Meditopes and meditope-binding antibodies and uses thereof

A complex comprising:

• a meditope-enabled antibody or antigen-binding fragment thereof, wherein said meditope-enabled antibody or antigen-binding fragment thereof comprises a heavy chain variable (VH) region;
• a heavy chain constant region (CH) or portion thereof;
• a light chain variable (VL) region comprising a threonine at position 40, an asparagine at position 41, an isoleucine or valine at position 83, and an aspartate at position 85, according to Kabat numbering;
• and a light chain constant region (CL) or portion thereof;
• wherein the meditope-enabled antibody or antigen-binding fragment thereof comprises a meditope-binding site which (i) comprises threonine, asparagine and aspartate at residues 40, 41 and 85, respectively, and isoleucine or valine at residue 83 of the VL of the meditope-enabled antibody or antigen-binding fragment thereof, and glutamine, isoleucine, glutamine at residues 39, 89, and 105, respectively, and leucine or serine at residue 108 of the VH of the meditope-enabled antibody or antigen-binding fragment thereof, both according to Kabat numbering and (ii) can bind to a peptide comprising the amino acid sequence of SEQ ID NO:
• 1 or 2;
• a meditope bound to the meditope-binding site;
• and
• a chemotherapeutic agent conjugated to the meditope,
• wherein the meditope comprises a peptide of:
• C-QFDLSTRRLK-C(SEQ ID NO:
• 1),
• wherein:
• the meditope-enabled antibody or antigen-binding fragment thereof does not specifically bind to the epitope of an EGFR that is specifically bound by cetuximab.