HER2 Directed Dendritic Cell Vaccine During Neoadjuvant Therapy of HER2+Breast Cancer

The trial will consist of two phases. The first lead in phase will enroll 12 participants evenly divided into two arms (alternating enrollment) with different initial priming study vaccination schedules. Arm A: One DC1 study vaccination per week x 3 weeks. Arm B: Two DC1 study vaccinations per week (given 3 days apart for example Mon and Thurs or Tues and Friday) x 3 weeks. Following accrual of this initial group of 12 participants, HER2 ELISPOT post study vaccination responses will be assessed to determine which of the two sequences provides the greater increase in anti HER2 response at week 4 over baseline. This will determine which sequence will be used in the second expansion phase of accrual. If both arms are determined equal then Arm A will be selected as the default sequence. Second phase of accrual will consist of 14 additional participants to undergo study vaccination using the optimal schedule declared in the first phase of the trial. The trial will consist of two phases. The first lead in phase will enroll 12 participants evenly divided into two arms (alternating enrollment) with different initial priming study vaccination schedules. Arm A: One DC1 study vaccination per week x 3 weeks Arm B: Two DC1 study vaccinations per week (given 3 days apart for example Mon and Thurs or Tues and Friday) x 3 weeks. Following accrual of this initial group of 12 participants, HER2 ELISPOT post study vaccination responses will be assessed to determine which of the two sequences provides the greater increase in anti HER2 response at week 4 over baseline. This will determine which sequence will be used in the second expansion phase of accrual. If both arms are determined equal then Arm A will be selected as the default sequence. Second phase of accrual will consist of 14 additional participants to undergo study vaccination using the optimal schedule declared in the first phase of the trial.