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
- NCT06998407RecruitingPhase 1/Phase 2
Study of AVZO-023 for advanced solid tumors
This trial tests a new drug, AVZO-023, alone or with other treatments, for people with advanced solid tumors that have not responded to standard therapy. The goal is to see if it can shrink tumors or slow their growth.
Los Angeles, CaliforniaAges 18 years+ - NCT06827613RecruitingPhase 1/Phase 2
Study of invikafusp alfa plus sacituzumab govitecan for advanced solid tumors
This trial tests a new drug combination for people with advanced breast cancer (triple-negative or hormone receptor-positive). The goal is to see if the combination helps shrink tumors or slow their growth.
Los Angeles, 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.
Glendale, CaliforniaAges 18 years+ - NCT04852887RecruitingPhase 3
Testing shorter breast radiation after low-risk hormone breast cancer
This Phase 3 trial studies whether “less intense” radiation can work as well as standard radiation for certain early-stage hormone receptor–positive, HER2-negative breast cancers that have a low Oncotype DX score. It may help reduce treatment burden while keeping cancer control strong.
Auburn, CaliforniaAges 50–70 - NCT06778863RecruitingPhase 1
A study of CLSP-1025 for adults with certain solid tumors
This trial tests a new drug called CLSP-1025 for people with advanced solid tumors that have a specific change in the p53 gene (R175H). The drug targets this change to help fight the cancer.
Los Angeles, CaliforniaAges 18 years+ - NCT04333706RecruitingPhase 1/Phase 2
Sarilumab plus capecitabine for certain breast cancers
This trial studies whether adding sarilumab to capecitabine can shrink or control metastatic or high-risk breast cancer that lacks HER2 and is either triple-negative or hormone-resistant. It aims to find a safe dose first, then look at how well the treatment works compared with historical results.
Los Angeles, CaliforniaAges 18–99 - NCT07401381RecruitingPhase 1
Injectable vs. oral letrozole in early breast cancer
This study compares a new injectable form of the drug letrozole with the standard oral pill. It aims to find out if the injection works as well as the pill for women who have already taken letrozole for their early breast cancer and have finished their initial treatment.
Beverly Hills, CaliforniaAges 18–80 - NCT07087691Recruiting
Testing a device to mark breast cancer for surgery and monitoring
This trial tests a device called OneMark that helps doctors find and track breast cancer during surgery and follow-up. It may help make sure the cancer is removed completely.
La Jolla, 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.
Cerritos, CaliforniaAges 18 years+ - NCT03990896RecruitingPhase 2
Talazoparib for metastatic breast cancer with BRCA body DNA changes
This Phase 2 trial tests talazoparib, a targeted cancer medicine, in people with metastatic breast cancer that has a harmful BRCA1 or BRCA2 mutation found in tumor DNA circulating in the blood. If you qualify, the goal is to see how well this treatment works when the mutation is detected this specific way.
San Francisco, CaliforniaAges 18 years+ - NCT03804944RecruitingPhase 2
Vaccine trial for hormone-positive breast cancer
This Phase 2 study tests an individualized vaccine made from your tumor information to help your immune system fight hormone-positive breast cancer. You may be able to participate if you meet specific hormone-receptor, health, and treatment-timing requirements.
Los Angeles, CaliforniaAges 18–90 - NCT06172478RecruitingPhase 2
HER3-DXd for advanced solid tumors after prior treatment
This trial tests a new targeted drug called HER3-DXd for people with several types of advanced solid tumors that have stopped responding to standard treatments. The drug is an antibody-drug conjugate, designed to deliver chemotherapy directly to cancer cells that have a protein called HER3 on their surface.
Duarte, CaliforniaAges 18 years+ - NCT07186296Recruiting
Emerald blood test study for new cancer diagnosis
This study is testing a blood test that looks for signs of lung, breast, colorectal, pancreatic, or ovarian cancer. If you have just been told you might have one of these cancers and haven't started treatment yet, this study may be an option to help learn more about your cancer from a simple blood draw.
Long Beach, CaliforniaAges 45 years+ - NCT06840886RecruitingPhase 1
Study of PHST001 for advanced solid tumors
This trial tests an experimental drug called PHST001 for people with advanced solid tumors that have stopped responding to standard treatments. The study aims to see if PHST001 can help shrink or control the tumor.
Beverly Hills, CaliforniaAges 18 years+ - NCT05564377RecruitingPhase 2
Find targeted cancer treatments using genetic testing
This study matches people with advanced solid tumors to targeted treatment plans based on genetic testing. It also requires tumor sample testing to help doctors choose the most promising therapy for your specific tumor changes.
Arroyo Grande, CaliforniaAges Any age - NCT06492616RecruitingPhase 3
Elacestrant versus standard hormone therapy for early breast cancer
This trial compares a new medicine, elacestrant, to the usual hormone therapy for people with early-stage breast cancer that is hormone receptor-positive and HER2-negative, and who have a high chance of it coming back. The goal is to see if elacestrant works better at preventing the cancer from returning.
Bakersfield, CaliforniaAges 18 years+ - NCT05696626RecruitingPhase 3
Test a new pill plus abemaciclib versus standard therapy
This Phase 3 study compares lasofoxifene plus abemaciclib versus fulvestrant plus abemaciclib for ER-positive, HER2-negative breast cancer that has an ESR1 mutation. It looks for better tumor control in people whose cancer has progressed on hormone therapy (an aromatase inhibitor) and who meet specific safety and testing requirements.
Santa Rosa, CaliforniaAges 18 years+ - NCT05983432RecruitingPhase 1
Study of BL-B01D1 for advanced lung and other solid tumors
This trial tests an experimental drug called BL-B01D1 for people with several types of advanced solid tumors, especially non-small cell lung cancer and breast cancer. It's designed for those whose cancer has continued to grow after standard treatments.
Beverly Hills, CaliforniaAges 18 years+ - NCT01034033Recruiting
Blood and tumor genetic study for BRCA and related risks
This study collects blood (and possibly tumor tissue) to learn how certain inherited gene changes relate to breast and ovarian cancer risk. It may help researchers understand which people are most likely to develop these cancers and how tumors differ in high-risk patients.
Stanford, CaliforniaAges 18 years+ - NCT03418961RecruitingPhase 3
Study of heart-risk management for metastatic HER2 breast cancer
This trial follows people with metastatic HER2-positive breast cancer who are at higher risk for heart damage while on HER2-targeted therapy. Some participants are randomly assigned to different monitoring/heart-protection approaches to see what best helps keep the heart safe.
Mission Hills, CaliforniaAges 18 years+ - NCT06580002RecruitingPhase 2
Can Riluzole Help with Chemo Brain? A Pilot Study
This study tests if a medicine called riluzole (currently used for ALS) can help with 'chemo brain' – memory and thinking problems after cancer treatment. It is for people who feel their mental sharpness has declined after breast cancer therapy, certain chemotherapies, or brain radiation.
Orange, CaliforniaAges 18 years+ - NCT07214532Recruiting
Using a blood test to guide breast cancer therapy
This study tests whether a blood test can help decide when to start additional hormone-blocking therapy for early-stage breast cancer. It aims to see if starting therapy only when the test detects cancer DNA is as effective as giving it to everyone.
Loma Linda, CaliforniaAges 18 years+ - NCT06084481RecruitingPhase 1
Study of a new drug for advanced solid tumors
This study tests a new intravenous drug called ABBV-400 in people with certain advanced solid tumors that have not responded to other treatments. The goal is to see if it can slow or stop tumor growth and to check for side effects.
Duarte, CaliforniaAges 18 years+ - NCT07647328RecruitingPhase 3
Camizestrant and ribociclib for advanced hormone-receptor-positive breast cancer
This trial tests a combination of two drugs (camizestrant and ribociclib) for advanced breast cancer that is hormone-receptor-positive and HER2-negative. The study aims to see if this combination helps patients whose cancer cannot be surgically removed or treated with radiation alone.
Palo Alto, CaliforniaAges 18–130
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.
- USC Norris Comprehensive Cancer Center · 6 studies
- City of Hope · 5 studies
- Cedars-Sinai Medical Center · 3 studies
- Contra Costa Regional Medical Center · 3 studies
- Epic Care-Dublin · 3 studies
- UC San Diego Moores Cancer Center · 3 studies
- University of California, Davis · 3 studies
- Bay Area Breast Surgeons Inc · 2 studies
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.