Synthesis of [64Cu]Cu-NOTA-Bn-GE11 for PET imaging of EGFR-rich tumors.

Epidermal growth factor receptors (EGFR) are over-expressed in many different types of cancer, thus, are logical targets for both diagnosis and therapy. Antibodies and antibody fragments targeting the extracellular EGF receptor and small molecules targeting the intracellular tyrosine kinase (TK) part of EGFR have been developed as possible diagnostic EGFR imaging agents. Recently, a 12-amino acid peptide, GE11, was identified using phage display screening to have high affinity for EGFR (Kd=22nM). Reported in vitro and in vivo characteristics of GE11 suggest that positron-labeled GE11 may be a useful PET imaging agent in selecting patients with EGFR-rich tumors who can most benefit from anti- EGFR therapy. To enable the exploration of this possibility, positron emitting [64Cu]Cu-NOTA-Bn-GE11 was prepared for further evaluation as PET EGFR imaging agent.