Purpose: To study the safety, best dose, effects (good and bad), and anti-cancer activity of STX-478, an experimental PI3K inhibitor, alone or with fulvestrant (Faslodex®) hormone therapy.

Who is this for?: People with advanced (stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) breast cancer with a PI3K mutation. You must not have a PTEN, AKT, or mTOR mutation. View full eligibility criteria

Purpose: To study the dose, safety, side effects, and anti-cancer activity of giving the targeted therapies capivasertib and palbociclib (Ibrance®) with the anti-estrogen therapy fulvestrant (Faslodex®).

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) estrogen receptor-positive (ER+), HER2-negative (HER2-) breast cancer. Your cancer must have progressed on anti-estrogen therapy. View full eligibility criteria

Purpose: To use genetic testing to match people to treatments and help doctors plan better treatments.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) breast cancer who have received at least 1 line of therapy for advanced disease or who have no standard treatment options available. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of RLY-2608 PI3Kα inhibitor plus fulvestrant (Faslodex®) hormone therapy versus capivasertib (Truqap®) AKT inhibitor plus fulvestrant (Faslodex®).

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) breast cancer with a PIK3CA mutation whose cancer has progressed while receiving 1 or 2 lines of hormone therapy and a CDK4/6 inhibitor. You must not have received certain treatments that are listed below. View full eligibility criteria

Purpose: To study the safety, best dose, effects (good and bad), and anti-cancer activity of elacestrant (Orserdu®) hormone therapy in combination with other anti-cancer therapies.

Who is this for?: People with metastatic (stage IV) estrogen receptor positive (ER+), HER2 negative (HER2-) breast cancer who have not received treatment with chemotherapy or elacestrant (Orserdu®) for advanced/metastatic disease. View full eligibility criteria

Purpose: To study the safety, best dose, and effects (good and bad) of MEN2312, an experimental KAT6 inhibitor, alone or with elacestrant (Orserdu®) hormone therapy.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+) breast cancer who have received a CDK4/6 inhibitor with hormone therapy for advanced disease. You must have received no more than 6 lines of therapy for advanced disease, including no more than 2 lines of chemotherapy and/or antibody drug conjugates (ADC). View full eligibility criteria

Purpose: To study the safety, best dose, and effects (good and bad) of alisertib, an experimental AURKA inhibitor, with standard of care hormone therapy.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) breast cancer who have received at least two hormone therapies including a CDK4/6 inhibitor with hormone therapy for advanced disease. You must not have received chemotherapy for advanced disease. View full eligibility criteria

Purpose: To study the safety, side effects, dose, and anti-cancer activity of giving PF-07248144 alone, in combination with fulvestrant, or with palbociclib and letrozole.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) estrogen-receptor positive (ER+), HER2-negative (HER2-) breast cancer whose disease progressed after receiving a CDK 4/6 inhibitor and anti-estrogen therapy. View full eligibility criteria

Purpose: To study the safety, best dose, effects (good and bad), and anti-cancer activity of ETX-636, an experimental targeted therapy, with fulvestrant (Faslodex®) hormone therapy.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) breast cancer with PIK3CA mutations who have received at least 1 CDK4/6 inhibitor and hormone therapy. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of PF-07220060, an experimental CDK4 inhibitor, with letrozole (Femara®) hormone therapy compared to standard of care treatment.

Who is this for?: People with newly diagnosed advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) breast cancer who have not yet received treatment for advanced disease. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of OP-1250, an experimental hormone therapy, with ribociclib (Kisqali®) CDK 4/6 inhibitor or alpelisib (Piqray®) PI3K inhibitor.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) breast cancer who have received 1-2 hormone therapies for advanced or metastatic disease. You must not have received more than 1 chemotherapy for advanced or metastatic disease. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of enzalutamide (Xtandi®), an experimental hormone therapy, alone or with mifepristone, an experimental hormone therapy, compared to standard of care chemotherapy.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) triple negative (ER- or ER low, PR- or PR low, HER2-) or ER low, androgen receptor positive (AR+) breast cancer who have received 0-1 lines of chemotherapy for advanced disease. View full eligibility criteria

Purpose: To study the anti-cancer activity and safety of giving the experimental anti-estrogen therapy giredestrant alone or with a CDK 4/6 inhibitor, an AKT inhibitor, a PI3K inhibitor, or chemotherapy.

Who is this for?: Women with advanced (some stage III) or metastatic (stage IV) estrogen-receptor positive (ER+), HER2-negative (HER2-) breast cancer whose disease progressed while taking anti-hormone therapy with a CDK 4/6 inhibitor and who have not received chemotherapy for metastatic disease. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of inavolisib (Itovebi®) PI3K inhibitor with palbociclib (Ibrance®) CDK4/6 inhibitor and letrozole (Femara®) aromatase inhibitor.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) breast cancer with a PIK3CA mutation. You must have been diagnosed with de novo advanced/metastatic breast cancer or received at least 2 years of hormone therapy and completed hormone therapy at least 1 year before your advanced/metastatic diagnosis. You must have not yet received treatment for advanced disease. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of giredestrant, an experimental hormone therapy, compared with fulvestrant (Faslodex®) hormone therapy in combination with a CDK4/6 inhibitor.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) estrogen receptor positive (ER+), HER2 negative (HER2-) breast cancer who not have received treatment (except for surgery or radiation) for advanced disease. View full eligibility criteria

Purpose: To compare the safety, effects (good and bad), and anti-cancer activity of Tersolisib (LY4064809), an experimental PI3Ka inhibitor, with standard of care CDK4/6 inhibitor and hormone therapy.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) or HER2 low breast cancer with a PIK3CA mutation. You may have received 0-2 prior treatments for advanced or metastatic breast cancer. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of BMS-986500, a CDK4/6 inhibitor.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+) breast cancer. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of LY4257496 GRPR radiopharmaceutical with or without standard of care therapy.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) estrogen receptor positive (ER+) breast cancer. Your tumor must be positive for gastrin-releasing peptide receptor (GRPR). View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of lasofoxifene, an experimental hormone therapy, with abemaciclib (Verzenio®) CDK4/6 inhibitor.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) estrogen receptor positive (ER+), HER2 negative (HER2-) breast cancer with an ESR1 mutation. You must have received an aromatase inhibitor with palbociclib (Ibrance®) or ribociclib (Kisqali®) CDK4/6 inhibitor as your first line of hormone therapy for advanced disease. You must not have received more than 1 line of chemotherapy for advanced disease. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of belzutifan (MK-6482), an experimental targeted therapy, with hormone therapy compared to standard of care targeted therapy and hormone therapy.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) estrogen receptor positive (ER+), HER2 negative (HER2-) breast cancer who have received at least 1 line of hormone therapy for advanced disease. You must not have received chemotherapy or a PARP inhibitor for advanced disease. View full eligibility criteria

Purpose: To study the safety, best dose, and effects (good and bad) of RLY-2608 alone and in combination with fulvestrant (Faslodex®).

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) breast cancer with a PIK3CA mutation. View full eligibility criteria

Purpose: To compare the safety, effects (good and bad), and anti-cancer activity of saruparib, an experimental PARP1 inhibitor, with camizestrant, an experimental hormone therapy, to standard of care CDK4/6 inhibitor with hormone therapy.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) or HER2 low (IHC 1+ or IHC 2+/ISH-) breast cancer with BRCA1, BRCA2, or PALB2 mutations. View full eligibility criteria

Purpose: To study the safety, best dose, and effects (good and bad) of 177Lu-Lu-NeoB, an experimental radioactive drug, with ribociclib (Kisqali®) targeted therapy and fulvestrant (Faslodex®) hormone therapy.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) estrogen receptor positive (ER+), HER2 negative (HER2-) or HER2 low, gastrin releasing peptide receptor (GRPR) positive (GRPR+) breast cancer who have received no more than 1 line of therapy for advanced disease. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of ECI830, an experimental; CDK2 inhibitor, with ribociclib (Kisqali®) CDK4/6 inhibitor and fulvestrant (Faslodex®) hormone therapy.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) breast cancer who have received an aromatase inhibitor or tamoxifen (Nolvadex®) with a CDK4/6 inhibitor. You must not have received more than 2 lines of hormone therapy. View full eligibility criteria

Purpose: To study the safety, best dose, and effects (good and bad) of PMD-026, an experimental targeted therapy, with fulvestrant (Faslodex®) hormone therapy.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-), RSK2 positive (RSK2+) breast cancer who have received a CDK4/6 inhibitor with hormone therapy for advanced disease. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of AVZO-023 CDK4 inhibitor in combination with hormone therapy and an experimental CDK2 inhibitor.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) breast cancer. You must not have received CDK2, 4, and/or 6 inhibitors. You must not have active, untreated brain metastases. View full eligibility criteria

Purpose: To study the safety, best dose, effects (good and bad), and anti-cancer activity of OKI-219, an experimental PI3Kα inhibitor, with fulvestrant (Faslodex®) hormone therapy or trastuzumab (Herceptin®) anti-HER2 targeted therapy.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) or HER2 positive (HER2+) breast cancer with a PI3KαH1047R mutation. View full eligibility criteria

Purpose: To study the safety, best dose, effects (good and bad), and anti-cancer activity of RGT-419B, an experimental type of targeted therapy called a CDK 2/4/6 inhibitor, alone and with hormone therapy.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) breast cancer that has progressed after treatment with a CDK 4/6 inhibitor and hormone therapy. You must not have received more than 1 line of chemotherapy. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of gedatolisib, an experimental targeted therapy, with standard of care CDK4/6 inhibitor and hormone therapy compared to standard of care alone.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) breast cancer who were diagnosed with advanced disease during or within 1 year of completing hormone therapy. You must have not yet received treatment for advanced disease. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of palazestrant (OP-1250), an experimental hormone therapy.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) estrogen receptor positive (ER+), HER2 negative (HER2-) breast cancer who have received a CDK4/6 inhibitor with hormone therapy for advanced disease. You must not have received chemotherapy or more than 2 lines of hormone therapy for advanced disease. View full eligibility criteria

Purpose: To study the safety, best dose, effects (good and bad), and anti-cancer activity of elacestrant, an experimental hormone therapy, alone or with abemaciclib (Verzenio®) CDK 4/6 inhibitor.

Who is this for?: People with metastatic (stage IV) estrogen receptor positive (ER+), HER2 negative (HER2-) or HER2 low breast cancer that has spread to the brain (brain metastasis) who have received at least 1 hormone therapy, up to 2 chemotherapies, and up to 2 CDK 4/6 inhibitors for metastatic disease. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of GDC-4198 CDK2/4/6 inhibitor and giredestrant oral SERD compared with abemaciclib (Verzenio®) CDK4/6 inhibitor and giredestrant.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) estrogen receptor positive (ER+), HER2 negative (HER2-) breast cancer who have experienced disease progression during or after receiving a CDK4/6 inhibitor and hormone therapy. You must not have received more than 1 line of therapy or chemotherapy. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of BGB-21447, an experimental targeted therapy, with fulvestrant (Faslodex®) hormone therapy, with or without BGB-43395, an experimental CDK4 inhibitor.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) breast cancer who have received at least 2 lines of therapy for advanced disease and hormone therapy with a CDK4/6 inhibitor for early stage or advanced disease. View full eligibility criteria

Purpose: To study the safety, best dose, effects (good and bad), and anti-cancer activity of evexomostat (SDX-7320), an experimental polymer drug conjugate, with fulvestrant (Faslodex®) hormone therapy and alpelisib (Piqray®) PI3K inhibitor.

Who is this for?: Women with advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) breast cancer with a PIK3CA mutation who have high blood sugar. You must have received hormone therapy and a CDK 4/6 inhibitor. View full eligibility criteria

Purpose: To study the safety, best dose, effects (good and bad), and anti-cancer activity of ARTS-021, an experimental CDK2 inhibitor, alone or with other anti-cancer drugs.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) or HER2 low breast cancer who have received a CDK4/6 inhibitor with hormone therapy for advanced disease. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of AMXT 1501 and DFMO when combined with standard treatments.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) breast cancer with alterations in the genes, PIK3CA, AKT1, or PTEN, whose cancer has progressed on at least 2 hormone therapies. View full eligibility criteria

Purpose: To study the safety, best dose, and effects (good and bad) of BTX-9341, an experimental CDK4/6 inhibitor, with fulvestrant (Faslodex®) hormone therapy.

Who is this for?: Advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) breast cancer who have received 1-2 lines of hormone therapy with CDK4/6 inhibitor. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of PF-07248144 plus fulvestrant (Faslodex®).

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) breast cancer whose cancer has progressed while receiving hormone therapy and/or palbociclib (Ibrance®), ribociclib (Kisqali®), or abemaciclib (Verzenio®). You must not have received more than 2 prior lines of therapy for your advanced or metastatic cancer or prior chemotherapy, including antibody-drug conjugates (ADCs). View full eligibility criteria

Purpose: To study increasing the dose of CDK4/6 inhibitors to help people manage side effects and continue taking CDK4/6 inhibitors as prescribed.

Who is this for?: People at least 65 years old with metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) breast cancer who are planning to receive a CDK4/6 inhibitor with hormone therapy. View full eligibility criteria

Purpose: To study the safety, best dose, effects (good and bad), and anti-cancer activity of INX-315, an experimental CDK2 inhibitor, alone or with other anti-cancer therapies.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) estrogen receptor positive (ER+), HER2 negative (HER2-) breast cancer who have received treatment with a CDK4/6 inhibitor or CCNE1 amplified breast cancer with no standard treatment options available. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of an experimental vaccine with immunotherapy.

Who is this for?: People with metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) or HER2 low breast cancer who have received at least 1 line of therapy. View full eligibility criteria

Purpose: To study how well functional imaging PET/CT scans with FFNP can predict your cancer's response to abemaciclib (Verzenio®) CDK4/6 inhibitor with standard of care hormone therapy.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) estrogen receptor positive (ER+ or ER low), HER2 negative (HER2-) or HER2 low breast cancer who are planning to receive abemaciclib (Verzenio®). You must have received no more than 1 line of chemotherapy for advanced disease. You must not have liver only metastases. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of palazestrant oral SERD/CERAN plus ribociclib (Kisqali®) CDK4/6 inhibitor versus letrozole (Femara®) hormone therapy plus ribociclib (Kisqali®).

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) estrogen receptor positive (ER+), HER2 negative (HER2-) breast cancer who have not yet received treatment for their advanced cancer. You must not have received fulvestrant (Faslodex®) or elacestrant (Orserdu®) at any time. View full eligibility criteria

Purpose: To study the safety, best dose, effects (good and bad), and anti-cancer activity of alpelisib (Piqray®) PI3K inhibitor and tucatinib (Tukysa) anti-HER2 targeted therapy with or without fulvestrant (Faslodex®) hormone therapy.

Who is this for?: People with metastatic (stage IV) HER2 positive (HER2+) breast cancer with a PIK3CA mutation who have received 2+ anti-HER2 targeted therapies. View full eligibility criteria

Purpose: To study the safety, best dose, effects (good and bad), and anti-cancer activity of BGB-43395, an experimental CDK4 inhibitor, alone or with fulvestrant (Faslodex®) or letrozole (Femara®) hormone therapy.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) breast cancer who have received hormone therapy and a CDK4/6 inhibitor. You must not have received more than 2 lines of chemotherapy for advanced disease. View full eligibility criteria

Purpose: To compare the anti-cancer activity of MK-5684 hormone therapy to the standard of care hormone therapy treatment.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) breast cancer whose cancer has progressed during or after at least one line of hormone therapy. View full eligibility criteria

Purpose: To study the safety, best dose, effects (good and bad), and anti-cancer activity of EP0062, an experimental hormone therapy.

Who is this for?: Postmenopausal women with advanced (some stage III) or metastatic (stage IV) estrogen receptor positive (ER+), HER2 negative (HER2-) or HER2 low, androgen receptor positive (AR+) breast cancer with no standard treatment options available. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of BG-75202 KAT6A/B inhibitor alone and in combination with other therapies.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) breast cancer who have received 1 to 3 prior lines of therapy. You must not have received more than 2 lines that included chemotherapy and/or an antibody-drug conjugate (ADC). View full eligibility criteria

Purpose: To compare the safety, effects (good and bad), and anti-cancer activity of hormone therapy and capecitabine (Xeloda®) chemotherapy and use MammaPrint® and BluePrint tests to guide treatment decisions.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) breast cancer who have received treatment with hormone therapy and a CDK4/6 inhibitor. You must not have received chemotherapy or more than 1 line of hormone therapy for advanced disease or have a PIK3CA mutation. View full eligibility criteria

Purpose: To determine if stopping treatment with abemaciclib (Verzenio®) for 1 month (called a drug holiday) improves the effects (good and bad) and anti-cancer activity of abemaciclib (Verzenio®) with fulvestrant (Faslodex®).

Who is this for?: Women with metastatic (stage IV) ER positive (ER+) or ER Low (1%-10% ER), HER2 negative (HER2-) breast cancer that has progressed on a CDK4/6 inhibitor in combination with an aromatase inhibitor immediately before enrolling in this study. View full eligibility criteria

Purpose: To study the safety, best dose, effects (good and bad), and anti-cancer activity of AZD8421, an experimental CDK2 inhibitor, with camizestrant, an experimental SERD, and a CDK4/6 inhibitor.

Who is this for?: Women with advanced (some stage III) or metastatic (stage IV) estrogen receptor positive (ER+), HER2 negative (HER2-) breast cancer who have received a CDK4/6 inhibitor. View full eligibility criteria

Purpose: To study if FES-PET/CT scans can help find a personalized dose of tamoxifen (Nolvadex®).

Who is this for?: People with advanced (some stage III) or metastatic (stage IV), estrogen receptor positive (ER+), HER2 negative (HER2-) breast cancer that tests positive for a ESR1 mutation. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of elacestrant (Orserdu®) hormone therapy alone or combined with a CDK4/6 inhibitor.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) estrogen receptor positive (ER+), HER2 negative (HER2-) breast cancer with an ESR1 mutation. You must have received at least 2 types of hormone therapy, at least one of which was received in combination with a CDK4/6 inhibitor for your advanced or metastatic cancer. You must not have received elacestrant (Orserdu®). View full eligibility criteria

Purpose: To study the safety, best dose, effects (good and bad), and anti-cancer activity of AND019, an experimental hormone therapy.

Who is this for?: Postmenopausal women with advanced (some stage III) or metastatic (stage IV) estrogen receptor positive (ER+), HER2 negative (HER2-) breast cancer who have received standard treatment with at least 1 line of hormone therapy and no more than 1 line of chemotherapy for advanced/metastatic disease. You must not have received treatment with fulvestrant (Faslodex®) or any other SERD. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of GVV858 in combination with fulvestrant (Faslodex®).

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) breast cancer whose cancer has progressed on or after hormone therapy in combination with a CDK4/6 inhibitor. You must not have received more than 2 lines of hormone therapy. You must not have received chemotherapy, or an antibody-drug conjugate (ADC) for advanced disease. Your tumor must have an abnormality called CCNE1 amplification. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of PF-08032562 and fulvestrant (Faslodex®).

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) breast cancer whose cancer has progressed after receiving at least 1 line of CDK4/6 inhibitor and at least 1 line of hormone therapy. View full eligibility criteria

Purpose: To compare a low dose of leuprolide (Lupron®), a high dose of leuprolide (Lupron®), and goserelin (Zoladex®) for their ability to reduce estrogen production.

Who is this for?: Pre-menopausal or peri-menopausal women with stage I, stage II, stage III, or stage IV (metastatic) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) breast cancer who are planning to receive a gonadotropin releasing hormone (GnRH) agonist plus hormone therapy. You must have completed chemotherapy if recommended. View full eligibility criteria

Purpose: To study the anti-cancer activity and side effects of giving the CDK 4/6 inhibitor abemaciclib (Verzenio®), hormone therapy, and stereotactic radiation therapy together to treat brain metastases.

Who is this for?: People with metastatic (stage IV) hormone receptor-positive, HER2 negative (HER2-) breast cancer that has spread to the brain. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of tamoxifen (Nolvadex®) hormone therapy with pegylated liposomal doxorubicin (Doxil®) chemotherapy.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) triple negative (ER- or ER low, PR-, HER2- or HER2 low) breast cancer who have received at least 2 lines of therapy. View full eligibility criteria

Purpose: To study whether providing cancer treatment in the home is preferred over the traditional clinic setting.

Who is this for?: People with stage I, stage II, stage III, or stage IV (metastatic) breast cancer who live in the Florida panhandle area, who are receiving and tolerating standard treatment for their cancer, and who plan to continue to receive these medications for the next 3 months or more. You must not be receiving all your medications by mouth. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of an experimental dendritic cell vaccine with elacestrant (Orserdu®) hormone therapy.

Who is this for?: People with metastatic (stage IV) hormone receptor positive (ER+ or ER low and/or PR+ or PR low), HER2 negative (HER2- or HER2 low) breast cancer with ESR1 mutations. You must have received a CDK4/6 inhibitor with hormone therapy for metastatic disease. View full eligibility criteria

Purpose: To study a new order of giving currently approved drugs to treat metastatic breast cancer.

Who is this for?: Women with metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) breast cancer who have received an aromatase inhibitor or tamoxifen (Nolvadex®). View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of afuresertib (LAE002), an experimental AKT inhibitor, with fulvestrant (Faslodex®) hormone therapy.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) hormone positive (ER+ and/or PR+), HER2 negative (HER2-) breast cancer with PIK3CA, AKT1, or PTEN mutations that has progressed after 1 -2 lines of therapy. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of lenvatinib (Lenvima®) tyrosine kinase inhibitor, pembrolizumab (Keytruda®) PD-1 inhibitor, and fulvestrant (Faslodex®) hormone therapy.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) estrogen receptor positive (ER+) or ER low, HER2 negative (HER2-) breast cancer who have received hormone therapy with a CDK4/6 inhibitor for advanced disease. You must not have received more than 2 lines of chemotherapy for advanced disease or a PD-1/PD-L1 inhibitor. View full eligibility criteria

Purpose: To study the safety, dose, side effects and anti-cancer activity of giving the CDK 4/6 inhibitor abemaciclib (Verzenio®) together with bicalutamide (Casodex®), an anti-androgen drug.

Who is this for?: Postmenopausal women with advanced (some stage III) or metastatic (stage IV) androgen receptor positive (AR+) HER2 negative breast cancer. You must have received at least one line of therapy for advanced disease. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of hormone therapy and targeted therapy based on biomarker testing.

Who is this for?: Post-menopausal women with advanced (some stage III) or metastatic (stage IV) estrogen receptor positive (ER+) or ER low, HER2 negative (HER2-) or HER2 low breast cancer. You must have received treatment with palbociclib (Ibrance®), ribociclib (Kisqali®), or abemaciclib (Verzenio®) for advanced disease. View full eligibility criteria

Purpose: To study the safety, best dose, and effects (good and bad) of olaparib (Lynparza®) PARP inhibitor with estradiol (Estrace®) hormone therapy.

Who is this for?: Postmenopausal women with advanced (some stage III) or metastatic (stage IV) estrogen receptor positive (ER+), HER2 negative (HER2-) breast cancer who have received at least 1 line of hormone therapy for advanced disease. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of estradiol (Estrace®) hormone therapy.

Who is this for?: Postmenopausal women with advanced (some stage III) or metastatic (stage IV) estrogen receptor positive (ER+) breast cancer who have received at least 1 line of hormone therapy for advanced disease. View full eligibility criteria

Purpose: To study the safety, effects (good and bad), and anti-cancer activity of capecitabine (Xeloda®) chemotherapy and elacestrant (Orserdu®) oral SERD versus capecitabine alone.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) estrogen receptor positive (ER+), HER2 negative (HER2-) breast cancer whose cancer has progressed while receiving 1 or 2 lines of hormone therapy and palbociclib (Ibrance®), ribociclib (Kisqali®), or abemaciclib (Verzenio®) for at least 6 months. View full eligibility criteria

Purpose: To study the safety, best dose, effects (good and bad), and anti-cancer activity of VS-6766, an experimental RAF/MEK inhibitor, with abemaciclib (Verzenio®) CDK 4/6 inhibitor and fulvestrant (Faslodex®) hormone therapy.

Who is this for?: People with advanced (some stage III) or metastatic (stage IV) hormone receptor positive (ER+ and/or PR+), HER2 negative (HER2-) breast cancer. You must have received treatment with fulvestrant (Faslodex)® for advanced/metastatic disease and a CDK 4/6 inhibitor after surgery (adjuvant) or for advanced/metastatic disease. View full eligibility criteria