In some aspects, the invention relates to an antibody-drug conjugate, comprising an anti-epidermal growth factor receptor (“EGFR”) antibody; a linker; and an active agent. The antibody-drug conjugate may comprise a self-immolative group. The linker may comprise an O-substituted oxime, e.g., wherein the oxygen atom of the oxime is substituted with a group that covalently links the oxime to the drug; and the carbon atom of the oxime is substituted with a group that covalently links the oxime to the antibody.