What does targeting blood vessels have to do with immunotherapy?

Malignant tumors hijack the circulatory system by forming new blood vessels to sustain tumor growth in a process called angiogenesis. Newly targeted immunotherapies are geared towards interfering with pro-angiogenic signals from tumors, aiming to delay their growth and even cause them to shrink. Anti-angiogenic immunotherapy also prevents large tumors from metastasizing. Drugs which induce oxygen starvation primarily act through the vascular endothelial growth factor (VEGF) signaling pathway.¹ Additional information on immunotherapy can be found in our resource center here.

Reference:
1. R.R. Ramjiawan, et al., "Anti-angiogenesis for cancer revisited: Is there a role for combinations with immunotherapy?" Angiogenesis 20(2): 185-204, 2017.