A cancer vaccine consisting of a human epidermal growth factor receptor variant III (EGFRvIIi)-specific peptide conjugated to the non-specific immunomodulator keyhole limpet hemocyanin (KLH) with potential antineoplastic activity. Vaccination with rindopepimut may elicit a cytotoxic T-lymphocyte (CTL) immune response against tumor cells expressing EGFRvIII. EGFRvIII, a functional variant of EGFR that is not expressed in normal tissues, was originally discovered in glioblastoma multiforme (GBM) and has also been found in various other cancers such as breast, ovarian, metastatic prostate, colorectal, and head and neck cancers. EGFRvIII contains an 83 amino acid deletion in its extracellular domain and has been shown to transform NIH/3T3 mouse embryonic fibroblast cells in vitro.