Personalized Cancer Vaccine (PCV) Strategy in Triple Negative Breast Cancer Patients

Step 0 Inclusion Criteria: * Newly diagnosed, previously untreated, locally advanced non-metastatic triple negative breast cancer (as defined by the most recent ASCO/CAP guidelines). Permissible staging per AJCC is as follows: * T1c, N1-N2 * T2, N0-N2 * T3, N0-N2 * At least 18 years of age. * Adequate tissue available for nucleic acid isolation/PCV design or willing to undergo biopsy if adequate tissue is not available. * Adequate cardiac function per treating physician and a candidate for the KEYNOTE 522 regimen (or receiving the KEYNOTE 522 regimen for no more than one month). Note that patients who are already receiving the KEYNOTE 522 regimen at the time of screening must have adequate archival tissue for nucleic acid isolation/PCV design (biopsy will not be permitted). * TIL percentage \< 10% (performed on SOC biopsy). * Ability to understand and willingness to sign an IRB approved written informed consent document. Legally authorized representatives may sign and give informed consent on behalf of study participants. Step 0 Exclusion Criteria: * Prior or concurrent malignancy whose natural history has the potential to interfere with the safety or efficacy assessment of the investigational regimen. Patients with prior or concurrent malignancy that does NOT meet that definition are eligible for this trial. * Received prior chemotherapy, targeted therapy, or radiation therapy within the past 12 months. * Received prior therapy with an anti-PD-1, anti-PD-L1, or ant…