Clinical trials · California
Metastatic Breast Cancer clinical trials in California
We’re tracking 203 recruiting metastatic breast cancer studies with a site in California — including Phase 1, Phase 1/Phase 2, Phase 2 and Phase 3 studies, each written for real people, not researchers.
Recruiting studies in California
- NCT07391774RecruitingPhase 3
Hormone therapy with or without chemo for early breast cancer
This trial tests whether skipping chemotherapy and using only hormone therapy with a drug called ribociclib works as well as chemotherapy followed by hormone therapy with ribociclib for certain early breast cancers that have a low risk of coming back.
Auburn, CaliforniaAges 18 years+ - NCT06058377RecruitingPhase 3
Adding immunotherapy to chemo for stage II-III breast cancer
This trial tests whether adding the immunotherapy drug durvalumab to standard chemotherapy works better than chemo alone for people with hormone receptor positive, HER2 negative breast cancer that is stage II or III and has a high-risk genetic score (MammaPrint High Risk 2).
Auburn, CaliforniaAges 18 years+ - NCT06103864RecruitingPhase 3
Study of Dato-DXd with or without durvalumab for advanced triple-negative breast cancer
This trial is testing whether a new drug combination (Dato-DXd with or without durvalumab) works better than standard chemotherapy plus pembrolizumab for people with a certain type of advanced triple-negative breast cancer that has a protein called PD-L1. The study aims to find a more effective treatment option for this specific group.
Duarte, CaliforniaAges 18 years+ - NCT07191717RecruitingPhase 2
Imlunestrant and abemaciclib for early ER+ breast cancer
This trial tests whether adding two targeted drugs, imlunestrant and abemaciclib, to your usual hormone therapy can lower the chance of your breast cancer coming back. It is for people with early-stage ER+ breast cancer who have no signs of cancer on scans but have tiny amounts of tumor DNA in their blood (called ctDNA).
Los Angeles, CaliforniaAges 18 years+ - NCT07492641RecruitingPhase 3
A new drug plus letrozole for advanced HR+ breast cancer
This trial tests a new medicine (BGB-43395) combined with letrozole against the usual CDK4/6 inhibitor plus letrozole. It is for people with advanced or metastatic HR-positive, HER2-negative breast cancer who have not yet had treatment for advanced disease.
Fountain Valley, CaliforniaAges 18 years+ - NCT07085767RecruitingPhase 3
Palazestrant and ribociclib for first-line advanced breast cancer
This trial tests a new drug (palazestrant) combined with ribociclib for people with a common type of advanced breast cancer that is estrogen receptor-positive and HER2-negative. You may qualify if you haven't had treatment for advanced disease and your cancer has either just been found or came back long after completing hormone therapy.
Beverly Hills, CaliforniaAges 18 years+ - NCT07007559RecruitingPhase 2
Evorpacept with trastuzumab and chemo for HER2-positive breast cancer
This study tests an experimental drug called evorpacept when given with trastuzumab and chemotherapy for people with HER2-positive breast cancer that has spread. The goal is to see if this combination can shrink tumors or slow down the cancer.
Duarte, CaliforniaAges 18 years+ - NCT06518057RecruitingPhase 2
Sparing memory during brain radiation for leptomeningeal metastases
This trial tests a special type of radiation that avoids the memory center of the brain (the hippocampus) while treating cancer that has spread to the lining of the brain and spinal cord. It may help reduce side effects on thinking and memory for people with breast or lung cancer.
San Francisco, CaliforniaAges 18 years+ - NCT04768426RecruitingPhase 2
Watching DNA in blood while taking capecitabine after breast cancer
This trial checks how a blood test that looks for cancer DNA (ctDNA) changes during and after you take capecitabine after early triple-negative breast cancer. It aims to see whether these blood test results can help monitor the chance of the cancer coming back.
Stanford, CaliforniaAges 18 years+ - NCT03424005RecruitingPhase 1/Phase 2
Testing new drug combinations for advanced breast cancer
This study tests how well and how safely different combinations of cancer drugs work for people with metastatic or inoperable locally advanced breast cancer. It may help by finding a better treatment option and collecting information to guide future care.
Duarte, CaliforniaAges 18 years+ - NCT05304962RecruitingPhase 1
Test drug RGT-419B for advanced ER+ HER2- breast cancer
This Phase 1 study tests a new drug (RGT-419B), given alone or with hormone (endocrine) therapy, in people with advanced ER-positive, HER2-negative breast cancer that has progressed after standard treatments. It looks mainly at safety and early signs of how well the treatment may work.
La Jolla, CaliforniaAges 18 years+ - NCT07405801RecruitingPhase 2
Inavolisib plus ribociclib plus fulvestrant for advanced breast cancer
This trial tests a combination of three drugs (inavolisib, ribociclib, and fulvestrant) compared to a placebo plus two of the drugs (ribociclib and fulvestrant) for people with advanced hormone receptor-positive breast cancer who have not had prior treatment for advanced disease. The goal is to see if adding inavolisib improves outcomes.
Anaheim, CaliforniaAges 18 years+ - NCT07100106RecruitingPhase 1/Phase 2
Study of GDC-4198 alone or with giredestrant for advanced breast cancer
This trial tests a new treatment (GDC-4198) alone or with another drug (giredestrant) compared to a standard combination (abemaciclib and giredestrant) for people with advanced hormone receptor-positive, HER2-negative breast cancer that has progressed after previous treatments.
Duarte, CaliforniaAges 18 years+ - NCT03723928Recruiting
Blood test–guided monitoring for metastatic breast cancer treatment
This study checks whether specific blood “tumor marker” levels can help monitor how hormone receptor–positive, HER2-negative metastatic breast cancer responds to first-line therapy. It uses regular blood tests (and sometimes scans) to see if this marker-based monitoring is useful and reliable.
Irvine, CaliforniaAges 18 years+ - NCT07368998RecruitingPhase 2
Study of inavolisib plus fulvestrant for advanced breast cancer
This trial tests whether a new targeted pill (inavolisib) plus hormone therapy (fulvestrant) can slow or stop breast cancer growth in people whose cancer has a specific genetic change called a PIK3CA mutation. It is for patients whose disease worsened after previous hormone-and-CDK-inhibitor treatment.
Los Angeles, CaliforniaAges 18 years+ - NCT06324357RecruitingPhase 1/Phase 2
Zongertinib for HER2-positive cancers that have spread
This trial tests a new pill called zongertinib, alone or with other drugs, for people with HER2-positive cancers (like breast, stomach, or colorectal cancer) that have spread and are no longer responding to standard treatments. The goal is to find the best dose and see if it can help shrink tumors or slow the disease.
Cerritos, CaliforniaAges 18 years+ - NCT07512271Recruiting
AI Education Tool for Breast Cancer Patients
This study tests a new computer-based education module created by artificial intelligence to help breast cancer patients understand their diagnosis and treatment options. The goal is to see if this tool helps patients feel more informed and prepared for their care.
San Francisco, CaliforniaAges 18 years+ - NCT06551116Recruiting
Better HER2 testing for HER2-low breast cancer on Enhertu
This study looks at using a more detailed lab test to measure HER2 levels in people with HER2-low metastatic breast cancer who are starting or have just started treatment with Enhertu. The goal is to see if this test can help doctors better understand who might benefit from Enhertu.
San Francisco, CaliforniaAges 18 years+ - NCT06042569RecruitingPhase 2
Lower-dose chemo for older women with HER2-negative breast cancer
This trial tests whether a lower dose of two chemotherapy drugs (docetaxel and cyclophosphamide) works well for women 65 and older with early-stage HER2-negative breast cancer. The goal is to maintain effectiveness while reducing side effects in this group.
Duarte, CaliforniaAges 65 years+ - NCT06065748RecruitingPhase 3
New hormone therapy for advanced breast cancer after prior treatment
This trial tests a new oral hormone therapy, giredestrant, against a standard hormone therapy (fulvestrant) when both are given with a CDK4/6 inhibitor. It is for people with advanced ER-positive, HER2-negative breast cancer that has come back after initial hormone therapy, and who have not yet had other treatments for advanced disease.
Auburn, CaliforniaAges 18 years+ - NCT06435429RecruitingPhase 3
Zanidatamab vs trastuzumab for HER2+ breast cancer
This study compares a new drug called zanidatamab against trastuzumab (Herceptin), both given with a chemotherapy of your doctor's choice. It is for people with HER2-positive breast cancer that has spread and who have already tried T-DXd treatment.
San Francisco, CaliforniaAges 18 years+ - NCT05786664Recruiting
Breast cancer survivor study collecting your health samples
This study invites women who finished treatment for non-metastatic invasive breast cancer to share health information and biological samples for future research. It may help scientists understand survivorship and improve care after treatment.
Los Angeles, CaliforniaAges 18 years+ - NCT05812807RecruitingPhase 3
Pembrolizumab versus monitoring after triple-negative breast cancer response
This trial checks whether giving pembrolizumab (an immunotherapy) after surgery helps people with triple-negative breast cancer reduce the chance of the cancer coming back, compared with close monitoring only. It’s for patients who had no remaining invasive cancer after neoadjuvant chemotherapy plus pembrolizumab.
Arroyo Grande, CaliforniaAges 18 years+ - NCT06876714RecruitingPhase 3
Shorter vs Longer HER2 Therapy for Breast Cancer with Complete Response
This trial compares 6 months versus 12 months of HER2-targeted therapy for people with HER2+ breast cancer who had a complete response after chemo and trastuzumab. The goal is to see if a shorter treatment is just as effective.
Arroyo Grande, CaliforniaAges 18 years+
Metastatic Breast Cancer trials by city in California
Where these studies are running in California
Institutions with a site for the recruiting metastatic breast cancer studies listed above.
- University of California, Irvine Medical Center / UC Irvine Health · 6 studies
- City of Hope Comprehensive Cancer Center · 5 studies
- Cedars-Sinai Cancer - Tarzana · 4 studies
- Sutter Medical Center Sacramento · 4 studies
- Tower Hematology Oncology Medical Group · 4 studies
- UC Irvine Health · 4 studies
- UC San Diego Moores Cancer Center · 4 studies
- University of California, San Francisco · 4 studies
What taking part in a metastatic breast cancer study involves
A screening visit first
Before anything else, the study team checks whether you fit — usually a visit with some tests. You can stop at any point, and screening is typically free.
Care at a nearby site
Study visits happen at a clinic or hospital taking part. Many studies cover the cost of the study treatment and related visits, and some reimburse travel.
You stay in control
Taking part is voluntary and you can leave a study at any time, for any reason, without affecting your regular care.
The team decides eligibility
Our fit check is a helpful first read, not a decision. The study team makes the final call after reviewing your health history.
Metastatic Breast Cancer trials in other states
Common questions
- Are there metastatic breast cancer clinical trials in California?
- Yes. We're currently tracking 203 recruiting metastatic breast cancer studies with a site in California, each rewritten in plain language so you can see what it's testing and who it's for.
- How do I find out if I qualify for a metastatic breast cancer study in California?
- Each study lists its eligibility rules — age, diagnosis, prior treatments. On every trial page we explain these in plain language and offer a short, optional pre-screen for a fit read. The study team makes the final decision.
- Do I have to live in California to take part?
- Not necessarily. These studies have a site in California, but eligibility is about your health, not your address — some people travel to take part, and a few studies reimburse travel. The study team can tell you what's required.
- Does it cost anything to join a metastatic breast cancer trial?
- Using Clin2 is always free. Many trials cover the study treatment and related visits; some reimburse travel. The study team explains exactly what's covered before you decide.
Not the right time?
New metastatic breast cancer studies open in California regularly. Set up a health profile and we’ll quietly watch for studies that fit you and email you when one opens.
Clin2 helps you find and understand clinical trials and does not provide medical advice. Study data comes from ClinicalTrials.gov. Talk with your doctor about whether a specific trial is right for you.