Plasma Tie2 trajectories identify vascular response criteria for VEGF inhibitors across advanced biliary tract, colorectal and ovarian cancers

•We identify pTie2 as the first cross-tumour, generic VEGFi, vascular response biomarker.•A vascular response is defined as at least a 25% reduction in Tie2 within 9 weeks of starting a VEGFi.•Biliary tract cancer patients attaining a vascular response have improved progression-free and overall survival from a VEGFi.•Tie2-defined vascular response is valid across both principal classes of VEGFi.•pTie2 helps predict tumour progression 6 weeks earlier than radiological computed tomography in 61% of patients.