On-Q-ity is commercializing a microfluidic approach developed at MGH for capturing rare circulating tumor cells for quantification and analysis. Image credit: Lecia V. Sequist, Sunitha Nagrath, Mehmet Toner, Daniel A. Haber, and Thomas J. Lynch
One of the most lethal events in cancer is the process of metastasis — when cells from an initial tumor spread throughout the body to generate new tumors. Circulating tumor cells (CTCs) are cancer cells that invade the bloodstream to circulate through the body; not surprisingly, they have been linked to metastasis. Knowing the status of a patient’s CTCs could be enormously helpful in diagnosis and monitoring of treatment. However, it can be difficult to detect CTCs among billions of blood cells since the frequency of CTCs may be as low as 1 cell per billion blood cells.
On-Q-ity is one company tackling this problem with a microfluidic approach. Using technology commercialized out of Mehmet Toner’s lab at the Massachusetts General Hospital, On-Q-ity uses an array of microfabricated posts to filter the blood. The posts are coated with antibodies to epithelial cell adhesion molecule (EpCAM). Tumor cells that flow through the device stick to the posts and are trapped for counting or further analysis. Once the CTCs are captured, the next question is — how to best analyze them to inform diagnosis and treatment? The microfluidic capture of CTCs is just one part of On-Q-ity’s strategy; its portfolio also includes a number of DNA repair biomarkers for monitoring the effectiveness of therapy. One advantage of the anti-EpCAM approach is that it could be used on a variety of solid tumor types; On-Q-ity is currently exploring use in breast, prostate, lung cancer, and others.
However, On-Q-ity is not the only player in this space. Veridex’s CellSearch is a competing CTC diagnostic that is already available on the market. The Veridex approach is non-microfluidic, however similarly uses anti-EpCAM antibodies. In a recent paper, researchers connected with On-Q-ity claim the microfluidic approach is superior to CellSearch because of its higher sensitivity and ability to keep the trapped CTCs alive for further analysis. In addition to Veridex, On-Q-ity is competing against several other groups looking to enter the same market (e.g., Biocept, MIRACLE project, CytoScale).
For a glimpse of the CTC chip in action, see this recent video from On-Q-ity’s associated academic research team at Mass General (video of CTC chip begins around 1:10):