Dr. Messersmith on the Need for Biomarkers to Distinguish Between VEGF Inhibitors in CRC

Wells A. Messersmith, MD, co-leader of the Developmental Therapeutics Program, and director, GI Cancer Program, and professor of medicine, at the University of Colorado School of Medicine, discusses the need for biomarkers to distinguish between VEGF inhibitors in colorectal cancer (CRC).

There is a lack of validated biomarkers for angiogenesis inhibitors in CRC, says Messersmith. There are several drugs that target VEGF, such as bevacizumab (Avastin), or PlGF, such as aflibercept (Zaltrap). Moreover, there are agents that hit VEGFR-2, such as ramucirumab (Cyramza). All these agents can be used in the second-line setting in CRC. The problem is that there are no means of predicting who is going to benefit and who is not going to benefit from these agents.

Right now, it's entirely empirical, says Messersmith. A lot of effort has gone into looking at the soluble levels of potential markers, the microvessel density, and the expression of endothelial cells. However, none of those trials ended up being positive. As such, patients are being treated with the understanding that there is likely some subset that benefits from this approach without any clarity as to who those specific patients are.