Disclosed are compositions of matter, methods, and protocols useful for treatment of cancer through induction of anti-angiogenic immune responses by vaccination together with immune modulation triggered by checkpoint inhibitors. The invention provides placenta, placental endothelial, placental fibroblasts, and mixtures thereof as immunogens, whose anti-angiogenic activity is augmented by utilization of checkpoint inhibitors. Means of differentiating tumor cells directly into endothelial or endothelial-like cells and utilizing said cells as immunogens for the purpose of inducing immunity against blood vessels feeding tumors. In one embodiment CTLA4 blockade is performed in combination with an immunogen capable of triggering immunity towards tumor endothelial cells. In another embodiment blockade of the PD1-PD1 ligand pathway is performed in combination with induction of anti-angiogenic immune response.
