Actinium Ac 225 RTX-2358

**Semantic type:** Pharmacologic Substance

**Definition:** A radioconjugate composed of a fibroblast activation protein (FAP)-targeting moiety, labeled with the alpha-emitting radioisotope actinium Ac 225, with potential antineoplastic activity. Upon administration of actinium Ac 225 RTX-2358, the FAP-targeting moiety targets and binds to FAP-expressing cancer-associated fibroblasts (CAFs) and FAP-expressing tumor cells. Upon binding, the radioisotope moiety delivers a cytotoxic dose of alpha radiation to the FAP-expressing CAFs and tumor cells. FAP, a cell surface protein, is overexpressed on CAFs in the tumor microenvironment (TME) and certain tumor cells.

**Synonyms:** - Actinium Ac 225 Labeled-RTX-2358 - Actinium Ac 225-RTX-2358 - [Ac225]RTX-2358