DecipHER Trial - DC1 Tx for Early-Stage TNBC and ER Low Positive Breast Cancer

Inclusion Criteria: * A diagnosis of HER2-negative breast cancer. * Diagnosis of HR negative or HR low positive tumor. * Clinical stage T1c, nodal stage N1-N2 or stage T2-4, nodal stage N0-N2 breast cancer. * Participant must be medically and surgically appropriate to undergo neoadjuvant chemotherapy regimen followed by standard of care local therapy as determined by their treating physician. * Age ≥18 years. * ECOG performance status 0 or 1. * Patients must have normal organ and marrow function, as defined below, within 14 days of registration: * \*Absolute neutrophil count (ANC) ≥ 1500/μL * \*Platelets ≥ 75 000/μL * \*Total bilirubin ≤ 1.5 x institutional ULN, except patients with Gilbert's syndrome in whom total bilirubin must be \< 3.0 mg/dL * \*AST/ALT ≤ 3 x institutional ULN * \*Creatinine ≤ 1.5 x institutional ULN * Left ventricular ejection fraction above institutional lower limit of normal (by echocardiogram or MUGA scan). * Female patients of childbearing potential must agree to use dual methods of contraception and have a negative serum pregnancy test at screening. Acceptable methods of contraception are condoms with contraceptive foam, oral, implantable or injectable contraceptives, contraceptive patch, intrauterine device, diaphragm with spermicidal gel, or a sexual partner who is surgically sterilized or post-menopausal. Effective methods of contraception must be used throughout the study and for 5 months following the last dose. To show that women do not have childbearing potential, postmenopausal women must be amenorrheic for at least 12 months naturally (and not because of/following chemotherapy) or patients must be surgically sterile. * Ability to understand and the willingness to sign a written informed consent agreement prior to study registration. Exclusion Criteria: * Patients who received prior anthracycline-based chemotherapy for the treatment of any cancer. * Patients with inflammatory breast cancer. * Patients must not be receiving any other investigational agents or active antineoplastic therapies. * Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements. * Patients with active autoimmune disease or history of autoimmune disease that might recur, which may affect vital organ function or require immune-suppressive treatment, including chronic prolonged systemic corticosteroid use (defined as corticosteroid use lasting one month or more). * Female patients who are pregnant or nursing. * No other prior malignancy is allowed, except for the following: a. adequately treated basal-cell or squamous-cell skin cancer, b. in situ cervical cancer, c. or any other cancer from which the patient has been disease free for at least 3 years. * History of testing positive for human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS). * History of positive test for Hepatitis B or Hepatitis C virus indicating acute or chronic infection. * Patients who have received a live attenuated vaccine ≤ 30 days prior to registration. * Unable to comply with the treatment schedule and study procedures for any reason. * Previously treated with breast cancer-directed vaccine therapies in prior 3 months. * Previously treated with any form HER2- or HER3-primed DC1 therapy.