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BACKGROUND: Amivantamab is a novel bispecific antibody that simultaneously targets the epidermal growth factor receptor (EGFR) and the hepatocyte growth factor receptor (HGFR/c-MET) that are overexpressed in several types of cancer including triple negative breast cancer (TNBC). Targeting both receptors simultaneously can overcome resistance to mono-targeted therapy. The purpose of this study is to develop (89)Zr-labeled Amivantamab as a potential companion diagnostic imaging agent to Amivantamab therapy using various preclinical models of TNBC for evaluation. METHODS: Amivantamab was conjugated to desferrioxamine (DFO) and radiolabeled with (89)Zr to obtain [(89)Zr]ZrDFO-Amivantamab. Binding of the bispecific [(89)Zr]ZrDFO-Amivantamab as well as its mono-specific “single arm” antibody controls were determined in vitro and in vivo. Biodistribution studies of [(89)Zr]ZrDFO-Amivantamab were performed in MDA-MB-468 xenografts to determine the optimal imaging time point. PET/CT imaging with [(89)Zr]ZrDFO-Amivantamab or its isotype control was performed in a panel of TNBC xenografts with varying levels of EGFR and c-MET expression. RESULTS: [(89)Zr]ZrDFO-Amivantamab was synthesized with a specific activity of 148 MBq/mg and radiochemical yield of ≥ 95%. Radioligand binding studies and western blot confirmed the order of EGFR and c-MET expression levels: HCC827 lung cancer cell (positive control) > MDA-MB-468 > MDA-MB-231 > MDA-MB-453. [(89)Zr]Zr-DFO-Amivantamab demonstrated bispecific binding in cell lines co-expressed with EGFR and c-MET. PET/CT imaging with [(89)Zr]ZrDFO-Amivantamab in TNBC xenografted mice showed Standard Uptake Value (SUV(mean)) of 6.0 ± 1.1 in MDA-MB-468, 4.2 ± 1.4 in MDA-MB-231, and 1.5 ± 1.4 in MDA-MB-453 tumors, which are consistent with their receptors’ expression levels on the cell surface. CONCLUSION: We have successfully prepared a radiolabeled bispecific antibody, [(89)Zr]ZrDFO-Amivantamab, and evaluated its pharmacologic and imaging properties in comparison with its single arm antibodies and non-specific isotype controls. [(89)Zr]ZrDFO-Amivantamab demonstrated the greatest uptake in tumors co-expressing EGFR and c-MET.