1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-lutetium-177 complex (177Lu-DOTA-hapten)

The DOTA/radiohapten motif, specifically when complexed with Lutetium-177 (177Lu), serves as the therapeutic payload in pretargeted radioimmunotherapy (PRIT) systems utilizing the SmartD2 binding domain. SmartD2 is a high-affinity, engineered humanized single-chain variable fragment (scFv) designed to recognize and bind the DOTA-metal complex with picomolar affinity (Cheal et al., 2014). In this clinical approach, a bispecific molecule—such as a Self-Assembling Disassembling Antibody (SADA) construct—is first administered to target tumor-specific antigens like GD2 or GPA33 (Santich et al., 2021). Once the bispecific has localized to the tumor and cleared from systemic circulation, the 177Lu-DOTA-hapten is administered, where it is rapidly captured by the SmartD2 domain on the tumor-bound antibody. This two-step process allows for high radiation doses to be delivered to the tumor while minimizing exposure to healthy tissues, particularly the bone marrow, due to the rapid renal clearance of the small-molecule radiohapten (Y-mAbs Therapeutics, 2023). The DOTA/radiohapten motif is thus a critical synthetic target that enables the precise delivery of ionizing radiation to malignant cells.

Other names

DOTA-radiohapten177Lu-DOTA-BnRadiohapten motifDOTA-metal complex177Lu-DOTA

Pretargeted radioimmunotherapy (PRIT) via capture of the radiohapten by a tumor-localized bispecific antibody containing the SmartD2 binding domain.