Parsortix system harvests intact CTCs for single-cell whole genomic sequencing from frozen and fresh blood samples with the same efficiency

Detection of druggable mutations in CTCs enriched from frozen samples may aid treatment decisions in the clinical setting

GUILDFORD, UK / ACCESSWIRE / May 27, 2022 / ANGLE plc (AIM:AGL)(OTCQX:ANPCY), a world-leading liquid biopsy company, is pleased to announce that a leading cancer research institute, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy, has published results of work undertaken in advanced non-small cell lung cancer (NSCLC) and sarcoma patients. The institute demonstrated that the Parsortix^® system could successfully isolate circulating tumour cells (CTCs) from frozen peripheral blood mononuclear cell (PBMC) samples. PBMC samples contain any blood cell with a nucleus, including white blood cells and CTCs, but has been depleted of red blood cells which do not have a nucleus. The potential ability to process frozen samples could allow for retrospective analyses and improve sample sharing capabilities in multicentre studies.

Isolated CTCs were stained to assess phenotype and identify CTCs for single cell retrieval, followed by low-pass copy number analysis through whole genome sequencing. In addition, CTCs were analysed for clinically actionable mutations by digital PCR.

The Parsortix system was selected for its ability to harvest CTCs from mesenchymal tumours, such as sarcoma, and CTCs that have undergone epithelial to mesenchymal transition, as may occur in NSCLC. This is clinically relevant because, although the transition to a mesenchymal phenotype is associated with increased metastatic potential and worse prognosis, many CTC isolation methods, including the leading antibody-based system, only identify cells expressing epithelial markers.

CTCs could be isolated with the same efficiency from both fresh blood samples and frozen PBMCs. Subsequent automated single-CTC retrieval allowed the authors to identify CTCs based on their abnormal DNA copy number profiles, of which a similar number of CTCs were identified in both fresh and frozen samples. Long-term freezing of samples (1-3yrs), from NSCLC patients, had no detrimental effect on CTC isolation or identification. This study also showed that the majority of CTCs isolated were non-epithelial, further highlighting the importance of marker-independent CTC isolation.

Importantly, CTCs isolated from frozen NSCLC patient PBMCs using the Parsortix system were analysed for epidermal growth factor receptor (EGFR) mutations, with results showing good concordance with the primary tissue. Analysis and the potential to track druggable mutations, such as EGFR, in CTCs from frozen PBMC samples over multiple time points may help inform treatment decisions and investigate therapy response in the clinical setting, in a retrospective manner.

Dr Giulia Bertolini and Dr Vera Cappelletti, Department of Experimental Oncology, National Cancer Institute of Milan, commented:

"This study demonstrates the feasibility of CTC analyses in cryopreserved PBMCs and represents an advance in blood sample management for CTC studies, allowing for a better selection of informative time points to longitudinally investigate tumor progression/response to therapy thereby enabling retrospective studies."

ANGLE Founder and Chief Executive, Andrew Newland, added:

"We are pleased to report on the use of the Parsortix system for the unbiased isolation and molecular characterisation of CTCs from frozen PBMC samples with similar success as from fresh blood samples. This approach may help facilitate studies that require time-dependent sampling or are completed across multiple centres. DNA analysis of the cancer cells harvested by the Parsortix system offers the potential to track druggable mutations in CTCs as an aid to future treatment decisions for patients with NSCLC."

The research has been published as a peer-reviewed publication in the Journal Clinical Chemistry and is available online at https://angleplc.com/library/publications/.

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About ANGLE plc www.angleplc.com

ANGLE is a world leading liquid biopsy company with sample-to-answer solutions. ANGLE's proven patent protected platforms include a circulating tumor cell (CTC) harvesting technology known as the Parsortix^® system and a downstream analysis system for cost effective, highly multiplexed analysis of nucleic acids and proteins.

ANGLE's Parsortix^® system is FDA cleared for its intended use in metastatic breast cancer and is currently the first and only FDA cleared medical device to harvest intact circulating cancer cells from blood.

Intended use

The Parsortix^® PC1 system is an in vitro diagnostic device intended to enrich circulating tumor cells (CTCs) from peripheral blood collected in K₂EDTA tubes from patients diagnosed with metastatic breast cancer. The system employs a microfluidic chamber (a Parsortix cell separation cassette) to capture cells of a certain size and deformability from the population of cells present in blood. The cells retained in the cassette are harvested by the Parsortix PC1 system for use in subsequent downstream assays. The end user is responsible for the validation of any downstream assay. The standalone device, as indicated, does not identify, enumerate or characterize CTCs and cannot be used to make any diagnostic/prognostic claims for CTCs, including monitoring indications or as an aid in any disease management and/or treatment decisions.

The Parsortix system enables a liquid biopsy (a simple blood test) to be used to provide the circulating metastatic breast cancer cells to the user in a format suitable for multiple types of downstream analyses. The system is based on a microfluidic device that captures cells based on a combination of their size and compressibility. The system is epitope independent and can capture all phenotypes of CTCs (epithelial, mesenchymal and EMTing CTCs) as well as CTC clusters in a viable form (alive). CTCs harvested from the system enable a complete picture of a cancer to be seen; as being an intact cell they allow DNA, RNA and protein analysis as well as cytological and morphological examination and may provide comparable analysis to a tissue biopsy in metastatic breast cancer. Because CTC analysis is a non-invasive process, unlike tissue biopsy, it can be repeated as often as needed. This is important because cancer develops and changes over time and there is a clear medical need for up-to-date information on the status of a patient's tumor. In addition, the live CTCs harvested by the Parsortix system can be cultured, which offers the potential for testing tumor response to drugs outside the patient.

The Parsortix technology is the subject of 26 granted patents in Europe, the United States, China, Australia, Canada, India, Japan and Mexico with three extensive families of patents are being progressed worldwide.

In the United States, the Parsortix^® PC1 system has received a Class II Classification from FDA for use with metastatic breast cancer patients. FDA clearance is seen as the global gold standard. ANGLE's Parsortix system is the first ever FDA cleared system for harvesting CTCs for subsequent analysis. ANGLE has applied the IVD CE Mark to the same system for the same intended use in Europe.

ANGLE has also completed two separate 200 subject clinical studies under a program designed to develop an ovarian cancer pelvic mass triage test, with the results showing best in class accuracy (AUC-ROC) of 95.1%. The pelvic mass triage assay has undergone further refinement and optimisation and a 200 patient clinical verification study has now completed enrolment.

ANGLE's technology for the multiplex evaluation of proteins and nucleic acids of all types is called the HyCEAD^TM platform and is based on a patented flow through array technology. It provides for low cost, highly multiplexed, rapid and sensitive capture of targets from a wide variety of sample types. A proprietary chemistry approach (the HyCEAD method) allows for the capture and amplification of over 100 biomarkers simultaneously in a single reaction. The HyCEAD system is extremely sensitive and is ideal for measuring gene expression and other markers directly from Parsortix harvests and was used in the ovarian cancer pelvic mass triage test to achieve best in class accuracy (AUC-ROC) of 95.1%.

ANGLE's proprietary technologies can be combined to provide automated, sample-to-answer results in both centralised laboratory and point-of-use cartridge formats.

ANGLE has established formal collaborations with world-class cancer centres and major corporates such as Abbott, Philips and QIAGEN, and works closely with leading CTC translational research customers. These Key Opinion Leaders (KOLs) are working to identify applications with medical utility (clear benefit to patients), and to secure clinical data that demonstrates that utility in patient studies. The body of evidence as to the benefits of the Parsortix system is growing rapidly from our own clinical studies in metastatic breast cancer and ovarian cancer and also from KOLs with 60 peer-reviewed publications and numerous publicly available posters from 31 independent cancer centres, available on our website.

ANGLE has established clinical services laboratories in the UK and the United States to accelerate commercialisation of the Parsortix system and act as demonstrators to support product development. The laboratories offer services globally to pharmaceutical and biotech customers for use of Parsortix in cancer drug trials and, once the laboratories are accredited and tests validated, will provide Laboratory Developed Tests (LDTs) for patient management.

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SOURCE: ANGLE PLC