Angle PLC Announces US and EU Patents for Innovative CellKeep(TM) Slide

Published April 22, 2024

Proprietary cell recovery device and method eliminates over 70% of CTC cell loss from standard microscopy techniques increasing assay sensitivity

GUILDFORD, SURREY / ACCESSWIRE / April 22, 2024 / 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 that the European Patent Office has granted a European Patent for its innovative CellKeep™ slide. A formal communication has also been received from the United States Patent and Trademark Office indicating that grant of the equivalent US patent application is imminent.

The proprietary CellKeep slide is the result of a three-year development effort by ANGLE to address CTC loss endemic in standard laboratory microscopy techniques for the cytological analysis of CTCs. The result is a new device and method to attach cells to the slide, which extensive inhouse testing has demonstrated, eliminates over 70% of CTC loss experienced when using standard techniques.

The Parsortix® system efficiently captures CTCs from blood and these remain intact and viable (live) prior to downstream analysis. When visualising CTCs by microscopy there is a critical step to transfer CTCs to a slide for biomarker labelling. In-house testing has shown that standard laboratory techniques, used worldwide, result in a high rate of cell loss (>50%) and cause damage to CTCs. Reducing cell loss to a minimum is critical for subsequent analysis of CTCs as they are present in very low numbers in the blood.

ANGLE has developed the CellKeep slide to reduce cell loss during the transfer of CTCs to the microscope slide and to protect the morphology of the harvested cells. The technique also reduces costs by concentrating the CTCs into a smaller area on the slide, thereby limiting the quantity of high-cost antibodies and imaging time required to identify and analyse cells.

In analytical studies, CTCs were harvested from duplicate cancer patient blood samples and deposited on either standard microscope slides or ANGLE's new CellKeep slides, then processed and stained for CTC biomarkers. The study demonstrated that the use of CellKeep slides significantly increased the identification of CTCs with higher sample positivity rates, and better preservation of CTC morphology and clusters.

The new CellKeep slide is an integral part of ANGLE's Portrait®+ CTC staining kit which is available for customers to identify and enumerate CTCs harvested using the Parsortix system.

ANGLE Chief Executive Officer, Andrew Newland, commented:
"We are delighted to have secured intellectual property rights for our proprietary CellKeep slide in two major jurisdictions. Following harvesting of rare CTCs from patient blood samples using the Parsortix system, the CellKeep slide and associated methodology will significantly improve the capture of CTCs for microscopy-based biomarker assays and will enhance sensitivity across ANGLE's assay portfolio. This is a significant technology advancement for the CTC liquid biopsy field and another step towards enabling biomarker-guided precision medicine for people with cancer.

ANGLE Chief Scientific Officer, Karen Miller commented:
"We are pleased to share our success in securing IP rights for ANGLE's CellKeep slide which enhances the capture of CTCs on to slides and facilitates evaluation of cancer cell biomarkers. This technology is a significant advancement over current standards for CTCs and has the potential to capture other cell types from body fluids such as blood, urine or cerebrospinal fluid, for subsequent analysis.

For further information:

ANGLE plc+44 (0) 1483 343434

Andrew Newland, Chief Executive

Ian Griffiths, Finance Director

Berenberg (NOMAD and Corporate Broker)

Toby Flaux, Ciaran Walsh, Milo Bonser

+44 (0) 20 3207 7800

FTI Consulting

Simon Conway, Ciara Martin

Matthew Ventimiglia (US)

+44 (0) 203 727 1000

+1 (212) 850 5624

The information contained within this announcement is deemed by the Company to constitute inside information as stipulated under the EU Market Abuse Regulation (596/2014). Upon the publication of this announcement via a regulatory information service, this information is considered to be in the public domain.

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

For Frequently Used Terms, please see the Company's website on

Notes for editors

About ANGLE plc

ANGLE is a world-leading liquid biopsy company with innovative circulating tumour cell (CTC) solutions for use in research, drug development and clinical oncology using a simple blood sample. ANGLE's FDA cleared and patent protected circulating tumour cell (CTC) harvesting technology known as the Parsortix® PC1 System enables complete downstream analysis of the sample including whole cell imaging and proteomic analysis and full genomic and transcriptomic molecular analysis.

ANGLE's commercial businesses are focusing on diagnostic products and clinical services. Diagnostic products include the Parsortix® system and associated consumables. The clinical services business is offered through ANGLE's GCP-compliant laboratory. Services include custom assay development and clinical trial sample testing for pharma.

Over 90 peer-reviewed publications have demonstrated the performance of the Parsortix system. For more information, visit

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