Parsortix based PD-L1 assay showcased at AACR

CTC PD-L1 assay enables longitudinal monitoring of PD-L1 status in lung cancer patients and may help to advance personalised treatment

ANGLE plc (AIM:AGL OTCQX:ANPCY), a world-leading liquid biopsy company with innovative circulating tumour cell (CTC) solutions for use in research, drug development and clinical oncology, is pleased to announce the publication of new data at the American Association for Cancer Research (AACR) Special Conference in Cancer Research, Liquid Biopsy: From Discovery to Clinical Implementation, in San Diego, US from 13 to 16 November 2024.

ANGLE is presenting a poster entitled "Investigating PD-L1 status in circulating tumor cells isolated from the blood samples of lung cancer patients". The poster presentation reports on ANGLE's immunofluorescence assay for the identification of different CTC phenotypes (epithelial, mesenchymal and those transitioning) and the determination of Programmed Death Ligand-1 (PD-L1) status. Analytical verification demonstrated that the assay successfully produced linear data with high analytical sensitivity1 and specificity2 for epithelial, mesenchymal, blood lineage and PD-L1 markers.

PD-L1 allows cancer cells to evade the host immune response when upregulated, and assessment of PD-L1 status in tumour tissue can indicate if immunotherapy has the potential to be an effective treatment. However, lung tissue biopsies can be challenging and expensive and are not always successful, plus PD-L1 status in tumour tissue can become outdated during tumour evolution and may not be representative of metastatic sites. ANGLE has developed a liquid biopsy assay that allows for minimally invasive, longitudinal monitoring of PD-L1 status in CTCs harvested using the Parsortix® system.

The assay identified CTCs in 91% (29/32) of metastatic lung cancer patients assessed as part of an ongoing longitudinal study, presenting with a range of phenotypes. PD-L1 positive CTCs were observed in 72% of patients with a PD-L1 positive tissue biopsy and in 27% of patients with a PD-L1 negative tissue biopsy, demonstrating the potential for improved assessment of tumour heterogeneity through analysis of PD-L1 status in CTCs.

A patient case study revealed that CTC PD-L1 status varied between blood draws, showing discordance with the initial tumour biopsy at multiple time points. The results presented in this study demonstrate the potential for the development of CTC-based dynamic PD-L1 testing to advance personalised treatment for metastatic lung cancer patients.

Chief Scientific Officer, Karen Miller, commented:

"We are pleased to have presented this poster at the AACR Special Conference in Cancer Research. The results of this study further demonstrate the utility of ANGLE's PD-L1 assay. Longitudinal monitoring is essential to the advancement of personalised medicine, and we look forward to contributing to this advancement and supporting the needs of our pharma customers through development of our CTC-based assays."

The poster is available for review at: https://angleplc.com/resources/posters/

For Research Use Only. Not for use in diagnostic procedures.

• Analytical sensitivity = proportion of harvested cells known to express the marker(s) of interest which were marker positive in the assay.
• Analytical specificity = proportion of harvested cells known to NOT express the marker(s) of interest which were marker negative in the assay.