Mateon Therapeutics Inc is a US-based biopharmaceutical company which is focused on the development of vascular disrupting agents (VDA), for the treatment of cancer. VDA targets the vasculature of cancer tumors and obstructs a tumor's blood supply without disrupting the blood supply to normal tissues. The company is engaged in developing clinical stage investigational drugs that is CA4P and OXi4503. CA4P s a reversible tubulin-binding agent that selectively targets endothelial cells, which make up the interior lining of blood vessel walls in solid tumors; and OXi4503 which is a novel, dual-mechanism VDA, to reduce tumor blood flow and it also forms a potentially anti-proliferative metabolite.