NCIt definition : A vaccine comprised of estrogen receptor alpha (ERa; estrogen receptor 1; ESR1) mutant
peptides, combined with the immunoadjuvants granulocyte-macrophage colony-stimulating
factor (GM-CSF) and montanide ISA, with potential immunomodulating and antineoplastic
activities. Upon subcutaneous administration, the ESR1 mutant peptides in the ESR1
peptides/GM-CSF/montanide ISA vaccine may activate the immune system to induce an
immune response against tumor cells expressing these ESR1 mutations. Constitutively
activating mutations in ESR1 sometimes emerge with the treatment of estrogen receptor
(ER)-positive breast cancer with endocrine therapy, leading to resistance to endocrine
therapy. GM-CSF and montanide ISA potentiate the anti-tumor immune response.;