Inclusion Criteria:

1. Subjects will be between the ages of 15 and 75, inclusive. 2. Subjects must have a histologically confirmed diagnosis of a solid tumor metastatic to bone, or a histologically confirmed diagnosis of a solid tumor to the bone or metastatic to the bone. 3. Subjects must have measurable disease on anatomic imaging that is also avid for phosphonate compounds as demonstrated by a positive 99mTc diphosphonate bone scan. Not all lesions must be positive on bone scan. 4. Adequate organ function, including: i. Adequate renal function, defined as a measured creatinine clearance >70 mL/min/1.73 m2 or normal radioisotope glomerular filtration rate (GFR). ii. Adequate hematologic function, defined as a platelet count >100,000 cells/mm3 and an absolute neutrophil count (ANC) >1,000 cells/mm3. 5. Life expectancy of at least eight weeks. 6. Karnofsky performance status >50%. 7. Subjects must have adequately recovered from the effects of any prior chemotherapy, as determined by the treating physician and study team, based in part on organ function defined above. Toxicities from previous therapies must have recovered to CTCAE v5.0 grade ≤1. Subjects with Grade 2 anemia per CTCAE v5.0 will be permitted as long as the subject has normal cardiac function. 8. Adequate cardiac function. Subjects with previously identified cardiac disease will be eligible, as 153Sm-DOTMP is not expected to cause cardiac dysfunction and is only expected to result in very transient hypocalcemia. 9. A stem cell product collected either by peripheral stem cell mobilization or bone marrow harvest prior to the infusion of CycloSam® must be available, prior to trial entry. A minimum of 2 x 106 CD34+ cells/kg ideal body weight are required. 10. Female subjects of child-bearing potential (defined as premenopausal and capable of becoming pregnant) must have a negative serum pregnancy test at the Screening visit. Females must be surgically sterile, postmenopausal for at least one year prior to Screening (no other medical cause involved) with a Follicle Stimulating Hormone (FSH) level of greater than 40 mIU/mL or must be using a highly effective method of birth control and agree to its use for at least 30 days following the last dose of 153Sm-DOTMP. Highly effective methods of contraceptive are defined as tubal ligation or an approved hormonal contraceptive such as oral contraceptives, patches, implants, injections, rings, or hormonally-impregnated intrauterine device. 11. Male subjects with partners of child-bearing potential must agree to use highly effective methods of contraception for at least 90 days after the last dose of 153Sm-DOTMP. 12. The subject and/or the subject's legally authorized guardian, if the subject is a minor, must acknowledge in writing that informed consent to become a study subject has been obtained, in accordance with institutional policies approved by the U.S. Department of Health and Human Services. 13. Subjects must have previously received effective treatment for their underlying disease and have no potentially curative options available. 14. The concurrent use of hormonal therapies or bisphosphonates is acceptable, provided the latter do not render target lesions invisible on 99mTc bone scan. Subjects will have the option to re-screen up to once more after seven days if they do not initially meet all of the inclusion criteria

Exclusion Criteria:

1. Subject is pregnant or breastfeeding. 2. Subject is sexually active and does not agree to use accepted, effective forms of contraceptive. 3. Subject has received prior radiotherapy to all known areas of current active disease. 4. Subject has a body mass index (BMI) > 50 kg/m2.

Inclusion Criteria:

• HER2-positive status will be based on pretreatment biopsy material and defined as an immunohistochemistry (IHC) score of 3+ and/or positive by in situ hybridization (ISH) according to current American Society of Clinical Oncology (ASCO) College of American Pathologists (CAP) guidelines. Central testing is not required * Known hormone receptor (HR) status as defined by ASCO/CAP guidelines (based on pretreatment biopsy material). Hormone receptor positive status can be determined by either known positive estrogen receptor (ER) or known positive progesterone receptor (PR) status; hormone receptor negative status must be determined by both known negative ER and known negative PR
• Patients with clinical stage T1-4, N0-3 disease at presentation and residual invasive disease postoperatively as defined above are eligible. (Note: Patients with T1a/bN0 tumors are not eligible at initial breast cancer diagnosis are not eligible)
• Patients with residual HR-negative, HER2 positive (+) disease in the breast and/or lymph nodes per the surgical pathology report are eligible; however, patients with HR+ HER2+ cancers must have node-positive residual disease per the surgical pathology report in order to qualify for the study. The presence of residual invasive disease in the breast is not mandatory for these patients
• Patients with weakly ER-positive (1-10%) breast cancer (based on the pretreatment core biopsy) are eligible even if they have node-negative disease per the surgical pathology report
• The residual disease tissue (breast and/or lymph nodes) is not required to be HER2-positive, as eligibility for NCI-2020-03770 (A011801) is based on a positive HER2 status at the time of the initial breast cancer diagnosis * Note: The presence of micrometastases in lymph nodes after preoperative therapy counts as residual disease, whereas the presence of isolated tumor cells does not
• Patients with synchronous bilateral invasive disease are eligible provided both lesions were confirmed to be HER2-positive, and at least one of the lesions meets the criteria outlined above. Multifocal disease is allowed, as long as the largest biopsied breast tumor was HER2-positive
• Patients must have received neoadjuvant chemotherapy with one of the following regimens: docetaxel/trastuzumab/pertuzumab (THP), paclitaxel/methotrexate/cisplatin (TMP), doxorubicin/cyclophosphamide/paclitaxel/trastuzumab/pertuzumab (AC-TH(P)); docetaxel/carboplatin/trastuzumab/pertuzumab (TCH(P)); fluorouracil/doxorubicin/cyclophosphamide-docetaxel/trastuzumab/pertuzumab (FAC-TH(P)), or fluorouracil/epirubicin/cyclophosphamide-docetaxel/trastuzumab/pertuzumab (FEC-TH(P)). Note: apart from TCHP, where T is docetaxel, treatment with docetaxel or paclitaxel is acceptable
• Prior receipt of T-DM1 in the neoadjuvant setting is not allowed.
• Prior treatment must have consisted of >= 6 cycles of chemotherapy and HER2-directed therapy, with a total duration of >= 12 weeks, including at least 9 weeks of preoperative taxane and trastuzumab with or without pertuzumab (or Food and Drug Administration [FDA]-approved biosimilars). Patients who have received at least 9 weeks of preoperative taxane, pertuzumab and margetuximab are also eligible if they received >= 6 cycles of systemic therapy prior to enrollment. Note: Patients who complete at least nine of a planned twelve doses of weekly paclitaxel, or three of a planned four doses of docetaxel, but discontinue prematurely due to toxicity are eligible. Patients receiving dose-dense chemotherapy regimens are also eligible. Prior use of nab-paclitaxel (Abraxane) instead of paclitaxel or docetaxel is permitted. Prior use of subcutaneous trastuzumab (Hylecta) and subcutaneous trastuzumab and pertuzumab (Phesgo) is also allowed.
• Patients who received neoadjuvant systemic therapy which included experimental HER2-targeted therapy/therapies are potentially eligible, as long as the investigational agent was not a HER2-targeted antibody-drug conjugate (e.g. T-DM1, DS-8201a [trastuzumab deruxtecan]) or a HER2 targeted tyrosine kinase inhibitor (TKI) (e.g. tucatinib, lapatinib, neratinib).
• Patients may have received =< 1 cycles of T-DM1 in the adjuvant setting. Note: These patients will be randomized to receive a further 14 cycles of T-DM1 and tucatinib/placebo as tolerated. The most recent cycle of T-DM1 should have been administered =< 5 weeks prior to registration * Note: Both of the following two criteria need to be met for the patient to be eligible for this study
• An interval of no more than 12 weeks between the completion date of the last definitive treatment (e.g. postoperative chemotherapy or radiation, or if neither given, breast surgical date) and the date of registration. Concurrent radiation therapy is permitted while receiving study treatment
• Patients must be registered on study within =< 180 days of the date of the most recent definitive breast cancer surgery (not including reconstructive surgery)
• All systemic chemotherapy should have been completed preoperatively unless participating in EA1181 (CompassHER2 pathologic complete response [pCR]) or the BIG DECRESCENDO Trial (which is very similar to CompassHER2 pCR in terms of study design, drugs, and eligibility). However, patients who received 4 cycles of neoadjuvant THP off study can receive a further 2-4 cycles of chemotherapy postoperatively to meet eligibility for A011801. Patients who participated in EA1181 or MA41 and proceeded to surgery immediately after the de-escalated trial regimen must receive postoperative chemotherapy to complete a total of >= 6 cycles of systemic treatment prior to enrollment on A011801, as outlined above (e.g. 4 cycles pre-operatively, and 2 cycles post-operatively). The postoperative chemotherapy regimen prescribed is at the discretion of the treating oncologist (i.e. 2-4 cycles AC or THP, other). Continuation of trastuzumab + pertuzumab (HP) pre- or post-operatively as maintenance therapy (while awaiting a surgical date or an official pathology report) is allowed for all study participants
• Toxicities related to prior systemic treatment should have resolved or be at baseline, apart from alopecia and peripheral neuropathy =< grade 1
• Adequate excision: surgical removal of all clinically evident disease in the breast and lymph nodes as follows:
• Breast surgery: total mastectomy with no gross residual disease at the margin of resection, or breast-conserving surgery with histologically negative margins of excision
• For patients who undergo breast-conserving surgery, the margins of the resected specimen must be histologically free of invasive tumor and ductal carcinoma in situ (DCIS) as determined by the local pathologist. If pathologic examination demonstrates tumor at the line of resection, additional operative procedures may be performed to obtain clear margins. If tumor is still present at the resected margin after re-excision(s), the patient must undergo total mastectomy to be eligible. Patients with margins positive for classic lobular carcinoma in situ (LCIS) are eligible without additional resection
• Lymph node surgery ** The axilla needs to be evaluated with either sentinel node biopsy or axillary lymph node dissection. If patients have a sentinel lymph node biopsy and sentinel nodes are negative, no further axillary treatment is necessary. If patients have isolated tumor cells (ITCs) in the setting of residual breast disease, at least one of the following is required: axillary lymph node dissection (ALND) or planned nodal irradiation. If patients have micro- or macro-metastatic nodal disease, ALND and planned nodal irradiation are required. Of note, co-enrollment on Alliance A011202 is not allowed
• Eastern Cooperative Oncology Group (ECOG) performance status 0-1
• Absolute neutrophil count (ANC) >= 1,000/mm^3
• Hemoglobin >= 8 g/dL (Note: packed red blood cells [PRBC] transfusion is not permitted to achieve eligibility)
• Platelet count >= 100,000/mm^3
• Creatinine =< 1.5 x upper limit of normal (ULN)
• Total bilirubin =< 1.0 x upper limit of normal (ULN) or direct bilirubin within the institutional normal range for patients with Gilbert's syndrome
• Aspartate aminotransferase (AST)/alanine aminotransferase (ALT) =< 2.5 x upper limit of normal (ULN)
• Screening left ventricular ejection fraction (LVEF) >= 50% on echocardiogram (ECHO) or multiple-gated acquisition (MUGA) after receiving neoadjuvant chemotherapy and no decrease in LVEF by more than 15% absolute percentage points from the pre-chemotherapy LVEF. Or, if pre-chemotherapy LVEF was not assessed, the screening LVEF must be >= 55% after completion of neoadjuvant chemotherapy. Note: LVEF assessment may be repeated once up to 3 weeks following the initial screening assessment to assess eligibility

Exclusion Criteria:

• No adjuvant treatment with any anti-cancer investigational drug within 28 days prior to registration
• Not pregnant and not nursing, because this study involves an agent that has known genotoxic, mutagenic and teratogenic effects. Therefore, for women of childbearing potential only, a negative serum pregnancy test done =< 7 days prior to registration is required
• Patients with known active and/or untreated hepatitis B or hepatitis C or chronic liver disease are ineligible. Patients with a diagnosis of hepatitis B or C that has been treated and cleared and normal liver function are eligible to participate in the study if the other eligibility parameters are met
• Stage IV (metastatic) breast cancer
• History of any prior (ipsi- or contralateral) invasive breast cancer within 3 years of registration
• Patients with ER+ HER2+ residual invasive disease that is lymph node-negative per the surgical pathology report
• Evidence of recurrent disease following preoperative therapy and surgery
• Patients for whom radiotherapy would be recommended for breast cancer treatment but for whom it is contraindicated because of medical reasons (e.g., connective tissue disorder or prior ipsilateral breast radiation)
• History of exposure to the following cumulative doses of anthracyclines: doxorubicin > 240 mg/m^2; epirubicin or liposomal doxorubicin-hydrochloride (Myocet) > 480 mg/m^2. For other anthracyclines, exposure equivalent to doxorubicin > 240 mg/m^2
• Cardiopulmonary dysfunction as defined by any of the following:
• History of National Cancer Institute (NCI) CTCAE version (v) 5.0 grade >= 3 symptomatic congestive heart failure (CHF) or New York Heart Association (NYHA) criteria class >= II
• Angina pectoris requiring anti-anginal medication, serious cardiac arrhythmia not controlled by adequate medication, severe conduction abnormality, or clinically significant valvular disease
• High-risk uncontrolled arrhythmias: i.e., atrial tachycardia with a heart rate > 100/min at rest, significant ventricular arrhythmia (ventricular tachycardia) or higher-grade atrioventricular block (AV)-block (second degree AV-block type 2 [Mobitz 2] or third degree AV-block)
• Significant symptoms (grade >= 2) relating to left ventricular dysfunction, cardiac arrhythmia, or cardiac ischemia while or since receiving preoperative therapy
• History of a decrease in left ventricular ejection fraction (LVEF) to < 40% with prior trastuzumab treatment (e.g., during preoperative therapy)
• Uncontrolled hypertension (systolic blood pressure > 180 mmHg and/or diastolic blood pressure > 100 mmHg)
• Current severe, uncontrolled systemic disease
• Major surgical procedure unrelated to breast cancer or significant traumatic injury within 28 days prior to registration or anticipation of the need for major surgery during the course of study treatment
• History of intolerance, including grade 3 to 4 infusion reaction or hypersensitivity to trastuzumab or murine proteins or any components of the product
• Peripheral neuropathy of any etiology that exceeds grade 1
• Assessment by the investigator as being unable or unwilling to comply with the requirements of the protocol
• Use of a strong CYP3A4 or CYP2C8 inhibitor within 2 weeks, or use of a strong CYP3A4 or CYP2C8 inducer within 5 days prior to registration is prohibited.
• Please note that use of sensitive CYP3A substrates should be avoided two weeks before registration and during study treatment. Additionally, CYP3A4 or CYP2C8 inducers are prohibited as concomitant medications within 5 days following discontinuation of tucatinib treatment. Patients who require medications that are known to be sensitive substrates of CYP3A4 with a narrow therapeutic window should be excluded.

Inclusion Criteria:

1. Histologically confirmed carcinoma of a primary tumor site and stage indicated in Table 3 of the protocol. 2. Tumor with HPV16 genotype as determined by testing performed in a Clinical Laboratory Improvement Amendments (CLIA) certified laboratory. 3. HLA-A*02:01 allele determined by testing performed in a CLIA certified laboratory. Participants may be enrolled based on low resolution typing (i.e., HLA-A*02) but the HLA-A*02:01 allele type must be confirmed prior to apheresis. 4. Measurable disease per RECIST Criteria Version 1.1 or PERCIST. 5. Age > 18 years. 6. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 at screening. 7. Negative pregnancy test for women under 55 and all women who have had a menstrual period in the last 12 months. A pregnancy tests is not required for women who have had a bilateral oophorectomy or hysterectomy. 8. Men and women of child-bearing potential must agree to use adequate contraception (i.e., intrauterine device, hormonal barrier method of birth control; abstinence; tubal ligation or vasectomy) prior to study entry and for four months after treatment. Should a women become pregnant or suspect she is pregnant while she is participating in this study, she should inform her treating physician immediately. 9. Seronegative for HIV antibody, hepatitis B surface antigen (sAg), and hepatitis C antibody. If a hepatitis C antibody test is positive, then testing for antigen by reverse transcription polymerase chain reaction (RT-PCR) must be negative. 10. Participants must have organ and marrow function as defined below: 1. Leukocytes > 3,000/Mantle cell lymphoma (mcL) 2. Absolute neutrophil count > 1,500/mcL 3. Platelets > 100,000/mcL 4. Hemoglobin > 9.0 g/dL 5. Total bilirubin within normal institutional limits except in participants with Gilbert's Syndrome who must have a total bilirubin < 3.0 mg/dL. 6. Serum aspartate aminotransferase (AST) (SGOT)/ alanine transaminase (ALT)(SGPT) < 2.5 x upper limit of normal (ULN) 7. Calculated creatinine clearance (CrCl) >50 mL/min/1.73 m2for participants with creatinine levels above institutional normal (by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation). 8. international normalized ratio (INR) or activated partial thromboplastin time ( aPTT) ≤1.5 X ULN unless the subject is receiving anticoagulant therapy. Subjects on anticoagulant therapy must have a PT or aPTT within therapeutic range and no history of severe hemorrhage. 11. Participants must be able to understand and be willing to sign the written informed consent document. 12. Participants must agree to participate in protocol CINJ 192103 (Pro2021002307) for gene therapy long term follow up and in protocol Cancer Institute of New Jersey (CINJ) 192002 (Pro2021000281) for biospecimen collection study.Note: Patients may have undergone minor surgical procedures with the past three weeks, aslong as all toxicities have recovered to Grade 1 or less.

Exclusion Criteria: Subjects who meet any of the following criteria will be excluded from

participation in this study: 1. Prior systemic therapy or definitive chemoradiation for the cancer that is being treated on this protocol. 2. Current treatment with another investigational agent. 3. History of severe allergic reactions to compounds of similar chemical or biological composition to agents used in this study. 4. Uncontrolled intercurrent illness such as active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations at the time of treatment that would limit compliance with study requirements. 5. Subjects with HLA-A*02:01 damaging mutation or allele loss or other molecular resistance detected by research or clinical sequencing will not be eligible. 6. Documented LVEF of less than or equal to 45% tested. The following participants will undergo cardiac evaluations: 1. Clinically significant atrial and/or ventricular arrhythmias including but not limited to: atrial fibrillation, ventricular tachycardia, second or third degree heart block or 2. Age > 50 years old 7. Participants with baseline screening pulse oxygen level of <92% on room air will not be eligible. If the underlying cause of hypoxia improves, they may be reevaluated. 8. Because there is an unknown but potential risk for adverse events in nursing infants secondary to treatment of the mother with E7 TCR T cells, breastfeeding should be discontinued if the mother is treated with E7 TCR T cells. These potential risks may also apply to other agents used in this study. 9. Participants with a systemic immunodeficiency including acquired deficiency such as HIV or primary immunodeficiency such as Severe Combined Immunodeficiency Disease are ineligible. The experimental treatment being evaluated in this protocol depends on an intact immune system. Participants who have decreased immune competence may be less responsive to the treatment. 10. Participants on immunosuppressive drugs including corticosteroids unless meeting criteria outlined in Section 6.1 (Prohibited Medications). 11. Participants with potentially severe autoimmune diseases such as Crohn's disease, ulcerative colitis, rheumatoid arthritis, autoimmune hepatitis, autoimmune pancreatitis, or systemic lupus erythematosus are not eligible. Patients with less severe autoimmune diseases such as hypothyroidism, vitiligo, and other minor autoimmune disorders are eligible. 12. Participants with prior or concurrent malignancy whose natural history or treatment is unlikely to interfere with the safety or efficacy assessments of the investigational regimen are eligible for this trial. Examples include, but are not limited to: 1. Carcinoma in situ 2. Cutaneous skin cancers requiring only local excision 3. Low grade non-muscle invasive bladder cancer 4. Low grade prostate cancer 13. Subjects who received a live vaccine within 30 days prior to enrollment are not eligible. 14. Determination by the Principal Investigator that participation is not in the best interest of the research subject or may jeopardize the safety of the subject or integrity of the clinical trial data.

Key Inclusion Criteria

Patient has ECOG performance status of 0-1One or more documented primary oncogenic PIK3CA mutation(s) in blood and/or tumor perlocal assessment
• Other potentially oncogenic PIK3CA mutations may be considered but must be approved by the Sponsor prior to enrollment.Part 1 - Ability to provide archived tumor tissue or be willing to undergo pretreatmenttumor biopsy to assess PIK3CA status retrospectively Part 2 - Submit tumor tissue priorto study drug initiation for determination of PIK3CA mutation retrospectively.Key Inclusion for RLY-2608 Single Agent Arm
• [For Part 1]: Evaluable disease per RECIST v1.1
• [For Part 2]: Measurable disease per RECIST v1.1
• Disease that is refractory to standard therapy, intolerant to standard therapy, or has declined standard therapy.
• Part 1- histologically or cytologically confirmed diagnosis of unresectable or metastatic solid tumor
• Part 2 - Unresectable or metastatic solid tumor with PIK3CA mutation(s) and one of the following tumor types:Group 1: clear cell ovarian cancer Group 2: head and neck squamous cell carcinoma Group3: cervical cancer Group 4: other solid tumors, excluding colorectal, clear cell ovarian,head and neck squamous cell, and cervical cancers Group 5: unresectable or metastaticsolid tumors with PIK3CA double mutationsKey Inclusion for Combination Arms
• [For Part 1 and Part 2]: Evaluable disease per RECIST v1.1
• [For Part 1 and Part 2]: Male or female with histologically or cytologically confirmed diagnosis of HR+, HER2- unresectable or metastatic breast cancer that is not amenable to curative therapy. Females may be postmenopausal, premenopausal, or perimenopausal. Premenopausal or perimenopausal females must have a histologically or cytologically confirmed diagnosis of HR+ HER2- advanced or metastatic breast cancer that is not amenable to curative therapy and must have been previously treated with GnRH agonist at least 4 weeks prior to start of study drug
• [For Part 1 and Part 2]: Had previous treatment for breast cancer with: 1. ≤1 line of chemotherapy in the metastatic setting 2. ≥1 cyclin-dependent kinases (CDK) 4/6 inhibitor, in either the adjuvant and/or metastatic setting 3. ≥1 antiestrogen therapy in either adjuvant and/or metastatic setting, including, but not limited to, selective estrogen-receptor degraders (eg, fulvestrant), selective estrogen receptor modulators (eg, tamoxifen), and aromatase inhibitors (AI) (letrozole, anastrozole, exemestane), and 4. ≥1 PARP inhibitor, if appropriate, if documented germline BRCA1/2 mutation Note: Systemic local, loco-regional, or adjuvant treatment with chemotherapy and PARP inhibitors is not to be included in enumeration or previous treatment[For RLY-2608 + fulvestrant arm; Part 2, Group 2]: Received prior treatment with a PI3Kαinhibitor and discontinued the inhibitor due to intolerance and not disease progression,where intolerance is defined as treatment discontinuation due to treatment related AE(eg. hyperglycemia, rash, diarrhea, stomatitis) other than severe hypersensitivityreaction and/or life-threatening reactions, such as anaphylaxis and Stevens-Johnsonsyndrome.

Key Exclusion Criteria

Prior treatment with PI3Kα, AKT, or mTOR inhibitors (except for RLY-2608 + fulvestrantarm, Part 2, Group 2).Type 1 or Type 2 diabetes requiring antihyperglycemic medication, or fasting plasmaglucose ≥140 mg/dL and glycosylated hemoglobin (HbA1c) ≥7.0%.History of hypersensitivity to PI3K inhibitors. For combination arms only:hypersensitivity to fulvestrant, palbociclib, and/or ribociclib, as appropriate for thecombination.For triple combination arms only: history of pneumonitis or interstitial lung disease.For the single agent and combination arms other than with ribociclib: mean QT intervalcorrected using Fridericia's formula (QTcF) >480 msec. For the combination arms withribociclib: mean QTcF ≥450 msec.Patient has a history of prolonged QT syndrome or torsades de pointes. Patient has afamilial history of prolonged QT syndrome.Clinically significant, uncontrolled cardiovascular disease CNS metastases or primary CNStumor that is associated with progressive neurologic symptoms

Inclusion Criteria:

1. Patient has signed the informed consent before all study specific activities are conducted. 2. Women or men aged ≥18 years (or the minimum age of consent in accordance with the local law), at the time of informed consent signature. Female patients may be of any menopausal status.
• Postmenopausal status is defined by: 1. Age ≥60 years 2. Age <60 years and amenorrhea for 12 or more months (in the absence of chemotherapy, tamoxifen, toremifene, or ovarian suppression) or a follicle-stimulating hormone (FSH) value >40 mIU/mL and an estradiol value<40 pg/mL (140 pmol/L) or in postmenopausal ranges per local reference ranges 3. Documentation of prior surgical sterilization (i.e., bilateral tubal ligation, total hysterectomy, or bilateral oophorectomy, at least 1 month before first dose of trial therapy).
• Premenopausal and perimenopausal women (who do not fit postmenopausal criteria) and men must be concurrently receiving a luteinizing hormone-releasing hormone (LHRH) agonist initiated at least 4 weeks before the start of trial therapy and are planning to continue LHRH agonist treatment during the study treatment.
• For perimenopausal women to be considered of non-childbearing potential, FSH levels must be >40 mIU/ml. 3. Histopathological or cytological confirmed ER+, HER2-, breast cancer, per local laboratory, as per the American Society of Clinical Oncology (ASCO)/College of American Pathologists(CAP) guidelines (Allison et al, 2020, Wolff et al, 2018). Note: In the context of this trial, ER status will be considered positive if ≥10% of tumor cells demonstrate positive nuclear staining by immunohistochemistry, with or without PGR positivity. . 4. At least 1 not previously irradiated measurable lesion as per RECIST version 1.1 and/or at least 1 lytic or mixed (lytic +sclerotic) bone lesion with identifiable soft tissue components meeting the definition of measurability by RECIST version 1.1 that can be evaluated by CT or MRI; patients with sclerotic/osteoblastic bone lesions only in the absence of measurable disease are not eligible. 5. ECOG performance status of 0 or 1. 6. Patient has adequate bone marrow and organ function, as defined by the following laboratory values: 1. Absolute neutrophil count (ANC) ≥1.5 × 10^9/L 2. Platelets ≥100 × 10^9/L 3. Hemoglobin ≥9.0 g/dL 4. Potassium, sodium, calcium (corrected for serum albumin) and magnesium CTCAE grade ≤1 5. Creatinine is ≤ 1.5 x ULN or if creatinine is > 1.5 x ULN, then creatinine clearance must be ≥50 mL/min based on the Cockcroft-Gault formula. Note: C-G formula:
• Creatinine clearance (male) = ([140-age in years] × weight in kg)/ ([serum creatinine in mg/dL] × 72)
• Creatinine clearance (female) = (0.85 × [140-age in years] × weight in kg)/ ([serum creatinine in mg/dL] × 72) 6. Serum albumin ≥3.0 g/dL (≥30 g/L) 7. In absence of liver metastases, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 3.0 × ULN. If the patient has liver metastases, ALT and AST ≤ 5 × ULN 8. Total serum bilirubin <1.5 × ULN except for patients with Gilbert's syndrome who may be included if the total serum bilirubin is ≤3.0 × ULN or direct bilirubin ≤ 1.5 × ULN.

Exclusion Criteria:

1. Active or newly diagnosed CNS metastases, including meningeal carcinomatosis. Note: Patients with stable brain or subdural metastases are allowed if the patient has completed local therapy and was on a stable or decreasing dose of corticosteroids at baseline for management of brain metastasis for at least 4 weeks before starting treatment in this study. The dose must be ≤2.0 mg/day of dexamethasone or equivalent. Any signs (e.g., radiologic) or symptoms of brain metastases must be stable for at least 4 weeks before starting study treatment. 2. Patients with advanced, symptomatic visceral spread, that are at risk of life-threatening complications in the short term, including massive uncontrolled effusions (peritoneal, pleural, pericardial), pulmonary lymphangitis, or liver involvement >50%. 3. Prior chemotherapy or elacestrant in the advanced/metastatic setting. 4. Patients with known germline BRCA mutation without prior treatment with a PARP inhibitor before study entry. 5. Prior therapy with elacestrant or other investigational selective estrogen receptor degraders (SERDs), or investigational alike agents such as selective estrogen receptor modulators (SERM), selective estrogen receptor covalent antagonists (SERCANs), complete estrogen receptor antagonists (CERANs), and proteolysis-targeting chimeras (PROTACs), in the metastatic setting. Prior treatment with fulvestrant is not exclusionary as it is an approved medication. 6. Patient has a concurrent malignancy or history of invasive malignancy within 3 years of enrollment, except basal or squamous cell skin cancer, superficial bladder cancer, or carcinoma in situ of the cervix that has completed curative therapy. Other malignancies with low risk of recurrence may be considered eligible with Sponsor approval. 7. Uncontrolled significant active infections. • Patients with HBV and/or HCV infection must have undetectable viral load during screening. • Patients known to be HIV+ are allowed if they have undetectable viral load at baseline. 8. Documented pneumonitis/ILD prior to Cycle 1 Day 1. 9. Major surgery within 28 days before starting trial therapy. 10. Inability to take oral medications, refractory or chronic nausea, gastrointestinal conditions (including significant gastric or bowel resection), history of malabsorption syndrome, or any other uncontrolled gastrointestinal condition that impact the absorption of the study drug. 11. Known intolerance to elacestrant or any of its excipients. 12. Pregnant and breast-feeding women are excluded from the study. In addition, women of childbearing potential are excluded who: • Within 28 days before starting trial therapy, did not use a highly effective method of contraception. • Do not agree to use a highly effective method of contraception (Appendix F) or abstain from heterosexual intercourse throughout the entire study period and for 120 days after trial therapy discontinuation. 13. Men or women who do not agree to abstain from donating sperm or ova, or to use a highly effective method of contraception, during the course of the treatment period and for 120 days after the last dose of study treatment. 14. Patient is currently receiving or received any of the following medications prior to first dose of trial therapy: • Anti-cancer therapy within 14 days (28 days for anticancer antibody based treatment) or 5 half-lives, whichever is shorter. Please note: Toxicity from prior therapy must be resolved to NCI CTCAE version 5.0 Grade ≤1, except alopecia and peripheral sensory neuropathy (Grade ≤2). • Known strong or moderate inducers or inhibitors of cytochrome P450 (CYP) 3A4 within 14 days or 5 half-lives, whichever is shorter, (refer to http://medicine.iupui.edu/clinpharm/ddis/ or https://www.fda.gov/drugs/drug-interactions-labeling/drug-development-and-drug-inter actions-table-substrates-inhibitors-and-inducers). • Herbal preparations/medications within 7 days. These include, but are not limited to, St. John's wort, kava, ephedra (ma huang), gingko biloba, dehydroepiandrosterone (DHEA), yohimbe, saw palmetto, and ginseng. • Vaccination, including but not limited to vaccination against COVID-19, during the 7 days prior to randomization. 15. Evidence of ongoing alcohol or drug abuse as assessed by the investigator. 16. Any severe medical or psychiatric condition that, in the Investigator's opinion, would preclude the patient's participation in a clinical study.Additional Eligibility for the Alpelisib Combination (Phase 1b and Arm A)

Inclusion:

In general, the SmPC of the respective combination drug should be consulted forinstructions/restrictions with respect to interactions with concomitant medications. 1. PIK3CA mutation by local laboratory assessment. 2. One or up to two prior hormonal therapies in the advanced or metastatic setting, one of which was in combination with a CDK4/6 inhibitor.Exclusion: 1. Prior therapy with alpelisib or any other PI3K inhibitor. 2. Type 1 diabetes or uncontrolled type 2 diabetes (fasting plasma glucose level of >140 mg/dL [7.7 mmol/L], or glycosylated hemoglobin [HbA1c] level of >6.4%). 3. Known intolerance to alpelisib or any of its excipients. 4. Patient is currently receiving or received drugs known to be a BCRP inhibitor within 14 days or 5 half-lives, whichever is shorter, prior to first dose of trial therapy 5. Patient has ongoing osteonecrosis of the jaw from previous or concurrent treatment with bisphosphonates or denosumabAdditional Eligibility for the Everolimus Combination (Phase 1b and Arm B)

Inclusion:

1. One or up to two prior hormonal therapies in the advanced or metastatic setting, one of which was in combination with a CDK4/6 inhibitor.Exclusion: 1. Prior therapy with everolimus. 2. Known intolerance to everolimus or any of its excipients.Additional Eligibility for the Abemaciclib Combination (Arm C)

Inclusion:

1. One or up to two prior hormonal therapies in the advanced or metastatic setting, one of which was in combination with a CDK4/6 inhibitor.Exclusion: 1. Prior therapy with abemaciclib in the advanced or metastatic setting. Adjuvant therapy with abemaciclib is exclusionary if the patient relapsed within the past 12 months. 2. Known intolerance to abemaciclib or any of its excipients.Additional Eligibility for the Ribociclib Combination (Phase 1b and Arm C)

Inclusion:

1. One or up to two prior hormonal therapies in the advanced or metastatic setting, one of which was in combination with a CDK4/6 inhibitor.Exclusion: 1. Prior therapy with ribociclib in the metastatic setting. Prior adjuvant therapy with ribociclib is also exclusionary if the patient relapsed within the past 12 months. 2. Known intolerance to ribociclib or any of its excipients. 3. QTcF values ≥450 msec. 4. Patients who already have or who are at significant risk of developing QTc prolongation, including patients with:
• Long QT syndrome
• Uncontrolled or significant cardiac disease including recent (6 months) myocardial infarction, congestive heart failure, unstable angina, and brady-arrhythmias
• Electrolyte abnormalities 5. Patient is currently receiving or received drugs known to prolong QT interval within 14 days or 5 half-lives, whichever is shorter, before the first dose of trial therapy.Additional Eligibility for the Palbociclib Combination (Phase 1b)

  Inclusion:

  1. One or up to two prior hormonal therapies in the advanced or metastatic setting, one of which was in combination with a CDK4/6 inhibitor.Exclusion: 1. Prior therapy with palbociclib in the metastatic setting. 2. Known intolerance to palbociclib or any of its excipientsAdditional Eligibility for the Palbociclib Combination (Arm D)

  Inclusion:

  1. One or up to two prior hormonal therapies in the advanced or metastatic setting.Exclusion: 1. Prior therapy with a CDK4/6i in the metastatic setting. 2. Known intolerance to palbociclib or any of its excipients.Additional Eligibility for the Abemaciclib Combination (Arm D)

  Inclusion:

  1. One or up to two prior hormonal therapies in the advanced or metastatic setting.Exclusion: 1. Prior therapy with any CDK4/6i in the metastatic setting. 2. Known intolerance to abemaciclib or any of its excipients.Additional Eligibility for Ribociclib Combination (Arm D)

  Inclusion:

  1. One or up to two prior hormonal therapies in the advanced or metastatic setting.Exclusion: 1. Prior therapy with a CDK4/6i in the advanced or metastatic setting. 2. Known intolerance to ribociclib or any of its excipients. 3. QTcF values ≥450 msec. 4. Patients who already have or who are at significant risk of developing QTc prolongation, including patients with:
  • Long QT syndrome
  • Uncontrolled or significant cardiac disease including recent (6 months) myocardial infarction, congestive heart failure, unstable angina, and brady-arrhythmias
  • Electrolyte abnormalities 5. Patient is currently receiving or received drugs known to prolong QT interval within 14 days or 5 half-lives, whichever is shorter, before the first dose of trial therapy.

Inclusion Criteria:

• Documented radiographic and histopathologic confirmed primary localized invasive breast cancer.
• Histologically documented TNBC (estrogen receptor negative [ER-]/progesterone receptor negative [PR-]/human epidermal growth factor 2 negative [HER2-]) defined as ER-negative and PR-negative (≤5% positive cells stain by IHC for both ER and PR), and negative HER2eu- status, confirmed on tumor sample.
• HER2eu negative will be defined as one of the following criteria:
• IHC 0 or 1+
• Single-probe average HER2 gene copy number of <6 signalsucleus
• Dual-probe fluorescent in-situ hybridization (FISH) HER2eu chromosome 17 (CEP17) non-amplified ratio of <2
• Globo H IHC H-score ≥15 from the residual primary site/or lymph node (if primary site is not available) tumor obtained at time of definitive surgery. Globo H expression will be determined during pre-screening by Central lab. Instructions for submission of slides/tumor tissue blocks are provided in the protocol and study Lab Manual.
• No evidence of metastatic disease in chest, abdomen and pelvis by CT or other adequate imagining during the Screening Phase. Imaging within 3 months prior to randomization is acceptable as baseline scan. Bone scans and imaging of the brain at screening is optional, and should be symptom directed.
• High risk patients with no evidence of disease after completing standard treatment and meeting ONE of the following criteria:
• Neoadjuvant chemotherapy followed by definitive surgery: Residual invasive disease following neoadjuvant chemotherapy defined as: A contiguous focus of residual invasive cancer in the surgical breast measuring ≥1 cm in diameter and/or with residual invasive cancer in at least one axillary node (micrometastases or macrometastases), as determined by local pathology review.
• Definitive surgery followed by adjuvant chemotherapy: Pathological Stage IIB, Stage IIIA , Stage IIIB, or Stage IIIC disease according to the 8th edition of the American Joint Committee on Cancer (AJCC) Cancer Staging Manual.
• Must have completed a standard taxane, and/or anthracycline-based multi-agent chemotherapy regimen either in the neoadjuvant or adjuvant setting (e.g., National Comprehensive Cancer Network recommended regimens):.
• At least 4 cycles of a standard multi-agent chemotherapy regimen must have been received, unless precluded by toxicities
• Post operative adjuvant capecitabine or a platinum monotherapy in patients with residual disease after neoadjuvant chemotherapy is allowed.
• Randomization must occur within 12 weeks after completion of standard of care treatment (surgery and/or chemotherapy) and within 46 weeks from the date of definitive surgery. Note: patients receiving adjuvant capecitabine or platinum monotherapy after neoadjuvant multi-agent chemotherapy may be randomized and initiate study treatment during (or within 12 weeks after completion of) the adjuvant capecitabine or platinum monotherapy.
• All treatment-related toxicities resolved to Grade <1 on National cancer institute Common Terminology Criteria for Adverse Events (NCI-CTCAE version 5.0) criteria (except hair loss and ≤Grade 2 neuropathy, which are acceptable).
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
• Females must be either of non-childbearing potential, i.e., surgically sterilized (have documented sterilization, bilateral oophorectomy/salpingectomy at least 3 months before the start of the trial and/or hysterectomy), or one year postmenopausal; or if of childbearing potential must have a negative pregnancy test (urine or serum) at randomization.
• Males and females of childbearing potential and their partners must be willing to use effective contraception during the entire Treatment Phase period and for at least 4 weeks (28 days) after the last dose of study treatment.
• Adequate hematological, hepatic and renal function as defined below:
• Absolute neutrophil count (ANC) ≥1,500/µL
• Platelets ≥75,000/µL
• Hemoglobin ≥8.5g/dL
• Serum creatinine ≤1.5 × upper limit of normal (ULN) or calculated creatinine clearance ≥55 mL/min for subjects with creatinine levels >1.5 × institutional ULN (glomerular filtration rate can also be used in place of creatinine or creatinine clearance may be calculated per institutional standard)
• Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤3 × ULN
• Alkaline Phosphatase (ALP) ≤2.5 × ULN
• Serum total bilirubin ≤1.5 × ULN (unless Gilbert's disease is documented)
• Consent to participate with a signed and dated Institutional Review Board (IRB)/Independent Ethics Committee (IEC) approved patient informed consent for the study prior to beginning any specific study procedures.
• Ability to understand and willingness to complete all protocol required procedures.

Exclusion Criteria:

• Local recurrence of or previous history of ipsilateral or contralateral invasive breast cancer within 10 years prior to randomization.
• Definitive clinical or radiologic evidence of metastatic disease
• Synchronous bilateral breast cancer, unless both tumors are confirmed as TNBC.
• Have received any post-operative immunotherapy with antigen, antibody, immune checkpoint inhibitors (Programmed cell death-1 [PD-1]/ Programmed cell death-ligand-1inhibitors [PD-L-1], anti-cytotoxic T lymphocyte associated protein 4 [CTLA 4] therapy), or other anti-cancer vaccines (neoadjuvant receipt of immune checkpoint inhibitors will not be exclusionary if the patient meets all other eligibility criteria).
• Concomitant treatment with approved anticancer therapy or immunotherapy including checkpoint inhibitors (e.g. PD-1 inhibitors) or other investigational therapy, if expected during the study. Adjuvant capecitabine or platinum monotherapy is allowed during the study.
• A history of other malignancies (except non melanoma skin carcinoma, carcinoma in situ of the uterine cervix, follicular or papillary thyroid cancer) within 5 years prior to randomization.
• Have any active autoimmune disease or disorder that requires systemic immunosuppressive/immunomodulatory therapy. NOTE: Autoimmune diseases that are confined to the skin (e.g., psoriasis) that can be treated with topical steroids alone are allowed during the study.
• Oral/parenteral corticosteroid treatment (>5 mg/day of prednisone/equivalent), within 2 weeks prior to randomization or anytime during the study. NOTE: inhaled steroids for treatment of asthma; and topical steroids are allowed during the study.
• Any known uncontrolled concurrent illness that would limit compliance with study requirements, including but not limited to ongoing or active infections, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, psychiatric disorders, or substance abuse.
• Any known hypersensitivity to active/inactive ingredients in the study drug formulation or known severe allergy or anaphylaxis to fusion proteins.
• Prior receipt of a glycoconjugate vaccine for cancer immunotherapy.
• Known history or positive for human immunodeficiency virus (HIV positive), unless on effective anti-retroviral therapy with undetectable viral load within 6 months of therapy (note: HIV testing not required for study entry).
• Known active hepatitis B virus (HBV) or hepatitis C virus (HCV) infection prior to randomization. Patients who have completed curative therapy for HCV are eligible. For patients with evidence of chronic HBV infection, the HBV viral load must be undetectable on suppressive therapy. (note: HBV/HCV testing is not required for study entry).
• Any condition, including significant diseases and/or laboratory abnormalities that would place the patient at unacceptable risk for study participation.
• Currently pregnant or breastfeeding women.
• Currently participating in or has participated in a breast cancer therapeutic clinical trial within 4 weeks (24 days) prior to randomization.

1. Inclusion Criteria: Subjects must meet all the following criteria to participate in

this study. 1. Signed, written informed consent obtained prior to any study procedures. 2. Age > 18 years at the time of informed consent. 3. Metastatic solid tumor with ≥ 10% of tumor cells positive for KK-LC-1 by IHC assay. Due to the low frequency of KK-LC-1 expression in most cancers, screening will focus on gastric, NSCLC, TNBC, and cervix cancers. The IHC test will be performed by the Rutgers Cancer Institute, Department of Biorepository Services. 4. HLA-A*01:01 allele by HLA haplotype test. 5. Measurable disease per RECIST Criteria Version 1.1 at time of enrollment. 6. Prior treatment with cancer type-specific standard of care systemic cancer therapy is required. Standard treatment options must be considered and declined. Documentation of rationale is required if a subject is deemed unsuitable for standard therapy. 7. Subjects with < 3 brain metastases that have been treated with surgery or stereotactic radiosurgery are eligible. Lesions that have been treated with stereotactic radiosurgery must be clinically stable for one month before protocol treatment. Patients with surgically resected brain metastases are eligible. 8. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 at screening. 9. Negative pregnancy test for women under 55 and all women who have had a menstrual period in the last 12 months. A pregnancy tests is not required for women who have had a bilateral oophorectomy or hysterectomy. 10. Women of child-bearing potential must agree to use adequate contraception (i.e., intrauterine device, hormonal barrier method of birth control; abstinence; tubal ligation or vasectomy) prior to study entry and for 12 months after treatment. Should a women become pregnant or suspect she is pregnant while she is participating in this study, she should inform her treating physician immediately. 11. Participants must have organ and marrow function as defined below: 1. Leukocytes > 3,000/mcL 2. Absolute neutrophil count > 1,500/mcL 3. Platelets > 100,000/mcL 4. Hemoglobin > 9.0 g/dL 5. Total bilirubin within normal institutional limits except in participants with Gilbert's Syndrome who must have a total bilirubin < 3.0 mg/dL. 6. Serum AST (SGOT)/ALT (SGPT) < 2.5 x ULN 7. Calculated creatinine clearance (CrCl) >50 mL/min/1.73 m2for participants with creatinine levels above institutional normal (by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation). 8. INR or a PTT ≤1.5 X ULN unless the subject is receiving anticoagulant therapy. Subjects on anticoagulant therapy must have a PT or PTT within therapeutic range and no history of severe hemorrhage. 12. Serology:
• HIV antibody negative
• Hepatitis B antigen negative
• Hepatitis C antibody negative or HCV RNC negative (i.e., no current HCV infection) 13. More than four weeks must have elapsed since any prior systemic therapy at the time the patient receives the KK-LC-1 TCR T cells. Adverse events from prior therapy must have resolved to ≤ grade 1 according to CTCAE Version 5.0 or have demonstrated clinical stability and meet the eligibility criteria for the protocol. 14. Oxygen saturation ≥ 92% on room air. 15. Left ventricular ejection fraction ≥45% by echocardiogram or MUGA for patients 50 years of age or older.

Exclusion Criteria: Subjects who meet any of the following criteria will be excluded from

participation in this study: 1. Current treatment with another investigational agent. 2. History of severe allergic reactions to compounds of similar chemical or biologic composition to agents in used in study. 3. Uncontrolled intercurrent illness such as active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations at the time of treatment that would limit compliance with study requirements. 4. Because there is an unknown but potential risk for adverse events in nursing infants secondary to treatment of the mother with KK-LC-1 TCR T cells, breastfeeding should be discontinued if the mother is treated with KK-LC-1 TCR cells. The potential risks may also apply to other agents used in this study. 5. Participants with a systemic immunodeficiency including acquired deficiency such as HIV or primary immunodeficiency such as Severe Combined Immunodeficiency Disease are ineligible. The experimental treatment being evaluated in this protocol depends on an intact immune system. Participants who have decreased immune competence may be less responsive to the treatment. 6. Participants on immunosuppressive drugs including corticosteroids unless meeting criteria outlined in Section 6.1 (Prohibited Medications). 7. Subjects with HLA-A*01:01 damaging mutation or allele loss or other molecular resistance detected by clinical or research genomic profiling will not be eligible. 8. Participants with potentially severe autoimmune diseases such as Crohn's disease, ulcerative colitis, rheumatoid arthritis, autoimmune hepatitis, autoimmune pancreatitis, or systemic lupus erythematosus are not eligible. Patients with less severe autoimmune diseases such as hypothyroidism, vitiligo, and other minor autoimmune disorders are eligible. 9. Participants with prior or concurrent malignancy whose natural history or treatment is unlikely to interfere with the safety or efficacy assessments of the investigational regimen are eligible for this trial. Examples include, but are not limited to: 1. Carcinoma in situ 2. Cutaneous skin cancers requiring only local excision 3. Low grade non-muscle invasive bladder cancer 4. Low grade prostate cancer Participants with prior or concurrent malignancy that do not meet the above criteria are excluded. 10. Subjects who received a live vaccine within 30 days prior to enrollment are not eligible. 11. Determination by the Principal Investigator that participation is not in the best interest of the research subject or may jeopardize the safety of the subject or integrity of the clinical trial data.

Inclusion criteria for Part A and B (HER2-negative) and Part Z (HER2-positive) cohorts:

1. Written informed consent, according to local guidelines, signed and dated by the patient or by a legal guardian prior to the performance of any study-specific procedures, sampling, or analyses 2. Women and men at least 18 years-of-age at the time of signature of the informed consent form (ICF) 3. Histologically documented locally advanced or metastatic breast cancer 4. Triple-negative breast cancer (TNBC) patients should have received at least 1 but no more than 5 prior lines of chemotherapy in the metastatic setting 5. Parts A and B patients only: Patients with HR+ HER2-negative MBC should have received prior treatment with endocrine therapy +CDK 4/6 inhibitor. No limit to prior endocrine therapy regimens, but no more than 2 prior chemotherapy regimens in the metastatic setting are allowed. HR+ = Estrogen receptor (ER) and/or Progesterone (PgR) positivity that are defined as ≥1% of cells expressing HR via IHC analysis. HER2 negativity is defined as either of the following: IHC 0, IHC 1+, or IHC 2+/in situ hybridization (ISH) negative. 6. Part B patients only: Patients with HER2-negative MBC will be included into one of the following 2 subgroups: 1) MBC HR+, HER2-, regardless of HER3 expression, who have received trastuzumab deruxtecan and/or sacituzumab govitecan, or, 2) mTNBC, regardless of HER3 expression, who have received sacituzumab govitecan and/or datopotamab deruxtecan. 7. Part Z patients only: should have documented HER2-positive expression as per American Society of Clinical Oncology - College of American Pathologists guidelines based on local testing. 8. Part Z patients only: should have had prior treatment with at least 2 anti-HER2 therapies, 1 of which must be trastuzumab deruxtecan. These patients must have experienced disease progression after receiving trastuzumab deruxtecan. 9. At least 1 measurable lesion per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 (bone-only disease excluded) 10. Patients who have received radiation or surgery for brain metastases are eligible if therapy was completed ≥4 weeks prior to initiation of study treatment (2 weeks for patients who received palliative radiation therapy), there is no evidence of central nervous system disease progression on a scan or mild neurologic symptoms, and there is no requirement for chronic corticosteroid therapy for the treatment of brain metastases 11. Willingness to undergo pre-treatment biopsy and on-treatment biopsies; must have a tumor amenable to pre-treatment biopsy (unless archived tissue is available and was obtained within 2 months prior to starting treatment) and on-treatment biopsy (excludes bone lesions and previously irradiated lesions) 12. Eastern Cooperative Oncology Group (ECOG) Performance Status score of 0 or 1 13. Has adequate organ function within 7 days before the start of study treatment, defined as:
• Platelet count ≥100 × 109/L
• Hemoglobin (Hb) ≥9 g/dL (transfusion and/or growth factor support allowed)
• Absolute neutrophil count ≥1.5 × 109/L
• Prothrombin time (PT) and partial thromboplastin time (PTT) ≤1.5 × the upper limit of normal (ULN), except for patients on coumadin-derivative anticoagulants or other similar anticoagulant therapy, who must have PT-international normalized ratio (INR) within therapeutic range as deemed appropriate by the Investigator
• Serum creatinine ≤1.5 × ULN, or creatinine clearance ≥50 mL/min as calculated using the modified Cockcroft-Gault equation; confirmation of creatinine clearance is only required when creatinine is >1.5 × ULN
• AST/ALT ≤3 × ULN (if liver metastases are present, ≤5 × ULN)
• Total bilirubin ≤1.5 × ULN if no liver metastases or <3 × ULN in the presence of documented Gilbert's syndrome or liver metastases
• Serum albumin ≥2.5 g/dL 14. Male patients with female partners of childbearing potential and female patients of childbearing potential are required to use two forms of acceptable contraception, including one barrier method, during their participation in the study and for at least 7 months following last dose. Male patients must also refrain from donating sperm during their participation in the study.

Exclusion Criteria

Patients who meet any of the following criteria will be excluded from study entry:Exclusion criteria for Parts A and B (HER2-negative) and Part Z (HER2-positive) cohorts: 1. Treatment with any of the following:
• Any systemic anti-cancer chemotherapy, small molecule, biologic, hormonal agent, or immune checkpoint inhibitor therapy from a previous treatment regimen or clinical study within 21 days prior to the first dose of patritumab deruxtecan
• Prior treatment with any HER3-targeting agent
• Major surgery (excluding placement of vascular access) within 4 weeks of the first dose of study drug treatment
• Radiotherapy treatment to more than 30% of the bone marrow or with a wide field of radiation within 4 weeks of the first dose of study drug treatment, or palliative radiation therapy within 2 weeks of the first dose of study drug treatment
• Chloroquine /hydroxychloroquine ≤14 days prior to the first dose of study drug treatment 2. Has any hypersensitivity to drug substances or inactive ingredients in drug product 3. Has any history of ILD (including pulmonary fibrosis or radiation pneumonitis), has clinically significant ILD, or is suspected to have such disease by imaging during screening. If imaging findings are unlikely to indicate a history of pneumonitis, then the Investigator should discuss the considerations with the Medical Monitor about potential enrollment and record the reasoning in the source documentation. 4. Clinically severe pulmonary compromise (based on Investigator's assessment) resulting from intercurrent pulmonary illnesses including, but not limited to:
• Any underlying pulmonary disorder (e.g., pulmonary emboli, severe asthma, severe chronic obstructive pulmonary disease, restrictive lung disease, pleural effusion)
• Any autoimmune, connective tissue or inflammatory disorder with pulmonary involvement (e.g., rheumatoid arthritis, Sjögren's syndrome, sarcoidosis) OR prior pneumonectomy 5. With the exception of alopecia, any unresolved toxicities from prior therapy greater than Common Terminology Criteria for Adverse Events (CTCAE) Grade 1 or baseline at the time of starting study treatment. Note: patients with chronic Grade 2 toxicities who are asymptomatic or adequately managed with stable medication may be eligible with approval by the Medical Monitor. 6. Leptomeningeal metastases or evidence of spinal cord compression or brain metastases, defined as being clinically active and symptomatic, or requiring therapy with corticosteroids or anticonvulsants to control associated symptoms. Patients with clinically inactive or treated brain metastases who are asymptomatic (i.e., without neurologic signs or symptoms and do not require treatment with corticosteroids or anticonvulsants) may be included in the study. Patients must have a stable neurologic status for at least 2 weeks prior to Cycle 1 Day 1. 7. Women who are pregnant, nursing, or plan to become pregnant while in the study and for at least 7 months after the last administration of study treatment 8. Men who plan to father a child while in the study and for at least 7 months after the last administration of study treatment 9. Uncontrolled or significant cardiovascular disorder prior to Cycle 1 Day 1, including:
• Mean resting corrected QT interval using Fridericia's formula (QTcF) prolongation to >470 ms for females and >450 ms for males in three successive screening measurements
• Patients with a left ventricular ejection fraction (LVEF) <50%
• Resting systolic blood pressure >180 mmHg or diastolic blood pressure >110 mmHg).
• Documented myocardial infarction within 6 months
• Congestive heart failure (New York Heart Association ≥ Grade 2 within 28 days 10. Has known clinically significant corneal disease from prior therapies such as drug-induced keratitis 11. Is receiving chronic systemic corticosteroids dosed at >10 mg prednisone or equivalent anti-inflammatory activity or any form of immunosuppressive therapy prior to Cycle 1 Day 1. Patients who require use of bronchodilators, inhaled or topical steroids, or local steroid injections may be included in the study. 12. As judged by the Investigator, any evidence of severe or uncontrolled systemic diseases, including uncontrolled hypertension, uncontrolled diabetes mellitus, active bleeding diatheses, or active infection, including hepatitis B, hepatitis C, and human immunodeficiency virus. Screening for chronic conditions is not required. 13. Presence of other active invasive cancers other than the one treated in this study within 3 years prior to screening, except appropriately treated basal cell carcinoma of the skin, in situ carcinoma of uterine cervix, or other local tumors considered cured by local treatment 14. Psychological, familial, sociological, or geographical conditions that do not permit compliance with the protocol and/or follow-up procedures outlined in the protocol Additional exclusion criteria only for Parts A and B (HER2-negative) cohorts: 15. Patients with HER2+ breast cancer per ASCO-CAP guidelines 16. Part A only: Prior treatment with an antibody drug conjugate that consists of an exatecan derivative that is a topoisomerase I inhibitor (e.g., trastuzumab deruxtecan, DS-1062a [datopotamab deruxtecan], and DS-7300a [B7-H3 DXd-ADC]) 17. Part B patients only: Prior treatment with trastuzumab deruxtecan, sacituzumab govitecan, and/or datopotamab deruxtecan with any of the following:
• A severe reaction or severe tolerability issues that necessitated stopping treatment with the therapy
• Any unresolved toxicities from the prior therapy greater than Grade 1, with the exception of alopecia Additional exclusion criteria only for Part Z (HER2-positive) cohort: 18. Treatment with any of the following:
• Prior treatment with an antibody drug conjugate that consists of an exatecan derivative that is a topoisomerase I inhibitor except trastuzumab deruxtecan
• Prior treatment with trastuzumab deruxtecan within 4 weeks prior to the first dose of patritumab deruxtecan 19. Uncontrolled or significant cardiovascular disease, including history of myocardial infarction within 6 months before enrollment 20. A severe reaction or severe tolerability issues that necessitated stopping treatment with trastuzumab deruxtecan 21. Any unresolved toxicities from prior therapy with trastuzumab deruxtecan

Inclusion Criteria:

• A patient cannot be considered eligible for this study unless ALL of the following conditions are met.
• The patient or a legally authorized representative must provide study-specific informed consent prior to pre-entry and, for patients treated in the U.S., authorization permitting release of personal health information.
• Female patients must be greater than or equal to 18 years of age.
• Patients must be premenopausal (evidence of functioning ovaries) at the time of pre-entry. For study purposes, premenopausal is defined as:
• Age 50 years or under with spontaneous menses within 12 months; or
• Age greater than 50-60 years with spontaneous menses within 12 months plus follicle-stimulating hormone (FSH) and estradiol levels in the premenopausal range; or
• Patients with amenorrhea due to IUD or prior uterine ablation must have FSH and estradiol levels in the premenopausal range; or
• Patients with prior hysterectomy must have FSH and estradiol levels in the premenopausal range.
• The patient must have an ECOG performance status of less than or equal to 2 (or Karnofsky greater than or equal to 60%).
• Patients may have ipsilateral or contralateral synchronous breast cancer if the highest stage tumor meets entry criteria, and the other sites of disease would not require chemotherapy or HER2-directed therapy.
• Patients may have multicentric or multifocal breast cancer if the highest stage tumor meets entry criteria, and the other sites of disease would not require chemotherapy or HER2-directed therapy.
• Patient may have undergone a total mastectomy, skin-sparing mastectomy, nipple-sparing mastectomy, or a lumpectomy.
• For patients who undergo a lumpectomy, the margins of the resected specimen or re-excision must be histologically free of invasive tumor and DCIS (ductal carcinoma in situ) with no ink on tumor as determined by the local pathologist. If pathologic examination demonstrates tumor at the line of resection, additional excisions may be performed to obtain clear margins. Positive posterior margin is allowed if surgeon deems no further resection possible. (Patients with margins positive for LCIS (lobular carcinoma in situ) are eligible without additional resection.)
• For patients who undergo mastectomy, the margins must be free of residual gross tumor. (Patients with microscopic positive margins are eligible if post-mastectomy RT (radiation therapy) of the chest wall will be administered.)
• Patient must have undergone axillary staging with sentinel node biopsy (SNB), targeted axillary dissection (TAD), or axillary lymph node dissection (ALND).
• The following staging criteria must be met postoperatively according to AJCC 8th edition criteria:
• By pathologic evaluation, primary tumor must be pT1-3. (If N0, must be T1c or higher.)
• By pathologic evaluation, ipsilateral nodes must be pN0 or pN1 (pN1mi, pN1a, pN1b, pN1c).
• Patients with positive isolated tumor cells (ITCs) in axillary nodes will be considered N0 for eligibility purposes.
• Patients with micrometastatic nodal involvement (0.2-2 mm) will be considered N1.
• Oncotype DX RS (recurrence score) requirements*:
• If node-negative:
• Oncotype DX RS must be RS 21-25, or
• Oncotype DX RS must be 16-20 and disease must be high clinical risk, defined as: low histologic grade with primary tumor size greater than 3 cm, intermediate histologic grade with primary tumor size greater than 2 cm, or high histologic grade with primary tumor size greater than 1 cm.
• If 1-3 nodes involved:
• Oncotype DX RS must be less than 26. * Patients with a "Low Risk" or "MP1" MammaPrint (a genomic test that analyzes the activity of certain genes in early-stage breast cancer) result must have eligibility assessed with an Oncotype DX RS at pre-entry (see Section 3.1). Blocks or unstained slides must be sent to the Genomic Health centralized laboratory for testing at no cost to these patients. If MammaPrint High Risk or MP2, these patients are not eligible.
• The tumor must be ER and/or PgR-positive (progesterone receptor) by current ASCO/CAP guidelines based on local testing results. Patients with greater than or equal to 1% ER and/or PgR staining by IHC will be classified as positive.
• The tumor must be HER2-negative by current ASCO/CAP (American Society of Clinical Oncology/College of American Pathologists) guidelines based on local testing results.
• The interval between the last surgery for breast cancer (including re-excision of margins) and pre-entry must be no more than 16 weeks.
• Short course of endocrine therapy of less than 6 weeks duration before pre-entry is acceptable either as neoadjuvant or adjuvant therapy. An Oncotype DX RS must be performed on core biopsy specimen obtained prior to initiation of neoadjuvant endocrine therapy if received.
• Patients with a prior or concurrent non-breast malignancy whose natural history or treatment does not have the potential to interfere with the safety or efficacy assessment of the investigational regimen are eligible for this trial. This would include prior cancers treated with curative intent.
• HIV-infected patients on effective anti-retroviral therapy with undetectable viral load within 6 months are eligible for this trial.
• Radiation therapy should be used according to standard guidelines; the intended radiation therapy should be declared prior to pre-entry.

Exclusion Criteria:

• • Definitive clinical or radiologic evidence of metastatic disease.
• pT4 (pathological state) tumors, including inflammatory breast cancer.
• History of ipsilateral or contralateral invasive breast cancer. (Patients with synchronous and/or previous DCIS or LCIS are eligible.)
• If prior ipsilateral DCIS was treated with lumpectomy and XRT (ionizing radiation therapy), a mastectomy must have been performed for the current cancer.
• Life expectancy of less than 10 years due to co-morbid conditions in the opinion of the investigator.Known results from most recent lab studies obtained as part of routine care prior tostudy entry showing ANY of the following values:
• ANC (absolute neutrophil count) less than 1200/mm3;
• Platelet count less than 100,000/mm3;
• Hemoglobin less than 10 g/dL;
• Total bilirubin greater than ULN (upper limit of normal) for the lab or greater than 1.5 x ULN for patients who have a bilirubin elevation due to Gilbert's disease or similar syndrome involving slow conjugation of bilirubin;
• AST(aspartate aminotransferase)(SGOT)/ALT (alanine transminase)(SGPT): greater than 3 × institutional ULN;
• Renal function of GFR (glomular filtration rate) less than 30 mL/min/1.73m2.
• Patients with known history or current symptoms of cardiac disease, or history of treatment with cardiotoxic agents, should have a clinical risk assessment of cardiac function using the New York Heart Association Functional Classification. To be eligible for this trial, patients should be class 2B or better.
• Non-epithelial breast malignancies such as sarcoma or lymphoma.
• Any treatment with radiation therapy, chemotherapy, or biotherapy administered for the currently diagnosed breast cancer prior to pre-entry. (Patients with prior ET of more than 6 weeks duration for treatment of this cancer are not eligible.) Prior tamoxifen given for breast cancer prevention is allowed. Prior AI or GnRH for fertility preservation is allowed.
• Hormonally based contraceptive measures must be discontinued prior to pre-entry (including progestin/progesterone IUDs).
• Patients with evidence of chronic hepatitis B virus (HBV) infection are ineligible unless the HBV viral load is undetectable on suppressive therapy. Patients with a history of hepatitis C virus (HCV) infection are ineligible unless they have been treated and cured or have an undetectable HCV viral load if still on active therapy.
• Pregnancy or lactation at the time of pre-entry. (Note: Pregnancy testing according to institutional standards for women of childbearing potential must be performed within 2 weeks prior to pre-entry.)
• Other conditions that, in the opinion of the investigator, would preclude the patient from meeting the study requirements or interfere with interpretation of study results.

Inclusion Criteria:

• Participant must be ≥ 18 years, at the time of signing the ICF.
• Histologically confirmed Stage II or III unilateral or bilateral primary invasive TNBC or hormone receptor-low/HER2-negative breast cancer
• ECOG PS of 0 or 1
• Provision of acceptable tumor sample
• Adequate bone marrow reserve and organ function
• Contraceptive use by males or females should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies.Exclusion criteria:
• History of another primary malignancy except for malignancy treated with curative intent with no known active disease within 3 years before randomization and of low potential risk for recurrence.
• Evidence of distant disease.
• Clinically significant corneal disease.
• Has active or uncontrolled hepatitis B or C virus infection.
• Known HIV infection that is not well controlled.
• Uncontrolled infection requiring i.v. antibiotics, antivirals or antifungals; suspected infections; or inability to rule out infections.
• Known to have active tuberculosis infection
• Resting ECG with clinically significant abnormal findings.
• Uncontrolled or significant cardiac disease.
• History of non-infectious ILD/pneumonitis
• Any prior or concurrent surgery, radiotherapy or systemic anticancer therapy for TNBC or hormone receptor-low/HER2-negative breast cancer
• For females only: is pregnant (confirmed with positive serum pregnancy test) or breastfeeding, or planning to become pregnant.
• Female participants should refrain from breastfeeding from enrolment throughout the study and for at least 7 months after last dose of study intervention, or as dictated by local PI for SoC if longer.

Inclusion Criteria:

• Have a diagnosis of ER+, HER2- early-stage, resected, invasive breast cancer without evidence of distant metastasis.
• Participants must have received at least 24 months but not more than 60 months of any adjuvant ET, from time of adjuvant ET initiation.
• Participants may have received (neo) adjuvant chemotherapy and/or targeted therapy with a CDK4/6- or PARP- inhibitor.
• Must have an increased risk of disease recurrence based on clinical-pathological risk features.
• Have a Performance Status of 0 or 1 on the Eastern Cooperative Oncology Group scale.
• Have adequate organ function.

Exclusion Criteria:

• Have any evidence of metastatic disease (including contralateral ALN) or inflammatory breast cancer at primary breast cancer diagnosis.
• Participants with more than a 6-month consecutive gap in therapy during the course of prior adjuvant ET.
• Participants who have completed or discontinued prior adjuvant ET >6 months prior to screening.
• Participants with a history of previous breast cancer are excluded, with the exception of ipsilateral DCIS treated by locoregional therapy alone ≥5 years ago.
• Pregnant, breastfeeding, or expecting to conceive or father children within the projected duration of the trial, starting with the screening visit through 180 days after the last dose of study intervention.
• Participant has previously received ET of any duration for breast cancer prevention (tamoxifen or AIs) or raloxifene.
• Participants with a history of any other cancer.
• Have serious preexisting medical conditions that, in the judgment of the investigator, would preclude participation in this study.

Inclusion Criteria:

• Age >= 18 years
• Eastern Cooperative Oncology Group (ECOG) Performance Status 0-2
• Triple Negative Breast Cancer:
• Patients with a history of stage T1cN1-2 or T2-4N0-2 breast cancer according to the primary tumor-regional lymph node anatomic staging criteria of the American Joint Committee on Cancer (AJCC), 8th edition as determined by the investigator in radiologic assessment, clinical assessment or both
• Patients must have no residual invasive disease in the breast or lymph nodes after the completion of neoadjuvant therapy. Residual ductal carcinoma in situ (DCIS) is allowed. Isolated tumor cells are considered node-negative
• Estrogen (ER) and progesterone (PR) =< 10%; HER2-negative by American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines (immunohistochemistry [IHC] and fluorescence in situ hybridization [FISH])
• If invasive disease was present in both breasts, participation in the study is permitted as long as the eligibility criteria are met for both tumors/breasts
• Patients must have received neoadjuvant chemotherapy in combination with pembrolizumab for a minimum of 6 cycles. All systemic chemotherapy and ICI therapy should have been completed preoperatively
• An interval of no more than 12 weeks between the completion date of the final surgery and the date of randomization * Note: Adjuvant radiation can be given on study. If given, it is encouraged to be given concurrently with pembrolizumab, per investigator discretion. Treatment with adjuvant pembrolizumab is strongly discouraged prior to participation in this trial, but if administered (e.g., if patients are awaiting pathology results), pembrolizumab may be administered for up to 6 weeks post-surgery and must be completed prior to registration
• Use of investigational anti-cancer agents must be discontinued at time of registration
• Adequate excision: Surgical removal of all clinically evident disease in the breast and lymph nodes as follows:
• Breast surgery: Total mastectomy or breast-conserving surgery with histologically negative margins, including no ink on tumor for DCIS, at the time of excision ** For patients who undergo breast-conserving surgery, the margins of the resected specimen must be histologically free of ductal carcinoma in-situ (DCIS) as determined by the local pathologist. If pathologic examination demonstrates DCIS at the line of resection, additional operative procedures may be performed to obtain clear margins. If DCIS is still present at the resected margin after re-excision(s), the patient must undergo total mastectomy to be eligible. Patients with margins positive for classic lobular carcinoma in situ (LCIS) are eligible without additional resection
• Lymph node surgery:
• For a patient with clinically N0 disease, a sentinel lymph node biopsy should have been performed at time of surgical evaluation, and if pathologically node positive, the patient is no longer eligible. Isolated tumor cells are considered node-negative
• For a patient with clinically N1 disease at diagnosis (with positive results from a fine-needle aspiration, core biopsy, or sentinel node biopsy performed prior to preoperative therapy) additional surgical evaluation of the axilla following preoperative therapy is required *** If they become cN0 (no palpable adenopathy), then a sentinel lymph node biopsy could have been performed at time of surgery (axillary dissection would also be permitted); if the sentinel lymph node biopsy is positive, the patient is no longer eligible
• If sentinel node biopsy performed before preoperative therapy was negative, no additional surgical evaluation of the axilla is required after preoperative therapy. If sentinel node biopsy performed before preoperative therapy was positive, an ALND is required after preoperative therapy
• If the only sentinel node identified by isotope scan is in the internal mammary chain, surgical evaluation of the axilla is still required
• If sentinel node evaluation after preoperative therapy is negative, no further additional surgical evaluation of the axilla is required
• Axillary dissection without sentinel node evaluation is permitted as the initial or sole axillary evaluation after preoperative therapy
• If breast-conserving surgery was performed but patient will not be receiving breast radiation, the patient is not eligible
• Not pregnant and not nursing, because this study involves an agent whose genotoxic, mutagenic and teratogenic effects on the developing fetus and newborn are unknown. Therefore, for women of childbearing potential only, a negative serum or urine pregnancy test done =< 7 days prior to randomization is required
• Absolute neutrophil count (ANC) >= 1,000/mm^3
• Platelet Count >= 100,000/mm^3
• Estimated glomerular filtration rate (eGFR) >= 15 mL/min/1.73m^2
• Total Bilirubin =<1.5 x upper limit of normal (ULN) * Patients with Gilbert's disease with a total bilirubin =< 2.5 x ULN and direct bilirubin within normal limits are permitted
• Aspartate aminotransferase (AST) serum aspartate aminotransferase [SGOT] / alanine aminotransferase (ALT) serum glutamic pyruvic transaminase [SGPT] =< 3 x institutional ULN
• Patients must be willing to provide tumor tissue from the diagnostic core biopsy. If inadequate tumor tissue is available, patients are still eligible to participate in the trial
• Patients with a prior or concurrent malignancy whose natural history or treatment does not have the potential to interfere with the safety or efficacy assessment of the investigational regimen are eligible for this trial
• Patients with known history or current symptoms of cardiac disease, or history of treatment with cardiotoxic agents, should have a clinical risk assessment of cardiac function using the New York Heart Association Functional Classification. To be eligible for this trial, patients should be class 2B or better
• Human immunodeficiency virus (HIV)-infected patients on effective anti-retroviral therapy with undetectable viral load within 6 months prior to registration are eligible for this trial

Exclusion Criteria:

• No stage IV (metastatic) breast cancer
• No history of any prior (ipsi- or contralateral) invasive breast cancer. Prior DCIS is allowed
• No evidence of recurrent disease following preoperative therapy and surgery
• No known active liver disease, e.g. due to hepatitis B virus (HBV), hepatitis C virus (HCV), autoimmune hepatic disorders, or sclerosing cholangitis
• No history of intolerance, including Grade 3 or 4 infusion reaction or hypersensitivity to pembrolizumab or murine proteins or any components of the product * Note: Prior immune-related adverse events (irAEs) are allowed if they resolved and the patient tolerated subsequent therapy without requiring chronic steroids for the irAE
• No medical conditions that require chronic systemic steroids (>10 mg prednisone daily or equivalent) or any other form of immunosuppressive medications and has required such therapy in the last two years. Replacement therapy (e.g. thyroxine, insulin, or physiologic corticosteroid replacement therapy for adrenal or pituitary insufficiency, etc.) is not considered a form of systemic therapy
• Patients who are unable or unwilling to comply with the requirements of the protocol per investigator assessment are not eligible