Comparing Giredestrant with Fulvestrant for estrogen receptor-positive, HER2-negative advanced breast
Official title: 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)
A Phase III Randomized, Open-Label Study Evaluating Efficacy and Safety of Giredestrant Compared With Fulvestrant, Both Combined With a CDK4/6 Inhibitor, in Patients With Estrogen Receptor-Positive, HER2-Negative Advanced Breast Cancer With Resistance to Prior Adjuvant Endocrine Therapy
Interventions
Giredestrant
Giredestrant 30 milligrams (mg) orally (PO) once a day (QD) on Days 1-28 of each 28-day cycle until progressive disease (PD) or unacceptable toxicity.
Fulvestrant
Fulvestrant 500 mg intramuscularly (IM) on Days 1 and 15 of Cycle 1 and on Day 1 of each subsequent 28-day cycle until PD or unacceptable toxicity.
Abemaciclib
If chosen by the investigator as the CDK4/6i, participants will receive abemaciclib 150 mg PO twice per day (BID) on Days 1-28 of each 28-day cycle until PD or unacceptable toxicity.
Palbociclib
If chosen by the investigator as the CDK4/6i, participants will receive palbociclib 125 mg PO QD on Days 1-21 of each 28-day cycle until PD or unacceptable toxicity.
Ribociclib
If chosen by the investigator as the CDK4/6i, participants will receive ribociclib 600 mg PO QD on Days 1-21 of each 28-day cycle until PD or unacceptable toxicity.
LHRH Agonist
Only pre/perimenopausal female participants and male participants will receive a luteinizing hormone-releasing hormone (LHRH) agonist locally approved for use in breast cancer on Day 1 of each 28-day treatment cycle.
FoundationOne Liquid CDx Assay (F1LCDx)
F1LCDx is a next-generation sequencing (NGS)-based in vitro diagnostic test that detects and analyses genomic alterations in circulating cell-free DNA (cfDNA) isolated from plasma derived from the anti-coagulated peripheral whole blood of cancer patients. It will be used to determine the eligibility of participants requiring confirmation of ESR1 mutation status (mutation detected \[ESR1m\] vs. no mutation detected \[ESR1nmd\]).
Canadian Sites (16)
Cross Cancer Institute
Edmonton, Alberta, Canada
Royal Victoria Regional Health Centre
Barrie, Ontario, Canada
Credit Valley Hospital/Carlo Fidani Peel Regional Cancer Centre
Mississauga, Ontario, Canada
Lakeridge Health Oshawa
Oshawa, Ontario, Canada
Thunder Bay Regional Health Sciences Centre
Thunder Bay, Ontario, Canada
North York General Hospital
Toronto, Ontario, Canada
Princess Margaret Cancer Center
Toronto, Ontario, Canada
CIUSSS du Saguenay Lac-Saint-Jean, Chicoutimi Hospital
Chicoutimi, Quebec, Canada
CISSS Chaudière-Appalaches
Lévis, Quebec, Canada
Centre Hospitalier de l'Universite de Montreal (CHUM)
Montreal, Quebec, Canada
McGill University Health Centre - Glen Site
Montreal, Quebec, Canada
CHU de Québec - Hôpital du Saint-Sacrement
Québec, Quebec, Canada
Hopital regional de saint jerome
Saint-Jérôme, Quebec, Canada
Centre hospitalier regional de Trois-Rivieres
Trois-Rivières, Quebec, Canada
Allan Blair Cancer Centre
Regina, Saskatchewan, Canada
Saskatoon Cancer Centre
Saskatoon, Saskatchewan, Canada
Eligibility Criteria
See who this study is looking for13 criteria
The trial’s own eligibility text, word for word from the registry. Only the trial site can say who takes part.
Inclusion
- +Eastern Cooperative Oncology Group Performance Status (ECOG PS) 0-1
- +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 baselineBaselineYour starting measurements, taken before treatment begins.Read more → 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
- +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 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
- −Prior systemic therapy (e.g., prior chemotherapy, immunotherapy, or biologic therapy) for locally advanced unresectable or metastatic breast cancer
In plain language
Assembled directly from this trial’s registry record. Every sentence traces to a field below — nothing here is generated or interpreted.
What this study is
This study is testing a treatment for a condition.
Phase 3Phase 3A large study comparing a treatment against the current standard.Read more → — a large study comparing this against the current standard, usually across many hospitals.
What is being given or done in this study: Giredestrant, Fulvestrant, Abemaciclib, Palbociclib, and 3 more.
From the trial registry
Built from these fields:
- designModule.designInfo.primaryPurpose
- designModule.phases
- armsInterventionsModule.interventions[].name
How the study is run
Which group you would be placed in is decided by chance, like a coin flip — not by you and not by your doctor.
This study is open-labelOpen-labelEveryone knows which treatment is being given — nothing is hidden.Read more →: everyone knows which treatment is being given, including you and the study team.
From the trial registry
Built from these fields:
- designModule.designInfo.allocation
- designModule.designInfo.maskingInfo.masking
Is there a placebo?
This study does not list a placeboPlaceboA dummy treatment with no active medicine, used for comparison.Read more → group.
One group receives an existing treatment, so the two can be compared.
There are 2 groups in this study.
From the trial registry
Built from this field:
- armsInterventionsModule.armGroups[].type
Who the study is looking for
The study lists a minimum age of 18 years, with no upper limit given.
The study is open to people of any sex.
The study does not accept healthy volunteersHealthy volunteerSomeone without the condition being studied who takes part anyway.Read more →.
These are the criteria the study lists. Only the trial siteTrial siteA hospital or clinic where a study is actually run.Read more → can decide whether someone can take part.
From the trial registry
Built from these fields:
- eligibilityModule.minimumAge
- eligibilityModule.sex
- eligibilityModule.healthyVolunteers
How big and how long
The study aims to enrol about 1,050 people.
The study is currently expected to finish around February 2029.
The main measurement is taken over: From randomizationRandomisedWhich group you go into is decided by chance, not by you or your doctor.Read more → to first occurrence of progressive disease (PD) or death (up to 5 years).
From the trial registry
Built from these fields:
- designModule.enrollmentInfo.count
- statusModule.completionDateStruct.date
- outcomesModule.primaryOutcomes[].timeFrame
What the study measures
Progression-Free Survival (PFS) in the ESR1 mutation (ESR1m) Subgroup — measured over From randomizationRandomisedWhich group you go into is decided by chance, not by you or your doctor.Read more → to first occurrence of progressive disease (PD) or death (up to 5 years).
PFS in the Full Analysis Set (FAS) Population — measured over From randomization to first occurrence of PD or death (up to 5 years).
From the trial registry
Built from these fields:
- outcomesModule.primaryOutcomes[].measure
- outcomesModule.primaryOutcomes[].timeFrame
Source: NCT06065748 on ClinicalTrials.gov. The full registry text is further down this page — this summary never replaces it.
Not medical advice. What do these terms mean?
What is being tested — in plain terms
About GiredestrantDrug
Giredestrant 30 milligrams (mg) orally (PO) once a day (QD) on Days 1-28 of each 28-day cycle until progressive disease (PD) or unacceptable toxicity.
From the trial registry — its own words, unedited.
What a drug is here: A medicine — a chemical or small-molecule treatment — given as the thing being studied.
Read the full explanation → · in clinical review
About FulvestrantDrug
Fulvestrant 500 mg intramuscularly (IM) on Days 1 and 15 of Cycle 1 and on Day 1 of each subsequent 28-day cycle until PD or unacceptable toxicity.
From the trial registry — its own words, unedited.
What a drug is here: A medicine — a chemical or small-molecule treatment — given as the thing being studied.
Read the full explanation → · in clinical review
About AbemaciclibDrug
If chosen by the investigator as the CDK4/6i, participants will receive abemaciclib 150 mg PO twice per day (BID) on Days 1-28 of each 28-day cycle until PD or unacceptable toxicity.
From the trial registry — its own words, unedited.
What a drug is here: A medicine — a chemical or small-molecule treatment — given as the thing being studied.
Read the full explanation → · in clinical review
About PalbociclibDrug
If chosen by the investigator as the CDK4/6i, participants will receive palbociclib 125 mg PO QD on Days 1-21 of each 28-day cycle until PD or unacceptable toxicity.
From the trial registry — its own words, unedited.
What a drug is here: A medicine — a chemical or small-molecule treatment — given as the thing being studied.
Read the full explanation → · in clinical review
About RibociclibDrug
If chosen by the investigator as the CDK4/6i, participants will receive ribociclib 600 mg PO QD on Days 1-21 of each 28-day cycle until PD or unacceptable toxicity.
From the trial registry — its own words, unedited.
What a drug is here: A medicine — a chemical or small-molecule treatment — given as the thing being studied.
Read the full explanation → · in clinical review
About LHRH AgonistDrug
Only pre/perimenopausal female participants and male participants will receive a luteinizing hormone-releasing hormone (LHRH) agonist locally approved for use in breast cancer on Day 1 of each 28-day treatment cycle.
From the trial registry — its own words, unedited.
What a drug is here: A medicine — a chemical or small-molecule treatment — given as the thing being studied.
Read the full explanation → · in clinical review
About FoundationOne Liquid CDx Assay (F1LCDx)Diagnostic test
F1LCDx is a next-generation sequencing (NGS)-based in vitro diagnostic test that detects and analyses genomic alterations in circulating cell-free DNA (cfDNA) isolated from plasma derived from the anti-coagulated peripheral whole blood of cancer patients. It will be used to determine the eligibility of participants requiring confirmation of ESR1 mutation status (mutation detected \[ESR1m\] vs. no mutation detected \[ESR1nmd\]).
From the trial registry — its own words, unedited.
What a diagnostic test is here: A scan, blood test, or other test being studied for how well it detects or measures something.
Read the full explanation → · in clinical review
Common questions
Answered from this trial’s registry record. Where the record doesn’t say, these answers say so rather than filling the gap.
Am I eligible for this trial?
Only the trial siteTrial siteA hospital or clinic where a study is actually run.Read more → can decide whether someone can take part. Concord cannot make that determination, and neither can any tool that has not examined you.
What the study lists: a minimum age of 18 years.
The full inclusionInclusion criteriaThe things you must have or be for a study to consider you.Read more → and exclusion criteriaExclusion criteriaThe things that would prevent someone from taking part.Read more → are published on this page, exactly as the study team wrote them.
The useful next step is to bring this trial to your doctor. Answering a few questions first gives them something concrete to review.
From the trial registry
- eligibilityModule.minimumAge
- eligibilityModule.eligibilityCriteria
Is there a placebo?
This study does not list a placeboPlaceboA dummy treatment with no active medicine, used for comparison.Read more → group.
One group receives an existing treatment so the two can be compared.
From the trial registry
- armsInterventionsModule.armGroups[].type
Would I know which treatment I am getting?
This study is open-labelOpen-labelEveryone knows which treatment is being given — nothing is hidden.Read more →: everyone knows which treatment is being given, including you and the study team.
Which group you would be placed in is decided by chance, like a coin flip — not by you and not by your doctor.
From the trial registry
- designModule.designInfo.maskingInfo.masking
- designModule.designInfo.allocation
Who can join?
The study lists a minimum age of 18 years, with no upper limit given.
It is open to people of any sex.
It does not accept healthy volunteersHealthy volunteerSomeone without the condition being studied who takes part anyway.Read more →.
Only the trial siteTrial siteA hospital or clinic where a study is actually run.Read more → can confirm whether a particular person can take part.
From the trial registry
- eligibilityModule.minimumAge
- eligibilityModule.sex
- eligibilityModule.healthyVolunteers
How long would this take?
The study's main measurement is taken over: From randomizationRandomisedWhich group you go into is decided by chance, not by you or your doctor.Read more → to first occurrence of progressive disease (PD) or death (up to 5 years).
The study as a whole is currently expected to finish around 2029-02-12.
How long any one person takes part can differ from the study length. The study team can tell you what the schedule looks like in practice.
From the trial registry
- outcomesModule.primaryOutcomes[].timeFrame
- statusModule.completionDateStruct.date
How many people are taking part?
The study aims to enrol about 1,050 people.
From the trial registry
- designModule.enrollmentInfo.count
Where is this happening?
This study lists 17 locations, including: Edmonton, Alberta, Canada; Barrie, Ontario, Canada; Mississauga, Ontario, Canada; Oshawa, Ontario, Canada; Thunder Bay, Ontario, Canada; Toronto, Ontario, Canada, and 11 more.
Sites can open and close during a study, so confirm with the team before travelling.
From the trial registry
- trial_locations
About This Trial
This is a Phase III, randomized, open-label multicenter study that will evaluate the efficacy and safety of giredestrant compared with fulvestrant, both in combination with the investigator's choice of a CDK4/6 inhibitor (palbociclib, ribociclib or abemaciclib), in participants with estrogen receptor-positive (ER+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer who have developed resistance to adjuvant endocrine therapy.
Other Sites (3)
Henry Ford Hospital
Detroit, Michigan, United States
Queens Hospital Cancer Center
Jamaica, New York, United States
Northwest Medical Specialties
Tacoma, Washington, United States
Worth passing on?
Save it to the Care Package and send it to them, or to their doctor, in one message. Whether they follow it up is theirs to decide.
Review the Care PackageThis page is for informational purposes only and does not constitute medical advice. Clinical trial eligibility can only be determined by the trial site after proper screening. Trial information is sourced from ClinicalTrials.gov and may not reflect the most current status. Always consult your healthcare provider before making decisions about clinical trial participation.