Clinical trials · California
Locally Advanced Breast Cancer clinical trials in California
We’re tracking 124 recruiting locally advanced breast cancer studies with a site in California — including Phase 1, Phase 1/Phase 2, Phase 2, Phase 3 and Phase 4 studies, each written for real people, not researchers.
Recruiting studies in California
- NCT05216432RecruitingPhase 1
RLY-2608 for PIK3CA-mutant advanced solid tumors and breast cancer
This early study (Phase 1) tests RLY-2608, a targeted cancer drug for tumors with a PIK3CA mutation. It studies the drug alone and combined with hormone therapy (and sometimes CDK4/6 or CDK4 medicines) to see safety, dose, and whether it can shrink tumors.
San Diego, 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+ - NCT05455619RecruitingPhase 1/Phase 2
Targeted drugs for PI3K-altered, HR+/HER2- breast cancer
This Phase 1/2 trial tests how well a combination of targeted medicines works for advanced or returning HR+/HER2- breast cancer that has a PI3K pathway change (such as PIK3CA, PTEN, or AKT1). It may help by blocking growth signals in the cancer and is especially for people whose cancer has progressed after hormone therapy and a CDK4/6 inhibitor.
Newport, CaliforniaAges 18 years+ - NCT05508906RecruitingPhase 1
Test drug OP-1250 with other medicines in ER-positive breast cancer
This Phase 1b study tests OP-1250 (palazestrant) combined with other targeted medicines for ER-positive, HER2-negative advanced or metastatic breast cancer. It mainly looks at safety and correct dosing, but may also help shrink tumors or slow growth.
San Francisco, CaliforniaAges 18 years+ - NCT05524584RecruitingPhase 2
Anastrozole, fulvestrant, and abemaciclib for hormone-positive breast cancer
This trial tests whether combining three medicines can better control hormone-receptor–positive, HER2-negative metastatic breast cancer that cannot be cured with surgery or radiation. It may help shrink tumors and slow disease growth compared with standard hormone therapy approaches.
Orange, CaliforniaAges 18 years+ - NCT05579366RecruitingPhase 1/Phase 2
Study drug for advanced ovarian and other solid cancers
This Phase 1/2 trial studies Rinatabart Sesutecan to treat advanced cancers, with special focus on certain ovarian cancer types. It’s meant for people whose cancer has come back or has not responded to prior treatments.
Los Angeles, 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+ - NCT05774951RecruitingPhase 3
Camizestrant for hormone-positive, HER2-negative early breast cancer
This trial tests camizestrant, a medicine that blocks estrogen signaling, to help prevent hormone-positive, HER2-negative early breast cancer from coming back. You may be eligible if your cancer has higher- or intermediate-risk features and you already completed at least 2 years of hormone therapy.
Anaheim, CaliforniaAges 18–130 - NCT05888532RecruitingPhase 1/Phase 2
Testing a copper-based scan and treatment in advanced cancers
This Phase 1/2 trial studies a copper-labeled medicine called 64Cu-GRIP B in people with advanced, metastatic cancers. It may help doctors see where cancer is and how well the drug works, especially alongside immune checkpoint therapy for some cancer types.
San Francisco, CaliforniaAges 18 years+ - NCT05894239RecruitingPhase 3
Tested targeted drug for HER2-positive breast cancer with PIK3CA changes
This Phase 3 study tests inavolisib plus Phesgo versus placebo plus Phesgo in people whose breast cancer has both HER2-positive and PIK3CA-mutated tumor markers. The goal is to see if adding inavolisib improves how well the treatment controls the cancer and how safe it is.
Burbank, CaliforniaAges 18 years+ - NCT05952557RecruitingPhase 3
Camizestrant after surgery for hormone-sensitive early breast cancer
This trial studies whether adding camizestrant (a hormone-blocking medicine) after breast cancer surgery can lower the chance the cancer returns in ER+/HER2− early breast cancer. It is designed for people who have had definitive local treatment and are being considered for additional “prevention” hormone therapy.
Duarte, CaliforniaAges 18–130 - 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.
Orange, CaliforniaAges 18 years+ - NCT06016738RecruitingPhase 3
Palazestrant vs standard therapy for advanced breast cancer
This trial compares a new oral drug, palazestrant (OP-1250), to standard hormone therapies for people with ER+/HER2- advanced breast cancer that has worsened after prior hormone therapy. It tests whether palazestrant can better control the cancer.
Fountain Valley, CaliforniaAges 18 years+ - NCT06072612RecruitingPhase 3
Bria-IMT plus CPI vs standard care for advanced breast cancer
This trial tests a new combination of two immunotherapy drugs (Bria-IMT and a checkpoint inhibitor) against your doctor's choice of standard treatments. It is for people with advanced breast cancer that has spread and who have already tried several prior therapies.
Anaheim, CaliforniaAges 18 years+ - NCT06099769RecruitingPhase 2
Testing enzalutamide with or without mifepristone for AR-positive breast cancer
This trial tests if adding the drug mifepristone to the standard antiandrogen enzalutamide works better than enzalutamide alone or chemotherapy for people with a specific type of breast cancer that has androgen receptors. It aims to find a new targeted treatment option for triple-negative or ER-low breast cancer.
San Francisco, CaliforniaAges 18 years+ - 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+ - NCT06224673RecruitingPhase 2
Testing ARX788 for HER2-low advanced breast cancer
This trial tests a new drug, ARX788, for people with HER2-low breast cancer that has spread or cannot be removed by surgery. The goal is to see if ARX788 helps shrink or control the cancer.
San Francisco, CaliforniaAges 18 years+ - NCT06242470RecruitingPhase 1
Study of MGC026 for advanced solid tumors
This trial tests a new drug called MGC026 that targets a protein called B7-H3 on cancer cells, aiming to shrink or slow different advanced solid tumors. It is an early-phase study to find the right dose and check safety.
Los Angeles, CaliforniaAges 18 years+ - NCT06263543RecruitingPhase 2
Sequencing antibody-drug conjugates in ER+, HER2-low breast cancer
This trial tests different sequences of antibody-drug conjugates (a type of targeted chemotherapy) for people with ER-positive, HER2-low or ultra-low metastatic breast cancer that has stopped responding to hormone therapy and has progressed on Enhertu. You must have had 1–4 prior chemotherapies for metastatic disease.
Los Angeles, CaliforniaAges 18 years+ - NCT06312176RecruitingPhase 3
Study of new drugs for HR+/HER2- advanced breast cancer
This trial tests two new drugs (sacituzumab tirumotecan and pembrolizumab) against standard treatments for a type of advanced breast cancer that is hormone receptor positive and HER2 negative. It's for people whose cancer has worsened despite hormone therapy with a CDK4/6 inhibitor.
Fullerton, CaliforniaAges 18 years+ - NCT07452224RecruitingPhase 2
Combination treatment for advanced lung cancer
This trial tests a new drug, ILKN421H, combined with pembrolizumab (a type of immunotherapy) for people with advanced non-small cell lung cancer (NSCLC) that has not responded to standard treatments or has not been treated before. It aims to see if this combination can help shrink tumors or slow their growth.
Los Angeles, CaliforniaAges 18 years+ - NCT07357597RecruitingPhase 4
Preventing mouth sores during breast or lung cancer treatment
This trial tests whether a steroid mouthwash can prevent mouth sores caused by the drug Datopotamab Deruxtecan (Dato-DXd). It is for people with certain types of advanced breast cancer or lung cancer who are about to start Dato-DXd for the first time.
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.
Duarte, CaliforniaAges 18–130 - NCT06440005RecruitingPhase 1
Testing AGX101 for advanced solid tumors
This study tests a new drug called AGX101 for people with advanced solid tumors that have not responded to other treatments. The goal is to see if it is safe and if it can shrink tumors or slow their growth.
Los Angeles, CaliforniaAges 18 years+
Locally Advanced Breast Cancer trials by city in California
Where these studies are running in California
Institutions with a site for the recruiting locally advanced breast cancer studies listed above.
- Research Site · 4 studies
- University of California, San Francisco · 4 studies
- City of Hope Comprehensive Cancer Center · 3 studies
- Providence Medical Foundation · 3 studies
- University of California San Diego · 3 studies
- University of California, Los Angeles (UCLA) · 3 studies
- Hoag Memorial Hospital Presbyterian · 2 studies
- University of California, Irvine Medical Center / UC Irvine Health · 2 studies
What taking part in a locally advanced 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.
Locally Advanced Breast Cancer trials in other states
Common questions
- Are there locally advanced breast cancer clinical trials in California?
- Yes. We're currently tracking 124 recruiting locally advanced 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 locally advanced 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 locally advanced 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 locally advanced 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.