Company spokeswoman Charlotte Arnold says that Genentech researchers are looking for tests to help predict how patients will respond to Avastin.
Angiogenesis (growth of blood vessels that feed a tumor) is dependent on VEGF (Vascular Endothelial Growth Factor), a chemical signal produced by cells that stimulates the growth of new blood vessels.
Avastin has been known to be driven by the VEGF pathway. Avastin directly binds to VEGF to directly inhibit angiogenesis. Avastin blocks VEGF and causes existing microcapillaries to die. This is what is measured with an AngioRx Assay (which simultaneously measures direct anti-tumor activity and anti-vascular activity), death of existing endothelial (and associated) cells.
One aspect of this functional profiling assay is that microvascular viability can measure dead microvascular cells in tissue, fluid and peripheral blood specimens to identify potential responders to anti-angiogenic drugs and to assess direct and potentiating anti-angiogenic effects.
The major obstacle in controlling cancer drug prices is the widespread inappropriate use of anti-cancer drugs. As the increasing numbers and types of anti-cancer drugs are developed, oncologists become more and more likely to misuse them in their practice. There is seldom a "standard" therapy which has been proven to be superior to any other therapy. What may work for one, may not work for another.
One breast cancer patientís life saving therapy is anotherís pulmonary embolism without clinical benefit. Until such time as cancer patients are selected for therapies predicated upon their own unique biology, we will confront one Avastin after another.
The solution to this problem has been to investigate the VEGF targeting agents in each individual patientís tissue culture, alone and in combination with other drugs, to gauge the likelihood that vascular targeting will favorably influence each patientís outcome. The results to date in patients with non-small cell lung cancer, colorectal cancer and even rare tumors (like medullary carcinoma of the thyroid) suggest this to be a highly productive direction for future development.