By Herina Ayot Cancer, the second leading cause of death in the
United States after cardiovascular disease, is a persisting
problem that many talk about but few have yet to find effective
treatments. The American Cancer Society estimates that 569,490
people died from cancer in the United States in 2010. Many
cancers, such as pancreatic, lung and liver cancer, have few
effective treatments and very low survival rates. Threshold
Pharmaceuticals (THLD) takes advantage of the differences in
metabolic activity between cancerous and normal, healthy
biological tissue. Tumors are infused with considerably aberrant
blood vessels that have a decreased ability to transport
nutrients, leading to low oxygen levels (hypoxia) and modified
sugar consumption within the tumor. To this end, the company has
developed a prodrug that is only activated in the presence of
low oxygen content, therefore targeting cancerous masses. Tumor
hypoxia, or low oxygen concentration represents a compelling
target for anti-cancer intervention. C