Parsortix label-free circulating tumour cell harvest

What it does. Blood flows through a stepped microfluidic channel whose gaps narrow to a few micrometres. Large, stiff tumour cells are held in the steps while smaller, deformable blood cells pass. Reversing the flow releases the trapped cells intact, so they can be counted, stained, cultured or sequenced. Because the capture depends on physical properties rather than EpCAM, it also holds mesenchymal-like and cluster cells that antibody systems miss.

Regulatory status and evidence. In May 2022 the FDA granted De Novo authorisation to the Parsortix PC1 system for capturing and harvesting circulating tumour cells from the blood of patients with metastatic breast cancer for later analysis; it is CE marked in Europe. The clearance covers harvesting, not any specific clinical claim, so the downstream test decides what the cells mean. ANGLE, the developer, has built assays on the harvested cells for HER2, androgen receptor variants and DNA damage response markers and offers them as a service to pharmaceutical trials.

Who should have it and what changes. Nothing changes in routine care yet: harvested cells feed research and trial biomarkers rather than approved treatment decisions. Its promise is access to live tumour cells without a biopsy, for example to test protein targets that DNA cannot show, such as HER2 or oestrogen receptor on metastatic cells, and to grow cells for functional testing. Availability is through ANGLE's laboratories and partner sites; cost is that of a specialised research assay.