Developing the VTX-1 liquid biopsy system: Fast and label-free enrichment of circulating tumor cells

CTCs can be isolated from a simple blood draw and may be representative of the diverse cancer patient biology because tumor cells are circulating in the blood stream from multiple tumor sites. The VTX-1 Liquid Biopsy System was designed to automate the isolation of clinically relevant CTC populations, making the CTCs available for easy analysis by a variety of techniques. In this publication, the transition from a cutting-edge microfluidic innovation in the research setting to a commercial, automated system for isolating CTCs directly from whole blood is outlined.

A number of improvements are reviewed as the technology transitioned into a commercial product. These improvements include better material for the microfluidic fabrication, automating the fluid processing in the chip, and the optimization of isolation protocols. The commercial VTX-1 Liquid Biopsy System is shown to recover spiked breast and lung cancer cell lines at a rate of 69% and 79.5% respectively while achieving a purity as low as <100 white blood cells per mL of blood processed.

To show the utility of the platform for cancer research, several downstream applications are demonstrated on the CTCs isolated by the VTX-1. Clonogenic and cell invasion assays demonstrate that the cells isolated by the VTX-1 are intact and undisturbed by the processing, resulting in direct access to the cell's cancer biology. To demonstrate that the VTX-1 can also process mouse samples, CTCs are isolated from two patient-derived orthotopic xenograft mouse models.