Tumor-localized Streptavidin or Avidin via Pretargeted Monoclonal Antibody (None)

Tumor-localized streptavidin or avidin, used in conjunction with pretargeted monoclonal antibodies (mAbs), is a molecular targeting strategy that leverages the extremely high affinity between biotin and either streptavidin or avidin. This approach is primarily utilized for tumor imaging and therapy, particularly in radioimmunodetection and radioimmunotherapy. The system involves a multi-step process where a biotinylated mAb localizes to the tumor, followed by the administration of streptavidin or avidin to bind the biotin. Finally, radiolabeled biotin (or other therapeutic/diagnostic agents conjugated with biotin) is injected, binding to the streptavidin/avidin already localized at the tumor site. This allows for highly selective delivery of imaging agents or therapeutics specifically to tumors while minimizing exposure of normal tissues.

Multistep binding cascade exploiting high-affinity interaction between protein & ligand for targeted delivery of diagnostic or therapeutic agents.