Lead-212-DOTAM binding site on bispecific antibody (212Pb-DOTAM docking epitope)

The Lead-212-DOTAM binding site on a bispecific antibody is an engineered molecular recognition element designed for pre-targeted alpha-particle therapy (TAT) [1, 2]. In this therapeutic strategy, a bispecific antibody (bsAb) is administered first; one arm of the antibody binds to a specific tumor-associated antigen, while the other arm—the docking epitope—remains available to capture a subsequently administered radioligand [2, 3]. The radioligand consists of the alpha-emitting isotope Lead-212 (212Pb) stabilized by the macrocyclic chelator DOTAM (1,4,7,10-tetrakis(carbamoylmethyl)-1,4,7,10-tetraazacyclododecane) [3, 4]. This pre-targeting approach allows the large antibody to achieve optimal tumor localization and clear from the bloodstream before the short-lived, highly potent alpha emitter is introduced, thereby minimizing systemic radiation exposure [1, 5]. Once the 212Pb-DOTAM is injected, it rapidly docks with the epitope on the tumor-bound antibody, delivering high-energy alpha radiation directly to the malignant cells [2, 4]. This technology is particularly effective for treating solid tumors while sparing sensitive tissues like the bone marrow [1, 5].

Other names

anti-Pb-DOTAM capture arm212Pb-DOTAM paratopeAlphaRetargeting docking siteanti-DOTAM scFvLead-212-DOTAM docking epitope

Pre-targeted alpha therapy (TAT) via high-affinity capture of radiolabeled ligands