FL-261

FL-261 is a novel radionuclide drug conjugate (RDC) vector targeting the mesenchymal-epithelial transition factor (c-MET), developed by Full-Life Technologies using their proprietary UniRDC™ platform. As a theranostic agent, FL-261 can be labeled with different radioisotopes: [111In]In-FL-261 for SPECT/CT imaging and [225Ac]Ac-FL-261 for targeted alpha therapy. It demonstrates high binding affinity (KD = 7.5 nM) and significant selectivity (over 450-fold) for c-MET compared to other receptor tyrosine kinases. In preclinical models, including non-small cell lung cancer (NSCLC) and patient-derived xenografts (PDX) refractory to c-MET antibody-drug conjugates (ADCs), [225Ac]Ac-FL-261 has shown potent anti-tumor activity and tumor regression with a favorable safety profile.