Angle client demonstrates new use for 'Parsortix' system

Liquid biopsy company Angle said on Monday that one of its leading customers, the Disseminated Cancer Cell Network (DCCNet) in Duesseldorf, has published new results in a peer-reviewed journal of work done to harvest circulating tumor cells (CTCs) from diagnostic leukapheresis (DLA) samples.

The AIM-traded firm explained that leukapheresis was a standard procedure routinely used in the clinic to enrich mononuclear cells - certain types of white blood cells - from blood for various applications, including stem cell harvest, with the remainder of the blood returned to the circulation.

It said the DCCNet had previously published that, during DLA, several litres of patient blood could be processed, resulting in a DLA product of typically 40 ml containing primarily white blood cells, but also CTCs.

They demonstrated that DLA resulted in more patients with CTCs harvested, and an increase of the median CTC numbers by 30-fold, compared to analysis of blood samples.

The method had been validated by the DCCNet and a European multi-centre study in metastatic prostate and breast cancer patients, demonstrating that the workflow yielded “significantly higher” CTC numbers, and that the procedure could be safely performed in different clinical environments.

The researchers reportedly found that Angle’s ‘Parsortix’ system was “highly effective” in reducing the white blood cell background from DLA products, without interfering with the viability of captured CTCs.

That was a major prerequisite to allow successful processing of the DLA product in future clinical situations with low CTC numbers, and to enable CTC culturing.

Without Parsortix enrichment, white blood cells apparently rapidly outgrew the CTC cultures.

The increased number of viable CTCs and the enhanced sample purity improved the ability to culture the CTCs, Angle said.

Culturing CTCs was a “challenging task”, it said, and the new approach opened the potential for chemo-sensitivity testing in-vitro on isolated and cultured CTCs, to determine which drugs could benefit the patient.

The researchers also demonstrated that the DLA sample could be cryopreserved and stored with minimal CTC loss prior to processing with the Parsortix system.

It said the cryopreserved CTCs retained their viability and genomic aberrations and mutation profiles were unchanged.

The researchers believed that the DLA process was “useful” where the patient had a low number of CTCs, and a simple blood test was unlikely to recover sufficient CTCs, whereas the DLA process sampled 200x more blood volume and was more likely to recover CTCs.

“The use of diagnostic leukapheresis blood product provides larger numbers of CTCs than a normal blood sample,” said Dr Hans Neubauer of the University Hospital and medical faculty at the Heinrich-Heine University of Duesseldorf.

“The Parsortix system provides an easy solution for enriching the sample and harvesting these CTCs keeping the cells alive and undamaged.

“The workflow we have developed to culture these cells will allow an intensification of research into new diagnostic and therapeutic solutions.”

Angle founder and chief executive Andrew Newland added that the DLA approach processed “much larger volumes” of patient blood, opening the potential for use of the Parsortix system even when - due to patient condition - there were only very few CTCs present.

“Cryopreservation is important as it allows patient samples to be stored for many years and then analysed by Parsortix once patient outcome is known,” Newland said.