Breast Cancer Vaccine in Combination With Pembrolizumab for Treatment of Persistent, Recurrent, or Metastatic Breast Cancer

PRIMARY OBJECTIVES: I. To evaluate the safety of the allogeneic GM-CSF-secreting breast cancer vaccine SV-BR-1-GM (SV-BR-1-GM) regimen when administered in combination with pembrolizumab in patients with human leukocyte antigen (HLA) match. (Phase I) II. To evaluate the overall response rate of the SV-BR1-GM regimen in combination with pembrolizumab. (Phase II) SECONDARY OBJECTIVES: I. To evaluate the non-progressive rate of the SV-BR-1-GM regimen in combination with pembrolizumab. II. To evaluate the duration of response of the SV-BR-1-GM regimen in combination with pembrolizumab. III. To evaluate immune responses elicited by the SV-BR-1-GM regimen when administered in combination with pembrolizumab. IV. To evaluate patient and tumor characteristics that may be predictive of responses to the SV-BR-1-GM regimen when administered in combination with pembrolizumab. V. To evaluate quality of life (QOL) in patients administered the SV-BR-1-GM regimen in combination with pembrolizumab by the Edmonton Symptom Assessment Survey. OUTLINE: Patients receive cyclophosphamide intravenously (IV) over 1-2 hours on day 1, SV-BR-1-GM intradermally (ID) on day 3, pembrolizumab IV over 30 minutes on day 5, and interferon-alpha-2b ID on days 5 and 7. Cycles repeat every 21 days for up to 2 years in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up at 2-4 weeks and then every 3 months for 1 year.