Meditope variants and methods for their use are provided herein. A meditope variant as described herein comprises a peptide having a sequence CQFDLSTRRLKC (SEQ ID NO:1) or CQYNLSSRALKC (SEQ ID NO:2) that has one or more modifications at of least one amino acid residue of the sequence. Multivalent meditope variant tethering entities are also provided. Such entities may include two or more meditopes coupled via a long linker, multivalent scaffold, biotin-streptavidin, or IgG Fc domain. Further, methods of treating, imaging or diagnosing a disease or condition are provided. Such methods may include administering a therapeutically effective amount of a pharmaceutical composition to a subject, the pharmaceutical compound comprising an antibody-meditope complex; a multivalent tethering agent in combination with a monoclonal antibody or functional fragment thereof; or a combination thereof.