On-Q-ity, a next-generation personalized diagnostics company dedicated to improving cancer therapy effectiveness, announced that its novel, dual-capture platform technology, the On-Q-ity Circulating Cancer Capture and Characterization Chip (C5), has demonstrated 94-97 percent cell capture efficiency of tumor cells by combining size and affinity capture technology versus using affinity alone. 

Analyzing and characterizing circulating tumor cells (CTCs) in blood can identify cancer cells and cancer cell mutations to provide physicians with clear guidance for improved cancer diagnosis, treatment monitoring and earlier recurrence detection for their patients.

The study compared On-Q-ity’s dual capture chip, combining size and antibody affinity, with a chip using antibody affinity alone.  Researchers used “spiked” tumor cells, or culture-maintained cells, that were then counted and added to normal blood, for the uniform blood samples. Each chip used an antibody for EpCAM (epithelial cell adhesion molecule) expression, a protein associated with almost all carcinomas, to capture the CTCs.  The On-Q-ity C5 chip also used gradient sizing to isolate those cancer cells that may not have been captured through antibody affinity.
 
“Current methods used to trap CTCs are primarily based on affinity for EpCAM positive cells. However, such methods miss the low EpCAM expressing cells or EpCAM negative cells,” said Walter P. Carney, Ph.D, Chief Scientific Officer at On-Q-ity.  “The strength of the On-Q-ity C5 system is that it allows capture based on both size and affinity, thereby finding those cells that express low levels of EpCAM or that are even EpCAM negative.”
 
On-Q-ity researchers found that the spiked cell capture is greatly improved when combining size and affinity, whether or not the tumor cells express EpCAM, thereby increasing the capture rate from 51-55 percent using just affinity to 94-97 percent using both affinity and size gradient on the chip.
 
“The strength of the On-Q-ity C5 platform is its flexibility to go beyond just EpCAM capture,” said Carney.   “We believe that captured CTCs will serve as a ‘bag of biomarkers’ that will become the foundation for our molecular diagnostics business by providing greater insight into the mechanisms that drive CTCs, leading to better treatments for cancer patients.”
 
On-Q-ity researchers are conducting additional studies to evaluate this platform’s use in late-stage lung cancer, as well as colon and prostate cancers.

Date: April 5, 2011
Source: On-Q-ity