Disclosed herein is a tissue-targeting complex comprising a tissue targeting moiety selected from antibodies, antibody constructs, fragments of antibodies, constructs of fragments or a mixture thereof, peptide, amino acid, steroidal or non-steroidal hormone, folate, estrogen, testosterone or biotin, an octadentate hydroxypyridinone-containing ligand and the ion of an alpha-emitting 227-thorium radionuclide, such as the 4+ ion of an alpha-emitting thorium radionuclide. Specifically comprising an octadentate ligand comprising at least one chelating moiety of formula I, and more specifically comprising 4 independently chosen moieties of formula I, more specifically comprising at least on 3,2-hydroxypyridinone moiety. Specific embodiments include tetra-tert-butyl(((((2-3-Cbzaminopropanamido)ethyl)azanediyl)bis(ethane-2,1-diyl))bis(azanetriyl)tetrakis(ethane-2,1-diyl)tetracarbamate, and benzyl (1-(3-(benzyloxy)-1-methyl-2-oxo-1,2-dihydropyridin-4-yl)-5-(2-(3-(benzyloxy)-1-methyl-2-oxo-1,2-dihydropyridine-4-carboxamido)ethyl)-8-(2-(bis(2-(3-(benzyloxy)-1-methyl-2-oxo-1,2-dihydropyridine-4-carboxamido)ethyl)amino)ethyl)-1,12-dioxo-2,5,8,11-tetraazatetradecan-14-yl)carbamate. Additionally disclosed is the use of said complex in the treatment of hyperplastic or neoplastic disease, such as carcinoma, sarcoma, myeloma, leukemia, lymphoma, or mixed type cancer.
