This is a pilot protocol to evaluate the safety, feasibility, and immunogenicity of a personalized breast cancer vaccine based utilizing whole exome sequencing data of a patient's residual breast tumor following neoadjuvant chemotherapy.

Inclusion Criteria:

• Patient has stage II-III ER/PR less than or equal to 10% HER2 negative by FISH and/or IHC breast cancer treated with standard of care neoadjuvant systemic chemotherapy and surgical resection with significant residual breast tumor (equivalent to RCB II or III) disease.
• Patient has sufficient residual viable primary breast tumor or ipsilateral breast axillary nodal metastatic cancer tissue accessible to Moffitt for whole exome sequencing.
• Patient is 18 years of age or older.
• Eastern Cooperative Oncology Group (ECOG) performance status of 0-1
• Patients must have adequate organ and marrow function.
• 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 without radiologic evidence of active metastatic disease and who are within 18 months of their last dose curative intent chemotherapy and/or radiotherapy (whichever is later) for the purposes of study enrollment.
• Women of child-bearing potential must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation. Should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately.
• Ability to understand and the willingness to sign a written informed consent document.

Exclusion Criteria:

• Patients with known active locally advanced unresectable or metastatic cancer.
• Patients with significant uncontrolled intercurrent illness or autoimmune disease requiring systemic immunosuppressants that would be deemed unsuitable to participate in the study by the Principal Investigator (PI).
• Patients who have a medical issue in the opinion of the treating physician and/or PI that would make them unsuitable for pheresis.
• Patients who are currently receiving any other investigational agents.
• Patients with psychiatric illness/social situations that would limit compliance with study requirements.
• Pregnant women are excluded from this study.