A Study to Learn How Well Participants With a Specific Type of Early Breast Cancer (ER-Positive, HER2-Negative) Tolerate and Stay on Treatment With Giredestrant and How They Feel During Treatment

RecruitingPhase 3

A Phase IIIb, Single-arm, Open-Label, Multicenter Study Evaluating the Treatment Adherence, Tolerability, and Patient-Reported Outcomes of Giredestrant in Patients With Estrogen Receptor-Positive, HER2-Negative Early Breast Cancer

Who can join

Ages 18 and older · All sexes

Full eligibility criteria

Inclusion Criteria:

* Histologically confirmed diagnosis of ER-positive, HER2-negative, Stage I-III, breast cancer
* Definitive surgery of primary breast tumor(s) and axillary lymph nodes (axillary lymph node dissection and/or sentinel lymph node biopsy)
* Participants must have completed any prior adjuvant chemotherapy before enrollment, if given
* Eastern Cooperative Oncology Group (ECOG) Performance Status 0, 1, or 2
* Adequate organ function
* Men and pre- or perimenopausal women must receive a concurrent approved luteinizing hormone-releasing hormone agonist

Exclusion Criteria:

* Pregnant or breastfeeding, or intending to become pregnant during the study or within the timeframe in which contraception is required
* Diagnosis of inoperable locally advanced or Stage IV breast cancer
* History of any prior (ipsilateral and/or contralateral) invasive breast cancer or ductal carcinoma in situ (DCIS)
* Planned surgery during the study
* Prior treatment with giredestrant, selective estrogen receptor degraders (SERDs), or investigational endocrine agents
* Active cardiac disease or history of cardiac dysfunction

About the study

The purpose of this study is to evaluate treatment adherence, tolerability, and patient-reported outcomes of participants with estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative early breast cancer (eBC) who are treated with giredestrant.

The study will have two cohorts. Cohort A will comprise a broad upfront patient population with low-, medium-, or high-risk eBC. Cohort B will comprise patients with medium- or high-risk eBC who have completed adjuvant treatment with cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6i) (abemaciclib or ribociclib) and endocrine therapy and who are now switching to giredestrant monotherapy.

What is being tested

Giredestrant (drug)

Sponsor: Hoffmann-La Roche · Participants: 1,500 · Started: Nov 30, 2026

Contact the study team

Reference Study ID Number: BO46775 https://forpatients.roche.com/ No attachments to email below. · Phone: 888-662-6728 (U.S. Only)

Official record on ClinicalTrials.gov — NCT07827573

Locations in the U.S.

Oregon	Hematology Oncology Salem, Salem
Virginia	Virginia Cancer Institute, Richmond

Conditions

Breast Cancer

From ClinicalTrials.gov, data retrieved Nov 15, 2026. Each study sets its own eligibility; the study team decides who can join.