ANGLE PLC (AIM:AGL, OTCQX:ANPCY), a world-leading liquid biopsy company, said it has presented results from a proof of concept study at the International Society of Liquid Biopsy meeting held in Miami, Florida on October 20-22, 2022.
The company noted that the study demonstrated that both circulating tumour cells (CTCs) and cell-free circulating tumour DNA (ctDNA) can be analysed from a single blood sample. The results show that removal of plasma from blood samples for ctDNA analysis does not impact on the number or quality of CTCs which can be successfully isolated from the same sample using the company's Parsortix system, it added.
In a statement, ANGLE founder and chief executive, Andrew Newland, commented: "We are pleased to share the results of our own in-house research which further showcases the utility of the Parsortix system for the unbiased isolation of CTCs which, in combination with plasma removal, allows for the additional analysis of ctDNA. Although ctDNA is established in the US market for targeted treatment selection, CTCs provide information that is both complementary and additional to that which can be provided using ctDNA alone. This is recognised by the National Cancer Institute, who highlight the unmet need for transcriptional and protein analysis to truly enable precision medicine."
Liquid biopsy, utilising CTCs and ctDNA, has the potential to characterise cancer at genetic, transcriptional, and protein levels simultaneously. This is not achievable with a single-timepoint tissue biopsy or with ctDNA alone since ctDNA does not allow for RNA sequencing or protein analysis. Several studies have assessed the value of combining multiple blood-based analytes for informing on a variety of oncological conditions including, but not limited to, lung cancer and metastatic breast cancer. These studies conclude that multimodal assessment, including dual analyte analysis of CTCs and ctDNA, can provide complementary information valuable for prognostic, therapy selection and patient monitoring purposes, the company noted.
The study aimed to establish a workflow to allow the isolation of both ctDNA and CTCs from a single blood sample. Both spiked cell samples (blood samples collected from eight healthy volunteers spiked with cultured cancer cells) and 13 metastatic breast cancer (MBC) patient samples were included in the study. Two blood samples were taken from each donor or patient and samples were run in parallel down each workflow; plasma was removed by centrifugation of one sample per donor (for ctDNA analysis), whilst the other sample was not centrifuged (plasma remained in the sample). The cellular component left in each centrifuged tube was resuspended in solution and then processed using the Parsortix system and CTCs detected via immunofluorescence.
In the spiked healthy volunteer samples, the percentage of CTCs detected was comparable between samples processed with and without plasma. This finding was confirmed in the MBC samples; CTCs were identified in 39% of patient samples with matched findings for both workflows. Similarly, the number and size of CTC clusters were equivalent in both samples with and without plasma.
The company said the study demonstrates the feasibility of combining CTC isolation using the Parsortix system with plasma removal for subsequent ctDNA analysis from a single tube of blood with minimal additional sample handling. This opens the possibility for clinical laboratories to broaden the clinical utility of their assays and maximise the value of each patient's sample. Despite the emerging realisation of the benefit of a combinatorial approach to blood analysis, the logistics revolving around access to both a CTC enrichment platform and a ctDNA sequencing platform at the same site has so far limited such analysis.
ANGLE said it believes there will be significant demand from biopharma companies for an assay that combines ctDNA and CTCs, adding that the workflow presented, demonstrating effective CTC isolation utilising the Parsortix system with concurrent removal of plasma for ctDNA analysis, puts ANGLE in a highly competitive position in this emerging arena.