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RecruitingLast updated: 1 May 2026

EMBER-4: Measuring how well a new hormone therapy (imlunestrant) works compared to standard hormone therapy (tamoxifen, anastrozole, letrozole, or exemestane) in people with early breast cancer that is ER+ and HER2-A Randomized, Open-Label, Phase 3 Study of Adjuvant Imlunestrant vs Standard Adjuvant Endocrine Therapy in Patients Who Have Previously Received 2 to 5 Years of Adjuvant Endocrine Therapy for ER+, HER2- Early Breast Cancer With an Increased Risk of Recurrence

Trial purpose

Medical clipboardCancer treatment

Tumor type

Breast Cancers Breast

Age

People18+

Trial acronym

EMBER-4

Clinical summary

Summary

Eligible participants will be randomly allocated to one of two arms.

In Arm 1 (Experimental), participants will receive imlunestrant, administered orally.

In Arm 2 (Active Comparator), participants will receive the Investigator's choice of tamoxifen, anastrozole, letrozole or exemestane, administered as per local approved label.

Conditions

This trial is treating people with ER+, HER2- early stage invasive breast cancer that has been removed with surgery and does not have any evidence of distant metastasis

Eligibility

Inclusion

  • Have a diagnosis of ER+, HER2- early-stage, resected, invasive breast cancer without evidence of distant metastasis.
  • Participants must have received at least 24 months but not more than 60 months of any adjuvant ET, from time of adjuvant ET initiation.
  • Participants may have received (neo) adjuvant chemotherapy and/or targeted therapy with a CDK4/6- or PARP- inhibitor.
  • Must have an increased risk of disease recurrence based on clinical-pathological risk features.
  • Have a Performance Status of 0 or 1 on the Eastern Cooperative Oncology Group scale.
  • Have adequate organ function.

Exclusion

  • Have any evidence of metastatic disease (including contralateral ALN) or inflammatory breast cancer at primary breast cancer diagnosis.
  • Participants with more than a 6-month consecutive gap in therapy during the course of prior adjuvant ET.
  • Participants who have completed or discontinued prior adjuvant ET >6 months prior to screening.
  • Participants with a history of previous breast cancer are excluded, with the exception of ipsilateral DCIS treated by locoregional therapy alone ≥5 years ago.
  • Pregnant, breastfeeding, or expecting to conceive or father children within the projected duration of the trial, starting with the screening visit through 180 days after the last dose of study intervention.
  • Participant has previously received ET of any duration for breast cancer prevention (tamoxifen or AIs) or raloxifene.
  • Participants with a history of any other cancer.
  • Have serious preexisting medical conditions that, in the judgment of the investigator, would preclude participation in this study.

Inclusion

  • Your cancer has not spread to other parts of the body (localised).
  • You are able to swallow medication by mouth.
  • You have had a certain type of treatment or surgical procedure.

Exclusion

  • You have certain types of non-cancer medical conditions.
  • You have had certain treatments, surgical procedures or drugs.
Message

Clinical trials have complex eligibility criteria, and other criteria may apply for this trial. Ask your doctor about whether this trial could be right for you.

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More information

Trial Identifiers

Information on this page is partially produced from ClinicalTrials.gov, EU Clinical Trials Register *. View further details about this trial on the registry via the links below:

Trial sponsor

Eli Lilly and Company

Scientific Title

A Randomized, Open-Label, Phase 3 Study of Adjuvant Imlunestrant vs Standard Adjuvant Endocrine Therapy in Patients Who Have Previously Received 2 to 5 Years of Adjuvant Endocrine Therapy for ER+, HER2- Early Breast Cancer With an Increased Risk of Recurrence

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