actinium Ac 225 DOTATATE RYZ101

A radioconjugate consisting of the somatostatin analog tyrosine-3-octreotate (Tyr3-octreotate or TATE) labeled, via the macrocyclic chelating agent 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetra-acetic acid (DOTA), with the alpha-emitting radioisotope actinium Ac 225, with potential antineoplastic activity. Upon administration of actinium Ac 225 DOTATATE RYZ101, the TATE moiety targets and binds to SSTRs, with a much higher affinity for type 2 SSTR, present on the cell membranes of many types of neuroendocrine tumors (NETs). Upon binding, the radioisotope moiety delivers a cytotoxic dose of alpha radiation to SSTR-expressing tumor cells. SSTRs have been shown to be present in large numbers on NETs and their metastases, while most other normal tissues express low levels of SSTRs.