Nelipepimut-S Plus GM-CSF Vaccine Therapy in Treating Patients With Breast Cancer

This phase II trial studies how well nelipepimut-S plus GM-CSF vaccine therapy or sargramostim works in treating patients with breast cancer. Vaccines made from peptide or antigen and/or a person's white blood cells mixed with tumor proteins may help the body build an effective immune response to kill tumor cells that express breast cancer antigens. It is not yet known whether nelipepimut-S plus GM-CSF vaccine or sargramostim is more effective in treating patients with breast cancer.