Cancer Peptides Plus GM-CSF and Adjuvant in Breast Cancer

This is a phase I study looking at the safety of cancer peptides combined with adjuvant and GM-CSF in subjects with estrogen receptor (ESR) positive breast cancer. The primary objective of the study is to determine the safety of of the peptide vaccine. The secondary objective is to evaluate the immune response to the vaccine. The peptides used in this vaccine are derived from the estrogen receptor and are combined with the adjuvant Montanide ISA and GM-CSF to enhance their immune response. A peptide vaccine of these peptides may improve outcomes of patients with endocrine resistant breast cancer.