Biology Guided Therapy Recommendations for Treatment Determination of Hormone Receptor-Positive Advanced, Unresectable or Metastatic Breast Cancer, ENDORSE Trial

Starting soon · Phase 1

Conditions studied: Advanced Hormone Receptor-Positive Breast Carcinoma, Anatomic Stage III Breast Cancer AJCC v8, Anatomic Stage IV Breast Cancer AJCC v8, Metastatic Hormone Receptor-Positive Breast Carcinoma, Unresectable Hormone Receptor-Positive Breast Carcinoma

In brief

This clinical trial tests the feasibility and utility of a biology guided therapy recommendations report to aid in determining treatment of hormone receptor positive breast cancer that may have spread from where it first started to nearby tissue, lymph nodes, or distant parts of the body may have spread from where it first started to nearby tissue, lymph nodes, or distant parts of the body (advanced), that cannot be removed by surgery (unresectable) or that has spread from where it first started (primary site) to other places in the body (metastatic). The biology guided therapy recommendations report is developed from testing a patients tumor tissue when they have progression to see what medications may work best and what medications the cancer may be resistant to based on their tumor biology. Patients and their doctor then receive that report with the suggested treatments. Receiving a biology guided therapy recommendations report may be a feasible and useable way to aid in treatment determination for hormone receptor positive advanced, unresectable or metastatic breast cancer.

Key facts

Study ID: NCT07590583
Run by: City of Hope Medical Center
People needed: 20
Starts: 2026-12-19
Expected to finish: 2027-12-02
Last updated by the study team: 2026-05-15

Who can join

Age: 18 and older. Sex: any. Healthy volunteers: not accepted.

You may qualify if…

Participant must speak English
Documented informed consent of the participant and/or legally authorized representative.
Assent, when appropriate, will be obtained per institutional guidelines
Agreement to allow the use of archival tissue from diagnostic tumor biopsies
If unavailable, exceptions may be granted with study principal investigator (PI) approval
Age: ≥ 18 years
Patients must have histologically confirmed, unresectable or metastatic hormone receptor positive, HER2 breast cancer. Hormone receptor positive is defined as estrogen receptor >= 10% and/or progesterone receptor >= 10%. Her2 negative per American Society of Clinical Oncology/College of American Pathologists (ASCO-CAP) guidelines
Patient must have disease progression during or after prior endocrine therapy meeting one of the following criteria:
Disease progression on 1st line endocrine therapy for advanced/metastatic breast cancer.
Disease progression on or within 2 years of completion of treatment with a CDK4/6i in the adjuvant setting for early- stage breast cancer
Eastern Cooperative Oncology Group (ECOG) performance status of ≤ 2
Patient must have at least one lesion amenable to percutaneous core
Clinically appropriate for biopsy

You may not qualify if…

Prior treatment in the metastatic setting with capecitabine, phosphoinositide 3 kinase (PI3K) inhibitor, mechanistic target of rapamycin (mTOR) inhibitor, protein kinase B (Akt) inhibitor, selective estrogen receptor degrader (SERD), or HER2-targeted therapy, including neratinib
Known or untreated, or active, brain or leptomeningeal metastases that are deemed inappropriate to pursue therapy guided by systems medicine approach. Enrolled patients may receive radiation or other loco regional therapy prior to initiating systemic therapy on study. History of malignancies other than adequately treated non-melanoma skin cancer, curatively treated in situ cancer of the cervix, or other solid tumors not requiring active therapy
Life expectancy < 1 year
Pregnant or breastfeeding
Any other condition that would, in the Investigator's judgment, contraindicate the patient's participation in the clinical study due to safety concerns with clinical study procedures

Where it is running

City of Hope Medical Center — Duarte, California, United States
City of Hope at Irvine Lennar — Irvine, California, United States

Full record on ClinicalTrials.gov

Trial information comes from ClinicalTrials.gov and is refreshed daily. TrialsForMe does not provide medical care and does not run the studies it lists.