EACR 2025: Innovation in AR expression profiling

Poster presentation highlights development of a novel CTC-based assay

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 presentation of a poster at the European Association for Cancer Research (EACR) Congress, taking place in Lisbon, Portugal from 16-19 June 2025.

The poster entitled 'Combined microfluidic isolation and immunofluorescence staining of circulating tumour cells for the assessment of Androgen Receptor expression in metastatic prostate cancer blood samples', is being presented during the Biomarkers in Tissue and Blood session on Tuesday 17 June 2025.

This assay addresses a significant unmet need in prostate cancer. The androgen receptor (AR) plays a central role in driving disease growth and progression, and changes in AR can lead to resistance to current treatments and the development of advanced incurable disease known as metastatic castration-resistant prostate cancer (mCRPC). With at least 130 ongoing clinical studies and a projected AR inhibitor market value of US $9.8 billion by 2032, there is growing demand for assays that can monitor AR activity1.

ANGLE has developed a new approach for repeatable assessment of AR expression in prostate cancer patients using the Parsortix system and ANGLE's AR immunofluorescence assay. The assay was tested on blood spiked with prostate cancer cells exposed to increasing AR drug concentrations. The results showed a clear, statistically significant reduction in AR expression as AR-drug concentration increased, from over 80% AR-positive cells in untreated samples to under 20% at the highest drug level. This demonstrates the assay's high sensitivity and highlights its potential utility for pharmacodynamic assessment, enabling customers to monitor treatment response in real-time.

The assay was then validated in blood samples from 20 patients with mCRPC. 50% of patients were CTC-positive and all CTC-positive patients had AR-positive CTCs enabling the assessment of AR expression levels. CTC clusters, which are known to be up to 100 times more metastatic, were observed in 80% of CTC-positive patients. All CTCs detected were mesenchymal or undergoing EMT, highlighting the importance of using the marker-independent Parsortix system in this patient cohort.

This work demonstrates how ANGLE's Portrait AR workflow enables sensitive, real-time monitoring of AR expression from a simple blood draw. The assay is now available as part of ANGLE's assay menu to support pharma customers with longitudinal biomarker assessment in AR-targeted clinical trials.

The poster will be available on ANGLE's website from 20:00 on Tuesday 17 June: https://angleplc.com/resources/posters/

ANGLE Chief Scientific Officer, Karen Miller, commented:

"This work underscores the value of ANGLE's Parsortix system for enabling detailed protein analysis directly in intact CTCs. The androgen receptor assay development programme has successfully been completed, and we are excited by its potential to repeatably monitor drug response and resistance in prostate cancer trials. Sharing this data at EACR reflects our ongoing commitment to advancing precision oncology with innovative, real-world solutions."

• https://dataintelo.com/report/androgen-receptor-ar-inhibitor-market

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