Natera and Angiex announced they will use Natera’s Signatera minimal residual disease test in a Phase 1 trial of AGX101, a nuclear-delivered antibody-drug conjugate targeting TM4SF1. The companies plan longitudinal Signatera ctDNA testing to track treatment response during the trial. The trial is enrolling patients with unresectable locally advanced or metastatic solid tumors. Natera said personalized ctDNA metrics could complement imaging when radiologic changes do not reliably map to viable tumor dynamics. For ADC developers, the collaboration illustrates how molecular monitoring is being integrated early into therapeutic development to sharpen response interpretation and potentially speed iteration on biologic targeting and dosing strategies.