HER2 presentation at SABCS

Potential for stratification of breast cancer patients for treatment with HER2 antibody drug conjugates

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 an independent study, reporting on a novel, Parsortix®-based human epidermal growth factor receptor 2 (HER2) workflow at the prominent San Antonio Breast Cancer Symposium being held from 10 to 13 December 2024.

The findings, published by Weill Cornell Medicine, corroborate ANGLE's own findings from its HER2 assay development programme, and provide a semi-automated solution which may help to accelerate adoption of CTC-based HER2 tests. HER2 status is known to change in a significant proportion of breast cancer patients over time, so a minimally invasive, real-time assay is needed for dynamic HER2 assessment to enable targeted treatment selection and detection of emerging treatment resistance or progression.

HER2 is a protein that is associated with many cancers, and HER2 tumour marker testing is used to determine if targeted therapy will be effective. A quantitative HER2 test, that objectively measures HER2 expression levels, enables the identification of patients who are HER2-high, intermediate or low and therefore suitable for treatment with HER2-antibody drug conjugates (ADCs).

The poster reports on a study in 16 patients with metastatic breast cancer, in which the Parsortix system was used to isolate and harvest CTCs and CTC-clusters prior to automated imaging and classification as HER2-high, intermediate, low or negative. Using the Parsortix system, CTCs were identified in 100% of patients and their HER2 status classified. Importantly the study identified patients with HER2 expressing CTCs that had a HER2-negative tissue biopsy.

Over 60% of breast cancer patients have a HER2-negative tissue biopsy when diagnosed and, as a result, are currently excluded from prescription of HER2 targeted ADCs. The workflow presented in this poster has the potential to be used to assess the current HER2 status of these patients and identify those whose HER2 status has changed making them eligible for the treatment.

• Carolina Reduzzi, Assistant Professor of Cancer Biology Research in Medicine, Weill Cornell Medicine commented:

"We are pleased to present further data validating our workflow which enables quantitative and semi-automated assessment of HER2 in CTCs. HER2 is a major therapeutic target and an accurate and real-time assessment of HER2 status could be used to monitor CTCs over time to better guide treatment and identify patients with any detectable HER2 expression, or changes to HER2 expression, who could benefit from treatment with ADCs.

This methodology has the potential to be applied to a wide range of biomarkers and our ultimate goal is to develop automated workflows which enable longitudinal CTC assessment of biomarker status for targeted treatment selection or to predict treatment response."

ANGLE's Chief Scientific Officer, Karen Miller, commented:

"We are pleased to see new data that supports the utility of quantitative HER2 assessment on CTCs isolated using the Parsortix system and independently validates ANGLE's own findings from our HER2 assay development programme. HER2 status is known to change in up to 38% of breast cancer patients. As such real-time quantitative HER2 assessment is crucial for both effective treatment and to support patient stratification for clinical trials and insight into dynamic changes in HER2 status which may correlate to therapeutic response."

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