Purpose

This Phase III, randomized, open-label, multicenter study will evaluate the efficacy and safety of giredestrant plus everolimus compared with the physician's choice of endocrine therapy plus everolimus in participants with estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative locally advanced or metastatic breast cancer who have had previous treatment with cyclin-dependent kinase 4/6 inhibitors (CDK4/6is) and endocrine therapy, either in the locally advanced/metastatic or the adjuvant setting.

Condition

Eligibility

Eligible Ages
Over 18 Years
Eligible Genders
All
Accepts Healthy Volunteers
No

Inclusion Criteria

  1. Locally advanced unresectable or metastatic adenocarcinoma of the breast, not amenable to treatment with curative intent 2. Documented estrogen receptor-positive (ER+) tumor and HER2-negative tumor, assessed locally 3. Ability to provide a blood sample for circulating-tumor deoxyribonucleic acid (ctDNA) Estrogen Receptor 1 (ESR1) mutation status determination by central testing 4. Prior endocrine therapy (ET) in combination with cyclin-dependent kinase 4/6 inhibitors in either setting as follows: - Metastatic setting: Disease progression after ≥6 months on ET plus CDK4/6 inhibitor in the locally advanced or metastatic setting. If ET plus CDK4/6 inhibitor is not the most recent therapy, then patient must also have had disease progression after ≥4 months on most recent ET - Adjuvant Setting: Relapse either while taking or within 12 months of exposure to combination adjuvant ET and CDK4/6 inhibitor. Patients must have taken at least 12 months of adjuvant ET, 6 months of which was in combination with a CDK4/6 inhibitor. 5. Measurable disease as defined per RECIST v.1.1 or evaluable bone metastases. Patients with evaluable bone disease in the absence of measurable disease outside of the bone must have at least one predominantly lytic bone lesion confirmed by computed tomography (CT) or magnetic resonance imaging (MRI) which can be followed 6. Eastern Cooperative Oncology Group Performance Status 0-1 7. For women who are premenopausal or perimenopausal and for men: treatment with approved luteinizing hormone-releasing hormone (LHRH) agonist therapy for the duration of study treatment

Exclusion Criteria

  1. Prior treatment with another oral selective estrogen receptor degrader (SERD), proteolysis targeting chimera (PROTAC), complete estrogen receptor antagonist (CERAN), novel oral selective estrogen receptor modulator (SERM), or everolimus in any setting. Prior fulvestrant is allowed if treatment was terminated at least 28 days prior to randomization. Prior treatment with tamoxifen is allowed. 2. Progression on more than 2 prior lines of systemic endocrine therapy in the locally advanced unresectable or metastatic breast cancer setting 3. Prior chemotherapy for locally advanced unresectable or metastatic disease 4. Treatment with strong Cytochrome P450 3A4 (CYP3A4) inhibitors or inducers within 14 days or 5 drug elimination half-lives (whichever is longer) prior to randomization 5. Treatment with any investigational therapy within 28 days prior to initiation of study treatment 6. Major surgery, chemotherapy, radiotherapy, or other anti-cancer therapy within 14 days prior to randomization 7. History of any other malignancy other than breast cancer within 5 years prior to screening, except for appropriately treated carcinoma in situ of the cervix, nonmelanoma skin carcinoma, papillary thyroid cancer treated with surgery, Stage I endometrial cancer, or other non-breast cancers at very low risk of recurrence 8. Advanced, symptomatic, visceral spread that is at risk of life-threatening complications in the short term 9. Known active uncontrolled or symptomatic central nervous system (CNS) metastases, carcinomatous meningitis, or leptomeningeal disease 10. Active cardiac disease or history of cardiac dysfunction 11. Known clinically significant history of liver disease consistent with Child-Pugh Class B or C including active viral or other hepatitis virus, current alcohol abuse, or cirrhosis 12. Active inflammatory bowel disease, chronic diarrhea, short bowel syndrome, or major upper gastrointestinal (GI) surgery including gastric resection 13. Interstitial lung disease or severe dyspnea at rest or requiring oxygen therapy 14. Serious infection requiring oral or intravenous (IV) antibiotics, or other clinically significant infection, within 14 days prior to randomization 15. Any serious medical condition or abnormality in clinical laboratory tests that, in the investigator's judgment, precludes the patient's safe participation in and completion of the study 16. Known allergy or hypersensitivity to any of the study drugs or any of their excipients 17. For premenopausal or perimenopausal women and for men: known hypersensitivity to LHRH agonists 18. Pregnant or breastfeeding

Study Design

Phase
Phase 3
Study Type
Interventional
Allocation
Randomized
Intervention Model
Parallel Assignment
Primary Purpose
Treatment
Masking
None (Open Label)

Arm Groups

ArmDescriptionAssigned Intervention
Experimental
Giredestrant plus Everolimus
  • Drug: Giredestrant
    Participants will receive treatment with giredestrant 30 milligrams (mg) orally once a day (QD) on Days 1-28 of each 28-day cycle until unacceptable toxicity or disease progression as determined by the investigator according to Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST v1.1).
    Other names:
    • GDC-9545
    • RO7197597
    • RG6171
  • Drug: Everolimus
    Participants will receive treatment with everolimus 10 mg orally QD during each 28-day cycle until unacceptable toxicity or disease progression as determined by the investigator according to RECIST v1.1.
  • Drug: LHRH Agonist
    Only premenopausal/perimenopausal female participants and male participants will receive a luteinizing hormone-releasing hormone (LHRH) agonist on Day 1 of each 28-day treatment cycle. The investigator will determine and supply the appropriate LHRH agonist locally approved for use in breast cancer.
  • Drug: Dexamethasone Mouth Rinse
    A compounded alcohol-free mouthwash of dexamethasone (0.5 mg in 5 mL) will be supplied, where feasible. It is strongly recommended for prophylaxis or treatment of stomatitis/mucositis. Participants should use the alcohol-free mouthwash of dexamethasone four times QD for 8 weeks started concurrently with study treatment, and use it reactively thereafter with the first appearance of symptoms.
Active Comparator
Physician's Choice of Endocrine Therapy plus Everolimus
The physician's choice of endocrine therapy is defined as either exemestane, fulvestrant, or tamoxifen.
  • Drug: Exemestane
    If exemestane is chosen as the physician's choice of endocrine therapy, the participant will receive exemestane at a dose of 25 mg orally once a day (QD) on Days 1-28 of each 28-day cycle or as per local label, until unacceptable toxicity or disease progression as determined by investigator according to RECIST v1.1.
  • Drug: Fulvestrant
    If fulvestrant is chosen as the physician's choice of endocrine therapy, the participant will receive fulvestrant in the clinic at a dose of 500 mg intramuscularly on Day 1 and Day 15 of Cycle 1, then Day 1 of each cycle thereafter (1 cycle is 28 days) or as per local prescribing information, until unacceptable toxicity or disease progression as determined by investigator according to RECIST v1.1.
  • Drug: Tamoxifen
    If tamoxifen is chosen as the physician's choice of endocrine therapy, the participant will receive tamoxifen at a dose of 20 mg orally QD on Days 1-28 of each 28-day cycle or as per local prescribing information, until unacceptable toxicity or disease progression as determined by investigator according to RECIST v1.1.
  • Drug: Everolimus
    Participants will receive treatment with everolimus 10 mg orally QD during each 28-day cycle until unacceptable toxicity or disease progression as determined by the investigator according to RECIST v1.1.
  • Drug: LHRH Agonist
    Only premenopausal/perimenopausal female participants and male participants will receive a luteinizing hormone-releasing hormone (LHRH) agonist on Day 1 of each 28-day treatment cycle. The investigator will determine and supply the appropriate LHRH agonist locally approved for use in breast cancer.
  • Drug: Dexamethasone Mouth Rinse
    A compounded alcohol-free mouthwash of dexamethasone (0.5 mg in 5 mL) will be supplied, where feasible. It is strongly recommended for prophylaxis or treatment of stomatitis/mucositis. Participants should use the alcohol-free mouthwash of dexamethasone four times QD for 8 weeks started concurrently with study treatment, and use it reactively thereafter with the first appearance of symptoms.

More Details

Status
Active, not recruiting
Sponsor
Genentech, Inc.

Study Contact

Notice

Study information shown on this site is derived from ClinicalTrials.gov (a public registry operated by the National Institutes of Health). The listing of studies provided is not certain to be all studies for which you might be eligible. Furthermore, study eligibility requirements can be difficult to understand and may change over time, so it is wise to speak with your medical care provider and individual research study teams when making decisions related to participation.