Figure 1. Meditope-enabled mAbs. As reported by Donaldson et al., the Fab framework of the chimeric anti-epidermal growth factor receptor (EGFR) mAb Erbitux cetuximab contains a unique peptide-binding site that is distinct from the antibody's antigen-binding sites. This site is located in the center of a cavity formed by the mAb's light and heavy chains and can bind to engineered peptides called meditopes without interfering with antigen binding.

[I] The meditope-binding site can be engineered into other mAbs, such as the anti-HER2 (EGFR2; ErbB2; neu) mAb Herceptin trastuzumab.

Meditope-enabled mAbs can be conjugated to a broad range of molecules and thus represent a new avenue in antibody-drug conjugates. A meditope-enabled mAb can be used to target many otherwise nonspecific agents without the need to make additional modifications to the mAb itself.

[II] Potential applications include using meditope-enabled mAbs plus meditope-peptide conjugates to deliver imaging agents [green stars] or therapeutic payloads [red stars] to target cells.