NCT07499999

Randomized Double-Blind Phase II Trial of Baby Exemestane Versus Baby Tamoxifen in Post-Menopausal Women at High Risk for Breast Cancer

Randomized Double-Blind Phase II Trial of Baby Exemestane Versus Baby Tamoxifen in Post-Menopausal Women at High Risk for Breast Cancer (BabyTEARS)

• Status: Not Yet Recruiting
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 140 (estimated)
• Sponsor: Dana-Farber Cancer Institute · Academic / Other
• Sex: Female
• Age: —
• Healthy volunteers: Not accepted

Summary

The goal of this research study is to evaluate the efficacy and safety of low-dose exemestane versus low-dose tamoxifen in post-menopausal women at high risk for breast cancer. The names of the study drugs involved in this study are: * Exemestane (a type of steroidal aromatase inhibitor) * Tamoxifen (a type of selective estrogen receptor modulator)

Detailed description

This randomized, double-blind, phase II trial is to evaluate the efficacy and safety of low-dose "baby" exemestane versus low-dose "baby" tamoxifen in post-menopausal women at high risk for breast cancer. Both medications are used at full doses for breast cancer treatment and to reduce breast cancer risk. Low dose tamoxifen has been shown to be effective at reducing risk with better tolerance. Participants will be randomized into one of two study groups: Group A: Exemestane versus Group B: Tamoxifen. Randomization means a participant is placed into a study group by chance. Neither a participant or the research doctor will choose or know what group a participant is placed in. This is called a "double-blind". The U.S. Food and Drug Administration (FDA) has not approved tamoxifen or exemestane for ER+ DCIS, High Risk Lesions, or being at high-risk for breast cancer but it has been approved for other uses. The research study procedures include screening for eligibility, in-clinic visits, questionnaires, blood tests, Mammography scans, and bone density (DEXA) scans. Participation in this research study is expected to last about 12 months. It is expected that about 140 people will take part in this research study. The Breast Cancer Research Foundation is supporting this research study by providing funding. MRIGlobal is providing support by supplying the study drugs.

Conditions

• Breast Cancer
• Ductal Carcinoma
• Estrogen-receptor-positive Breast Cancer
• Atypical Lobular Hyperplasia
• BRCA2 Mutation
• CHEK2 Gene Mutation
• Ataxia Telangiectasia Mutated Gene Mutation

Interventions

Type	Name	Description
DRUG	Exemestane	A steroidal aromatase inhibitor, blinded capsules taken orally, per protocol.
DRUG	Tamoxifen	A selective estrogen receptor modulator, blinded capsules taken orally, per protocol.

Timeline

• Start date: 2026-09-09
• Primary completion: 2027-08-31
• Completion: 2028-08-31
• First posted: 2026-03-30
• Last updated: 2026-03-30

Locations

2 sites across 1 country: United States

Regulatory

• FDA-regulated drug study