Research has shown that controlling production
of new blood vessels can restrict tumor growth, often prolonging the life of the
cancer patient. Perhaps the most
widely-used anti-angiogenic agent to emerge to date is a drug called bevacizumab
(AvastinŽ, Genentech). Bevacizumab
was approved by the FDA for use in combination with intravenous
5-fluorouracil-based chemotherapy for first-line treatment of patients with
metastatic colorectal cancer.
However, bevacizumab has also shown activity in many other solid tumor types
such as breast, lung, and ovarian cancers.
As with most targeted-therapy drugs, bevacizumab does not necessarily
benefit every patient and it is expensive.
Further, no test currently exists that shows reliably who will benefit
from it.
The Weisenthal Cancer Group has developed an assay for microvascular viability (M.V.V.) to identify potential responders to bevacizumab, sorafenib, sunitinib, and other anti-angiogenic drugs and to assess previously unanticipated direct and potentiating anti-angiogenic effects of targeted therapy drugs such as erlotinib and gefitinib. Click here for a link to an article in Journal of Internal Medicine reporting development of the assay. Prior to development of the M.V.V. assay it was thought that the lack of an intact tumor micro-vasculature would prevent in vitro drug studies in disaggregated tissues. However, it was discovered that endothelial cells are present in tumor microclusters and it appears that drug effect upon these cells can be assessed in the M.V.V. assay (see diagram below). Confirmatory activities are ongoing. A patent application has been submitted which covers a range of sample preparation, assay targeting, drug exposure, sample analysis, and scoring methods. The M.V.V. assay is being offered as an adjunct to either a Weisenthal Cancer Group standard assay or an EGFRx™ tyrosine kinase assay. (click here to see sample M.V.V. assay reports).
