Natera partnered with Angiex to use its Signatera MRD assay in Angiex’s Phase 1 trial of AGX101, a nuclear-delivered TM4SF1-directed antibody-drug conjugate. The collaboration includes longitudinal Signatera testing for circulating tumor DNA to assess treatment response. The companies said ctDNA measurements may complement radiographic endpoints, especially when imaging changes do not clearly map to viable tumor burden. AGX101 is designed to target both TM4SF1-expressing tumor cells and tumor-associated endothelial cells. For trial teams, the deal reflects growing integration of tumor-informed MRD analytics into early-stage ADC development to refine response assessments.