hormone Therapy With Ribociclib for the Treatment of High Anatomic Stage Breast Cancer With Low Recurrence Risk, The RxFINE-Low Trial
  Recruiting · Phase 3 · Interventional · 1,978 enrolled · National Cancer Institute (NCI)
  NCT07391774updated 2026-06-12
• Hormone Therapy With or Without Combination Chemotherapy in Treating Women Who Have Undergone Surgery for Node-Negative Breast Cancer (The TAILORx Trial)
  Active not recruiting · Phase 3 · Interventional · 10,273 enrolled · National Cancer Institute (NCI)
  NCT00310180updated 2026-06-11
• Neoadjuvant Dalpiciclib + AI → SHR-A1811 for HR+/HER2-Low Breast Cancer
  Not yet recruiting · Phase 2 · Interventional · 20 enrolled · Tang-Du Hospital
  NCT07618923updated 2026-06-11
• Tamoxifen Citrate, Letrozole, Anastrozole, or Exemestane With or Without Chemotherapy in Treating Patients With Invasive RxPONDER Breast Cancer
  Active not recruiting · Phase 3 · Interventional · 5,018 enrolled · National Cancer Institute (NCI)
  NCT01272037updated 2026-06-11
• A Study Evaluating the Efficacy and Safety of Adjuvant Giredestrant Compared With Physician's Choice of Adjuvant Endocrine Monotherapy in Participants With Estrogen Receptor-Positive, HER2-Negative Early Breast Cancer (lidERA Breast Cancer)
  Active not recruiting · Phase 3 · Interventional · 4,170 enrolled · Hoffmann-La Roche
  NCT04961996updated 2026-06-10
• Phase IIIb Study of Ribociclib + ET in Early Breast Cancer
  Recruiting · Phase 3 · Interventional · 1,400 enrolled · Novartis Pharmaceuticals
  NCT05827081updated 2026-06-09
• Testing Low Dose Tamoxifen for Invasive Breast Cancer, LoTam Trial
  Suspended · Phase 3 · Interventional · 1,556 enrolled · Alliance for Clinical Trials in Oncology
  NCT06671912updated 2026-06-08
• A Study of the Impact of Endocrine Therapy on Surgical Outcomes in People With Lobular Breast Cancer
  Recruiting · Phase 2 · Interventional · 176 enrolled · Memorial Sloan Kettering Cancer Center
  NCT07483307updated 2026-06-04
• First-in-Human Study of Tersolisib (STX-478) as Monotherapy and in Combination With Other Antineoplastic Agents in Participants With Advanced Solid Tumors
  Recruiting · Phase 1 · Phase 2 · Interventional · 880 enrolled · Eli Lilly and Company
  NCT05768139updated 2026-06-04
• A Study of Tersolisib (LY4064809/STX-478) With Other Anti-Cancer Treatments in Participants With Advanced Breast Cancer With a Genetic Change (PIK3CA)
  Recruiting · Phase 3 · Interventional · 920 enrolled · Eli Lilly and Company
  NCT07174336updated 2026-06-04

Frequently asked questions

How does Exemestane work?

Breast cancer cell growth may be estrogen-dependent. Aromatase is the principal enzyme that converts androgens to estrogens both in pre- and postmenopausal women.

What is Exemestane used for?

According to FDA labeling, Exemestane carries indications including: Exemestane tablets are an aromatase inhibitor indicated for: adjuvant treatment of postmenopausal women with estrogen-receptor positive early breast cancer who have received two to three years of tamoxifen and are switched to exemestane tablets for completion of a total of five consecutive years of adjuvant hormonal therapy ( 14.1 ). treatment of advanced breast cancer in postmenopausal women whose disease has progressed following tamoxifen therapy ( 14.2 ).. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.

What class of drug is Exemestane?

Exemestane is classified as Aromatase inhibitors, Aromatase Inhibitor, Aromatase Inhibitors, Enzyme Inhibitors, Decreased Ovarian Estrogen Secretion.

What are the brand names for Exemestane?

Exemestane is marketed under brand names including Aromasin.

What are the contraindications for Exemestane?

Exemestane labeling lists contraindications including: Exemestane tablets are contraindicated in patients with a known hypersensitivity to the drug or to any of the excipients. Patients with a known hypersensitivity to the drug or to any of the excipients ( 4 ).. Always consult the full prescribing information and a clinician.