Clinical trials · California
Breast cancer clinical trials in California
We’re tracking 244 recruiting 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
- NCT06827236RecruitingPhase 1/Phase 2
Testing a new combination treatment for advanced breast cancer
This study tests two experimental drugs, BNT323 and BNT327, together in people with advanced breast cancer. The goal is to find the best dose and see if the combination is safe and helpful.
Beverly Hills, CaliforniaAges 18 years+ - 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+ - NCT06590857RecruitingPhase 1/Phase 2
Study of targeted radiation for advanced breast cancer
This trial tests a new type of radiation therapy that targets a specific protein on some breast cancer cells. It may help people whose cancer has stopped responding to other treatments.
Irvine, CaliforniaAges Any age - NCT04603209Recruiting
Check-in registry for radiation during breast-conserving surgery
This registry study tracks people with early-stage, single-area breast cancer to understand outcomes when radiation is given during breast-conserving surgery. It may help doctors improve treatment planning for patients like you.
Santa Monica, CaliforniaAges 18 years+ - NCT07741968Recruiting
Online program to ease fear of cancer returning
This study tests an online program designed to help women with advanced or certain types of breast or gynecologic cancer manage their fear of the disease progressing or returning. The program aims to reduce anxiety and improve quality of life.
Lancaster, CaliforniaAges 18 years+ - NCT07541079RecruitingPhase 3
Testing a New Breast Cancer Drug for Women Who Can't Tolerate Current Therapy
This study tests giredestrant, a new hormone-blocking medication, in postmenopausal women with early-stage ER+ breast cancer who have experienced intolerable side effects from their current aromatase inhibitor therapy. The trial will measure how well you tolerate this new drug and how it affects your quality of life.
Fountain Valley, CaliforniaAges 18 years+ - NCT07524322RecruitingPhase 1
RGT-490 for Advanced Cancers With PIK3CA Mutations
This study tests a new drug called RGT-490 in patients with advanced solid tumors (cancers that have spread or cannot be removed by surgery) that have a specific genetic change called a PIK3CA mutation. The drug is designed to block a protein involved in cancer cell growth.
Los Angeles, 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+ - NCT07505797Recruiting
Ultrasound imaging study for suspicious breast lesions
This study is testing a new ultrasound device (ATUSA) to see how well it can image breast lesions that have been classified as suspicious (BI-RADS 4 or 5). If you have a recent finding that needs further evaluation, this research might help improve detection methods.
Sacramento, CaliforniaAges 18–94 - NCT07487844Recruiting
Electric field therapy for breast cancer that has spread
This trial tests a new way to treat breast cancer that has spread to the skin or just under the skin. It uses short electric pulses to target tumors without cutting. The goal is to see if this approach can safely destroy cancer cells in those spots.
San Francisco, 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+ - NCT07383506RecruitingPhase 1
Study of a targeted pill for PIK3CA-mutated advanced cancers
This trial tests a new pill (CGT6297) that targets cancer cells with a specific PIK3CA gene change. It may be an option for people with certain advanced solid tumors, including endometrial or breast cancer, after standard treatments have stopped working.
Los Angeles, 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+ - NCT07318805RecruitingPhase 1
A study of PF-08032562 for advanced solid tumors
This study tests a new medicine, PF-08032562, for people with advanced breast or colorectal cancer that has not responded to prior treatments. It aims to see if the drug is safe and can help shrink or slow the cancer.
Duarte, CaliforniaAges 18 years+ - NCT07227233RecruitingPhase 2
AI-guided retrial of CDK4/6 inhibitors for advanced breast cancer
This trial tests whether an artificial intelligence (AI) tool can help doctors decide if it is safe and effective to give you a second course of a CDK4/6 inhibitor drug (like palbociclib, ribociclib, or abemaciclib) plus hormone therapy for advanced (unresectable or metastatic) HR+/HER2- breast cancer. The goal is to only treat people whose cancer is likely to respond based on a special AI analysis of their tumor tissue.
La Jolla, CaliforniaAges 18 years+ - NCT07211178Recruiting
Tracking cancer DNA in blood to detect early return of breast cancer
This study tracks tiny traces of cancer DNA in the blood over time to see if it can find early signs of breast cancer coming back. It looks at different types of breast cancer and at different points in a patient's treatment journey.
Whittier, CaliforniaAges 18–99 - NCT07208084Recruiting
A support program for Black women with breast cancer
This study tests a program called Project SOAR that offers group support and education for Black American women with breast cancer. It aims to help them feel more empowered and connected during their journey.
Los Angeles, 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+ - NCT07121972Recruiting
Validating AI for breast cancer risk prediction
This trial uses an AI model called Mirai to identify women at high risk for breast cancer based on their mammograms. If you are eligible, you may be invited for a breast MRI to better understand your risk.
San Diego, CaliforniaAges 40–89 - 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+ - NCT07102381RecruitingPhase 2
Zanidatamab plus chemo before surgery for HER2+ breast cancer
This trial tests a new drug called zanidatamab combined with chemotherapy to shrink HER2-positive breast cancer before surgery. It may help improve treatment outcomes for people with stage 2 or 3 breast cancer that has not spread.
Long Beach, 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+ - NCT07059884Recruiting
Exercise program to help people with cancer stay active
This trial tests a distance-based exercise program designed to help people on chemotherapy maintain their physical function and prevent disability. It is for patients with certain cancers who are working full-time and can participate in moderate physical activity.
Dublin, CaliforniaAges 18 years+ - NCT07054190RecruitingPhase 2
Testing inavolisib for early-stage PIK3CA-mutated breast cancer
This study tests a new drug called inavolisib for people with early-stage breast cancer that has a specific genetic change (PIK3CA mutation). The goal is to see if adding this drug to standard hormone therapy is safe and effective before surgery.
Los Angeles, CaliforniaAges 18 years+
Breast cancer trials by city in California
Where these studies are running in California
Institutions with a site for the recruiting breast cancer studies listed above.
- City of Hope · 3 studies
- Los Angeles Cancer Network · 3 studies
- University of California, San Francisco · 3 studies
- START Los Angeles · 2 studies
- UC San Diego Moores Cancer Center · 2 studies
- UCLA Jonsson Comprehensive Cancer Center · 2 studies
- Alta Bates Summit Medical Center-Herrick Campus
- Beverly Hills Cancer Center
What taking part in a 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.
Breast cancer trials in other states
Common questions
- Are there breast cancer clinical trials in California?
- Yes. We're currently tracking 244 recruiting 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 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 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 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.