[225Ac]Ac-FL-261

[225Ac]Ac-FL-261 is an investigational, potentially first-in-class c-MET-targeted alpha radioconjugate (targeted alpha therapy) developed by Full-Life Technologies. It consists of the alpha-emitting radionuclide Actinium-225 (225Ac) conjugated to the targeting vector FL-261, a peptide-based ligand that binds to the hepatocyte growth factor receptor (c-MET) with high affinity (KD of 7.5 nM) and over 450-fold selectivity over structurally similar receptor tyrosine kinases. Developed using Full-Life's proprietary UniRDC™ discovery platform, the drug is designed to deliver potent, localized alpha radiation directly to c-MET-expressing tumor cells, inducing lethal DNA double-strand breaks while minimizing damage to healthy tissues. It is being developed for multiple solid tumor indications, with an initial clinical focus on c-MET-expressing non-squamous non-small cell lung cancer (nsNSCLC). The U.S. FDA cleared its IND application, and Australian regulatory bodies (HREC/TGA) also granted clearance, enabling Phase 1 clinical evaluation.