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Study of Giredestrant for ER-Positive, HER2-Negative Advanced Breast Cancer

This study is looking at two different treatments for advanced breast cancer that is estrogen receptor-positive (ER+) and HER2-negative (HER2-), and has become resistant to previous hormone therapy. You would receive either giredestrant or fulvestrant, both given with a CDK4/6 inhibitor (palbociclib, ribociclib, or abemaciclib). Researchers want to see how well these combinations work to stop the cancer from growing (progression-free survival) and if they are safe. The study is for adults aged 18 and older with this specific type of breast cancer, and your tumor will be checked for an ESR1 mutation. About 1050 people are expected to join.

Study design
This is a Phase III, randomized, open-label study involving many centers. It aims to enroll about 1050 participants.
What's involved
Not specified in the trial record.
Compensation
Not stated in the trial record.
Follow-up
Participants will be followed from randomization until the cancer progresses or death, for up to 5 years.

AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.

NCT06065748

A Study to Evaluate Efficacy and Safety of Giredestrant Compared With Fulvestrant (Plus a CDK4/6 Inhibitor), in Participants With ER-Positive, HER2-Negative Advanced Breast Cancer Resistant to Adjuvant Endocrine Therapy (pionERA Breast Cancer)

Recruiting
PHASE3Ages 18+InterventionalTreatment
Hoffmann-La Roche
~1,050 participants
Updated 2026-08-05 on ClinicalTrials.gov
What's tested:GiredestrantFulvestrantAbemaciclibPalbociclibRibociclibLHRH Agonist

At a glance

Recruiting sites
269 of 352 listed sites are recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Progression-Free Survival (PFS) in the ESR1 mutation (ESR1m) Subgroup
Measured over From randomization to first occurrence of progressive disease (PD) or death (up to 5 years)
+1 more outcome measured

Conditions

Estrogen Receptor-Positive, HER2-Negative Advanced Breast Cancer

Explore related trials

Breast CarcinomaESR1 Gene

Where it's being run

352 sites across 107 states
China29
France13
Poland12
Germany11
Peru11
Argentina10
South Korea10
Spain10

Study leadership

  • Clinical Trials · STUDY_DIRECTOR · Hoffmann-La Roche

Who to contact

Reference Study ID Number: CO44657 https://forpatients.roche.com/ No attachments to email below.
[email protected]
888-662-6728 (U.S. Only)
Email the study team

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Do you actually qualify for this trial?

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Eligibility criteria

Inclusion

Locally advanced or metastatic adenocarcinoma of the breast, not amenable to treatment with curative intent
Documented estrogen receptor-positive (ER+), HER2-negative (HER2-) tumor assessed locally on the most recent tumor biopsy (or an archived tumor sample if a recent tumor sample is not available for testing)
Confirmed ESR1 mutation status (ESR1m versus ESR1nmd) in baseline circulating tumor DNA (ctDNA) through central laboratory testing
Resistance to prior adjuvant endocrine therapy (ET), which is defined as having relapsed with prior standard adjuvant ET, on-treatment after \>/=12 months or off-treatment within 12 months of completion. Prior use of adjuvant CDK4/6i is allowed (if relapse occurred \>/=12 months since completion).
No prior systemic anti-cancer therapy for advanced disease
Measurable disease as defined per RECIST v.1.1 or non-measurable (including bone-only) disease
Eastern Cooperative Oncology Group Performance Status (ECOG PS) 0-1
For pre/perimenopausal women and for men: willing to undergo and maintain treatment with approved LHRH agonist therapy (as per local guidelines) for the duration of study treatment

Exclusion

Prior systemic therapy (e.g., prior chemotherapy, immunotherapy, or biologic therapy) for locally advanced unresectable or metastatic breast cancer
Prior treatment with another SERD (e.g., fulvestrant, oral SERDs) or novel ER-targeting agents
Advanced, symptomatic, visceral spread that is at risk of life-threatening complications in the short term
Active cardiac disease or history of cardiac dysfunction
Clinically significant history of liver disease

What this trial measures

  • Progression-Free Survival (PFS) in the ESR1 mutation (ESR1m) SubgroupFrom randomization to first occurrence of progressive disease (PD) or death (up to 5 years)

    PFS is defined as the time from randomization to the first occurrence of PD, as determined by the investigator according to Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST v1.1), or death from any cause during the study.

  • PFS in the Full Analysis Set (FAS) PopulationFrom randomization to first occurrence of PD or death (up to 5 years)