Anti-vessel growth drugs (anti-VEGF) were first approved to treat gastrointestinal cancers, and the indications were subsequently expanded to other types of cancer. Doctors use anti-VEGF drugs in an effort to cut-off the blood supply to cancer, and thereby stop or slow the growth of cancer. Anti-VEGF drugs are expensive, at $30,000 per dose; and can cause unintended damage to adjacent tissue.

Intracellular chlamydia pathogens damage oxygen transport, across the cell wall; and generate angiogenesis (formation of new blood vessels). Dr. Warburg identified low oxygen in the cells as an essential feature of cancer; and angiogenesis is a hallmark of cancer. Anti-VEGF drugs may be effective in slowing cancer; however, anti-VEGF drugs do not address the root cause of new vessel formation–angiogenesis develops in response to low oxygen in the cells, caused by a chronic infection with an intracellular pathogen.