NCT07198724

ERADICATE: A Phase Ib/II Study of Elacestrant Plus Trastuzumab Deruxtecan in Patients With CDK4/6 Inhibitor and Endocrine-resistant HR+/HER2-low or HER2-ultralow Metastatic Breast Cancer

• Status: Recruiting
• Phase: Phase 1 / Phase 2
• Study type: Interventional
• Enrollment: 65 (estimated)
• Sponsor: Sarah Sammons, MD · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

The goal of this study is to evaluate the safety and efficacy of elacestrant in combination with trastuzumab deruxtecan (T-DXd) in participants with hormone receptor-positive (HR+), HER2-low or HER2-ultralow, metastatic breast cancer that is resistant to prior CDK4/6 inhibitor and endocrine therapy. The names of the study drugs involved in this study are: * Elacestrant (a type of selective estrogen receptor degrader) * Trastuzumab deruxtecan (a type of standard of care antibody drug conjugate)

Detailed description

This phase Ib/II, open-label, single-arm, investigator-initiated study is to evaluate the safety and efficacy of elacestrant in combination with trastuzumab deruxtecan (T-DXd) in participants with hormone receptor-positive (HR+), HER2-low or HER2-ultralow, metastatic breast cancer that is resistant to prior CDK4/6 inhibitor and endocrine therapy. This is a Phase I/II clinical trial. A Phase I clinical trial tests the safety of an investigational drug and also tries to define the appropriate dose of the investigational dose to use for further studies. "Investigational" means that the drug is being studied. The phase Ib dose-escalation portion of the study is to determine the recommended phase II dose (RP2D) of the Elacestrant in combination with trastuzumab deruxtecan, followed by a phase II expansion to further evaluate efficacy and safety at the RP2D. The research study procedures include screening for eligibility, in-clinic visits, blood tests, urine tests, Computerized Tomography (CT) scans, Magnetic Resonance Imaging (MRI) scans, electrocardiograms (ECGs), and tumor biopsies. The U.S. Food and Drug Administration (FDA) has not approved Elacestrant for CDK4/6 inhibitor and endocrine-resistant HR+/HER2-low or HER2-ultralow metastatic breast cancer but it has been approved for ER-positive, HER2-negative, ESR1-mutated advanced or metastatic breast cancer. The FDA has approved trastuzumab deruxtecan as a treatment option for CDK4/6 inhibitor and endocrine-resistant HR+/HER2-low or HER2-ultralow metastatic breast cancer. The FDA has not approved the combination of Elacestrant and Trastuzumab deruxtecan for CDK4/6 inhibitor and endocrine-resistant HR+/HER2-low or HER2-ultralow metastatic breast cancer. It is expected that about 65 people will take part in this research study. Stemline-Menarini is supporting this research study by providing the study drug, Elacestrant.

Conditions

• Metastatic Breast Cancer
• HER2 Low Breast Carcinoma
• HER2-negative Breast Cancer
• Breast Cancer
• Breast Cancer Female

Interventions

Type	Name	Description
DRUG	Elacestrant	Selective estrogen receptor degrader (SERD), film-coated tablet, taken orally per protocol.
DRUG	Trastuzumab Deruxtecan	HER2-directed antibody-drug conjugate, vial, via intravenous (into the vein) infusion per standard of care

Timeline

• Start date: 2025-11-17
• Primary completion: 2028-06-01
• Completion: 2038-06-01
• First posted: 2025-09-30
• Last updated: 2026-04-09

Locations

1 site across 1 country: United States

Regulatory

• FDA-regulated drug study