A radioimmunoconjugate composed of a humanized monoclonal antibody IgG1 directed against the epidermal growth factor receptor (EGFR) and labeled with the radioisotope indium In 111, with potential radioimaging activity. Indium In 111 anti-EGFR monoclonal antibody ABT-806 binds to a specific epitope of either wild-type or EGFR variant III mutant on tumor cells, thereby allowing imaging of EGFR-expressing tumor cells using gamma scintigraphy. ABT-806 is the humanized version derived from the predecessor chimeric monoclonal antibody 806. EGFR, a receptor tyrosine kinase overexpressed on the cell surfaces of many tumor cell types, plays a key role in tumor cell proliferation. Check foractive clinical trials using this agent.