Histamine-succinyl-glycine Epitope (HSG)

Histamine-succinyl-glycine (HSG) is a synthetic hapten used as an epitope for antibody recognition in pretargeting strategies for imaging and therapy. It consists of histamine, a succinyl linker, and glycine. It is not a therapeutic target itself but facilitates targeted delivery when used in conjunction with bispecific antibodies that bind both a tumor-associated antigen and the HSG hapten. Radiolabeled or drug-conjugated HSG derivatives are administered after the bispecific antibody has localized to the target site, allowing for selective binding and payload delivery.

Serves as a target for pre-localized bispecific antibodies, enabling targeted delivery of imaging agents or therapeutics.