Abstract: The present disclosure relates to antigen-binding agents that specifically bind to epidermal growth factor receptor variant III (EGFRvIII). Antigen-binding agents of the present disclosure include antibodies and antigen-binding fragments thereof, chimeric antigen receptors (CARs) and bi-specific T-cell engagers (BITE!), bispecific killer cell engagers (BiKEs) and bispecific killer cell engagers (TriKEs). Nucleic acid molecules and vectors expressing antibodies, antigen-binding fragments, CARs, BiTEs, BiKEs or TriKEs are also encompassed by the present disclosure. Immune cells engineered to express CARs, BiTEs, BiKEs or TriKEs may be used to specifically recognize and kill cells expressing EGFRvIII.