HER3 antibody radioconjugate

HER3 antibody radioconjugate (also known as ATNM-400 or HER3 ARC) is an investigational targeted radiopharmaceutical being developed by Actinium Pharmaceuticals in collaboration with ISU Abxis and AVEO Oncology. It consists of the fully human anti-HER3 (ErbB3) monoclonal antibody barecetamab (formerly ISU104) conjugated to a radioactive isotope payload, such as the alpha-emitter Actinium-225 (Ac-225) or the beta-emitter Lutetium-177 (Lu-177), typically using DOTA as a chelator. The antibody specifically targets HER3, a receptor tyrosine kinase overexpressed in various solid tumors (including prostate, non-small cell lung, breast, colorectal, and ovarian cancers) and associated with resistance to EGFR and HER2 inhibitors. Upon binding and internalization, the radioactive payload delivers localized radiation, inducing double-stranded DNA breaks and tumor cell death. A diagnostic imaging companion, Zr-89 barecetamab-DFO, is used for PET imaging and dosimetry to guide therapeutic dosing.

Other names

177Lu-HER3-ARC225Ac-HER3-ARCAc-225 barecetamab-DOTAAc225 barecetamab-DOTAAc 225 barecetamab-DOTAHER3 ARCHER-3 ARCHER 3 ARCHER3-ARCHER-3-ARCHER 3-ARCZr-89 barecetamab-DFOZr89 barecetamab-DFOZr 89 barecetamab-DFO[225Ac]-barecetamab-DOTA[89Zr]-barecetamab-DFO