This study evaluated the preclinical efficacy of [212Pb]Pb-TCMC-chOI-1, a 212Pb-labeled antibody targeting PTK7, for targeted alpha-emitting radionuclide therapy in bladder cancer using 2D adherent cultures (clonogenic assay) and 3D multicellular spheroid models (spheroid growth inhibition). This evidence concerns the gene PTK7 and urinary bladder carcinoma.