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
- 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+ - NCT06297265Recruiting
Gentle breast massage after lumpectomy for breast cancer
This trial studies whether a special gentle massage technique (manual lymphatic drainage) can help women who have had breast-conserving surgery and will receive whole breast radiation. The goal is to see if it reduces side effects and improves recovery.
Los Angeles, CaliforniaAges 18 years+ - NCT06293898RecruitingPhase 1
Study of BL-M07D1 for HER2-positive solid tumors
This trial tests a new drug, BL-M07D1, for people with advanced solid tumors that have a protein called HER2. It is for patients who have already tried at least two other standard treatments.
Duarte, CaliforniaAges 18 years+ - NCT06268665RecruitingPhase 2
Tart Cherry Juice for Preventing Nerve Damage from Chemotherapy
This study tests whether tart cherry juice can help prevent nerve damage (peripheral neuropathy) caused by the chemotherapy drug paclitaxel. Participants drink tart cherry juice daily during their 12 weeks of paclitaxel treatment.
Sacramento, CaliforniaAges 18 years+ - NCT06253871RecruitingPhase 1
Study of IAM1363 for HER2 Cancers
This trial tests a new oral drug called IAM1363 for people with HER2-altered cancers that have stopped responding to previous treatments. The goal is to see if the drug is safe and how well it works against these cancers.
La Jolla, 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+ - NCT06113016RecruitingPhase 2
Preventing frailty with fisetin and exercise in breast cancer survivors
This study tests whether adding a supplement called fisetin to an exercise program can help prevent frailty in women who have finished chemotherapy for early-stage breast cancer. If you are postmenopausal, have completed chemo within the last year, and can walk a certain distance, you may qualify.
Alhambra, CaliforniaAges Any age - NCT06092892RecruitingPhase 2
Upfront targeted lymph node removal for early breast cancer
This trial is for women age 45 and older with early ER-positive breast cancer that has spread to the lymph nodes under the arm. It tests a surgery approach where the main tumor and only a few key lymph nodes (rather than many) are removed.
Los Angeles, CaliforniaAges 45 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+ - NCT03452774Recruiting
AI matches your cancer tests to possible treatment trials
This trial uses an AI system to help match people with certain cancer types and specific tumor test results (like gene or protein markers) to relevant clinical trials. It may help you and your doctor find studies that fit your cancer biology faster.
Duarte, CaliforniaAges Any age - NCT05929768RecruitingPhase 3
Shorter chemo plus immunotherapy without anthracyclines for early TNBC
This Phase 3 trial tests whether a shorter course of chemotherapy plus immunotherapy can work as well as standard treatment for early-stage triple-negative breast cancer. It avoids anthracycline drugs and may help reduce exposure to those medicines if the shorter plan is effective and safe.
Walnut Creek, 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+ - 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.
Los Angeles, CaliforniaAges 18 years+ - NCT06075810RecruitingPhase 1
Oral MBQ-167 for advanced breast cancer
This trial tests an experimental oral drug, MBQ-167, for people with advanced breast cancer who have tried other treatments or have no standard options left. The goal is to see if the drug can help slow or stop the cancer.
Beverly Hills, CaliforniaAges 21 years+ - NCT04553770RecruitingPhase 2
Trastuzumab deruxtecan with or without anastrozole for early breast cancer
This Phase 2 study tests whether trastuzumab deruxtecan alone or combined with anastrozole can control early-stage breast cancer that is HER2-low and hormone-receptor positive. It aims to improve outcomes after initial surgical treatment by targeting cancer cells that may have low levels of HER2.
Fullerton, 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+ - NCT05964504Recruiting
Registry study for metastatic lobular breast cancer
This study collects health information from adults with invasive lobular breast cancer that has spread (metastatic) to help researchers understand factors linked to survival. Joining may help build better knowledge for future treatments and care planning.
San Diego, CaliforniaAges 18 years+ - NCT05941520RecruitingPhase 2
Acolbifene vs low-dose tamoxifen to prevent breast cancer
This Phase 2 trial compares acolbifene and low-dose tamoxifen to see which better lowers breast cancer risk in premenopausal women at high risk. You would be followed with health visits, blood tests, and a breast tissue sampling procedure.
Duarte, CaliforniaAges 35 years+ - NCT05902507Recruiting
MRI guidance during breast cancer radiation treatment
This trial studies using MRI images to help plan and guide radiation therapy after breast-conserving surgery. It may help doctors target the right area more accurately while keeping treatment standard and safe.
San Francisco, 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.
San Jose, 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+ - 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 - NCT05595499RecruitingPhase 2
Fisetin for better walking and strength in breast cancer survivors
This study tests whether fisetin (a natural compound) can improve physical function, like walking ability, in breast cancer survivors who feel frail. It may help strengthen muscles and improve daily activity after treatment.
Alhambra, CaliforniaAges Any age - NCT05579366RecruitingPhase 1/Phase 2
Study of rinatabart sesutecan for advanced solid tumors
This trial tests an investigational drug called rinatabart sesutecan (also known as Rina-S) for people with advanced solid tumors, including ovarian, endometrial, lung, breast, and other cancers. The drug is designed to target and kill cancer cells, and the study aims to see if it is safe and effective.
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 · 6 studies
- Cedars-Sinai Medical Center · 4 studies
- Alta Bates Summit Medical Center-Herrick Campus · 3 studies
- Cedars-Sinai Cancer - Tarzana · 3 studies
- Desert Regional Medical Center · 3 studies
- Huntington Memorial Hospital · 3 studies
- Loma Linda University Medical Center · 3 studies
- Mills Health Center · 3 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.